The Wild World of Rattan Palms

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There are a lot of big organisms out there. A small handful of these are truly massive. When someone mentions big plants, minds will quickly drift to giant sequoias or coastal redwoods. These species are indeed massive. The tallest tree on record is a coastal redwood measuring 369 feet tall. That's a whole lot of tree! What some may not realize is that there are other plants out there that can grow much "taller" than even the tallest redwood. For instance, there is a group of palms that hail from Africa, Asia, and Australasia that grow to staggering lengths albeit without the mass of a redwood.

You are probably quite familiar with some of these palm species, though not as living specimens. If you have ever owned or sat upon a piece of wicker furniture then you were sitting on pieces of a rattan palm. Rattan palms do not grow in typical palm tree fashion. Rattans are climbers, more like vines. All palms grow from a central part of the plant called the heart. They grow as bromeliads do, from meristem tissue in the center of a rosette of leaves. As a rattan grows, its stem lengthens and grabs hold of the surrounding vegetation using some seriously sharp, hooked spikes. For much of their early life they generally sprawl across the forest floor but the real goal of the rattan is to reach up into the canopy where they can access the best sunlight.

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Rattans are not a single taxonomic unit. Though they are all palms, at least 13 genera contain palms that exhibit this climbing habit. With over 600 species included in these groups, it goes without saying that there is a lot of variation on the theme. The largest rattan palms hail from the genus Calamus and all but one are native to Asia.

Many species of rattan have whip-like stems that would be easy to miss in a lush jungle. Be aware of your surroundings though, because these spikes are quite capable of ripping clothes and flesh to pieces. The rattans are like any other vine, sacrificing bulk for an easy ride into the light at the expense of whatever it climbs on. Indeed some get so big that they break their host tree. It is this searching, sprawling nature of the rattans that allow them to reach some impressive lengths. Some species of rattan have been reported with stems measuring over 500 feet!

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Getting back to what I mentioned earlier about wicker furniture, rattans are a very important resource for the people of the jungles in which they grow. They offer food, building materials, shelter materials, an artistic medium, and a source of economic gain. In many areas, rattans are being heavily exploited as a result. This is bad for both the ecology of the forest and the locals who depend upon these species.

The global rattan trade is estimated at around $4 billion dollars. Because of this, rattans are harvested quite heavily and many are cut at too young of an age to re-sprout meaning little to no recruitment occurs in these areas. There is a lot of work being done by a few organizations to try to set up sustainable rattan markets in the regions that have been hit the hardest. More information can be found at sites like the World Wildlife Fund.

Photo Credits: [1] [2] [3]

Further Reading: [1] [2] [3] [4]

The Plight of the African Violets

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For many of us, African violets (Saintpaulia spp.) are some of the first houseplants we learned how to grow. They are not true violets (Violaceae), of course, but rather members of the family Gesneriaceae. Nonetheless, their compact rosettes of fuzzy leaves coupled with regular sprays of colorful flowers has made them a multi-million dollar staple of the horticultural industry. Unfortunately their numbers in captivity overshadow a bleak future for this genus in the wild. Many African violets are teetering on the brink of extinction.

The genus Saintpaulia is endemic to a small portion of east Africa, with a majority of species being found growing at various elevations throughout the Eastern Arc Mountains of Kenya and Tanzania. Most of the plants we grow at home are clones and hybrids of two species, S. ionantha and S. confusa. Collected in 1892, these two species were originally thought to be the same species, S. ionantha, until a prominent horticulturist noted that there are distinct differences in the seed capsules each produced. Since the 1890's, more species have been discovered.

  Saintpaulia goetzeana

Saintpaulia goetzeana

Exactly how many species comprise this genus is still up for some debate. Numbers range from as many as 20 to as few as 6. Much of the early work on describing various Saintpaulia species involved detailed descriptions of the density and direction of hairs on the leaves. More recent genetic work considers some of these early delineations to be tenuous at best, however, even these modern techniques have resolved surprisingly little when it comes to a species concept within this group.

  Saintpaulia  sp.  in situ .

Saintpaulia sp. in situ.

Though it can be risky to try and make generalizations about an entire genus, there are some commonalities when it comes to the habitats these plants prefer. Saintpaulia grow at a variety of elevations but most can be found growing on rocky outcrops. Most of them prefer growing in the shaded forest understory, hence they do so well in our (often) poorly lit homes. Their affinity for growing on rocks means that many species are most at home growing on rocks and cliffs near streams and waterfalls. The distribution of most Saintpaulia species is quite limited, with most only known from a small region of forest or even a single mountain. Its their limited geographic distribution that is cause for concern.

  Saintpaulia ionantha  subsp.  grotei in situ.

Saintpaulia ionantha subsp. grotei in situ.

Regardless of how many species there are, one fact is certain - many Saintpaulia risk extinction if nothing is done to save them. Again, populations of Saintpaulia species are often extremely isolated. Though more recent surveys have revealed that a handful of lowland species are more widespread than previously thought, mid to highland species are nonetheless quite restricted in their distribution. Habitat loss is the #1 threat facing Saintpaulia. Logging, both legal and illegal, and farming are causing the diverse tropical forests of eastern Africa to shrink more and more each year. As these forests disappear, so do Saintpaulia and all of the other organisms that call them home.

There is hope to be had though. The governments of Kenya and Tanzania have recognized that too much is being lost as their forests disappear. Stronger regulations on logging and farming have been put into place, however, enforcement continues to be an issue. Luckily for some Saintpaulia species, the type localities from which they were described are now located within protected areas. Protection coupled with inaccessibility may be exactly what some of these species need to survive. Also, thanks to the ease in which Saintpaulia are grown, ex situ conservation is proving to be a viable and valuable option for conserving at least some of the genetic legacy of this genus.

  Saintpaulia intermedia

Saintpaulia intermedia

It is so ironic to me that these plants can be so common in our homes and offices and yet so rare in the wild. Despite their popularity, few recognize the plight of this genus. My hope is that, in reading this, many of you will think about what you can do to protect the legacy of plants like these and so many others. Our planet and the species that call it home are doomed without habitat in which to live and reproduce. This is why land conservation is an absolute must. Consider donating to a land conservation organization today. Here are two worth your consideration:

The Nature Conservancy

The Rainforest Trust

Photo Credits: [1] [2] [3] [4] [5]

Further Reading: [1] [2] [3] [4] [5]

The Carnivorous Dewy Pine

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The dewy pine is definitely not a pine, however, it is quite dewy. Known scientifically as Drosophyllum lusitanicum, this carnivore is odd in more ways than one. It is also growing more and more rare each year.

One of the strangest aspects of dewy pine ecology is its habitat preferences. Whereas most carnivorous plants enjoy growing in saturated soils or even floating in water, the dewy pine's preferred habitats dry up completely for a considerably portion of the year. Its entire distribution consists of scattered populations throughout the western Iberian Peninsula and northwest Morocco.

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Its ability to thrive in such xeric conditions is a bit of a conundrum. Plants stay green throughout the year and produce copious amounts of sticky mucilage as a means of catching prey. During the summer months, both air and soil temperatures can skyrocket to well over 100°F (37 °C). Though they possess a rather robust rooting system, dewy pines don't appear to produce much in the way of fine roots. Because of this, any ground water presence deeper in the soil is out of their reach. How then do these plants manage to function throughout the driest parts of the year?

During the hottest months, the only regular supply of water comes in the form of dew. Throughout the night and into early morning, temperatures cool enough for water to condense out of air. Dew covers anything with enough surface area to promote condensation. Thanks to all of those sticky glands on its leaves, the dewy pine possesses plenty of surface area for dew to collect. It is believed that, coupled with the rather porous cuticle of the surface of its leaves, the dewy pine is able to obtain water and reduce evapotranspiration enough to keep itself going throughout the hottest months. 

 Dewy pine leaves unfurl like fern fiddle heads as they grow.

Dewy pine leaves unfurl like fern fiddle heads as they grow.

As you have probably guessed at this point, those dewy leaves do more than photosynthesize and collect water. They also capture prey. Carnivory in this species evolved in response to the extremely poor conditions of their native soils. Nutrients and minerals are extremely low, thus selecting for species that can acquire these necessities via other means. Each dewy pine leaf is covered in two types of glands: stalked glands that produce sticky mucilage, and sessile glands that secrete digestive enzymes and absorb nutrients.

Their ability to capture insects far larger than one would expect is quite remarkable. The more an insect struggles, the more it becomes ensnared. The strength of the dewy pines mucilage likely stems from the fact that the leaves do not move like those of sundews (Drosera spp.). Once an insect is stuck, there is not much hope for its survival. Living in an environment as extreme as this, the dewy pine takes no chances.

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The taxonomic affinity of the dewy pine has been a source of confusion as well. Because of its obvious similarity to the sundews, the dewy pine has long been considered a member of the family Droseraceae. However, although recent genetic work does suggest a distant relationship with Droseraceae and Nepenthaceae, experts now believe that the dewy pine is unique enough to warrant its own family. Thus, it is now the sole species of the family Drosophyllaceae.

Sadly, the dewy pine is losing ground fast. From industrialization and farming to fire suppression, dewy pines are running out of habitat. It is odd to think of a plant capable of living in such extreme conditions as being overly sensitive but that is the conundrum faced by more plants than just the dewy pine. Without regular levels of intermediate disturbance that clear the landscape of vegetation, plants like the dewy pine quickly get outcompeted by more aggressive plant species. Its the fact that dewy pine can live in such hostile environments that, historically, has kept its populations alive and well.

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What's more, it appears that dewy pines have trouble getting their seeds into new habitats. Low seed dispersal ability means populations can be cut off from suitable habitats that are only modest distances away. Without a helping hand, small, localized populations can disappear alarmingly fast. The good news is, conservationists are working hard on identifying what must be done to ensure the dewy pine is around for future generations to enjoy.

Changes in land use practices, prescribed fires, wild land conservation, and incentives for cattle farmers to adopt more traditional rather than industrial grazing practices may turn the table on dewy pine extinction. Additionally, dewy pines have become a sort of horticultural oddity over the last decade or so. As dedicated growers perfect germination and growing techniques, ex situ conservation can help maintain stocks of genetic material around the globe.

Photo Credits: [1] [2] [3] [4] [5]

Further Reading: [1] [2] [3] [4]

 

 

Cycad Pollinators

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When it comes to insect pollination, flowering plants get all of the attention. However, flowers aren't the only game in town. More and more we are beginning to appreciate the role insects play in the pollination of some gymnosperm lineages. For instance, did you know that many cycad species utilize insects as pollen vectors? The ways in which these charismatic gymnosperms entice insects is absolutely fascinating and well worth understanding in more detail.

Cycads or cycad-like plants were some of the earliest gymnosperm lineages to arise on this planet. They did so long before familiar insects like bees, wasps, and butterflies came onto the scene. It had long been assumed that, like a vast majority of extant gymnosperms, cycads relied on the wind to get pollen from male cones to female cones. Indeed, many species certainly utilize to wind to one degree or another. However, subsequent work on a few cycad genera revealed that wind might not cut it in most cases.

 White-haired cycad ( Encephalartos friderici-guilielm i)

White-haired cycad (Encephalartos friderici-guilielmi)

It took placing living cycads into wind tunnels to obtain the first evidence that something strange might be going on with cycad pollination. The small gaps on the female cones were simply too tight for wind-blown pollen to make it to the ovules. Around the same time, researchers began noting the production of volatile odors and heat in cycad cones, providing further incentives for closer examination.

Subsequent research into cycad pollination has really started to pay off. By excluding insects from the cones, researchers have been able to demonstrate that insects are an essential factor in the pollination of many cycad species. What's more, often these relationships appear to be rather species specific.

  Cycadophila yunnanensis ,  C. nigra , and other beetles on a cone of  Cycas  sp.

Cycadophila yunnanensis, C. nigra, and other beetles on a cone of Cycas sp.

By far, the bulk of cycad pollination services are being performed by beetles. This makes a lot of sense because, like cycads, beetles evolved long before bees or butterflies. Most of these belong to the superfamily Cucujoidea as well as the true weevils (Curculionidae). In some cases, beetles utilize cycad cones as places to mate and lay eggs. For instance, male and female cones of the South African cycad Encephalartos friderici-guilielmi were found to be quite attractive to at least two beetle genera. 

Beetles and their larvae were found on male cones only after they had opened and pollen was available. Researchers were even able to observe adult beetles emerging from pupae within the cones, suggesting that male cones of E. friderici-guilielmi function as brood sites. Adult beetles carrying pollen were seen leaving the male cones and visiting the female cones. The beetles would crawl all over the fuzzy outer surface of the female cones until they became receptive. At that point, the beetles wriggle inside and deposit pollen. Seed set was significantly lower when beetles were excluded.

 Male cone of  Zamia furfuracea  with a mating (lek) assembly of  Rhopalotria mollis  weevils.

Male cone of Zamia furfuracea with a mating (lek) assembly of Rhopalotria mollis weevils.

For the Mexican cycad Zamia furfuracea, weevils also utilize cones as brood sites, however, the female cones go to great lengths to protect themselves from failed reproductive efforts. The adult weevils are attracted to male cones by volatile odors where they pick up pollen. The female cones are thought to also emit similar odors, however, larvae are not able to develop within the female cones. Researchers attribute this to higher levels of toxins found in female cone tissues. This kills off the beetle larvae before they can do too much damage with their feeding. This way, the cycad gets pollinated and potentially harmful herbivores are eliminated. 

Beetles also share the cycad pollination spotlight with another surprising group of insects - thrips. Thrips belong to an ancient order of insects whose origin dates back to the Permian, some 298 million years ago. Because they are plant feeders, thrips are often considered pests. However, for Australian cycads in the genus Macrozamia, they are important pollinators.

  Macrozamia macleayi  female cone.

Macrozamia macleayi female cone.

Thrip pollination was studied in detail in at least two Macrozamia species, M. lucida and M. macleayi. It was noted that the male cones of these species are thermogenic, reaching peak temperatures of around   104 °F (40 °C). They also produce volatile compounds like monoterpenes as well as lots of CO2 and water vapor during this time. This spike in male cone activity also coincides with a mass exodus of thrips living within the cones.

 Thrips ( Cycadothrips chadwicki ) leaving a thermogenic pollen cone of  Macrozamia lucida.

Thrips (Cycadothrips chadwicki) leaving a thermogenic pollen cone of Macrozamia lucida.

Thrips apparently enjoy cool, dry, and dark places to feed and breed. That is why they love male Macrozamia cones. However, if the thrips were to remain in the male cones only, pollination wouldn't occur. This is where all of that male cone metabolic activity comes in handy. Researchers found that the combination of rising heat and humidity, and the production of monoterpenes aggravated thrips living within the male cones, causing them to leave the cones in search of another home.

Inevitably many of these pollen-covered thrips find themselves on female Macrozamia cones. They crawl inside and find things much more to their liking. It turns out that female Macrozamia cones do not produce heat or volatile compounds. In this way, Macrozamia are insuring pollen transfer between male and female plants.

 Thrips up close.

Thrips up close.

Pollination in cycads is a fascinating subject. It is a reminder that flowering plants aren't the only game in town and that insects have been providing such services for eons. Additionally, with cycads facing extinction threats on a global scale, understanding pollination is vital to preserving them into the future. Without reproduction, species will inevitably fail. Many cycads have yet to have their pollinators identified. Some cycad pollinators may even be extinct. Without boots on the ground, we may never know the full story. In truth, we have only begun to scratch the surface of cycads and their pollinators.

Photo Credits: [1] [2] [3] [4] [5] [6] [7]

Further Reading: [1] [2] [3] [4] [5] [6]

Saving One of North America's Rarest Shrubs

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The chance to save a species from certain extinction cannot be wasted. When the opportunity presents itself, I believe it is our duty to do so. Back in 2010, such an opportunity presented itself to the state of California and what follows is a heroic demonstration of the lengths dedicated individuals will go to protect biodiversity. Thought to be extinct for 60 years, the Franciscan manzanita (Arctostaphylos franciscana) has been given a second chance at life on this planet.

California is known the world over for its staggering biodiversity. Thanks to a multitude of factors that include wide variations in soil and climate types, California boasts an amazing variety of plant life. Some of the most Californian of these plants belong to a group of shrubs and trees collectively referred to as 'manzanitas.' These plants are members of the genus Arctostaphylos, which hails from the family Ericaceae, and sport wonderful red bark, small green leaves, and lovely bell-shaped flowers. Of the approximately 105 species, subspecies, and varieties of manzanita known to science, 95 of them can be found growing in California.

It has been suggested that manzanitas as a whole are a relatively recent taxon, having arisen sometime during the Middle Miocene. This fact complicates their taxonomy a bit because such a rapid radiation has led manzanita authorities to recognize a multitude of subspecies and varieties. In California, there are also many endemic species that owe their existence in part to the state's complicated geologic history. Some of these manzanitas are exceedingly rare, having only been found growing in one or a few locations. Sadly, untold species were probably lost as California was settled and human development cleared the land. 

Such was the case for the Franciscan manzanita. Its discovery dates back to the late 1800's. California botanist and manzanita expert, Alice Eastwood, originally collected this plant on serpentine soils around the San Francisco Bay Area. In the years following, the growing human population began putting lots of pressure on the surrounding landscape.

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Botanists like Eastwood recognized this and went to work doing what they could to save specimens from the onslaught of bulldozers. Luckily, the Franciscan manzanita was one such species. A few individuals were dug up, rooted, and their progeny were distributed to various botanical gardens. By the 1940's, the last known wild population of Franciscan manzanita were torn up and replaced by the unending tide of human expansion into the Bay Area.

It was apparent that the Franciscan manzanita was gone for good. Nothing was left of its original populations outside of botanical gardens. It was officially declared extinct in the wild. Decades went by without much thought for this plant outside of a few botanical circles. All of that changed in 2009.

It was in 2009 when a project began to replace a stretch of roadway called Doyle Drive. It was a massive project and a lot of effort was invested to remove the resident vegetation from the site before work could start in earnest. Native vegetation was salvaged to be used in restoration projects but most of the clearing involved the removal of aggressive roadside trees. A chipper was brought in to turn the trees into wood chips. Thanks to a bit of serendipity, a single area of vegetation bounded on all sides by busy highway was spared from wood chip piles. Apparently the only reason for this was because a patrol car had been parked there during the chipping operation.

Cleared of tall, weedy trees, this small island of vegetation had become visible by road for the first time in decades. That fall, a botanist by the name of Daniel Gluesenkamp was driving by the construction site when he noticed an odd looking shrub growing there. Luckily, he knew enough about manzanitas to know something was different about this shrub. Returning to the site with fellow botanists, Gluesenkamp and others confirmed that this odd shrubby manzanita was in fact the sole surviving wild Franciscan manzanita. Needless to say, this caused a bit of a stir among conservationists.

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The shrub had obviously been growing in that little island of serpentine soils for quite some time. The surrounding vegetation had effectively concealed its presence from the hustle and bustle of commuters that crisscross this section of on and off ramps every day. Oddly enough, this single plant likely owes its entire existence to the disturbance that created the highway in the first place. Manzanitas lay down a persistent seed bank year after year and those seeds can remain dormant until disturbance, usually fire but in this case road construction, awakens them from their slumber. It is likely that road crews had originally disturbed the serpentine soils just enough that this single Franciscan manzanita was able to germinate and survive.

The rediscovery of the last wild Franciscan manzanita was bitter sweet. On the one hand, a species thought extinct for 60 years had been rediscovered. On the other hand, this single individual was extremely stressed by years of noxious car exhaust and now, the sudden influx of sunlight due to the removal of the trees that once sheltered it. What's more, this small island of vegetation was doomed to destruction due to current highway construction. It quickly became apparent that if this plant had any chance of survival, something drastic had to be done.

Many possible rescue scenarios were considered, from cloning the plant to moving bits of it into botanical gardens. In the end, the most heroic option was decided on - this single Franciscan manzanita was going to be relocated to a managed natural area with a similar soil composition and microclimate.

Moving an established shrub is not easy, especially when that particular individual is already stressed to the max. As such, numerous safeguards were enacted to preserve the genetic legacy of this remaining wild individual just in case it did not survive the ordeal. Stem cuttings were taken so that they could be rooted and cloned in a lab. Rooted branches were cut and taken to greenhouses to be grown up to self-sustaining individuals. Numerous seeds were collected from the surprising amount of ripe fruits present on the shrub that year. Finally, soil containing years of this Franciscan manzanita's seedbank as well as the microbial community associated with the roots, were collected and stored to help in future reintroduction efforts.

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Finally, the day came when the plant was to be dug up and moved. Trenches were dug around the root mass and a dozen metal pipes were driven into the soil 2 feet below the plant so that the shrub could safely be separated from the soil in which it had been growing all its life. These pipes were then bolted to I-beams and a crane was used to hoist the manzanita up and out of the precarious spot that nurtured it in secret for all those years.

Upon arriving at its new home, experts left nothing to chance. The shrub was monitored daily for the first ten days of its arrival followed by continued weekly visits after that. As anyone that gardens knows, new plantings must be babied a bit before they become established.  For over a year, this single shrub was sheltered from direct sun, pruned of any dead and sickly branches, and carefully weeded to minimize competition. Amazingly, thanks to the coordinated effort of conservationists, the state of California, and road crews, this single individual lives on in the wild.

Of course, one single individual is not enough to save this species from extinction. At current, cuttings, and seeds provide a great starting place for further reintroduction efforts. Similarly, and most importantly, a bit of foresight on the part of a handful of dedicated botanists nearly a century ago means that the presence of several unique genetic lines of this species living in botanical gardens means that at least some genetic variability can be introduced into the restoration efforts of the Franciscan manzanita.

In an ideal world, conservation would never have to start with a single remaining individual. As we all know, however, this is not an ideal world. Still, this story provides us with inspiration and a sense of hope that if we can work together, amazing things can be done to preserve and restore at least some of what has been lost. The Franciscan manzanita is but one species that desperately needs our help an attention. It is a poignant reminder to never give up and to keep working hard on protecting and restoring biodiversity.

Photo Credits: [1] [2] [3] [4]

Further Reading: [1] [2] [3] [4]

 

Prescribed Fire On An Illinois Prairie

Prairies are fire adapted ecosystems. For far too long, fires were sequestered. Today, more and more communities are coming around to the fact that fire can be used as a tool to bring life back to these endangered ecosystems. In this video, we get hands on experience with fire as a prairie restoration tool.

Producer, Editor, Camera: Grant Czadzeck (http://www.grantczadzeck.com)

Music by
Artist: Stranger In My Town
Track: Terra
https://strangerinmytown.bandcamp.com/

 

Daffodil Insights

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Daffodils seem to be everywhere. Their horticultural popularity means that, for many of us, these plants are among the first flowers we see each spring. Daffodils are so commonplace that it's as if they evolved to live in our gardens and nowhere else. Indeed, daffodils have had a long, long history with human civilization, so much so that it is hard to say when our species first started to cohabitate. Our familiarity with these plants belies an intriguing natural history. What follows is a brief overview of the world of daffodils. 

If you are like me, then you may have gone through most of your life not noticing much difference between garden variety daffodils. Though many of us will be familiar with only a handful of daffodil species and cultivars, these introductions barely scratch the surface. One may be surprised to learn that as of 2008, more than 28,000 daffodil varieties have been named and that number continues to grow each and every year. Even outside of the garden, there is some serious debate over the number of daffodil species, much of this having to do with what constitutes a species in this group.

  Narcissus poeticus

Narcissus poeticus

As I write this, all daffodils fall under the genus Narcissus. Estimates as to the number of species within Narcissus range from as few as 50 to as many as 80. The genus itself sits within the family Amaryllidaceae and is believed to have originated somewhere between the late Oligocene and early Miocene, some 18 to 30 million years ago. Despite its current global distribution, Narcissus are largely Mediterranean plants, with peak diversity occurring on the Iberian Peninsula. However, thanks to the aforementioned long and complicated history in cultivation, it has become quite difficult to understand the full range of diversity in form and habitat of many species. To understand this, we first need to understand a bit about their reproductive habits.

Much of the evolution of Narcissus seems to center around floral morphology and geographic isolation. More specifically, the length of the floral tube or "corona" and the position of the sexual organs within, dictates just who can effectively pollinate these plants. The corona itself is not made up of petals or sepals but instead, its tube-like appearance is due to a fusion of the stamens into the famous trumpet-like tube we know and love.

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Variation in corona shape and size has led to the evolution of three major pollination strategies within this genus. The first form is the daffodil form, whose stigma is situated at the mouth of the corolla, well beyond the 6 anthers. This form is largely pollinated by larger bees. The second form is the paperwhite form, whose stigma is situated more closely to or completely below the anthers at the mouth of the corona. This form is largely pollinated by various Lepidoptera as well as long tongued bees and flies. The third form is the triandrus form, which exhibits three distinct variations on stigma and anther length, all of which are situated deep within the long, narrow corona. The pendant presentation of the flowers in this group is thought to restrict various butterflies and moths from entering the flower in favor of bees.

  Narcissus tazetta

Narcissus tazetta

The variations on these themes has led to much reproductive isolation among various Narcissus populations. Plants that enable one type of pollinator usually do so at the exclusion of others. Reproductive isolation plus geographic isolation brought on by differences in soil types, habitat types, and altitudinal preferences is thought to have led to a rapid radiation of these plants across the Mediterranean. All of this has gotten extremely complicated ever since humans first took a fancy to these bulbs.

  Narcissus cyclamineus

Narcissus cyclamineus

Reproductive isolation is not perfect in these plants and natural hybrid zones do exist where the ranges of two species overlap. However, hybridization is made much easier with the helping hand of humans. Whether via landscape disturbance or direct intervention, human activity has caused an uptick in Narcissus hybridization. For centuries, we have been mixing these plants and moving them around with little to no record as to where they originated. What's more, populations frequently thought of as native are actually nothing more than naturalized individuals from ancient, long-forgotten introductions. For instance, Narcissus populations in places like China, Japan, and even Great Britain originated in this manner.

All of this mixing, matching, and hybridizing lends to some serious difficulty in delineating species boundaries. It would totally be within the bounds of reason to ask if some of the what we think of as species represent true species or simply geographic varieties on the path to further speciation. This, however, is largely speculative and will require much deeper dives into Narcissus phylogenetics.

  Narcissus triandrus

Narcissus triandrus

Despite all of the confusion surrounding accurate Narcissus taxonomy, there are in fact plenty of true species worth getting to know. These range in form and habit far more than one would expect from horticulture. There are large Narcissus, small Narcissus, there are Narcissus with yellow flowers and Narcissus with white flowers, some with upright flowers and some with pendant flowers. There are even a handful of fall blooming Narcissus. The variety of this genus is staggering if you are not prepared for it.

  Narcissus viridiflorus  - a green, fall-blooming daffodil

Narcissus viridiflorus - a green, fall-blooming daffodil

After pollination, the various Narcissus employ a seed dispersal strategy that doesn't get talked about enough in reference to this group. Attached to each hard, black seed are fatty structures known as eliasomes. Eliasomes attract ants. Like many spring flowering plant species around the globe, Narcissus utilize ants as seed dispersers. Ants pick up the seeds and bring them back to their nests. They go about removing the eliasomes and then discard the seed. The seed, safely tucked away in a nutrient-rich ant midden, has a much higher chance of germination and survival than if things were left up to simple chance. It remains to be seen whether or not Narcissus obtain similar seed dispersal benefits from ants outside of their native range. Certainly Narcissus populations persist and naturalize readily, however, I am not aware if ants have any part in the matter.

 The endangered  Narcissus alcaracensis .

The endangered Narcissus alcaracensis.

Despite their popularity in the garden, many Narcissus are having a hard go of it in the wild. Habitat destruction, climate change, and rampant collecting of wild bulbs are having serious impacts on Narcissus numbers. The IUCN considered at least 5 species to be endangered and a handful of some of the smaller species already thought to be extinct in the wild. In response to some of these issues, protected areas have been established that encompass at least some of the healthy populations that remain for some of these species.

If you are anything like me, you have ignored Narcissus for far too long. Sure, they aren't native to the continent on which I live, and sure, they are one of the most commonly used plants in a garden setting, but every species has a story to tell. I hope that, armed with this new knowledge, you at least take a second look at the Narcissus popping up around your neighborhood. More importantly, I hope this introduction makes you appreciate their wild origins and the fact that we still have much to learn about these plants. I have barely scratched the surface of this genus and there is more more information out there worth perusing. Finally, I hope we can do better for the wild progenitors of our favorite garden plants. They need all the help they can get and unless we start speaking up and working to preserve wild spaces, all that will remain are what we have in our gardens and that is not a future I want to be a part of.

Photo Credits: [1] [2] [3] [4] [5] [6] [7]

Further Reading: [1] [2] [3] [4] [5] [6] [7] [8] [9]

 

The Mighty Saguaro Cactus

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Where does one begin with a plant like the saguaro cactus (Carnegiea gigantea)? It is recognized the world over for its iconic appearance yet its native range is disproportionately small compared to its popularity. It is easily one of the most spectacular plants I have ever encountered and I will never forget the sound the wind makes as it blows over its spiny pleated trunk. It would be impossible to sum up our collective knowledge of this species in one article, however, I feel that some form of an introduction is necessary. Today I want to honor this icon of the Sonoran Desert.

The saguaro is the only member of the genus Carnegiea, which is part of a subtribe of cacti characterized by their columnar appearance. Despite its unique taxonomic affinity, the evolutionary origins of this cactus remains a bit of a mystery. Though it is undoubtedly related to other columnar cacti of the Americas, a proper family tree seems to be just out of our reach. Due to lots of convergent and parallel evolution as well as conflicts between genealogies and species histories, we still aren't sure of its evolutionary origins. What we do know about this species on a genetic level is nonetheless quite interesting. For instance the saguaro has one of the smallest chloroplast genomes of any non-parasitic plant and we aren’t exactly sure why this is the case.

Saguaro are long lived cacti. Estimating age of a cactus can be rather tricky considering that they don’t produce annual growth rings. This is where long term monitoring projects have come in handy. By observing hundreds of saguaro throughout the Sonoran Desert, experts believe that saguaro can regularly reach ages of 150 to 170 years and some individuals may be able to live for more than 200 years. Amazingly, it is thought that saguaro will not begin to grow their characteristic arms until they reach somewhere around 50 to 100 years of age. That being said, some saguaro never bother growing arms. It all depends on where the conditions they experience throughout their lifetime.

Growth for a saguaro depends on where they are rooted. Under favorable conditions, a saguaro can grow to heights of 50 feet or more, with the world record holder clocking in at a whopping 78 feet in height. Such growth becomes all the more impressive when you realize just how agonizingly slow the process can be. Studies have shown that juvenile saguaro only put on about 1.5 inches of growth in their first eight years of life.

Despite preconceived notions about the hardy nature of most cacti, saguaro have proven to be rather specific in their needs. They are limited in their growth and distribution by the availability of water and warm temperatures. Saguaro, especially young individuals, cannot tolerate periods of prolonged frost. Additionally, germination and seedling survival occur most frequently only during the wettest years. In fact, one study showed that successful years for reproduction in these beloved cacti were tied to volcanic eruptions that cooled the climate just enough to allow the young saguaro to become established.

Outside of volcanic eruptions, saguaro appear to have friends in the surrounding vegetation. Studies have shown that saguaro seedlings seem to do best when growing under the shade of trees like the palo verde (Parkinsonia florida), ironwood (Olneya tesota), and mesquite (Prosopis velutina). The microclimates produced by these trees are much more favorable for saguaro growth than are open desert conditions. In essence, these trees serve as nurseries for young saguaro until they are large enough to handle more exposed conditions. Their nursery habits are not mutually beneficial however as research suggests that saguaro eventually compete with the trees that once protected them for precious resources like nutrients and water.

 Saguaros outgrowing their palo verde nurse tree. 

Saguaros outgrowing their palo verde nurse tree. 

At roughly 35 years of age, a saguaro will begin to flower. Flowers are small compared to the size of the cactus but they are abundant. Most flowers are produced at the apex of the cactus and it is thought that the growth of saguaro arms is largely a way of increasing the reproductive potential of large individuals. The flowers are cream colored and night scented. They open in the evening but will stay open and continue to produce nectar well into the morning hours.

Though a wide variety of animals will visit these flowers, the main pollinators are bees during the day and lesser long-nosed bats at night. Interestingly, it has been found that certain amino acids within the nectar of the saguaro can actually help female bats sustain lactation while raising their young, making them a valuable food source for these flying mammals. Catering to such a broad spectrum of potential pollinators is thought to have evolved as a means of increasing seed set. Each saguaro ovary contains many ovules and the more pollen that makes it onto the stigma, the more seeds will be produced.

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 A lesser long-nosed bat pollinates a saguaro bloom.

A lesser long-nosed bat pollinates a saguaro bloom.

Due to their size and abundance, it is easy to understand why the saguaro is such an ecologically important species in the Sonoran Desert ecosystem. In essence, they function similar to trees in that they serve as vital sources of shelter and food for myriad desert animals. Woodpeckers, especially the gila and the gilded flicker, regularly hollow out and build nests in saguaro trunks. These hollows are subsequently used by many different bird, mammal, and reptile species. The flowers and fruits are important sources of food for wildlife.

 Gila woodpecker with its nesting hole.

Gila woodpecker with its nesting hole.

 Gila woodpecker holes become homes for other birds like owls. 

Gila woodpecker holes become homes for other birds like owls. 

 On rare occasions, woodpecker holes can even become home to other cacti!

On rare occasions, woodpecker holes can even become home to other cacti!

I sincerely hope that this brief introduction does at least some justice to the wonderful organism that is the saguaro cactus. The Sonoran Desert would be a shell of an ecosystem without its presence. What’s more, it has played a significant role in the culture of this region for millennia. Though it appears quite numerous on the landscape, the long-term status of the saguaro is cause for concern. Numerous declines have been reported throughout its range. With its slow growth rates and infrequent recruitment events, the saguaro can be quite sensitive to rapid changes in its environment. Luckily it has received special protection laws throughout its US range.

Photo Credits: [1] [2] [3] [4]


Further Reading: [1] [2] [3] [4] [5] [6] [7] [8] [9] 

The Other Pawpaws

  Asimina tetramera

Asimina tetramera

The pawpaw (Asimina triloba) has been called "America's forgotten fruit." Once quite popular among Native Americans and settlers alike, it fell out of the public eye until quite recently. If one considers the pawpaw "forgotten" then its relatives have been straight up ignored. Indeed, the pawpaw shares the North American continent with 10 other Asimina species. 

  Asimina angustifolia

Asimina angustifolia

The genus Asimina belongs to a family of plants called the custard apple family - Annonaceae. It is a large family that mostly resides in the tropics. In fact, the genus Asimina is the only group to occur outside of the tropics. Though A. triloba finds itself growing as far north as Canada, the other species within this genus are confined to southeastern North America in coastal plain communities. 

  Asimina parviflora

Asimina parviflora

As I mentioned above, there are 10 other species in the genus and at least one naturally occurring hybrid. For the most part, they all prefer to grow where regular fires keep competing vegetation at bay. They are rather small in stature, usually growing as shrubs or small, spindly trees. They can be rather inconspicuous until it comes time to flower.

  Asimina obovata

Asimina obovata

The flowers of the various Asimina species are relatively large and range in color from bright white to deep red, though the most common flower color seems to be creamy white. The flowers themselves give off strange odors that have been affectionately likened to fermenting fruit and rotting meat. Of course, these odors attract pollinators. Asimina aren't much of a hit with bees or butterflies. Instead, they are mainly visited by blowflies and beetles. 

  Asimina pygmaea

Asimina pygmaea

As is typical of the family, all of the Asimina produce relatively large fruits chock full of hard seeds. Seed dispersal for the smaller species is generally accomplished through the help of mammals like foxes, coyotes, raccoons, opossums, and even reptiles such as the gopher tortoise. Because the coastal plain of North America is a fire-prone ecosystem, most of the Asimina are well adapted to cope with its presence. In fact, most require it to keep their habitat open and free of too much competition. At least one species, A. tetramera, is considered endangered in large part due to fire sequestration.

  Asimina reticulata

Asimina reticulata

All of the 11 or so Asimina species are host plants for the zebra swallowtail butterfly (Eurytides marcellus) and the pawpaw sphinx moth (Dolba hyloeus). The specialization of these two insects and few others has to do with the fact that all Asimina produce compounds called acetogenins, which act as insecticides. As such, only a small handful of insects have adapted to be able to tolerate these toxic compounds. 

  Asimina tetramera

Asimina tetramera

Sadly, like all other denizens of America's coastal plain forest, habitat destruction is taking its toll on Asimina numbers. As mentioned above, at least one species (A. tetramera) is considered endangered. We desperately need to protect these forest habitats. Please support a local land conservation organization like the Partnership For Southern Forestland Conservation today!

See a list of the Asimina of North America here: [1] 

Photo Credits: Wikimedia Commons

Further Reading: [1] [2] [3] [4] [5]

An Endangered Iris With An Intriguing Pollination Syndrome

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The Golan iris (Iris hermona) is a member of the Oncocyclus section, an elite group of 32 Iris species native to the Fertile Crescent region of southwestern Asia. They are some of the showiest irises on the planet. Sadly, like many others in this section, the Golan iris is in real danger of going extinct.

The Golan iris has a rather limited distribution. Despite being named in honor of Mt. Hermon, it is restricted to the Golan Heights region of northern Israel and southwestern Syria. Part of the confusion stems from the fact that the Golan iris has suffered from a bit of taxonomic uncertainty ever since it was discovered. It is similar in appearance to both I. westii and I. bismarckiana with which it is frequently confused. In fact, some authors still consider I. hermona to be a variety of I. bismarckiana. This has led to some serious issues when trying to assess population numbers. Despite the confusion, there are some important anatomical differences between these plants, including the morphology of their rhizomes and the development of their leaves. Regardless, if these plants are in fact different species, it means their respective numbers in the wild decrease dramatically. 

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Like other members of the Oncocyclus group, the Golan iris exhibits an intriguing pollination syndrome with a group of bees in the genus Eucera. Their large, showy flowers may look like a boon for pollinators, however, close observation tells a different story. The Golan iris and its relatives receive surprisingly little attention from most of the potential pollinators in this region.

One reason for their lack of popularity has to do with the rewards (or lack thereof) they offer potential visitors. These irises produce no nectar and very little pollen. Because of this and their showy appearance, most pollinators quickly learn that these plants are not worth the effort. Instead, the only insects that ever pay these large blossoms any attention are male Eucerine bees. These bees aren't looking for food or fragrance, however. Instead, they are looking for a place to rest. 

 A Eucerine bee visiting a nectar source. 

A Eucerine bee visiting a nectar source. 

The Oncocyclus irises cannot self pollinate, which makes studying potential pollinators a bit easier. During a 5 year period, researchers noted that male Eucerine bees were the only insects that regularly visited the flowers and only after their visits did the plants set seed. The bees would arrive at the flowers around dusk and poke around until they found one to their liking. At that point they would crawl down into the floral tube and would not leave again until morning. The anatomy of the flower is such that the bees inevitably contact stamen and stigma in the process. Their resting behavior is repeated night after night until the end of the flowering season and in this way pollination is achieved. Researchers now believe that the Golan iris and its relatives are pollinated solely by these sleeping male bees.

Sadly, the status of the Golan iris is rather bleak. As recent as the year 2000, there were an estimated 2,000 Golan irises in the wild. Today that number has been reduced to a meager 350 individuals. Though there is no single smoking gun to explain this precipitous decline, climate change, cattle grazing, poaching, and military activity have exacted a serious toll on this species. Plants are especially vulnerable during drought years. Individuals stressed by the lack of water succumb to increased pressure from insects and other pests. Vineyards have seen an uptick in Golan in recent years as well, gobbling up viable habitat in the process.

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It is extremely tragic to note that some of the largest remaining populations of Golan irises can be found growing in active mine fields. It would seem that one of the only safe places for these endangered plants to grow are places that are extremely lethal to humans. It would seem that our propensity for violent tribalism has unwittingly led to the preservation of this species for the time being.

At the very least, some work is being done not only to understand what these plants need in order to germinate and survive, but also assess the viability of relocated plants that are threatened by human development. Attempts at transplanting individuals in the past have been met with limited success but thankfully the Oncocyclus irises have caught the eye of bulb growers around the world. By sharing information on the needs of these plants in cultivation, growers can help expand on efforts to save species like the Golan iris.

Photo Credits: [1] [2] [3] [4]

Further Reading: [1] [2] [3] [4]

 

Saving Bornean Peatlands is a Must For Conservation

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The leading cause of extinction on this planet is loss of habitat. As an ecologist, it pains me to see how frequently this gets ignored. Plants, animals, fungi - literally every organism on this planet needs a place to live. Without habitat, we are forced to pack our flora and fauna into tiny collections in zoos and botanical gardens, completely disembodied from the environment that shaped them into what we know and love today. That’s not to say that zoos and botanical gardens don’t play critically important roles in conservation, however, if we are going to stave off total ecological meltdown, we must also be setting aside swaths of land.

There is no way around it. We cannot have our cake and eat it too. Land conservation must be a priority both at the local and the global scale. Wild spaces support life. They buffer it from storms and minimize the impacts of deadly diseases. Healthy habitats filter the water we drink and, for many people around the globe, provide much of the food we eat. Every one of us can think back to our childhood and remember a favorite stretch of stream, meadow, or forest that has since been gobbled up by a housing development. For me it was a forested stream where I learned to love the natural world. I would spend hours playing in the creek, climbing trees, and capturing bugs to show my parents. Since that time, someone leveled the forest, built a house, and planted a lawn. With that patch of forest went all of the insects, birds, and wildflowers it once supported.

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Scenarios like this play out all too often and sadly on a much larger scale than a backyard. Globally, forests have felt taken the brunt of human development. Though it is hard to get a sense of the scope of deforestation on a global scale, the undisputed leaders in deforestation are Brazil and Indonesia. Though the Amazon gets a lot of press, few may truly grasp the gravity of the situation playing out in Southeast Asia.

Deforestation is a clear and present threat throughout tropical Asia. This region is growing both in its economy and population by about 6% every year and this growth has come at great cost to the environment. Indonesia (alongside Brazil) accounts for 55% of the world’s deforestation rates. This is a gut-wrenching statistic because Indonesia alone is home to the most extensive area of intact rainforest in all of Asia. So far, nearly a quarter of Indonesia’s forests have been cleared. It was estimated that by 2010, 2.3 million hectares of peatland forests had been felled and this number shows little signs of slowing. Experts believe that if these rates continue, this area could lose the remainder of its forests by 2056.

Consider the fact that Southeast Asia contains 6 of the world’s 25 biodiversity hotspots and you can begin to imagine the devastating blow that the levelling of these forests can have. Much of this deforestation is done in the name of agriculture, and of that, palm oil and rubber take the cake. Southeast Asia is responsible for 86% of the world’s palm oil and 87% of the world’s natural rubber. What’s more, the companies responsible for these plantations are ranked among some of the least sustainable in the world.

 Palm oil plantations where there once was rainforest. 

Palm oil plantations where there once was rainforest. 

Borneo is home to a bewildering array of life. Researchers working there are constantly finding and describing new species, many of which are found nowhere else in the world. Of the roughly 15,000 plant species known from Borneo, botanists estimate that nearly 5,000 (~34%) of them are endemic. This includes some of the more charismatic plant species such as the beloved carnivorous pitcher plants in the genus Nepenthes. Of these, 50 species have been found growing in Borneo, many of which are only known from single mountain tops.

It has been said that nowhere else in the world has the diversity of orchid species found in Borneo. To date, roughly 3,000 species have been described but many, many more await discovery. For example, since 2007, 51 new species of orchid have been found. Borneo is also home to the largest flower in the world, Rafflesia arnoldii. It, along with its relatives, are parasites, living their entire lives inside of tropical vines. These amazing plants only ever emerge when it is time to flower and flower they do! Their superficial resemblance to a rotting carcass goes much deeper than looks alone. These flowers emit a fetid odor that is proportional to their size, earning them the name “carrion flowers.”

  Rafflesia arnoldii  in all of its glory.

Rafflesia arnoldii in all of its glory.

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If deforestation wasn’t enough of a threat to these botanical treasures, poachers are having considerable impacts on Bornean botany. The illegal wildlife trade throughout southeast Asia gets a lot of media attention and rightfully so. At the same time, however, the illegal trade of ornamental and medicinal plants has gone largely unnoticed. Much of this is fueled by demands in China and Vietnam for plants considered medicinally valuable. At this point in time, we simply don’t know the extent to which poaching is harming plant populations. One survey found 347 different orchid species were being traded illegally across borders, many of which were considered threatened or endangered. Ever-shrinking forested areas only exacerbate the issue of plant poaching. It is the law of diminishing returns time and time again.

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But to lump all Bornean forests under the general label of “rainforest” is a bit misleading. Borneo has multitude of forest types and one of the most globally important of these are the peatland forests. Peatlands are vital areas of carbon storage for this planet because they are the result of a lack of decay. Whereas leaves and twigs quickly breakdown in most rainforest situations, plant debris never quite makes it that far in a peatland. Plant materials that fall into a peatland stick around and build up over hundreds and thousands of years. As such, an extremely thick layer of peat is formed. In some areas, this layer can be as much as 20 meters deep! All the carbon tied up in the undecayed plant matter is carbon that isn’t finding its way back into our atmosphere.

Sadly, tropical peatlands like those found in Borneo are facing a multitude of threats. In Indonesia alone, draining, burning, and farming (especially for palm oil) have led to the destruction of 1 million hectares (20%) of peatland habitat in only one decade. The fires themselves are especially worrisome. For instance, it was estimated that fires set between 1997-1998 and 2002-2003 in order to clear the land for palm oil plantations released 200 million to 1 billion tonnes of carbon into our atmosphere. Considering that 60% of the world’s tropical peatlands are found in the Indo-Malayan region, these numbers are troubling.

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The peatlands of Borneo are totally unlike peatlands elsewhere in the world. Instead of mosses, gramminoids, and shrubs, these tropical peatlands are covered in forests. Massive dipterocarp trees dominate the landscape, growing on a spongey mat of peat. What’s more, no water flows into these habitats. They are fed entirely by rain. The spongey nature of the peat mat holds onto water well into the dry season, providing clean, filtered water where it otherwise wouldn’t be available.

This lack of decay coupled with their extremely acidic nature and near complete saturation makes peat lands difficult places for survival. Still, life has found a way, and Borneo’s peatlands are home to a staggering diversity of plant life. They are so diverse, in fact, that when I asked Dr. Craig Costion, a plant conservation officer for the Rainforest Trust, for something approaching a plant list for an area of peatland known as Rungan River region, he replied:

“Certainly not nor would there ever be one in the conceivable future given the sheer size of the property and the level of diversity in Borneo. There can be as many as a 100 species per acre of trees in Borneo... Certainly a high percentage of the species would only be able to be assigned to a genus then sit in an herbarium for decades until someone describes them.”

And that is quite remarkable when you think about it. When you consider that the Rungan River property is approximately 385,000 acres, the number of plant species to consider quickly becomes overwhelming. To put that in perspective, there are only about 500 tree species native to the whole of Europe! And that’s just considering the trees. Borneo’s peatlands are home to myriad plant species from liverworts, mosses, and ferns, to countless flowering plants like orchids and others. We simply do not know what kind of diversity places like Borneo hold. One could easily spend a week in a place like the Rungan River and walk away with dozens of plant species completely new to science. Losing a tract of forest in such a biodiverse is a huge blow to global biodiversity.

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  Nepenthes ampullaria  relies on decaying plant material within its pitcher for its nutrient needs.

Nepenthes ampullaria relies on decaying plant material within its pitcher for its nutrient needs.

Also, consider that all this plant diversity is supporting even more animal diversity. For instance, the high diversity of fruit trees in this region support a population of over 2,000 Bornean orangutans. That is nearly 4% of the entire global population of these great apes! They aren’t alone either, the forested peatlands of Borneo are home to species such as the critically endangered Bornean white-bearded gibbon, the proboscis monkey, the rare flat-headed cat, and the oddly named otter civet. All these animals and more rely on the habitat provided by these forests. Without forests, these animals are no more.

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 The flat-headed cat, an endemic of Borneo. 

The flat-headed cat, an endemic of Borneo. 

At this point, many of you may be feeling quite depressed. I know how easy it is to feel like there is nothing you can do to help. Well, what if I told you that there is something you can do right now to save a 385,000 acre chunk of peatland rainforest? That’s right, by heading over to the Rainforest Trust’s website (https://www.rainforesttrust.org/project/saving-stronghold-critically-endangered-bornean-orangutan/) you can donate to their campaign to buy up and protect the Rungan River forest tract.

 Click on the logo to learn more!

Click on the logo to learn more!

By donating to the Rainforest Trust, you are doing your part in protecting biodiversity in one of the most biodiverse regions in the world. What’s more, you can rest assured that your money is being used effectively. The Rainforest Trust consistently ranks as one of the top environmental protection charities in the world. Over their nearly three decades of operation, the Rainforest Trust has protected more than 15.7 million acres of land in over 20 countries. Like I said in the beginning, habitat loss is the leading cause of extinction on this planet. Without habitat, we have nothing. Plants are that habitat and by supporting organizations such as the Rainforest Trust, you are doing your part to fight the biggest threats our planet faces. 

Further Reading: [1] [2] [3] [4] [5] [6] [7] [8] [9] [10]

Photo Credits: [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12]

Dipterocarp Forests

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Spend any amount of time reading about tropical forests around the world and you are destined to come across mention of dipterocarp forests. If you're anything like me, your initial thought might have been something along the lines of "what the heck does that mean?" Does it describe some sort of structural aspect of the forest, or perhaps a climatic component? To my surprise, dipterocarp forests refer to any forest in which the dominant species of trees are members of the family Dipterocarpaceae. Thus, I was introduced to a group of plants entirely new to me!

The family Dipterocarpaceae is comprised of 16 genera and roughly 700 species. Its members can be found throughout the tropical regions of the world, though they hit their greatest numbers in the forests of southeast Asia and specifically Borneo. As far as habit is concerned, the dipterocarps are largely arborescent, ranging in size from intermediate shrubs to towering emergent canopy trees. If you have watched a documentary on or been to a tropical forest, it is very likely that you have seen at least one species of dipterocarp.

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The dipterocarps have a long evolutionary history that stretches back to the early Triassic on the supercontinent of Gondwana. As this massive landmass proceeded to break apart, the early ancestors of this group were carried along with them. Today we can find members of this family in tropical regions of South America, Africa, and Asia. Taxonomically speaking, the family is further divided into three sub families that, to some degree, reflect this distribution.  The subfamily Monotoideae is found in Africa and Colombia, the subfamily Pakaraimoideae is found in Guyana, and the subfamily Dipterocarpoideae is found in Asia.

Biologically, the dipterocarps are quite fascinating. Some species can grow quite large. Three genera - Dryobalanops, Hopea, and Shorea - regularly produce trees of over 80 meters (260 feet) in height. The world record for dipterocarps belongs to an individual of Shorea faguetiana, which stands a whopping 93 meters (305 feet) tall! That's not to say all species are giants. Many dipterocarps live out their entire lives in the forest understory.

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For species growing in seasonal environments, flowering occurs annually or nearly so. Also, for dipterocarps that experience regular dry seasons, deciduousness is a common trait. For those growing in non-seasonal environments, however, flowering is more irregular and leaves are largely evergreen. Some species will flower once every 3 to 5 years whereas others will flower once every decade or so. In such cases, flowering occurs en masse, with entire swaths of forest bursting into bloom all at once. These mast years often lead to similar aged trees that all established in the same year. Though more work needs to be done on this, it is thought that various bee species comprise the bulk of the dipterocarp pollinator guild. 

Ecologically speaking, one simply cannot overstate the importance of this family. Wherever they occur, dipterocarps often form the backbone of the forest ecosystem. Their number and biomass alone is worth noting, however, these trees also provide fruits, pollen, nectar, and habitat for myriad forms of life. The larger dipterocarps are often considered climax species, meaning that they dominate in regions comprised of mostly primary forest. For the most part, these trees are able to take advantage of more successional habitats, however, this has been shown to be severely limited by the availability of localized seed sources. 

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Since we are on the topic of regeneration, a conversation about dipterocarps would not be complete if we didn't touch on logging. These trees are massive components of tropical economies. Their wood is highly coveted for a a variety of uses I won't go into here. The point is that, on a global scale, dipterocarp forests have taken a huge hit. Many species within this family are now threatened with extinction. Logging, both legal and illegal, specifically aimed at dipterocarps has seen the destruction of millions of acres of old growth dipterocarp forests. With them goes all of the life that they support.

It's not enough to protect individual species. We need to rally behind whole ecosystem protection. Without it, we literally have nothing. Luckily there are groups like the Center For International Forestry Research and the Forest Research Institute of Malaysia that are working hard on research, conservation, and improved forestry standards in an effort to ease up on the detrimental practices currently in place. Still, these efforts are not enough either. Without the care, concern, and most important, the funding from folks like us, little can be done to stop the tide. That is why supporting land conservation agencies is one of the most powerful things we can do for this planet and for each other. 

Some great land conservation organizations worth supporting:

The Rainforest Trust - https://www.rainforesttrust.org/

The Nature Conservancy - http://bit.ly/2B0hFm

The Rainforest Alliance - https://www.rainforest-alliance.org/

Photo Credits: [1] [2] [3] [4]

urther Reading: [1]

Arctic Foxes: The Unintentional Gardeners

Predators are an integral component of any healthy ecosystem. Their influence can even be felt at the botanical level via what are called top-down controls. Either through direct predation or through altering their behavior, predators influence the herbivores in any system, which usually results in healthier plant communities. This method is rather indirect but new evidence shows that in the Arctic tundra, a top predator is having quite a direct influence on plant communities.

What's not to love about Arctic foxes? All anthropomorphic views aside, Arctic foxes are important predators in this ecosystem. Although the food web complexity on the tundra is largely driven by limits to plant productivity, a paper published in 2016 shows that these little canids can have profound effects on vegetation. This doesn't have to do with predation directly but rather their reproductive behavior. 

Arctic foxes live, give birth, and raise their young in underground dens. Without these subterranean homes, the foxes would be much more vulnerable to other predators as well as the harsh Arctic climate. Dens don't happen overnight either. Suitable sites are tended for generations and some dens may well be more than a century old. All this equates to a lot of activity in and around a good den site. 

With an average litter size of 8 - 10 pups per female, one can imagine the food and waste buildup must be considerable. Like all predators, Arctic fox food and waste are rich in nitrogen and phosphorus compounds, the necessary building blocks of life. Many an onlooker has noticed that, unsurprisingly, plant growth around Arctic fox dens is much more lush than on the surrounding landscape. Until recently though, such differences have hardly been quantified.

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By examining the soil and plant characteristics around Artic fox dens in Canada and comparing these data to surrounding sites without Arctic fox dens, a team of researchers put the first comprehensive numbers to the effects of Arctic foxes on tundra plant communities. They found that soils from in and around Arctic fox dens contained significantly higher levels of nitrogen and phosphorus than did the surrounding control plots. What's more, these levels varied throughout the year. In June, for instance, soil nitrogen and phosphorus levels were 71% and 1195% higher than non-den soils. These levels seemed to switch later in the summer. In August, soil nitrogen from fox dens were 242% higher and soil phosphorus levels were 191% higher.

As you can probably imagine, all of these extra nutrients caused a change in vegetation around the dens. Den sites were far more productive in terms of vegetation. The team found that, on average, Arctic fox dens supported 2.8 times more plant biomass than did the surrounding area. The authors note that these were conservative estimates and that the true values are much higher. Taken together, these results demonstrate that far from simply being top predators, Arctic foxes are true ecosystem engineers, at least on local scales. This is especially important in such a demanding ecosystem as the Arctic tundra.

Photo Credits: [1] [2]

Further Reading: [1]

Botanical Gardens & Plant Conservation

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Botanical gardens are among my favorite places in the world. I find them both relaxing and stimulating, offering something for all of our senses. Botanical gardens are valuable for more than just their beauty. They serve a deeper purpose than simply showcasing endless poinsettia varieties or yet another collection of Dale Chihuly pieces (a phenomenon I can't quite wrap my head around). Botanical gardens are vitally important centers of ex situ plant conservation efforts.

Ex situ conservation literally means "off site conservation," when plants are grown within the confines of a botanical garden, often far away from their native habitats. This is an important process in and of its own because housing plants in different locations safeguards them from complete annihilation. Simply put, don't put all your endangered eggs in one basket.

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I don't think botanical gardens get enough credit for their conservation efforts. Sadly, such endeavors are often overshadowed. That's not to say we don't have a good handle on what is going on. In fact, a study published in August of 2017 looked at the status of ex situ plant conservation efforts around the globe.

The paper outlines a conservative estimate of the diversity of plants found in botanical gardens and highlights areas in desperate need of improvement. Utilizing a dataset compiled by Botanic Gardens Conservation International (BGCI), the team found that the world's botanical gardens contain somewhere around 30% or 105,209 of the 350,699 plant species currently known to science. In total, they estimate humanities various living collections contain representatives from roughly 90% of the known plant families. That is pretty impressive considering the scale of plant diversity on our planet.

 Proportions of the world's plants represented in botanical garden collections ( Source )

Proportions of the world's plants represented in botanical garden collections (Source)

Their research didn't stop there either. The team dove deeper into these numbers and found that there are some serious discrepancies in these estimates. For instance (and to my surprise), botanical gardens house more temperate plant species than they do tropical plant species. They estimated that nearly 60% of the world's temperate plant species are being grown in botanical gardens around the world but only 25% of tropical species. This is despite the fact that most of the world's plants are, in fact, tropical.

Similarly, only 5% of botanical garden collections are dedicated to non-vascular plants like mosses and liverworts. This is a shame not only because these plants are quite interesting and beautiful, but they also are descendants of the first plant lineages to make their way onto land. They are vital to understanding plant evolution as well as plant diversity.

As I mentioned above, ex situ conservation efforts are critical in fighting plant extinctions across the globe. With 1/5 of the world's plants at risk of extinction, the authors of the paper were particularly interested in how botanical gardens were doing in this regard. They found that although various institutions are growing nearly half of all the known threatened plant species on this planet, only 10% of their collection space is devoted to these species. It goes without saying that this number needs to improve if we are to stave off further extinctions.

Taken together, this study paints an interesting and informative picture of botanical garden collections on a global scale. They are doing amazing work to protect and showcase plant diversity. However, there is always a need for improvement. More space and effort needs to be made in ex situ plant conservation efforts. More plants, especially little known tropical species, need to be brought into cultivation. More space must be devoted to propagating threatened and endangered species. Finally, more attention must be given to natural plant diversity rather than gaudy cultivars. If you love botanical gardens as much as I do, please support them. As the authors so eloquently summarize, "Without deep sustained public support, the plant conservation movement will struggle."

Further Reading: [1]

 

 

Herbarium Biases

Humans carry countless biases with them wherever they go. Even the logical mind of a scientist is no stranger to prejudice. Identifying such biases in the way we do science is key to improving the discipline and, as computing power and access to big data increases, we are gaining a better understanding of just how prevalent our biases really are. A recent study that looked at herbarium collections around the world aims to do just that.

With herbaria closing shop around the globe, the need to digitize collections has never been more urgent. Although more and more collections are finding their way into digital libraries, a vast majority of herbarium collections risk being lost forever. This alone represents a major bias. Such organismal science has sadly been scoffed at in recent decades. Still, enough collections have been entered into databases that interesting patterns are starting to emerge. A team of researchers recently took a closer look at roughly 5 million digitized floras representing the most complete digital floras from Australia, South Africa, and New England.

In doing so, the team was able to find some startling biases in these collections. They broke them down into a handful of categories with the hope that botanists and ecologists can start to improve on these gaps over the coming decades. Although the floras they examined by no means represent anything close to a complete picture of our floristic understanding of the world, they nonetheless mirror issues that are sure to crop up no matter where collections have been made.

The first major category is that of spatial or geographic bias. This occurs whenever specimens are collected at a higher frequency in one place over another. There are likely many reasons for this - ease of access, proximity to research institutions, just to name a few. The team found that herbarium collections tended to occur in the same areas through time. What's more, they tended to occur more often near roads with a surprising 50% of specimens collected within 2 km of a roadside. This can result in a highly skewed perspective of the kind of taxa represented in a region. Roadside vegetation is comprised of species capable of dealing with runoff, soil compaction, and pollution, and is likely depauperate of taxa less able to handle such conditions. They also found a elevational bias, with a majority of specimens having been collected below 500 meters. 

 Maps demonstration spatial biases in herbarium collections. Those in red have more collections and those in blue have fewer collections.

Maps demonstration spatial biases in herbarium collections. Those in red have more collections and those in blue have fewer collections.

The second major category is that of temporal bias. This occurs whenever specimens are collected more frequently during certain parts of the year over others. The team found that collections disproportionately occurred during spring and summer months. As anyone who hikes can tell you, there is a lot of variation among plant communities from season to season and any good collection should sample a location multiple times a year. In addition to seasonal biases, the team also found extreme biases in terms of history. Collections in South Africa and Australia started to rise shortly after World War II and peaked in the 1980's and 1990's respectively. Compare this to New England where peak collections occurred nearly 100 years prior. If we are to track long term trends and changes in the flora of various regions, collections need to occur far more regularly. Obviously institutions have shied away from such investigations in recent decades. Only public interest and funding can reverse such trends, hopefully not before it is too late.

The third major bias they found is that of trait bias. This occurs whenever a collector specifically aims for species with a certain life history characteristic (annual vs. perennial, woody vs. herbacious) as well as species of conservation concern. Indeed, the team found that perennial species were over-represented in most herbarium collections. Also, gramminoids dominated herbarium collections in Australia and South Africa whereas herbs and trees were over-represented in New England. Another interesting pattern that emerged is that short plants had higher representation in harbaria than taller species. Obviously this has a lot to do with ease of collection.

Another pattern that emerged which is of conservation concern is that threatened or endangered species are severely under-represented in herbarium collections. Although care must be taken to not over-collect species whose numbers are dwindling, their lack of representation in herbarium collections can seriously hinder conservation efforts. Such under-represenation can lead to erroneous estimations of species abundances and distributions. It can also hinder our understanding of plant community dynamics.

The fourth major bias is that of phylogenetic bias. Certain clades are more sought after than others. This leads to a disproportionate amount of showy or valuable species turning up in herbaria around the globe. It also leads to an over-representation of potentially "useful" plant species in terms of things like medicines or dyes. This leaves a large portion of regional floras under-sampled. This in turn exacerbates issues relating to our understanding of plant community dynamics and the change in plant abundance and distribution through time.

Finally, the fifth major bias is that of collector bias. This pattern stems from the fact that in all the regions sampled for this study, a majority of the collections were made by only a handful of individuals. This means that all of these collections are the products of the habits and preferences of these collectors. Some collectors may favor sampling the entire flora of a region whereas others may favor certain clades over others. Similarly, some collectors may favor plants with interesting physiologies whereas other may favor plants with peculiar life-histories such as carnivores or succulents.

The use and importance of herbaria has changed a lot over the last two centuries. Whereas they largely started out as a tool for taxonomists, the utility of herbarium collections has since expanded into areas that were never thought possible. With the advent of new technologies, who knows what the future holds. Of course, this means nothing if interest and support for herbarium collections continues to decline. Their utility in the context of research and conservation cannot be understated. We need herbaria now more than ever. Understanding biases is a great step towards improving the discipline. We must aim to improve collections in these so-called cold spots and to avoid as many biases as possible in doing so.

Photo Credits: Wikimedia Commons

Further Reading: [1]

 

Eastern North America's Temperate Rainforest

I have often remarked that working in the southern Appalachian Mountains during the summer feels more like working in a rainforest than it does an eastern deciduous forest. Lots of rain, high humidity, and a bewildering array of flora and fauna conjure up images of some far away jungle. Only winter can snap this view out of ones head. I recently learned, however, that these feelings are not misplaced. Indeed, this region of southern Appalachia is considered a temperate rainforest. 

These mountains are old. They arose some 480 million years ago and have been shaping life in this region of North America ever since. Another thing these mountains are quite good at is creating their own weather systems. Here in southern Appalachia, warm, wet air from the Gulf of Mexico and western Atlantic blows northward until it hits the Appalachian Mountains. The mountainous terrain comprising parts of Pisgah, Nantahala, and Chattahoochee National Forests has been referred to as "the Blue Wall" and is responsible for the unique conditions that created this temperate rainforest.

As this air rises over their peaks, it begins to cool. As it does, water in the air condenses. This results in torrents of rain. On average, this area receives anywhere from 60 to 100+ inches of rain every year. The Appalachian temperate rainforest is second only to the Pacific Northwest in terms of rainfall in North America. All of this water and heat coupled with the age and relative stability of this ecosystem over time has led to the explosion of biodiversity we know and love today. 

Life abounds in the southern Apps. The plant diversity can be rather intimidating as species from the north mix with those coming up from the south. For instance, there are more tree species in these mountains than in all of Europe.  Rates of endemism in these mountains, both in terms of flora and fauna, are remarkable. There are relics of bygone eras that never expanded their range following repeated glaciations. What's more, a multitude of species combinations can be found as you go from low to high elevations. 

At lower elevation, forests are dominated by American beech (Fagus grandifolia), yellow birch (Betula alleghaniensis), maple (Acer spp.), birch (Betula spp.), and oak (Quercus spp.). Magnolias cover the humid coves. Mid elevations boast birches, mountain ash (Sorbus americana), and mountain maple (Acer spicatum). High elevations contain fraser fir (Abies fraseri) and redspruce (Picea rubens). Both the understory and the the mountain balds are home to a staggering array of different Heaths (Ericaceae). From Rhododendrons to azaleas and mountain laurels, the colors are like those lifted from an abstract painting. The forest floor is where I focus most of my energy. It is hard to capture the diversity of this habitat in only a few paragraphs. What I can say is that I haven't even scratched the surface. It seems like there is something new to see around every corner. 

The point I am trying to make is that this region is quite special. It is something worth protecting. From development to mining and changes in temperature and precipitation, human activities are exacting quite a toll on the Appalachian Mountains. The system is changing and there is no telling what the future is going to look like. Conserving wild places is a must. There is no way around it. Luckily there is a reason people love this place so very much. There are a lot of dedicated folks out there working to protect and conserve everything that makes southern Appalachia what it is. Get out there, enjoy, and support your local land trust!

Further Reading:  [1] 

Pitcher's Thistle and the Dunes It Calls Home

Sand dunes are harsh habitats for any organism to make a living. They are hot, they are low in nutrients, water doesn't stick around for very long, and they can be incredibly unstable. Despite these obstacles, dunes around the world host rather unique floras comprised of plants well suited to these conditions. Sadly, we humans have been pretty good at destroying many of these dune habitats. This is especially true along the shores of the Great Lakes. To put this in perspective, I would like us to take a closer look at a special Great Lakes dune denizen. 

Meet Pitcher's thistle (Cirsium pitcheri). It is a true dune plant and is endemic to the shores of the upper Great Lakes. Its a rather lanky plant, often looking as if it is having a hard time supporting its own weight. Despite its unkempt look, adult plants can reach heights of 3 feet, which is quite impressive given where it lives. It is covered in silvery hairs, giving the plant a shiny appearance. These hairs likely protect the plant from the onslaught of sun, abrasive wind-blown sand, and desiccation. One of the benefits of growing in such inhospitable places is that historically speaking, Pitcher's thistle could grow with little competition. Individual plants grow for roughly 5 to 8 years before flowering. After seeds are produced, the plant dies. The seedlings are then free to develop without being shaded out. 

The last century or so have not been good to Pitcher's thistle. Shoreline development, altered disturbance regimes, and isolation of various populations have fragmented its range and reduced its genetic diversity. To make matters worse, its remaining habitat is still shrinking. Shoreline development has altered wave action that is vital to these dune habitats. Waves that once brought in new sediments and built dunes are largely carving away what's left. They are eroding at an alarming rate that even dune-adapted plants like Pitcher's thistle can't keep up with. Recreational use of these habitats adds another layer as heavy foot traffic carves deep scars into these dunes, furthering their demise. 

One silver lining in all of this is that dedicated researchers are paying close attention to the natural history of this species. They have discovered some fascinating things that will help in the recovery of this special plant. For instance, it has been observed that although trampling doesn't necessarily kill Pitcher's thistle, it does damage sensitive buds. This often results in plants developing multiple flower heads. Although this sounds like a benefit, researchers discovered that these damaged plants actually produce fewer viable seeds despite producing more flowers. 

Also, they have found that American goldfinches are playing a considerable role in its reproductive success. Despite the tightly clasping, spiny bracts that protect the seeds, goldfinches have been found to reduce seed production by 90% as they forage for food and the fluffy seed hairs for nest building. Evidence suggests that goldfinches are more likely to target small, isolated populations of Pitcher's thistle rather than large, contiguous patches. The reason for this is anyone's guess but it does suggest that they way around this issue is to supplement dwindling populations with new plants grown from seed. 

Without intervention, it is very likely that Pitcher's thistle would go extinct in the near future. Luckily, researchers and federal officials are teaming up to make sure that doesn't happen. Long term population monitoring is in place throughout its range and a sandbox technique has been developed for germinating and growing up new individuals to supplement wild populations. Through habitat restoration efforts, supplementing of existing and the creation of new populations, the future of this charismatic dune thistle has gotten a little bit brighter. It isn't out of the metaphorical woods but there is reason for hope. 

Photo Credit: [1] 

Further Reading: [1]

1,730 New Plant Species Were Described in 2016

  Manihot debilis

Manihot debilis

The discovery of a new animal species is celebrated the world over. At the same time, plants are lucky to ever make headlines. This is a shame considering that plants form the backbone of all terrestrial ecosystems. The conversation is starting to change, however, as more and more people are waking up to the fact that plants are fascinating organisms in their own right. In a recent addition of Kew Garden's State of the World's Plants, they report on 1,730 newly described plant species from all over the world.

Begonia rubrobracteolata

The discovery of these new plants species is truly a global event. Central and South America, Africa, tropical Asia, and Madagascar saw the addition of many intriguing taxonomic novelties. For instance, Malaysia can now add 29 new species of Begonia to their flora. Africa can now boast to be the home of the largest species of Bougainvillea in the world. Standing at 3 meters in height, it is an impressive sight to behold. Madagascar was particularly fruitful (pun intended), adding 150 new species, subspecies, and varieties of Croton all thanks to the diligent work of the late Alan Radcliffe-Smith. 

  Commicarpus macrothamnum  Photo Credit: Ib Friis

Commicarpus macrothamnum Photo Credit: Ib Friis

One of the most exciting finds from Madagascar was a new genus of climbing bamboos named Sokinochloa. So far only 7 species have been named. The key to unlocking the diversity of this new genus lies in their flowers, which are not produced on a regular basis. Like many bamboos, the Sokinochloa produce flowers at intervals of 10 to 50+ years. The new discoveries did not consist entirely of small understory herbs either. Some of those 1,730 plants were massive forest trees.

  Sokinochloa australis

Sokinochloa australis

One of these new tree species is Africa's first endemic species of Calophyllum (Calophyllaceae). They were discovered during a survey for a uranium mine and, with fewer than 10 mature individuals, are considered critically endangered. Expeditions in Central America and the Andes turned up 27 new tree species in the genus Sloanea (Elaeocarpaceae) as well as 10 new species Trichilia, a genus of trees belonging to the mahogany family (Meliaceae).

The list could go on and on. Even more exiting is the fact that 2016 wasn't a particularly exceptional year for new plant discoveries. An estimated 2,000 new plant species are discovered on an annual basis. We aren't even close to grasping the full extent of plant diversity on this planet. What plants desperately need, however, is more attention. More attention leads to more scrutiny, more scrutiny leads to better understanding, and better understanding leads to improved conservation efforts. We could be doing a lot better with conservation efforts if we considered the plants whose very existence is essential for all life as we know it.

  Barleria mirabilis  Photo Credit :  Quentin Luke

Barleria mirabilis Photo Credit: Quentin Luke

  Tibouchina rosanae  Photo Credit: W Milliken

Tibouchina rosanae Photo Credit: W Milliken

  Englerophytum paludosum  Photo Credit: Xander van der Burgt

Englerophytum paludosum Photo Credit: Xander van der Burgt

You can download your own copy of the State of the World's Plants by clicking here

All photos thanks to the Royal Botanical Gardens at Kew unless otherwise noted.

Orchid Dormancy Mediated by Fungi

North America's terrestrial orchids seem to have mastered the disappearing act. When stressed, these plants can enter into a vegetative dormancy, existing entirely underground for years until the right conditions return for them to grow and bloom. Cryptic dormancy periods like this can make assessing populations quite difficult. Orchids that were happy and flowering one year can be gone the next... and the next... and the next...

How and why this dormancy is triggered has confused ecologists and botanists alike. Certainly stress is a factor but what else triggers the plant into going dormant? According to a recent paper published in the American Journal of Botany, the answer is fungal.

Orchids are the poster children for mycorrhizal symbioses. Every aspect of an orchid's life is dependent on these fungal interactions. Despite our knowledge of the importance of mycorrhizal presence in orchid biology, no one had looked at how the abundance of mycorrhizal fungi influenced the life history of these charismatic plants until now.

By observing the presence and abundance of a family of orchid associated fungi known as Russulaceae, researchers found that the abundance of mycorrhizal fungi in the environment is directly related to whether or not an orchid will emerge. The team focused on a species of orchid known commonly as the small whorled pogonia (Isotria medeoloides). Populations of this federally threatened orchid are quite variable and assessing their numbers is difficult.

The team found that the abundance of mycorrhizal fungi is not only related to prior emergence of these plants but could also be used as a predictor of future emergence. This has major implications for orchid conservation overall. It's not enough to simply protect orchids, we must also protect the fungal communities they associate with.

Research like this highlights the need for a holistic habitat approach to conservation issues. So many species are partners in symbiotic relationships and we simply can't value one partner over the other. If conditions change to the point that they no longer favor the mycorrhizal partner, it stands to reason that it would only be a matter of years before the orchids disappeared for good.

Photo Credit: NC Orchid

Further Reading: [1]

The Longleaf Pine: A Champion of the Coastal Plain

As far as habitat types are concerned, the longleaf pine savannas of southeastern North America are some of the most stunning. What's more, they are also a major part of one of the world's great biodiversity hotspots. Sadly, they are disappearing fast. Agriculture and other forms of development are gobbling up the southeast coastal plain at a bewildering rate. For far too long we have ignored, or at the very least, misunderstood these habitats. Today I would like to give a brief introduction to the longleaf pine and the habitat it creates.

The longleaf pine (Pinus palustris) is an impressive species. Capable of reaching heights of 100 feet or more, it towers over a landscape that boggles the mind. It is a landscape born of fire, of which the long leaf pine is supremely adapted to dealing with. These pines start out life quite differently than other pines. Seedlings do not immediately reach for the canopy. Instead, young long leaf pines spend their first few years looking more like a grass than a tree. Lasting anywhere between 5 to 12 years, the grass stage of development gives the young tree a chance to save up energy before it makes any attempt at vertical growth. 

The reason for this is fire. If young long leaf pines were to start their canopy race immediately, they would very likely be burned to death before they grew big enough to escape the harmful effects of fire. Instead, the sensitive growing tip is safely tucked away in the dense needle clusters. If a fire burns through the area only the tips of the needles will be scorched, leaving the rest of the tree safe and sound. During this stage, the tree is busy putting down an impressive root system. The taproot alone can reach depths of 6 to 9 feet!

Once a hardy root system has been formed and enough energy has been acquired, young longleaf pines go through a serious growth spurt. Starting in later winter or early spring, the grass-like tuft will put up a white growth tip called a candle. This tip shoots upwards quite rapidly, growing a few feet in only a couple of months. This is sometimes referred to as the bottlebrush phase because no horizontal branches are formed during this time. The goal at this point is to get the sensitive growing tip as far away from the ground as possible so as to avoid damaging fires. It is fun to encounter long leaf pines at this stage because like any young adult, they look a bit awkward.

 Photo Credit: Woodlot - Wikimedia Commons

Photo Credit: Woodlot - Wikimedia Commons

Once the tree reaches about 6 to 10 feet in height, it will finally begin to produce horizontal branches. This doesn't stop its canopy bid, however, as it still will put on upwards of 3 feet of vertical growth each year! Every year its bark grows thicker and thicker, thus each year it becomes more and more resistant to fire. Far from being a force to cope with, fire unwittingly gives longleaf pines a helping hand by clearing the habitat of potential competitors that are less adapted to dealing with burns. After about 30 years of growth, longleaf pines reach maturity and will start to produce fertile cones.

Before European settlement, longleaf pine savanna covered roughly 90,000,000 acres of southeastern North America. Clearing and development have reduced that to a mere 5% of its former glory. For far too long its coastal plain habitat was thought to be a flat, monotonous region created by early human burning in the last few thousand years. We now know how untrue those assumptions are. Sure, the region is flat but it is anything but monotonous. Additionally, the coastal plain is one of the most lightning prone regions in North America. Fires would have been a regular occurrence long before any humans ever got there. 

Red indicates forest loss between 2011 and 2014. http://glad.umd.edu/gladmaps

Evidence suggests that this coastal plain habitat has remained relatively stable for the last 62,000 years. As such, it is full of unique species. Surveys of the southeastern coastal plain have revealed multiple centers of plant endemism, rivaled in North America only by the southern Appalachian Mountains. In fact, taken together, the coastal plain forests are widely considered one of the world's biodiversity hotspots! Of the 62,000 vascular plants found in these forests, 1,816 species (29.3%) are endemic. Its not just plants either. Roughly 1,400 species of fish, amphibians, reptiles, birds, and mammals rely on the coast plain forests for survival.

Luckily, we are starting to wake up to the fact that we are losing one of the world's great biodiversity hotspots. Efforts are being put forth in order to conserve and restore at least some of what has been lost. Still, the forests of southeastern North America are disappearing at an alarming rate. Despite comprising only 2% of the world's forest cover, the southern forests are being harvested to supply 12% of the world's wood products. This is simply not sustainable. If nothing is done to slow this progress, the world stands to lose yet another biodiversity hotspot. 

If this sounds as bad to you as it does to me then you probably want to do something. Please check out what organizations such as The Longleaf Alliance, Partnership For Southern Forestland Conservation, The Nature Conservancy, and The National Wildlife Federation are doing to protect this amazing region. Simply click the name of the organization to find out more.

Further Reading: [1] [2] [3] [4]