American Heart's Tongue Fern

When looking for ferns, it is easy to have a specific kind of search imagine in your head. Your mind's eye is tuned into the long, lacy look of dissected fronds but there are ferns out there that will challenge you to break that mold. I have had the wonderful privilege of meeting some of these fern species this year, but there is one species in particular that has really stuck out.

Meet the American hart's tongue fern, Asplenium scolopendrium var. americanum. The hart's tongue, as you can see, is absolutely striking. Its long, slender, uncut fronds form a disheveled rosette and the sori running along the underside make each frond look like a big, green centipede. Asplenium scolopendrium itself is a wide ranging species of fern, growing on limestone outcroppings throughout Europe but populations in North America are rather sparse and disjunct. In fact, the U.S. Fish and Wildlife Service has listed it as a threatened species. There are some morphological distinctions between the European and North American populations but the major difference is in their number of chromosomes. European hart's tongues are diploid whereas North America's are tetraploid. Because of these differences, botanists consider them distinct varieties.

Why the American variety is so rare is not fully understood, but human activities have not helped matters. Mining, logging, and development have wiped out many historic populations of these ferns. Their habitat specificity mixed with their already low numbers make for little to no range expansion for most populations. They seem to grow in close association with dolomitic limestone, which is high in magnesium. 

They also seem to rely on a specific mix of bryophyte communities, low light levels, moisture, and snow pack in order to persist. Spores that land on significant bryophyte patches seem to germinate better. Young ferns seem to perform better in mixed light levels, especially near canopy gaps. It has also been shown that snow pack is directly correlated to the vigor of each population. In years with below average snow pack, the plants seem to have trouble retaining enough moisture to survive.

This is such an incredible species of fern. To lose it would mean a serious loss for our planet. There is a good effort being put forth to protect, study, grow, and form a deeper understanding with the American hart's tongue fern. The more we learn about this species, the better we can understand what it is going to take to ensure that it persists far into the future.

Photo Credit: James Johnson (http://imgur.com/a/J1Ez5)

Further Reading:
http://www.fws.gov/northeast/nyfo/es/amhtfrecovplan.pdf

http://www.bioone.org/doi/abs/10.3159/TORREY-D-11-00054.1

http://www.fs.fed.us/

http://www.centerforplantconservation.org/

Snuffing the Fire

Few childhood memories are more fond to me than catching fireflies on summer evenings. These little beetles are famous the world over for their dazzling light displays. Using chemical means, they are some of the most efficient light producers ever discovered. Their displays are for the purpose of mating and there are as many variations on the theme as there are species. Sadly, like so many natural wonders that we take for granted, fireflies are disappearing from our wild places. Future generations may never know the joys of these natural fireworks. 

Exactly why we are seeing a decline in fireflies is not certain. Researchers are only just beginning to uncover the secret world of the firefly. The answer is undoubtedly complex, however, evidence is beginning to pour in that we should look no farther than ourselves for the cause.

Fireflies require a few things to get by. The first is some sort of standing water. They seem to love ponds, creeks, rivers, and vernal pools. Second is tall grass and a lot of forest litter. Their larvae live and hunt in and amongst fallen logs and plant litter. Though we aren't entirely sure what their larvae eat, they are certainly hunting things like snails, slugs, and small insects, which also require moist areas with a lot of debris. Fireflies also need taller plants like grasses. They will climb up the stems to begin their aerial light displays. Finally, fireflies need darkness. They communicate by light and any surplus light sources are likely to mess them up. 

With increasing human development, former firefly habitat is giving way to paved roads and chemical laden lawns. Mowers run endlessly during the summer, eliminating fireflies and their habitat. People are needlessly clearing land of brush piles and fallen logs, which their larvae as well as their prey need. Light pollution is only getting worse too. As with many other insects, the wanton use of insecticides are undoubtedly taking their toll as well. Areas that once harbored huge populations of fireflies are quickly becoming overrun with human traffic as new housing, commercial and other forms of development garble up what free land remains. 

At this point you may be wondering what you can do to help. If you are a land owner, please consider the following:

- Turn off outside lights at night when they aren't needed
- Let logs and other plant debris accumulate in places around your property
- Consider creating a water feature of some sort
- Avoid the use of pesticides and fertilizers on your lawns
- Plant native plants
- Don't over-mow your lawn and leave some areas un-mowed

The best part about these solutions is that they benefit so much more than just fireflies. Native wildlife will be all the better if you take these steps to making your property more ecologically friendly. We are lucky to be aware of this issue but we must take matters into our own hands. Get out there and enjoy nature and try to be a bit of steward at the same time. 

Photo Credit: Peilun Hsu (http://bit.ly/1rJkufG)

Further Reading:
http://www.firefly.org/why-are-fireflies-disappearing.html