The Wild World of Rattan Palms

Calamus_gibbsianus.jpg

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.

3070456167_a06111dd01_o.jpg

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!

10368246_1018184728208392_2661304592123048565_n.jpg

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]

How Do Palms Survive Hurricanes?

US_Navy_050709-N-0000B-004_Hurricane_Dennis_batters_palm_trees_and_floods_parts_of_Naval_Air_Station_(NAS)_Key_West's_Truman_Annex.jpg

The destructive force of typhoons and hurricanes are no joking matter. Human structures are torn to shreds and flooded in the blink of an eye. It is devastating to say the least. With all of this destruction, one must wonder how native flora and fauna have coped with such forces over millions of years. The true survivors of these sorts of storms are the palms. What would completely shred an oak seems to ruffle a palm tree. What is it about palms that allows them to survive these storms intact? 

To better understand palm adaptations, one must first consider their place on the evolutionary tree. Palms are monocots and they have more in common with grasses than they do trees like oaks or pines. Their wood evolved independently of other tree species. Take a look at a palm stump. Instead of rings, you will see a dense structure of tiny straws that resemble the cross section of a telephone wire. This is because palms do not produce secondary xylem tissues that give other trees their rings. This makes them far more bendy than their dicotyledonous neighbors.

Whereas the woods of oaks and maples are really good at supporting a lot of branch weight, such wood is considerably more rigid than that of palms. Palms forgo heavy branches for large leaves and therefore invest more in flexibility. The main stems of some palm species can bend as much as 40 to 50 degrees before snapping, a perfect adaptation to dealing with regular storm surges. 

Palm_tree_trunk.jpg

Another adaptation of the palms are their leaves. Unlike most trees, palms don't bother with spindly branches. Instead, they produce a canopy of large leaves supported by a flexible midrib. These act sort of like large feathers, allowing their canopy to readily shed water and bend against even the strongest winds. Although their leaves will snap if buffeted hard enough, palm canopies accrue considerably less damage under such conditions. Another adaptation exhibited by palm leaves is their ability to fold up like a paper fan. This reduces their otherwise large surface area against powerful winds. 

Finally, palms have rather dense roots. They sacrifice size for quantity. Instead of a few large roots anchored into the soil, palms produce a multitude of smaller roots that spread out into the upper layers of the soil. This is especially useful when growing in sand. By increasing the number of roots they put down, palms are able to hold on to a larger volume of soil and therefore possess a much heavier base. This keeps them stranding upright in all but the worst conditions. 

Of course, these are rather broad generalizations. Not all palms have evolved in response to such punishing weather events. Research has shown that such adaptations are more prevalent in palms growing in places like the Caribbean than they are in palms growing in the rainforests of South America. Regardless, their phylogenetic history has stood the test of time and will continue to do so for quite some time. 

foto_0000000820150527132549.jpg

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

Further Reading: [1] [2]