When I announced (and by that I mean casually let slip) that I'd changed my major yet again - this time to ecology - I got the verbal equivalent of the smile-and-nod. At first, there were sounds of general approval, then a brief pause, and then, "what is ecology, exactly?" The short and sweet answer to that question is this: the study of all of the plants and animals in a given area and how they interact with each other and the abiotic (not alive) features of their environment. As an ecology student, there were a handful of case studies drilled into my head. In class after class, the same few examples were repeated, designed to distill the complexity of the web of life into manageable terms. One of these case studies is the Pacific coastal kelp forest and another is the longleaf pine forest. I'm currently hundreds of miles from one of these ecosystems and walking distance from the other.
Once covering nearly a billion acres of the southeastern United States, the longleaf pine forest ecosystem is now down to less than five percent of its original area. This is a shame because these forests are some of the most botanically diverse - supporting over 200 different plant species - and because so many rare creatures rely on them. One species inextricably linked with this forest is the gopher tortoise. The baby gopher tortoises that maraud around sandboxes in our commissary will eventually be released into the island's longleaf pine habitat. When they are ready to go out into the real world, they'll dig themselves burrows under fallen pine needles. If they were in a longleaf pine forest on the mainland, their empty burrows would be repurposed as homes for our nation's longest snake (and one of my favorites), the indigo snake. Not only are these guys non-venomous and not aggressive, they eat venomous snakes. For those folks not herpetologically inclined (i.e. don't dig snakes), these forests are also home to the endangered red-cockaded woodpecker.
Five species of pine grow on St. Catherines Island; longleaf, slash, pond, loblolly, and spruce pine. The best way to tell them apart is by looking at the cones and the needles (and by watching this video). The longleaf pines have - as one might expect - the longest needles, but also the biggest cones. The cones are about eight to ten inches long and are great for decorating the homes of lemur-watching interns. Inside these large cones are the seeds, each enclosed in a little wing-like case that helps it catch the wind and land where it won't compete with the mother tree. The trick to getting these seeds to germinate - and part of the reason the longleaf pine forest is now so rare - is fire. Contrary to popular belief, forest fires can be a good thing. In fact, pine trees produce sap that works a lot like lighter fluid and their bark is especially thick so that they can withstand being charred. When there is no fire to burn away the underbrush, other tree saplings can grow and eventually crowd out the longleaf pines. Slowly, prescribed burnings are being more accepted and incorporated into forest management plans, but the words "forest fire" still set off alarm bells for the general public.
St. Catherines is one of only three barrier islands in Georgia which have longleaf pine forest (the other two are Cumberland and Sapelo). Ours is on the northern part of the island. Mowing generally keeps down competing tree species, but controlled fires are set every few years. Most of the longleaf pines here are very old. A rash of logging in the late 30's felled the straighter, more desirable trees and those left were saved by their own crooked beauty. The tallest of them have been around for nearly a hundred years. The forest on the island differs a little from the case study I learned in school. For one, no indigo snakes. For another, we lack the characteristic wiregrass of longleaf pine forests on the mainland. That's because it can't handle the salty sea spray. We do have the tortoises (even though I've yet to see an adult) and several legumes that attract monarch butterflies. So, I guess we're a little weird out here, but what else is new?