GENERAL NOTES ABOUT THE YUCATAN'S FORESTS
The above picture can teach us some interest facts about the Yucatan's forests. The picture shows your author just outside Telchac Pueblo in northwestern Yucatan. Here's what we can learn from the picture:
- First of all, I'm not really that chubby. In the picture I'm wearing five shirts because when the picture was taken I was cold! Therefore, it's not always hot in the Yucatan. The Yucatan has very definite seasons.
- Most of the woody vegetation in the picture is leafless. That's because during the Yucatan's relatively cool dry season -- from about the end of November to mid May -- many deciduous trees and bushes lose their leaves. This cuts down on water loss from the leaves. When the rainy season returns in late May or so, woody branches sprout new stems and foliage.
- The picture shows rather low, scrubby vegetation. That's typical for northwestern Yucatan because, climatologically speaking, in the Yucatan, in general, the farther northwest you go the more arid it gets. There's low, scrubby, cactus-rich vegetation in the northwest, but tall, relatively lush forest in the southeast, and smoothly transitioning forest in between. Some species occur only in the more arid northwestern and northern zone while others live only in the southeastern and southern zone. Therefore, just because a species is featured here as a forest tree, it's not necessarily found throughout the Yucatan.
- In general, the farther southeast you go into rainier territory, the greater the species diversity of the forests. However, in more arid northwestern Yucatan the vegetation accommodates a surprising number of endemic species -- species that in the whole world are found only there. That's because, ecologically, the northern Yucatan constitutes an "island of aridness" with gene flow among individuals of a relatively small population. And in those TV documentaries about the Galapogos Islands, you've learned how new species are encouraged to arise on isolated islands.
