Yucatan Dry Deciduous Forest - Code: Ne5B

Because these Dry deciduous forests of the Yucatan Peninsula exist in a savanna climate (Koppen Awa) they vary greatly throughout the year; parched in the dry season and lush during the wet season. This habitat is found in the same areas that may have semi-evergreen forest, but in parts that have poorer soils, being mainly found on the very calcareous soils of the central peninsula.
It is not known if prior to intense cultivation by the Mayans,  much of this region was semi-evergreen forest, and this dry deciduous forest is a response to environmental degradation. The same is also true on the other end of the spectrum, where thornscrub that exists now may be a response to degradation of this dry deciduous forest. However these forests have a high percentage of plant endemism, so the extent of cover may have changed during the Holocene, but this forest has been a feature of the Yucatan for a very long time.
Both dry forests and semi-evergreen forests are highly susceptible to destruction through fire.
The defining feature of this habitat over a savanna type woodland is the intense wet season, which alternates with long periods of low rainfall, including a few months of near-total drought that is enough to kill most large, evergreen trees in areas of nutrient deficient soils.. In the wet season this habitat appears very similar to mesoamerican semi-evergreen forest or rainforest: water abounds, the canopy appears thick (though close inspection shows that the leaves are generally smaller than those in rainforest), and there is abundant, lush undergrowth. Visiting the forest during the dry season gives a very different impression: many of the plants have lost their leaves, the ground is covered with a thick layer of dry, brittle leaves, and the layer of brush at head height seems almost impenetrable.
The canopy of deciduous trees sits at a height of 40–65 ft. (12–20m) and is generally very open, with less than 50% cover during the wet season. The open nature of the canopy allows light to penetrate the forest and allow for a thick lower mid-story of evergreen trees. When this habitat is more open during the dry season, you can see that most trees are stout, quite thick for their height, and not as straight as trees in wetter forests. They are usually angled and gnarled, with branches starting much closer to the base of the trunk than in rainforest. The trees have a variety of canopy forms, with many of the smaller-leaved trees having a flatter shape than trees of closed forests. The canopy is dominated by Gumbo-limbo (Bursera simaruba), Spanish cedar (Cedrela odorata), and Spanish elm (Cordia alliodora).  One of the prominent features of this kind of forest, even notable in the wet season, is the abundance of baobab-like “kapok” trees such as Pochote (Ceiba aesculifolia) and other Ceiba spp. which store water in their trunk. Kapoks dominate the forest and are usually higher than the surrounding trees as well as much broader. The canopy has fewer vines and epiphytes than rainforest, but because of the deciduous nature of this forest, they are often more conspicuous than their rainforest counterparts.
The understory usually consists of small evergreen trees and shrubs such as the very distinctive Elephant's Foot Tree (Beaucarnea pliabilis), Bastard Logwood (Gymnopodium floribundum) , Cucumber Tree (Parmentiera aculeata), Florida fish poison tree (Piscidia piscipula),  and the Singapore graveyard flower (Plumeria obtusa), with a few younger deciduous canopy trees. Areas of thornbushes a micro habitat within this habitat and similar to those in in the surrounding Caribbean Thornscrub habitats, are dominated by acacias such as the  Yucatán Wattle (Acacia gaumeri), feather vachellia (Vachellia pennatula), Collins' Acacia (Vachellia collinsii), and Smooth Yucatán Wattle (Acacia gaumeri) and occur as both subcanopy trees and shrubs. It seems incongruous to have cactus and palms together, but in this forest you have Mexican organ pipe cactus (Pterocereus gaumeri) and dagger cactus (Stenocereus griseus) alongside Florida thatch Palm (Thrinax radiata).
Grasses and herbaceous plants are limited, distinguishing dry deciduous forest from woodland habitats such as Mesoamerican Grassland Savanna. Because of the thick undergrowth, walking through this habitat away from trails is generally difficult, especially in the wet season. In the dry season you can see the ground for 20–50 ft. (6–15m); in the wet season ground visibility is limited to 10–20 ft. (3–6m). At head height, visibility is limited year-round due to the thick understory.