Tropical Wet Forests (US and Mexico)

Tropical wet forests, as defined by the Holdridge Life Zones classification system, are ecosystems characterized by high rainfall (typically exceeding 2000 mm annually), high humidity, and consistently warm temperatures (averaging above 18°C or 64°F). While commonly associated with equatorial regions, their distribution is influenced by specific climatic and geographic conditions. In the context of the United States and Mexico, the occurrence of true tropical wet forests is limited due to their latitudinal position and prevailing climate patterns.

In the United States, true tropical wet forests are extremely rare. They are essentially restricted to small, isolated areas in Hawai'i, specifically on the windward slopes of some of the islands where orographic rainfall is substantial. These areas harbor a diverse array of endemic plant and animal species adapted to the persistently wet conditions. However, given the limited land area and isolation, they do not represent a significant portion of the US landscape.

In Mexico, the distribution of tropical wet forests is somewhat more extensive, though still localized. They are primarily found in the southern regions, particularly along the Gulf Coast states of Veracruz, Tabasco, and Chiapas, and in parts of the Yucatan Peninsula. These areas receive abundant rainfall from both Caribbean tropical storms and localized convective activity. Mexican tropical wet forests are characterized by tall, multi-layered canopies, high biodiversity, and a complex array of epiphytes, vines, and other plant life forms. The fauna includes a wide range of invertebrates, amphibians, reptiles, birds, and mammals, many of which are endemic or endangered.

Threats to tropical wet forests in both the US (Hawai'i) and Mexico include deforestation for agriculture, ranching, and logging; habitat fragmentation; invasive species; and climate change, which can alter rainfall patterns and increase the frequency and intensity of extreme weather events. Conservation efforts are essential to protect these unique and ecologically valuable ecosystems.