Skip J. Van Bloem Dept. of Agronomy PO Box 9030 UPR Mayaguez Mayaguez, Puerto Rico 00680 787 832-4040, Ext. 2218, 2442 svanbloem@uprm.edu
Ariel E. Lugo International Institute of Tropical Forestry USDA Forest Service 1201 Ceiba Street Jardin Botanico Sur Rio Piedras, Puerto Rico 00926-1119 787 766-5335 alug@fs.fed.us
The Atlantic Neotropical Domain (NeoNEON) spans South Florida, Puerto Rico, and the Virgin Islands. This domain is characteristic of the tropics by having great diversity, both in biota and in ecosystem types. The domain is home to high native biodiversity, but is also heavily impacted by introduced plant and animal species. There is no location in the domain that is greater than 80 km from the ocean and therefore the domain is heavily influenced by warm maritime climates and critically threatened by sea level rise. Average annual temperatures across the domain are >23ºC, and only South Florida gets frost. Nowhere in the United is there a greater chance of hurricane occurrence on an annual basis than in our domain. The domain is also heavily influenced by fluctuations in the Trade Winds, the North Atlantic Oscillation, flow of transequatorial air masses from the South Atlantic, and El Niño events. Seasonality is highly variable and is expected to be highly sensitive to climate change. Within this context, the three locations within the domain have some important differences. The Everglades and the Miami metropolitan area dominate South Florida. Puerto Rico boasts 6 different life zones, spanning from dry forest to lower montane rain forest. The life zone diversity in PR is primarily due to its central mountain range altering rainfall patterns, resulting in a range of annual rainfall from 800 mm to >3,500 mm. Elevation reaches 1338 m on Puerto Rico, over 400 m on the Virgin Islands, and only about 5 m in South Florida. The Virgin Islands are small, volcanic islands, but have sharp elevation gradients and are dominated by dry and moist forests.
A core site must be able to represent the general conditions across the domain. The 4,500-ha Guánica Forest, Puerto Rico (17.961N 66.842W) has the following features, which make it the best location to represent the domain:
1. It has a seasonal climate that is prone to periodic and episodic drought;
2. It has a mixture of introduced and native species.
3. Many of the dominant tree species are found throughout the domain, including the hammock forests in the Everglades and on the Virgin Islands.
4. It has a varied history of land use, and is being encroached upon by suburbs and industrial development on the north and east sides;
5. It is hurricane-prone;
6. Its phenology is highly tuned to rainfall events;
7. It has a long history of research and long-term research plots are already established;
8. It has upland, coastal, and mangrove forests; and
9. Its structure, function, and soils are representative of those found in other sites in the domain.
10. It is accessible, secure, and available for the NEON time frame and longer.
In addition, as a seasonally dry forest, Guánica also represents the most common life zone in the tropics and compares to seasonal temperate forests. Guánica Forest will contrast to wet forest core sites proposed by the Pacific Tropical Domain.