Working Group II: Impacts, Adaptation and Vulnerability

Other reports in this collection Biodiversity

Latin America is known as home to some of the Earth's greatest concentrations of biodiversity (Heywood and Watson, 1995; Harcourt and Sayer, 1996). Seven of the world's most diverse and threatened areas are in Latin America and the Caribbean (Myers et al., 2000). Of these, three rank among the world's five most critical hotspots. The tropical Andes qualifies as one of the world's two hyper-hot areas for its exceptional numbers of endemic plants and endemic vertebrates—the highest in the world. Maintenance of this diversity depends on the continued existence of representative areas of natural ecosystems (Fearnside and Ferraz, 1995; Fearnside, 1999). Dinerstein et al. (1995) have divided Latin America into 191 terrestrial "ecoregions" and collated information on the biodiversity importance and degree of risk of each in a systematic fashion to establish priorities for conservation. Many ecosystems already are at risk, without additional stresses expected from climatic change: 48% of all ecoregions are critical (18%) or endangered (30%); 32% are vulnerable, 16% are relatively stable, and 5% are relatively intact. Ecuador holds the distinction of being wholly covered by ecoregions with top priority at the regional level. The impacts of climate change can be expected to increase the risk of biodiversity loss in Latin America.

Central America has about 8% of the world's biodiversity concentrated in only 0.4% of the emerged surface of the planet. More than 15,000 species of plants and 1,800 species of vertebrates have been identified in the region. There are high quantities and variety of coastal wetlands in Central America. Central America's unique location between the Pacific Ocean and the Caribbean Sea—along with extreme climatic variations, tidal patterns, and geology—make these coastal wetlands among the most productive in the world (Tabilo-Valdivieso, 1997).

In addition to the loss of genetic resources, loss of productivity, and loss of ecosystem buffering against ecological perturbation, loss of biodiversity also may alter or impair the services that ecosystems provide (Naeem et al., 1994). For a 2xCO2 scenario, surface relative humidity zones shift upward by hundreds of meters during the winter dry season, when these forests typically rely mostly on moisture from cloud contact (Leo, 1995). At the same time, an increase in the warmth index implies increased evapotranspiration; this combination of reduce cloud contact and increased evapotranspiration could have serious conservation implications, as indicated in studies in anurans (Donnelly and Crump, 1998). The results of Pounds et al. (1999) indicate the association in populations of birds, lizards, and anurans with the same climatic patterns, implying a broad response to regional climate change. Other studies inspired by the climate-linked epidemic hypothesis have found that dry weather in 1983 increased the vulnerability of harlequin frogs (Atelopus varius) to lethal parasites along one stream (Crump and Pounds, 1985, 1989).

Suárez et al. (1999) have found that the coastal biodiversity (flora and fauna) in Cuba will be most affected by sea-level rise. Adaptation options include establishing a national legal system and a national strategy for conserving biodiversity that includes terrestrial, marine, or coastal reserves.

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