Haiti’s biodiversity threatened by nearly complete loss of primary forest

Abstract

Tropical forests hold most of Earth’s biodiversity. Their continued loss through deforestation and agriculture is the main threat to species globally, more than disease, invasive species, and climate change. However, not all tropical forests have the same ability to sustain biodiversity. Those that have been disturbed by humans, including forests previously cleared and regrown (secondary growth), have lower levels of species richness compared with undisturbed (primary) forests. The difference is even greater considering extinctions that will later emanate from the disturbance (extinction debt). Here, we find that Haiti has less than 1% of its original primary forest and is therefore among the most deforested countries. Primary forest has declined over three decades inside national parks, and 42 of the 50 highest and largest mountains have lost all primary forest. Our surveys of vertebrate diversity (especially amphibians and reptiles) on mountaintops indicates that endemic species have been lost along with the loss of forest. At the current rate, Haiti will lose essentially all of its primary forest during the next two decades and is already undergoing a mass extinction of its biodiversity because of deforestation. These findings point to the need, in general, for better reporting of forest cover data of relevance to biodiversity, instead of “total forest” as defined by the United Nation’s Food and Agricultural Organization. Expanded detection and monitoring of primary forest globally will improve the efficiency of conservation measures, inside and outside of protected areas.

Changing ecological communities along an elevation gradient in seasonally dry tropical forest on Hispaniola (Sierra Martín García, Dominican Republic)

“…Our research sets a baseline to help understand how species will respond to future habitat modification and climate change on Hispaniola. With extreme levels of habitat loss already fueling considerable extinction of amphibians and reptiles in the Haitian portion of Hispaniola (Hedges et al, ), it is more important than ever to survey any groups of Hispaniolan organisms to learn about their biology and begin to curtail the processes underlying their declines.…”

“…Our surveys took place on Hispaniola, a large Greater Antillean island comprising Haiti and the Dominican Republic. Given the extreme level of habitat loss in Haiti at all elevations, including evidence for ongoing species‐level extinction of vertebrates (Hedges et al, ), we chose a mountain range in nearby Dominican Republic to document ecological communities in a locality with relatively little current human impact. Essentially, all of the Sierra Martín García (SMG) is protected as a national park.…”

Apparent survival of a range-restricted montane forest bird species is influenced by weather throughout the annual cycle

“…Deforestation on the nonbreeding grounds has been linked to declines of Wood Thrush (Hylocichla mustelina) in Central America (Taylor and Stutchbury 2016) and Golden-winged Warblers (Vermivora chrysoptera) in northern South America (Kramer et al 2018), but our annual apparent survival estimates are likely too imprecise to detect any comparable trend in apparent survival. With Haiti's primary forests now almost completely vanished (Hedges et al 2018), conservation of remaining broadleaf forests in the Dominican Republic take on additional significance for Bicknell's Thrush.…”

Towards more effective integration of tropical forest restoration and conservation

“…A recent analysis in Brazil's Atlantic Forest showed that an estimated 27–32 percent of the endemic species in this biome are currently committed to extinction (Strassburg et al., ). Haiti has lost all but 0.32 percent of its primary forest and is undergoing a mass extinction of its endemic biodiversity (Hedges, Cohen, Timyan & Yang, ). Restoration efforts can build on the conservation of small fragments or transformation of agricultural fields into young forests or agroforests.…”