Forgotten forests - issues and prospects in biome mapping using Seasonally Dry Tropical Forests as a case study

SARKINEN, TIINA; IGANCI, JOÃO R.V.; LINARES-PALOMINO, REYNALDO ; SIMON, MARCELO; PRADO, DARIÉN

BMC Ecology

BioMed Central

Lugar: Londres; Año: 2011 vol. 11 p. 1 - 16

1472-6785

South America is one of the most species diverse continents in the world. Within South America diversity is not distributed evenly at both local and continental scales and this has led to the recognition of various areas with unique species assemblages. Several schemes currently exist which divide the continental-level diversity into large species assemblages referred to as biomes. Here we review five currently available biome maps for South America, including the WWF Ecoregions, the Americas basemap, the landcover map of South America, Morrone’s Biogeographic regions of Latin America, and the Ecological Systems Map. The comparison is performed through a case study on the Seasonally Dry Tropical Forest (SDTF) biome using herbarium data of habitat specialist species. Results Comparison of maps using SDTF species distribution data shows that despite the high spatial detail in remote sensing maps, they perform relatively poorly in delimiting biologically meaningful biomes. Maps based on floristic data show better performance in general, indicating that the structurally heterogeneous biome such as SDTFs cannot be distinguished based on remote sensed data alone. The poor performance can be attributed to two main factors: (1) the poor spatial resolution of the biome maps, and (2) their poor delimitation of SDTF. A new refined working map of South American SDTF biome is proposed, derived using the Biome Distribution Modelling (BDM) approach where georeferenced herbarium data is used in conjunction with bioclimatic data. Conclusions Georeferenced specimen data play potentially a promising role in biome mapping as they provide a tool for ground-truthing or validating biome maps in silico. We demonstrate that specimen data can also be used to model biome distributions through the BDM approach. The BDM performs well in predicting the distribution of the structurally heterogenous and strongly fragmented SDTF biome. Our study illustrates that herbarium specimen data in conjunction with recent advances in distribution modelling provides new methods for mapping poorly known, fragmented, or degraded vegetation. We wish to highlight that biome delimitation is not an exact science, and that transparency is needed on how biomes are used as study units in macroevolutionary and ecological research.