Collecting biodiversity

Collecting biodiversity There are major concerns about the use of primary species occurrence data that are rapidly becoming available on the internet for ecological studies. To this end, this research assessed the extent of biases associated with a herbarium dataset based is based on specimens collected in Guyana, Suriname and French Guiana. After getting an understanding of the biases, the database was used to: (a) develop a model to simulate relative abundance distributions in the herbarium; (b) to assess the roles of dispersal and environmental constraints in shaping the floristic composition of the Guianas; and (c) determine species richness and endemism patterns across the study area. More than 7,000 species and about 190,000 specimens were collected over the 2000 years period. The herbarium database showed historical, taxonomic, geographical and seasonal bias in collecting and these were demonstrated to have serious consequences when the database was used in a number of ecological applications. The model with the main strategy of “never collect the same species twice” generated species abundance distribution patterns comparable to those in the herbarium. Dispersal limitation rather than environmental constrains better describe the floristic composition across the study area. The species richness patterns modelled did not quite meet the expectations. Key words: herbarium database, bias, the Guianas, collector behavior, floristic composition,species richness maps