The rich databases of museums and herbaria serve as the primary data for the application of ecological niche models. Yet key assumptions about primary data often are either ignored or untested in model development. This project focuses on testing whether plant voucher specimens adequately sample the climatic gradient in two countries of conservation interest for CCSD: Ecuador and Bolivia. Note that ecological niche modeling may help to correct geographic sampling bias in the distribution of voucher specimens, but may be severely and adversely affected by environmental sampling bias. We have detected marked collection bias relative to several environmental variables in the countries of interest. Currently we are assessing the effect of such bias on

A) Partitioning of Ecuador into ten climate bins determined by mean annual precipitation in millimeters. B) Comparison of the distribution of proportion of geographic area (black bars labeled "expected") and proportion of plant voucher specimens (white bars labeled "observed") across the ten climate bins defined for Ecuador in A. C) Partitioning of Bolivia into ten climate bins determined by mean annual precipitation in millimeters. D) Comparison of the distribution of proportion of geographic area (black bars labeled "expected") and proportion of plant voucher specimens (white bars labeled "observed") across the ten climate bins defined for Bolivia in C. In Ecuador climate bins 1, 6, and 7 are under-sampled, and bins 2 and 3 are most clearly over-sampled. In Bolivia climate bin 1 (dry areas) is dramatically under-sampled while bin 3 is most clearly over-sampled

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Bette Loiselle

ANALYSIS UNIT