Congratulations to Cleber Ten Caten for his article being selected as the Cindy & Dan Carson Best Graduate Student Paper of the Year Award! Cleber’s paper, “Thinning occurrence points does not improve species distribution model performance” was published in the open-access journal Ecosphere.
Species distribution models (SDMs) are statistical methods that relate species occurrence data (localities where
a species was recorded) with environmental conditions to identify areas in the geographic
space that are environmentally suitable for species occurrences. SDMs produce maps
of species’ potential distributions and have become a key tool for answering macroecological
and biogeographic questions. While the ongoing development of several R packages have
simplified the use of SDMs, it also presents a problem because modelers are faced
with a wide range of methodological steps that need to be taken and that can directly
affect the quality of their models. Thinning occurrence data (i.e., the removal of some occurrence points from the original occurrence dataset)
is a methodological step commonly used to address biases that are
often found in occurrence data used in SDMs. Occurrence data can be thinned based
on how close they are in the geographic or environmental space. Thinning occurrence
data is used to allow only the most spatially or environmentally unique occurrences
to be used in the modeling process, thereby improving SDMs performance. While intuitive,
few studies have evaluated whether thinning actually improves SDMs performance, and
most of these studies are limited in scope.
In his study, Cleber used a set of virtual species and empirical species to demonstrate that thinning species occurrence points based on either geographic proximity or environmental distance actively reduced model performance, instead of the expected improvement that has led numerous researchers to thin their data! By showing that thinning occurrence data most likely negatively impacts SDMs, Cleber's work has broad implications with respect to designing conservation strategies. Read more about Cleber's exciting work here.