New paper out by the Record Lab: Does scale matter? A systematic review of incorporating biological realism when predicting changes in species distributions

Many ecologists and conservation biologists use species distribution models to predict where species should live based on factors like temperature, precipitation, and habitat.  This technique is really important for species or habitats that are hard to sample. If we want to conserve or protect these species, we need to have better information about where they live, thus we use models. However, using a survey of the literature from 2003-2015 we found that these studies are mostly being done in: 1) terrestrial systems (over 85%; few in marine or freshwater ecosystems), 2) North America or Europe (few studies in Africa, Asia), and 3) on plants, birds, or mammals (few on fish, amphibians, reptiles). We also found that scientists have been slow to incorporate factors into models that could greatly affect species distributions, such as dispersal and interactions with other species (e.g., competition, predation).  Importantly, very few studies reported the results of the models with and without these biological factors, making it difficult to know how important these factors might be now and in the future. Additionally, nearly half of studies did not use the model to predict where species might live in the future given climate change predictions, which we consider a missed opportunity. Lastly, with a limited set of studies, we found that the overall size of the study area (i.e., extent) and the cell size used in the model (i.e., grain) did not have an effect on the importance of dispersal and species interactions.  However, with a small sample size, we interpret this outcome cautiously and encourage scientists planning to use these models to carefully consider decisions about study extent and grain size.

Take home message: Conservation decisions could be driven by incomplete information – we need models of underrepresented ecosystems, taxa, and regions; models that consider the effects of climate change; and models that are more biologically realistic and robust.  

Check out the paper published in PLoS One here.

Research was funded by the National Science Foundation. The Ecological Society of America sponsored an early career workshop in 2013 that initiated this international collaboration of scientists from USA, Taiwan, and Israel.