How Useful Are Species Distribution Models for Managing Biodiversity under Future Climates?

Abstract

Climate change presents unprecedented challenges for biological conservation. Agencies are increasingly looking to modeled projections of species' distributions under future climates to inform management strategies. As government scientists with a responsibility to communicate the best available science to our policy colleagues, we question whether current modeling approaches and outputs are practically useful. Here, we synthesize conceptual problems with species distribution models (SDMs) associated with interspecific interactions, dispersal, ecological equilibria and time lags, evolution, and the sampling of niche space. Although projected SDMs have undoubtedly been critical in alerting us to the magnitude of climate change impacts, we conclude that until they offer insights that are more precise than what we can derive from basic ecological theory, we question their utility in deciding how to allocate scarce funds to large-scale conservation projects.

Alternative biological assumptions strongly influence models of climate change effects on mountain gorillas

“…Range reductions resulting from interactions with humans probably play an important role in modeling many other species (Richmond et al 2010), and can limit the utility of species distribution models. Other reasons why standard species distribution models may not reflect the entire ecological niche of a species include; that climatically suitable areas identified by standard SDMs cannot be reached by the species because of dispersal barriers, that the range has been reduced because of the influence of other species, or that the relevant predictor variables are not known or available (Davis et al 1998, Pearson and Dawson 2003, Guisan and Thuiller 2005, Jackson et al 2009, Sinclair et al 2010, Beale and Lennon 2012. Therefore, standard model evaluation methods such as the omission and commission rates presented here (Table 1) need to be interpreted with care.…”

What are the roles of species distribution models in conservation planning?

“…It is these future projections that have drawn the most criticism of SDMs, primarily because of inherent variability of the environmental parameters, the unknown migration ability of the species, and model uncertainty, which are not always incorporated into the predictions (Cayuela et al 2009;Coreau et al 2009;Elith & Leatherwick 2009;Franklin 2010;Sinclair et al 2010). Many of the same limits to static SDMs are at issue when linking SDMs to climate models.…”

“…An additional important limitation is that SDMs assume the surveys are detecting species across their potential range and that important environmental variables (including species interactions) have been considered in the model construction. For species currently confined to refugia, or which are so rare that they occupy only a small portion of their suitable habitat, the resulting distribution model does not reflect the true potential extent of the species and thus exaggerates the lack of potential habitat (Sinclair et al 2010;De Ornellas et al 2011). Despite these limitations, SDMs have advanced conservation efforts by allowing conservation planning for the current distribution of many critical species, such as large carnivores in North America (Carroll et al 2001) and Europe (Corsi et al 1999), and riverine fish communities in Mesoamerica (Esselman & Allan 2011).…”

Transactions

“…While tools for modelling ecological systems are improving in their level of sophistication, they are too crude at present to predict ecological futures with the certainty required by policy and management (Sinclair et al 2010). The tools and mechanisms used currently by land mangers for biodiversity conservation are simplistic in some respects, yet may be very effective for current conservation actions for biodiversity (e.g.…”

“…future) models. Consequently these outputs should be interpreted with considerable caution, and they will have limited use in forming policy or framing management actions (Sinclair et al 2010). In the interim, the only sensible performance criterion that can be applied to future models is whether they make ecological sense (e.g.…”