Addressing potential local adaptation in species distribution models: implications for conservation under climate change

Abstract

Species distribution models (SDMs) have been criticized for involving assumptions that ignore or categorize many ecologically relevant factors such as dispersal ability and biotic interactions. Another potential source of model error is the assumption that species are ecologically uniform in their climatic tolerances across their range. Typically, SDMs treat a species as a single entity, although populations of many species differ due to local adaptation or other genetic differentiation. Not taking local adaptation into account may lead to incorrect range prediction and therefore misplaced conservation efforts. A constraint is that we often do not know the degree to which populations are locally adapted. Lacking experimental evidence, we still can evaluate niche differentiation within a species' range to promote better conservation decisions. We explore possible conservation implications of making type I or type II errors in this context. For each of two species, we construct three separate Max-Ent models, one considering the species as a single population and two of disjunct populations. Principal component analyses and response curves indicate different climate characteristics in the current environments of the populations. Model projections into future climates indicate minimal overlap between areas predicted to be climatically suitable by the whole species vs. population-based models. We present a workflow for addressing uncertainty surrounding local adaptation in SDM application and illustrate the value of conducting population-based models to compare with whole-species models. These comparisons might result in more cautious management actions when alternative range outcomes are considered.

Eco‐evolution on the edge during climate change

“…Tools now exist to understand and predict evolution and make better informed management decisions despite uncertainty (Dittrich et al 2016, Hällfors et al 2016, Urban et al 2016. Here we suggest that evolution could increase range expansion rates and allow populations to adapt to novel conditions on their cool range margins.…”

Population-Level Differentiation in Growth Rates and Leaf Traits in Seedlings of the Neotropical Live Oak Quercus oleoides Grown under Natural and Manipulated Precipitation Regimes

“…Overall, our study shows the existence of important intraspecific genetic variation in leaf economics spectrum traits and growth rates in a long-lived tropical tree. These findings are critical to understanding how this keystone species will respond to climate change in the near future (Hällfors et al, 2016). …”

Forecasting range shifts of a cold‐adapted species under climate change: are genomic and ecological diversity within species crucial for future resilience?

“…However, predicting the extent and directionality of future distributional shifts remains challenging. Moreover, spatial variation in genetic and ecological diversity differentially affects locally adapted populations within species, but such variation has been incorporated in future predictions only recently (Fitzpatrick and Keller 2015, Gotelli and Stanton-Geddes 2015, Moran et al 2015, Hällfors et al 2016, Ikeda et al 2017. Moreover, spatial variation in genetic and ecological diversity differentially affects locally adapted populations within species, but such variation has been incorporated in future predictions only recently (Fitzpatrick and Keller 2015, Gotelli and Stanton-Geddes 2015, Moran et al 2015, Hällfors et al 2016, Ikeda et al 2017.…”