Intraspecific Niche Models for Ponderosa Pine (Pinus ponderosa) Suggest Potential Variability in Population-Level Response to Climate Change

Abstract

Unique responses to climate change can occur across intraspecific levels, resulting in individualistic adaptation or movement patterns among populations within a given species. Thus, the need to model potential responses among genetically distinct populations within a species is increasingly recognized. However, predictive models of future distributions are regularly fit at the species level, often because intraspecific variation is unknown or is identified only within limited sample locations. In this study, we considered the role of intraspecific variation to shape the geographic distribution of ponderosa pine (Pinus ponderosa), an ecologically and economically important tree species in North America. Morphological and genetic variation across the distribution of ponderosa pine suggest the need to model intraspecific populations: the two varieties (var. ponderosa and var. scopulorum) and several haplotype groups within each variety have been shown to occupy unique climatic niches, suggesting populations have distinct evolutionary lineages adapted to different environmental conditions. We utilized a recently available, geographically widespread dataset of intraspecific variation (haplotypes) for ponderosa pine and a recently devised lineage distance modeling approach to derive additional, likely intraspecific occurrence locations. We confirmed the relative uniqueness of each haplotype-climate relationship using a niche-overlap analysis, and developed ecological niche models (ENMs) to project the distribution for two varieties and eight haplotypes under future climate forecasts. Future projections of haplotype niche distributions generally revealed greater potential range loss than predicted for the varieties. This difference may reflect intraspecific responses of distinct evolutionary lineages. However, directional trends are generally consistent across intraspecific levels, and include a loss of distributional area and an upward shift in elevation. Our results demonstrate the utility in modeling intraspecific response to changing climate and they inform management and conservation strategies, by identifying haplotypes and geographic areas that may be most at risk, or most secure, under projected climate change.

Biogeographic barriers, Pleistocene refugia, and climatic gradients in the southeastern Nearctic drive diversification in cornsnakes (Pantherophis guttatus complex)

“…This is an important, but perhaps overlooked consideration when inferring suitable refugia during the LGM. Unique responses to climate change have been shown to occur between intraspecific groups, which can result in differences in adaptation or dispersal between populations within a species (Maguire, Shinneman, Potter, & Hipkins, ; Pearman, D'Amen, Graham, Thuiller, & Zimmermann, ). As expected, accounting for phylogeographic structure when forecasting species' distributions onto models of future climate change has demonstrated that predicted distributions are smaller than when not considering this structure (Valladares et al, ).…”

Climatic and Soil Factors Shape the Demographical History and Genetic Diversity of a Deciduous Oak (Quercus liaotungensis) in Northern China

“…Furthermore, to explain the demography of this oak species, we only considered seven simple scenarios with global population changes during the ABC analyses (Supplementary Figure S1 and Supplementary Table S4 ); also, the genetic structure of populations was not simulated due to small sample size and insufficient genetic information of the individuals in each phylogenetic cluster. Considering the potential variability of responses to climate change and environmental disturbance across intraspecific levels ( Maguire et al, 2018 ), the two genetic clusters of Q. liaotungensis (Figure 2 ) might be the result of differences in spatial and temporal responses during the glacial-interglacial transitions of the Quaternary. Moreover, gene flow between the two phylogenetic clusters and closely related species (e.g., Q. mongolica , Zeng et al, 2011 ) were not accounted for in our ABC simulation; all of these factors could lead to an underestimation of effective population sizes and time of population changes for Q. liaotungensis .…”

Tracking niche change through time: simultaneous inference of ecological niche evolution and estimation of contemporary niches

“…However, no current approach accounts for the historical role of speciation and adaptation in determining species present-day niches. While there have been several recent developments of ENMs that incorporate a phylogenetic dimension (Smith et al 2018; Morales-Castilla et al 2017; Maguire et al 2018), these have mostly aimed to account for the statistical problem of non-independence due to relatedness among contemporary species, rather than to model the historical development of niches through evolutionary time. By combining ENMs and niche evolution models in the same statistical framework, the approach we present in this paper allows for species present-day niches to be shaped by evolutionary history and allows us to test historical hypotheses of niche evolution.…”

“…While there have been advances in incorporating evolutionary information to improve current niche estimation (Smith et al 2018), such as estimating a species’ niche by aggregating its subspecies’ niches (Maguire et al 2018) or modelling niches of multiple species while accounting for their phylogenetic non-independence (Morales-Castilla et al 2017), we still lack a method that can simultaneously infer the history of niche evolution and estimate current niches. In this study, we present a method that combines, in a single statistical framework, an environmental niche model (ENM) and a phylogenetic comparative method (PCM) to reconstruct niche evolution.…”