Inferring the past to predict the future: climate modelling predictions and phylogeography for the freshwater gastropod Radix balthica (Pulmonata, Basommatophora)

Understanding the impact of past climatic events on species may facilitate predictions of how species will respond to future climate change. To this end, we sampled populations of the common pond snail Radix balthica over the entire species range (northwestern Europe). Using a recently developed analytical framework that employs ecological niche modelling to obtain hypotheses that are subsequently tested with statistical phylogeography, we inferred the range dynamics of R. balthica over time. A Maxent modelling for present-day conditions was performed to infer the climate envelope for the species, and the modelled niche was used to hindcast climatically suitable range at the last glacial maximum (LGM) c . 21 000 years ago. Ecological niche modelling predicted two suitable areas at the LGM within the present species range. Phylogeographic model selection on a COI mitochondrial DNA data set confirmed that R. balthica most likely spread from these two disjunct refuges after the LGM. The match observed between the potential range of the species at the LGM given its present climatic requirements and the phylogeographically inferred refugial areas was a clear argument in favour of niche conservatism in R. balthica , thus allowing to predict the future range. The subsequent projection of the potential range under a global change scenario predicts a moderate pole-ward shift of the northern range limits, but a dramatic loss of areas currently occupied in France, western Great Britain and southern Germany.     

A climate change context for the decline of a foundation tree species in south-western Australia: insights from phylogeography and species distribution modelling

Background and Aims A worldwide increase in tree decline and mortality has been linked to climate change and, where these represent foundation species, this can have important implications for ecosystem functions. This study tests a combined approach of phylogeographic analysis and species distribution modelling to provide a climate change context for an observed decline in crown health and an increase in mortality in Eucalyptus wandoo, an endemic tree of south-western Australia.Methods Phylogeographic analyses were undertaken using restriction fragment length polymorphism analysis of chloroplast DNA in 26 populations across the species distribution. Parsimony analysis of haplotype relationships was conducted, a haplotype network was prepared, and haplotype and nucleotide diversity were calculated. Species distribution modelling was undertaken using Maxent models based on extant species occurrences and projected to climate models of the last glacial maximum (LGM).Key Results A structured pattern of diversity was identified, with the presence of two groups that followed a climatic gradient from mesic to semi-arid regions. Most populations were represented by a single haplotype, but many haplotypes were shared among populations, with some having widespread distributions. A putative refugial area with high haplotype diversity was identified at the centre of the species distribution. Species distribution modelling showed high climatic suitability at the LGM and high climatic stability in the central region where higher genetic diversity was found, and low suitability elsewhere, consistent with a pattern of range contraction.Conclusions Combination of phylogeography and paleo-distribution modelling can provide an evolutionary context for climate-driven tree decline, as both can be used to cross-validate evidence for refugia and contraction under harsh climatic conditions. This approach identified a central refugial area in the test species E. wandoo, with more recent expansion into peripheral areas from where it had contracted at the LGM. This signature of contraction from lower rainfall areas is consistent with current observations of decline on the semi-arid margin of the range, and indicates low capacity to tolerate forecast climatic change. Identification of a paleo-historical context for current tree decline enables conservation interventions to focus on maintaining genetic diversity, which provides the evolutionary potential for adaptation to climate change.     

Postglacial colonization of Europe by the barbastelle bat: agreement between molecular data and past predictive modelling

The barbastelle (Barbastella barbastellus) is a rare forest bat with a wide distribution in Europe. Here, we combine results from the analysis of two mtDNA fragments with species distribution modelling to determine glacial refugia and postglacial colonization routes. We also investigated whether niche conservatism occurs in this species. Glacial refugia were identified in the three southern European peninsulas: Iberia, Italy and the Balkans. These latter two refugia played a major role in the postglacial colonization process, with their populations expanding to England and central Europe, respectively. Palaeo‐distribution models predicted that suitable climatic conditions existed in the inferred refugia during the last glacial maximum (LGM). Nevertheless, the overlap between the current and the LGM distributions was almost inexistent in Italy and in the Balkans, meaning that B. barbastellus populations were forced to shift range between glacial and interglacial periods, a process that probably caused some local extinctions. In contrast, Iberian populations showed a ‘refugia within refugium’ pattern, with two unconnected areas containing stable populations (populations that subsisted during both glacial and interglacial phases). Moreover, the match between LGM models and the refugial areas determined by molecular analysis supported the hypothesis of niche conservatism in B. barbastellus. We argue that geographic patterns of genetic structuring, altogether with the modelling results, indicate the existence of four management units for conservation: Morocco, Iberia, Italy and UK, and Balkans and central Europe. In addition, all countries sampled possessed unique gene pools, thus stressing the need for the conservation of local populations.     

Northern glacial refugia for the pygmy shrew Sorex minutus in Europe revealed by phylogeographic analyses and species distribution modelling

The southern European peninsulas (Iberian, Italian and Balkan) are traditionally recognized as glacial refugia from where many species colonized central and northern Europe after the Last Glacial Maximum (LGM). However, evidence that some species had more northerly refugia is accumulating from phylogeographic, palaeontological and palynological studies, and more recently from species distribution modelling (SDM), but further studies are needed to test the idea of northern refugia in Europe. Here, we take a rarely implemented multidisciplinary approach to assess if the pygmy shrew Sorex minutus, a widespread Eurasian mammal species, had northern refugia during the LGM, and if these influenced its postglacial geographic distribution. First, we evaluated the phylogeographic and population expansion patterns using mtDNA sequence data from 123 pygmy shrews. Then, we used SDM to predict present and past (LGM) potential distributions using two different training data sets, two different algorithms (Maxent and GARP) and climate reconstructions for the LGM with two different general circulation models. An LGM distribution in the southern peninsulas was predicted by the SDM approaches, in line with the occurrence of lineages of S. minutus in these areas. The phylogeographic analyses also indicated a widespread and strictly northern‐central European lineage, not derived from southern peninsulas, and with a postglacial population expansion signature. This was consistent with the SDM predictions of suitable LGM conditions for S. minutus occurring across central and eastern Europe, from unglaciated parts of the British Isles to much of the eastern European Plain. Hence, S. minutus likely persisted in parts of central and eastern Europe during the LGM, from where it colonized other northern areas during the late‐glacial and postglacial periods. Our results provide new insights into the glacial and postglacial colonization history of the European mammal fauna, notably supporting glacial refugia further north than traditionally recognized.     

Late‐glacial recolonization and phylogeography of European red deer (Cervus elaphus L.)

The Pleistocene was an epoch of extreme climatic and environmental changes. How individual species responded to the repeated cycles of warm and cold stages is a major topic of debate. For the European fauna and flora, an expansion–contraction model has been suggested, whereby temperate species were restricted to southern refugia during glacial times and expanded northwards during interglacials, including the present interglacial (Holocene). Here, we test this model on the red deer (Cervus elaphus) a large and highly mobile herbivore, using both modern and ancient mitochondrial DNA from the entire European range of the species over the last c. 40 000 years. Our results indicate that this species was sensitive to the effects of climate change. Prior to the Last Glacial Maximum (LGM) haplogroups restricted today to South‐East Europe and Western Asia reached as far west as the UK. During the LGM, red deer was mainly restricted to southern refugia, in Iberia, the Balkans and possibly in Italy and South‐Western Asia. At the end of the LGM, red deer expanded from the Iberian refugium, to Central and Northern Europe, including the UK, Belgium, Scandinavia, Germany, Poland and Belarus. Ancient DNA data cannot rule out refugial survival of red deer in North‐West Europe through the LGM. Had such deer survived, though, they were replaced by deer migrating from Iberia at the end of the glacial. The Balkans served as a separate LGM refugium and were probably connected to Western Asia with genetic exchange between the two areas.     

Palaeoclimatic models help to understand current distribution of Caucasian forest species

Spatial and temporal constraints on dispersal explain the absence of species from areas with potentially suitable conditions. Previous studies have shown that post‐glacial recolonization has shaped the current ranges of many species, yet it is not completely clear to what extent interspecific differences in range size depend on different dispersal rates. The inferred boundaries of glacial refugia are difficult to validate, and may bias spatial distribution models (SDMs) that consider post‐glacial dispersal constraints. We predicted the current distribution of 12 Caucasian forest plants and animals, factoring in the effective geographical distance from inferred glacial refugia as an additional predictor. To infer glacial refugia, we tested the transferability of the current SDMs based on the distribution of climatic variables, and projected the most transferable ones onto two climate scenarios simulated for the Last Glacial Maximum (LGM). We then calculated least‐cost distances from the inferred refugia, using elevation as a friction surface, and recalculated the current SDMs incorporating the distances as an additional variable. We compared the predictive powers of the initial with the final SDMs. The palaeoclimatic simulation that best matched the distribution of species was assumed to represent the closest fit to the true palaeoclimate. SDMs incorporating refugial distance performed significantly better for all but one studied species, and the Model for Interdisciplinary Research on Climate (MIROC) climatic simulation provided a more convincing pattern of the LGM climate than the Community Climate System Model (CCSM) simulation. Our results suggest that the projection of suitable habitat models onto past climatic conditions may yield realistic boundaries of glacial refugia, and that the current distribution of forest species in the study region is strongly associated with locations of former refugia. We inferred six major forest refugia throughout western Asia: (1) Colchis; (2) western Anatolia; (3) western Taurus; (4) the upper reaches of the Tigris River; (5) the Levant; and (6) the southern Caspian basin. The boundaries of the modelled refugia were substantially broader than the refugia boundaries inferred solely from pollen records. Thus, our method could be used to: (1) improve models of current species distributions by considering the dispersal histories of the species; and (2) validate alternative reconstructions of palaeoclimate with current distribution data. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 105 , 231–248.     

Ice age legacies in the geographical distribution of tree species richness in Europe

Aim This study uses a high‐resolution simulation of the Last Glacial Maximum (LGM) climate to assess: (1) whether LGM climate still affects the geographical species richness patterns in the European tree flora and (2) the relative importance of modern and LGM climate as controls of tree species richness in Europe. Location The parts of Europe that were unglaciated during the LGM. Methods Atlas data on the distributions of 55 tree species were linked with data on modern and LGM climate and climatic heterogeneity in a geographical information system with a 60‐km grid. Four measures of species richness were computed: total richness, and richness of the 18 most restricted species, 19 species of medium incidence (intermediate species) and 18 most widespread species. We used ordinary least‐squares regression and spatial autoregressive modelling to test and estimate the richness–climate relationships. Results LGM climate constituted the best single set of explanatory variables for richness of restricted species, while modern climate and climatic heterogeneity was best for total and widespread species richness and richness of intermediate species, respectively. The autoregressive model with all climatic predictors was supported for all richness measures using an information‐theoretic approach, albeit only weakly so for total species richness. Among the strongest relationships were increases in total and intermediate richness with climatic heterogeneity and in restricted richness with LGM growing‐degree‐days. Partial regression showed that climatic heterogeneity accounted for the largest unique variation fraction for intermediate richness, while LGM climate was particularly important for restricted richness. Main conclusions LGM climate appears to still affect geographical patterns of tree species richness in Europe, albeit the relative importance of modern and LGM climate depends on range size. Notably, LGM climate is a strong richness control for species with a restricted range, which appear to still be associated with their glacial refugia.     

Ice age distributions of European small mammals: insights from species distribution modelling

Aim In addition to the traditionally recognized Last Glacial Maximum (LGM, 21 ka) refuge areas in the Mediterranean region, more northerly LGM distributions for temperate and boreal taxa in central and eastern Europe are increasingly being discussed based on palaeoecological and phylogeographical evidence. Our aim was to investigate the potential refuge locations using species distribution modelling to estimate the geographical distribution of suitable climatic conditions for selected rodent species during the LGM. Location Eurasia. Methods Presence/absence data for seven rodent species with range limits corresponding to the limits of temperate or boreal forest or arctic tundra were used in the analysis. We developed predictive distribution models based on the species present‐day European distributions and validated these against their present‐day Siberian ranges. The models with the best predictors of the species distributions across Siberia were projected onto LGM climate simulations to assess the distribution of climatically suitable areas. Results The best distribution models provided good predictions of the present‐day Siberian ranges of the study species. Their LGM projections showed that areas with a suitable LGM climate for the three temperate species (Apodemus flavicollis, Apodemus sylvaticus and Microtus arvalis) were largely restricted to the traditionally recognized southern refuge areas, i.e. mainly in the Mediterranean region, but also southernmost France and southern parts of the Russian Plain. In contrast, suitable climatic conditions for the two boreal species (Clethrionomys glareous and Microtus agrestis) were predicted as far north as southern England and across southern parts of central and eastern Europe eastwards into the Russian Plain. For the two arctic species (Lemmus lemmus and Microtus oeconomus), suitable climate was predicted from the Atlantic coast eastward across central Europe and into Russia. Main conclusions Our results support the idea of more northerly refuge areas in Europe, indicating that boreal species would have found suitable living conditions over much of southern central and eastern Europe and the Russian Plain. Temperate species would have primarily found suitable conditions in the traditional southern refuge areas, but interestingly also in much of the southern Russian Plain.     

Refugia within refugia – patterns in endemism and genetic divergence are linked to Late Quaternary climate stability in the Iberian Peninsula

In Europe, southern peninsulas served as major refugia during Pleistocene cold periods. However, growing evidence has revealed complex patterns of glacial survival within these southern regions, with multiple glacial refugia within each larger refugial area. We investigated the extent to which patterns of endemism and phylogeographic are concordant across animal species in the Iberian Peninsula, one of the most important unglaciated areas in Europe during the Pleistocene, can be explained in terms of climatic stability. We found that historical climatic stability (notably climate velocity measures integrating macroclimatic shifts with local spatial topoclimate gradients) was often among the most important predictors of endemic species richness for different taxonomic groups using models that also incorporated measures of modern climate. Furthermore, for some taxonomic groups, climatic stability was also correlated with patterns of spatial concordance in interpopulation genetic divergence across multiple taxa, and private haplotypes were more frequently found in relatively stable areas. Overall, our results suggest that both endemism patterns and cross‐taxa concordant phylogeographic patterns across the Iberian Peninsula to some extent are linked to spatial variation in Late Quaternary climate stability, in agreement with the proposed ‘refugia‐within‐refugia’ scenario. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 113 , 13–28.     

Range and niche shifts in response to past climate change in the desert horned lizard Phrynosoma platyrhinos

During climate change, species are often assumed to shift their geographic distributions (geographic ranges) in order to track environmental conditions – niches – to which they are adapted. Recent work, however, suggests that the niches do not always remain conserved during climate change but shift instead, allowing populations to persist in place or expand into new areas. We assessed the extent of range and niche shifts in response to the warming climate after the Last Glacial Maximum (LGM) in the desert horned lizard Phrynosoma platyrhinos, a species occupying the western deserts of North America. We used a phylogeographic approach with mitochondrial DNA sequences to approximate the species range during the LGM by identifying populations that exhibit a genetic signal of population stability versus those that exhibit a signal of a recent (likely post‐LGM) geographic expansion. We then compared the climatic niche that the species occupies today with the niche it occupied during the LGM using two models of simulated LGM climate. The genetic analyses indicated that P. platyrhinos persisted within the southern Mojave and Sonoran deserts throughout the latest glacial period and expanded from these deserts northwards, into the western and eastern Great Basin, after the LGM. The climatic niche comparisons revealed that P. platyrhinos expanded its climatic niche after the LGM towards novel, warmer and drier climates that allowed it to persist within the southern deserts. Simultaneously, the species shifted its climatic niche towards greater temperature and precipitation fluctuations after the LGM. We concluded that climatic changes at the end of the LGM promoted both range and niche shifts in this lizard. The mechanism that allowed the species to shift its niche remains unknown, but phenotypic plasticity likely contributes to the species ability to adjust to climate change.     

Climatic stability in the Brazilian Cerrado: implications for biogeographical connections of South American savannas,species richness and conservation in a biodiversity hotspot

Aim To investigate the historical distribution of the Cerrado across Quaternary climatic fluctuations and to generate historical stability maps to test: (1) whether the ‘historical climate’ stability hypothesis explains squamate reptile richness in the Cerrado; and (2) the hypothesis of Pleistocene connections between savannas located north and south of Amazonia. Location The Cerrado, a savanna biome and a global biodiversity hotspot distributed mainly in central Brazil. Methods We generated occurrence datasets from 1000 presence points randomly selected from the entire distribution of the Cerrado, as determined by two spatial definitions. We modelled the potential Cerrado distribution by implementing a maximum‐entropy machine‐learning algorithm across four time projections: current, mid‐Holocene (6 ka), Last Glacial Maximum (LGM, 21 ka) and Last Interglacial (LIG, 120 ka). We generated historical stability maps (refugial areas) by overlapping presence/absence projections of all scenarios, and checked consistencies with qualitative comparisons with available fossil pollen records. We built a spatially explicit simultaneous autoregressive model to explore the relationship between current climate, climatic stability, and squamate species richness. Results Models predicted the LGM and LIG as the periods of narrowest and widest Cerrado distributions, respectively, and were largely corroborated by palynological evidence. We found evidence for two savanna corridors (eastern coastal during the LIG, and Andean during the LGM) and predicted a large refugial area in the north‐eastern Cerrado (Serra Geral de Goiás refugium). Variables related to climatic stability predicted squamate richness better than present climatic variables did. Main conclusions Our results indicate that Bolivian savannas should be included within the Cerrado range and that the Cerrado’s biogeographical counterparts are not Chaco and Caatinga but rather the disjunct savannas of the Guyana shield plateaus. Climatic stability is a good predictor of Cerrado squamate richness, and our stability maps could be used in future studies to test diversity patterns and genetic signatures of different taxonomic groups and as a higher‐order landscape biodiversity surrogate for conservation planning.     

Continental shelf as potential retreat areas for Austral‐Asian estrildid finches (Passeriformes: Estrildidae) during the Pleistocene

Studies dealing with changes of biodiversity in time and space constitute an important part of biogeography, ecology and conservation biology. Areas of long‐term climate stability are particularly interesting as they might have facilitated the survival of species over historical times and thus are crucial for understanding contemporary diversity patterns. In this study, we assessed the potential distribution of 23 estrildid finch species in order to analyse stability in recent and past diversity patterns and diversity centres in the Austral‐Asiatic region. We used Maxent to predict recent distributions of each species and to project them onto the climatic conditions of the Last Glacial Maximum (LGM, 21 000 yr BP) using two different scenarios (CCSM, MIROC). The resulting diversity patterns were tested on presence and possible shifts of distribution centres. Diversity patterns of forest‐ and savannah‐living species were considered combined and separately. During the LGM, potential diversity patterns of forest‐living species corroborated well with postulated rainforest refuges situated on the eastern coast of Cape York Peninsula. Our results indicate a remarkably high stability of existing diversity centres. Although projections into the past show some differences in detail in the extent and exact position of the diversity centres, they reveal largely congruent large scale patterns in both time slices. However, the models suggest a northward shift towards exposed continental shelf areas that where dry during the LGM. Clearly, centres of diversity were situated on this land bridge between Australia and New Guinea, highlighting their importance as areas of retreat for estrildid finches and maybe other savannah species in times of changing climatic conditions and associated sea‐level fluctuations.     

Uncommon paleodistribution patterns of Chrysolophus pheasants in east Asia: explanations and implications

Some modeling studies indicated that the past distributions of species in east Asia during the Last Interglacial (LIG) and Last Glacial Maximum (LGM) periods differ from those of European and North American species and the deviant Asian distribution pattern is known under the term ‘pre‐LGM expansion’. It represents the unusually similar distribution patterns between the current and the LGM scenario. However, there is still no satisfying explanation for this phenomenon so far. Therefore, we took the two recently separated pheasant species of genus Chrysolophus in east Asia as an example to test the pattern by performing ecological niche models. The main findings of this study include: 1) the paleodistributions of these two pheasants also corresponded to the ‘pre‐LGM expansion’ pattern; 2) climatic similarity results from mobility‐oriented parity analysis also revealed similar pattern for both species; 3) climate regimes of east Asia showed patterns different from those in Europe and North America in a climate shift towards drier conditions and stronger seasonality and to more extreme temperatures of the coldest months particularly during the LIG; 4) the two Chrysolophus species occupied significantly different ecological niches according to current distribution. We suggest that ecological segregation established in allopatric glacial refugia should be the main determinants for the separation of two Chrysolophus species until they came into extant post‐Pleistocene contact.     

Patterns of Diversity,Areas of Endemism,and Multiple Glacial Refuges for Freshwater Crabs of the Genus Sinopotamon in China (Decapoda: Brachyura: Potamidae)

Previous research has shown that the geographical distribution patterns of freshwater fishes and amphibians have been influenced by past climatic oscillations in China resulting from Pleistocene glacial activity. However, it remains unknown how these past changes have impacted the present-day distribution of Chinese freshwater crabs. This work describes the diversity and endemism of freshwater crabs belonging to Sinopotamon, a highly speciose genus endemic to China, and evaluates its distribution in terms of topography and past climatic fluctuations. Species diversity within Sinopotamon was found to be concentrated in an area from the northeastern edge of the Yunnan-Guizhou Plateau to the Jiangnan Hills, and three areas of endemism were identified. Multiple regression analysis between current climatic variables and Sinopotamon diversity suggested that regional annual precipitation, minimum temperature in the coldest month, and annual temperature range significantly influenced species diversity and may explain the diversity patterns of Sinopotamon. A comparison of ecological niche models (ENMs) between current conditions and the last glacial maximum (LGM) showed that suitable habitat for Sinopotamon in China severely contracted during the LGM. The coincidence of ENMs and the areas of endemism indicated that southeast of the Daba Mountains, and central and southeastern China, are potential Pleistocene refuges for Sinopotamon. The presence of multiple Pleistocene refuges within the range of this genus could further promote inter- and intraspecific differentiations, and may have led to high Sinopotamon species diversity, a high endemism rate and widespread distribution.     

The Iberian Peninsula as a potential source for the plant species pool in Germany under projected climate change

The application of niche-based modelling techniques to plant species has not been explored for the majority of taxa in Europe, primarily due to the lack of adequate distributional data. However, it is of crucial importance for conservation adaptation decisions to assess and quantify the likely pool of species capable of colonising a particular region under altered future climate conditions. We here present a novel method that combines the species pool concept and information about shifts in analogous multidimensional climate space. This allows us to identify regions in Europe with a current climate which is similar to that projected for future time periods in Germany. We compared the extent and spatial location of climatically analogous European regions for three projected greenhouse gas emission scenarios in Germany for the time period 2071–2080 (+2.4°C, +3.3°C, +4.5°C average increase in mean annual temperature) to those of the recent past in Europe (1961–90). Across all three scenarios, European land areas which are characterised by climatic conditions analogue to those found in Germany decreased from 14% in 1961–1990 to ca. 10% in 2071–2080. All scenarios show disappearing current climate types in Germany, which can mainly be explained with a general northwards shift of climatically analogous regions. We estimated the size of the potential species pool of these analogous regions using floristic inventory data for the Iberian Peninsula as 2,354 plant species. The identified species pool in Germany indicates a change towards warmth and drought adapted southern species. About one-third of the species from the Iberian analogous regions are currently already present in Germany. Depending on the scenario used, 1,372 (+2.4°C average change of mean annual temperature), 1,399 (+3.3°C) and 1,444 (+4.5°C) species currently not found in Germany, occur in Iberian regions which are climatically analogous to German 2071–80 climate types. We believe that our study presents a useful approach to illustrate and quantify the potential size and spatial distribution of a pool of species potentially colonising new areas under changing climatic conditions.     

Past,present, and future predictions on the suitable habitat of the Slender racer (Orientocoluber spinalis) using species distribution models

Species distribution models (SDMs) across past, present, and future timelines provide insights into the current distribution of these species and their reaction to climate change. Specifically, if a species is threatened or not well‐known, the information may be critical to understand that species. In this study, we computed SDMs for Orientocoluber spinalis, a monotypic snake genus found in central and northeast Asia, across the past (last interglacial, last glacial maximum, and mid‐Holocene), present, and future (2070s). The goal of the study was to understand the shifts in distribution across time, and the climatic factors primarily affecting the distribution of the species. We found the suitable habitat of O. spinalis to be persistently located in cold‐dry winter and hot summer climatic areas where annual mean temperature, isothermality, and annual mean precipitation were important for suitable habitat conditions. Since the last glacial maximum, the suitable habitat of the species has consistently shifted northward. Despite the increase in suitable habitat, the rapid alterations in weather regimes because of climate change in the near future are likely to greatly threaten the southern populations of O. spinalis, especially in South Korea and China. To cope with such potential future threats, understanding the ecological requirements of the species and developing conservation plans are urgently needed.     

Strong paleoclimatic legacies in current plant functional diversity patterns across Europe

Numerous studies indicate that environmental changes during the late Quaternary have elicited long‐term disequilibria between species diversity and environment. Despite its importance for ecosystem functioning, the importance of historical environmental conditions as determinants of FD (functional diversity) remains largely unstudied. We quantified the geographic distributions of plant FD (richness and dispersion) across Europe using distribution and functional trait information for 2702 plant species. We then compared the importance of historical and contemporary factors to determine the relevance of past conditions as predictors of current plant FD in Europe. For this, we compared the strength of the relationships between FD with temperature and precipitation stability since the LGM (Last Glacial Maximum), accessibility to LGM refugia, and contemporary environmental conditions (climate, productivity, soil, topography, and land use). Functional richness and dispersion exhibited geographic patterns with strong associations to the environmental history of the region. The effect size of accessibility to LGM refugia and climate stability since the LGM was comparable to that of the contemporary predictors. Both functional richness and dispersion increased with temperature stability since the LGM and accessibility to LGM refugia. Functional richness' geographic pattern was primarily associated with accessibility to LGM refugia growing degree‐days, land use heterogeneity, diversity of soil types, and absolute minimum winter temperature. Functional dispersion's geographic pattern was primarily associated with accessibility to LGM refugia growing degree‐days and absolute minimum winter temperature. The high explained variance and model support of historical predictors are consistent with the idea that long‐term variability in environmental conditions supplements contemporary factors in shaping FD patterns at continental scales. Given the importance of FD for ecosystem functioning, future climate change may elicit not just short‐term shifts in ecosystem functioning, but also long‐term functional disequilibria.     

Phylogeography of European moose (Alces alces) based on contemporary mtDNA data and archaeological records

Phylogeography can help to determine LGM refugia and postglacial migration routes. However, the locations of LGM refugial areas in eastern Europe are not clear. Moose (Alces alces) is presently a common species in central and north-eastern Europe, but there are no studies showing its phylogenetic pattern and genetic diversity across its whole continuous range. Moose never became extinct in the eastern part of its range, and the eastern mtDNA lineage has the largest effective population size. The present study shows the phylogeographic pattern and genetic diversity of European moose and compares the results of mtDNA analyses with the archaeological record of the species to identify its LGM refugia and postglacial migration routes. I combined the mtDNA control region sequences obtained in all studies of moose in Europe and western Asia. The genetic data were then compared with the archaeological records of the species dated to the LGM. I found that the European moose lineage inhabits Europe and western Asia. It is composed of two clades: the eastern and the central-western, consisting of a total of six discrete haplogroups. The most complex, the eastern clade, has the largest range. Some of the haplogroups have narrow or scattered distributions and two are common in almost the whole range. Genetic diversity hotspots were detected in contact zones of different mtDNA haplogroups rather than in the LGM refugial areas of moose. Archaeological records dated to the LGM were found in several localities in central, southern and eastern Europe as well as in western Asia. The range of the moose during the LGM was much larger than previously thought. The eastern clade survived the LGM in western Siberia, the Ural Mountains and Russian plain. LGM refugia of moose were also located in the Caucasus, Carpathians, Balkans and northern Italy.     

The shaping of genetic variation in edge‐of‐range populations under past and future climate change

With rates of climate change exceeding the rate at which many species are able to shift their range or adapt, it is important to understand how future changes are likely to affect biodiversity at all levels of organisation. Understanding past responses and extent of niche conservatism in climatic tolerance can help predict future consequences. We use an integrated approach to determine the genetic consequences of past and future climate changes on a bat species, Plecotus austriacus. Glacial refugia predicted by palaeo‐modelling match those identified from analyses of extant genetic diversity and model‐based inference of demographic history. Former refugial populations currently contain disproportionately high genetic diversity, but niche conservatism, shifts in suitable areas and barriers to migration mean that these hotspots of genetic diversity are under threat from future climate change. Evidence of population decline despite recent northward migration highlights the need to conserve leading‐edge populations for spearheading future range shifts.     

Niche shifting in response to warming climate after the last glacial maximum: inference from genetic data and niche assessments in the chisel‐toothed kangaroo rat (Dipodomys microps)

During Pleistocene glacial‐interglacial cycles, the geographic range is often assumed to have shifted as a species tracks its climatic niche. Alternatively, the geographic range would not necessarily shift if a species can adapt in situ to a changing environment. The potential for a species to persist in place might increase with the diversity of habitat types that a species exploits. We evaluate evidence for either range shift or range stability between the last glacial maximum (LGM) and present time in the chisel‐toothed kangaroo rat (Dipodomys microps), an endemic of the Great Basin and Mojave deserts. We modeled how the species’ range would have changed if the climatic niche of the species remained conserved between the LGM and present time. The climatic models imply that if D. microps inhabited the same climatic niche during the LGM as it does today, the species would have persisted primarily within the warm Mojave Desert and expanded northwards into the cold Great Basin only after the LGM. Contrary to the climatic models, the mitochondrial DNA assessment revealed signals of population persistence within the current distribution of the species throughout at least the latest glacial‐interglacial cycle. We concluded that D. microps did not track its climatic niche during late Pleistocene oscillations, but rather met the challenge of a changing environment by shifting its niche and retaining large portions of its distribution. We speculate that this kind of response to fluctuating climate was possible because of ‘niche drifting’, an alteration of the species’ realized niche due to plasticity in various biological characters. Our study provides an example of an approach to reconstruct species’ responses to past climatic changes that can be used to evaluate whether and to what extent taxa have capacity to shift their niches in response to the changing environment – information becoming increasingly important to predicting biotic responses to future environmental changes.