More Like this

1. Historical interactions are predicted to be disrupted under future climate change: The case of lace lichen and valley oak

   https://doi.org/10.1111/jbi.13442  

   Zhao, Jian‐Li ; Werth, Silke ; Ikegami, Makihiko ; Gugger, Paul F. ; Sork, Victoria L. ( November 2018 , Journal of Biogeography)

   The distributions and interactions of co‐occurring species may change if their ranges shift asymmetrically in response to rapid climate change. We aim to test whether two currently interacting taxa, valley oak (Quercus lobata) and lace lichen (Ramalina menziesii), have had a long‐lasting historical association and are likely to continue to associate in the future.

   Central western California, western United States of America

   Using population genetic analyses andMaxEntsoftware for ecological niche modelling, we estimate species’ distributions during the Last Interglacial, the Last Glacial Maximum, present, and future periods. Mantel and vertex (genetic connection) tests were used to examine the spatial congruence among taxa. To compare the modelled response to climate change, we estimated migration speed between respective time periods using vector analysis.

   We found significant genetic congruence between valley oak and the lichen's green algal photobiont, independent of geographic isolation and habitat isolation, which is consistent with long‐term association. Ecological niche models under past and future climate scenarios indicate that overlap of climatic niche sharing between valley oak and lace lichen might decrease in the future. Our models indicate that the speed of shifts in climate niches between these two taxa differed significantly in past periods from that of the present period.

   Our findings reveal that historical interactions between valley oak and lace lichen correlate with long‐term sharing of past climate niches. However, the future association of lace lichen with valley oak may be disrupted in parts of its current distribution due to differential discordance of climate niche shifts, species’ movements and generation times. This study illustrates the processes and patterns that allow long‐term association during historic climate change and how they are likely to change during rapid climate change.

    

   more » « less
2. Intraspecific trait variation across elevation predicts a widespread tree species' climate niche and range limits

   https://doi.org/10.1002/ece3.5969  

   Van Nuland, Michael E. ; Vincent, John B. ; Ware, Ian M. ; Mueller, Liam O. ; Bayliss, Shannon L. J. ; Beals, Kendall K. ; Schweitzer, Jennifer A. ; Bailey, Joseph K. ( April 2020 , Ecology and Evolution)

   Global change is widely altering environmental conditions which makes accurately predicting species range limits across natural landscapes critical for conservation and management decisions. If climate pressures along elevation gradients influence the distribution of phenotypic and genetic variation of plant functional traits, then such trait variation may be informative of the selective mechanisms and adaptations that help define climatic niche limits. Using extensive field surveys along 16 elevation transects and a large common garden experiment, we tested whether functional trait variation could predict the climatic niche of a widespread tree species (Populus angustifolia) with a double quantile regression approach. We show that intraspecific variation in plant size, growth, and leaf morphology corresponds with the species' total climate range and certain climatic limits related to temperature and moisture extremes. Moreover, we find evidence of genetic clines and phenotypic plasticity at environmental boundaries, which we use to create geographic predictions of trait variation and maximum values due to climatic constraints across the western US. Overall, our findings show the utility of double quantile regressions for connecting species distributions and climate gradients through trait‐based mechanisms. We highlight how new approaches like ours that incorporate genetic variation in functional traits and their response to climate gradients will lead to a better understanding of plant distributions as well as identifying populations anticipated to be maladapted to future environments.

    

   more » « less
3. Tracking lags in historical plant species’ shifts in relation to regional climate change

   https://doi.org/10.1111/gcb.13429  

   Ash, Jeremy D. ; Givnish, Thomas J. ; Waller, Donald M. ( August 2016 , Global Change Biology)

   Can species shift their distributions fast enough to track changes in climate? We used abundance data from the 1950s and the 2000s in Wisconsin to measure shifts in the distribution and abundance of 78 forest‐understory plant species over the last half‐century and compare these shifts to changes in climate. We estimated temporal shifts in the geographic distribution of each species using vectors to connect abundance‐weighted centroids from the 1950s and 2000s. These shifts in distribution reflect colonization, extirpation, and changes in abundance within sites, separately quantified here. We then applied climate analog analyses to compute vectors representing the climate change that each species experienced. Species shifted mostly to the northwest (mean: 49 ± 29 km) primarily reflecting processes of colonization and changes in local abundance. Analog climates for these species shifted even further to the northwest, however, exceeding species’ shifts by an average of 90 ± 40 km. Most species thus failed to match recent rates of climate change. These lags decline in species that have colonized more sites and those with broader site occupancy, larger seed mass, and higher habitat fidelity. Thus, species’ traits appear to affect their responses to climate change, but relationships are weak. As climate change accelerates, these lags will likely increase, potentially threatening the persistence of species lacking the capacity to disperse to new sites or locally adapt. However, species with greater lags have not yet declined more in abundance. The extent of these threats will likely depend on how other drivers of ecological change and interactions among species affect their responses to climate change.

    

   more » « less
4. Hydrologic refugia, plants, and climate change

   https://doi.org/10.1111/gcb.13629  

   McLaughlin, Blair C. ; Ackerly, David D. ; Klos, P. Zion ; Natali, Jennifer ; Dawson, Todd E. ; Thompson, Sally E. ( March 2017 , Global Change Biology)

   Climate, physical landscapes, and biota interact to generate heterogeneous hydrologic conditions in space and over time, which are reflected in spatial patterns of species distributions. As these species distributions respond to rapid climate change, microrefugia may support local species persistence in the face of deteriorating climatic suitability. Recent focus on temperature as a determinant of microrefugia insufficiently accounts for the importance of hydrologic processes and changing water availability with changing climate. Where water scarcity is a major limitation now or under future climates,hydrologic microrefugiaare likely to prove essential for species persistence, particularly for sessile species and plants. Zones of high relative water availability – mesic microenvironments – are generated by a wide array of hydrologic processes, and may be loosely coupled to climatic processes and therefore buffered from climate change. Here, we review the mechanisms that generate mesic microenvironments and their likely robustness in the face of climate change. We argue that mesic microenvironments will act as species‐specific refugia only if the nature and space/time variability in water availability are compatible with the ecological requirements of a target species. We illustrate this argument with case studies drawn from California oak woodland ecosystems. We posit that identification of hydrologic refugia could form a cornerstone of climate‐cognizant conservation strategies, but that this would require improved understanding of climate change effects on key hydrologic processes, including frequently cryptic processes such as groundwater flow.

    

   more » « less
5. Climatic niche comparisons of eastern North American and eastern Asian disjunct plant genera

   https://doi.org/10.1111/geb.13504  

   Melton, Anthony E. ; Clinton, Matthew H. ; Wasoff, Donald N. ; Lu, Limin ; Hu, Haihua ; Chen, Zhiduan ; Ma, Keping ; Soltis, Douglas E. ; Soltis, Pamela S. ( April 2022 , Global Ecology and Biogeography)

   While the floras of eastern Asia (EA) and eastern North America (ENA) share numerous genera, they have drastically different species richness. Despite an overall similarity in the quality of their temperate climates, the climate of EA is more spatially heterogeneous than that of ENA. Spatial environmental heterogeneity has been found to play a key role in influencing species richness in some regions. Here, we tested the following hypotheses: (a) EA species will occupy larger climatic niches than their ENA congeners, (b) congeners of EA‐ENA disjunct genera will occupy statistically equivalent climatic niches, and (c) congeners of EA‐ENA disjunct genera will occupy more similar climatic niches than expected by their respective physiographic context.

   North America and Asia.

   Present.

   Seed plants.

   Predictions generated by ecological niche models (ENMs) were compared for 88 species across 31 EA‐ENA disjunct genera. ENM predictions were assessed for geographic and ecological breadth. Tests for niche equivalency and similarity were performed for congeneric species pairs to determine if species of disjunct genera have experienced niche conservatism or divergence.

   EA species tend to occupy greater amounts of climatic niche space than their close relatives in ENA. Over two‐thirds of the conducted niche comparisons show that EA‐ENA congeners either occupy equivalent climatic niche space within these broader climatic regimes or occupy non‐equivalent niches that are as similar as expected given their physiographic contexts.

   EA species tend to occupy larger climatic niches, and congeners of EA‐ENA disjunct genera tend to occupy equivalent/similar niche space within their respective distributions, with differences in occupied niches possibly due to their respective physiographic contexts, highlighting how niche‐neutral processes and niche conservatism may affect the distributions of disjunct species.

    

   more » « less