Modern reliance on fossil fuels has ushered in extreme temperatures globally and abnormal precipitation patterns in many regions. Although the climate is changing rapidly, other agents of natural ...selection such as photoperiod remain constant. This decoupling of previously reliable environmental cues shifts adaptive landscapes, favors novel suites of traits and likely increases the extinction risk of local populations. Here, I examine the fitness consequences of changing climates. Meta-analyses demonstrate that simulated future climates depress viability and fecundity components of fitness for native plant species in the short term, which could reduce population growth rates. Contracting populations that cannot adapt or adjust plastically to new climates might not be capable of producing sufficient migrants to track changing conditions.
With continually increasing summer temperatures and intense heat waves, it can be easy to neglect the ecological effects of winter climate change. However, shifts in the climate during winter can ...have profound consequences for eco-evolutionary dynamics in extratropical latitudes and high-elevation locales. Climate change has increased winter temperatures, disrupted snowpack, and reduced ice cover (Rixen et al., 2022). Extreme losses of snowpack are projected for many regions by the end of the century (Talsma et al., 2022). Patterns of climate change are complex and region dependent, but winters are becoming less reliable overall, with elevated temperatures and altered snow dynamics. In ecosystems with cold winters, many plant species require exposure to low, but not necessarily freezing, temperatures for a prolonged period to break dormancy in the spring; this chilling requirement prevents leaf emergence, flowering, or germination from occurring in the middle of winter (Chuine et al., 2016). Warming winters have advanced the onset of spring and could result in insufficient overwinter chilling. In addition, spring and fall frosts that occur after plants become physiologically active can perturb phenology and reduce fitness. Finally, novel winter climates could disrupt biotic interactions among plants, their mutualists, and antagonists. Here, I discuss emerging research frontiers in these domains.
Summary
Plant–herbivore interactions have evolved in response to coevolutionary dynamics, along with selection driven by abiotic conditions. We examine how abiotic factors influence trait expression ...in both plants and herbivores to evaluate how climate change will alter this long‐standing interaction. The paleontological record documents increased herbivory during periods of global warming in the deep past. In phylogenetically corrected meta‐analyses, we find that elevated temperatures, CO2 concentrations, drought stress and nutrient conditions directly and indirectly induce greater food consumption by herbivores. Additionally, elevated CO2 delays herbivore development, but increased temperatures accelerate development. For annual plants, higher temperatures, CO2 and drought stress increase foliar herbivory. Our meta‐analysis also suggests that greater temperatures and drought may heighten florivory in perennials. Human actions are causing concurrent shifts in CO2, temperature, precipitation regimes and nitrogen deposition, yet few studies evaluate interactions among these changing conditions. We call for additional multifactorial studies that simultaneously manipulate multiple climatic factors, which will enable us to generate more robust predictions of how climate change could disrupt plant–herbivore interactions. Finally, we consider how shifts in insect and plant phenology and distribution patterns could lead to ecological mismatches, and how these changes may drive future adaptation and coevolution between interacting species.
Local adaptation has evolved in numerous taxa across the tree of life in response to divergent selection acting on populations that inhabit different environments (Briscoe Runquist et al., 2019; ...Hargreaves et al., 2019; Hereford, 2009). The genetic basis of local adaptation has intrigued researchers for decades. In their foundational reciprocal transplant study, Clausen and Hiesey (1960) evaluated the genetics of adaptation primarily using hybrid lines derived from crosses of low elevation and alpine Potentilla glandulosa (Rosaceae) ecotypes. Their work revealed that transgressive segregation can lead to a wider range of trait values than expressed by the parents, complex traits are often genetically correlated and evolve in tandem, and local adaptation is typically polygenic, that is, controlled by many loci of small effect (Clausen & Hiesey, 1960). Within the past 15 years, a burgeoning literature has investigated whether local adaptation evolves through genetic trade‐offs, such that local alleles at a QTL (quantitative trait locus) or candidate gene have a fitness advantage in their home environment, but suffer a fitness cost when transplanted into a contrasting habitat type (Mitchell‐Olds et al., 2007). Alternatively, local adaptation could arise through conditional neutrality, in which an allele native to one habitat type has elevated fitness in its home site relative to foreign alleles, but is not at a fitness disadvantage elsewhere. Conditional neutrality could maintain local adaptation if gene flow is spatially restricted (Hall et al., 2010). In a From the Cover article in this issue of Molecular Ecology, Wright et al. (2022) examined the genetic basis of local adaptation in white clover (Trifolium repens), discovering strong signatures of local adaptation, and revealing that both genetic trade‐offs and conditional neutrality contribute to local adaptation. The most surprising and intriguing result to emerge from this study was that variation in a key antiherbivore defence did not appear to influence contemporary patterns of local adaptation. Rather, divergence in life history strategies was crucial, with early reproduction favoured in the southern garden and delayed reproduction and longer lifespans emerging in the north. These findings highlight the challenges of identifying the multivariate targets of divergent selection in locally‐adapted systems, and reveal that not all traits that vary across populations contribute to adaptive differentiation. As studies continue to investigate local adaptation, experiments that manipulate environmental conditions and quantify the magnitude and direction of selection on traits will shed light on the processes that drive local adaptation.
Climate change poses critical challenges for population persistence in natural communities, for agriculture and environmental sustainability, and for food security. In this review, we discuss recent ...progress in climatic adaptation in plants. We evaluate whether climate change exerts novel selection and disrupts local adaptation, whether gene flow can facilitate adaptive responses to climate change, and whether adaptive phenotypic plasticity could sustain populations in the short term. Furthermore, we discuss how climate change influences species interactions. Through a more in‐depth understanding of these eco‐evolutionary dynamics, we will increase our capacity to predict the adaptive potential of plants under climate change. In addition, we review studies that dissect the genetic basis of plant adaptation to climate change. Finally, we highlight key research gaps, ranging from validating gene function to elucidating molecular mechanisms, expanding research systems from model species to other natural species, testing the fitness consequences of alleles in natural environments, and designing multifactorial studies that more closely reflect the complex and interactive effects of multiple climate change factors. By leveraging interdisciplinary tools (e.g., cutting‐edge omics toolkits, novel ecological strategies, newly developed genome editing technology), researchers can more accurately predict the probability that species can persist through this rapid and intense period of environmental change, as well as cultivate crops to withstand climate change, and conserve biodiversity in natural systems.
Contemporary climate change is proceeding at an unprecedented rate. The question remains whether populations adapted to historical conditions can persist under rapid environmental change. We tested ...whether climate change will disrupt local adaptation and reduce population growth rates using the perennial plant Boechera stricta (Brassicaceae). In a large‐scale field experiment conducted over five years, we exposed > 106 000 transplants to historical, current, or future climates and quantified fitness components. Low‐elevation populations outperformed local populations under simulated climate change (snow removal) across all five experimental gardens. Local maladaptation also emerged in control treatments, but it was less pronounced than under snow removal. We recovered local adaptation under snow addition treatments, which reflect historical conditions. Our results revealed that low elevation populations risk rapid decline, whereas upslope migration could enable population persistence and expansion at higher elevation locales. Local adaptation to historical conditions could increase vulnerability to climate change, even for geographically widespread species.
Here, we provide direct evidence that climate change has disrupted long‐standing patterns of local adaptation, favoring plants that evolved under hot and dry conditions. Previous empirical studies have suggested that climate change may induce maladaptation, but they have not included direct manipulations of climatic factors to document the extent to which populations were historically locally adapted or the degree to which climate change alters those patterns. Our revised manuscript fills key gaps in the literature by experimentally (1) recovering local adaptation under historical climate conditions, (2) establishing that climate change had already generated maladaptation and will continue to do so, and (3) revealing that upslope and migration could rescue populations demographically.
Premise
Global change has changed resource availability to plants, which could shift the adaptive landscape. We hypothesize that novel water and nutrient availability combinations alter patterns of ...natural selection on reproductive phenology in Boechera stricta (Brassicaceae) and influence the evolution of local adaptation.
Methods
We conducted a multifactorial greenhouse study using 35 accessions of B. stricta sourced from a broad elevational gradient in the Rocky Mountains. We exposed full siblings to three soil water and two nutrient availability treatment levels, reflecting current and projected future conditions. In addition, we quantified fitness (seed count) and four phenological traits: the timing of first flowering, the duration of flowering, and height and leaf number at flowering.
Results
Selection favored early flowering and longer duration of flowering, and the genetic correlation between these traits accorded with the direction of selection. In most treatments, we found selection for increased height, but selection on leaf number depended on water availability, with selection favoring more leaves in well‐watered conditions and fewer leaves under severe drought. Low‐elevation genotypes had the greatest fitness under drought stress, consistent with local adaptation.
Conclusions
We found evidence of strong selection on these heritable traits. Furthermore, the direction and strength of selection on size at flowering depended on the variable measured (height vs. leaf number). Finally, selection often favored both early flowering and a longer duration of flowering. Selection on these two components of phenology can be difficult to disentangle due to tight genetic correlations.
Environmental variation often induces shifts in functional traits, yet we know little about whether plasticity will reduce extinction risks under climate change. As climate change proceeds, ...phenotypic plasticity could enable species with limited dispersal capacity to persist in situ, and migrating populations of other species to establish in new sites at higher elevations or latitudes. Alternatively, climate change could induce maladaptive plasticity, reducing fitness, and potentially stalling adaptation and migration. Here, we quantified plasticity in life history, foliar morphology, and ecophysiology in Boechera stricta (Brassicaceae), a perennial forb native to the Rocky Mountains. In this region, warming winters are reducing snowpack and warming springs are advancing the timing of snow melt. We hypothesized that traits that were historically advantageous in hot and dry, low‐elevation locations will be favored at higher elevation sites due to climate change. To test this hypothesis, we quantified trait variation in natural populations across an elevational gradient. We then estimated plasticity and genetic variation in common gardens at two elevations. Finally, we tested whether climatic manipulations induce plasticity, with the prediction that plants exposed to early snow removal would resemble individuals from lower elevation populations. In natural populations, foliar morphology and ecophysiology varied with elevation in the predicted directions. In the common gardens, trait plasticity was generally concordant with phenotypic clines from the natural populations. Experimental snow removal advanced flowering phenology by 7 days, which is similar in magnitude to flowering time shifts over 2–3 decades of climate change. Therefore, snow manipulations in this system can be used to predict eco‐evolutionary responses to global change. Snow removal also altered foliar morphology, but in unexpected ways. Extensive plasticity could buffer against immediate fitness declines due to changing climates.
Evolutionary genetics of plant adaptation Anderson, Jill T; Willis, John H; Mitchell-Olds, Thomas
Trends in genetics,
07/2011, Letnik:
27, Številka:
7
Journal Article
Recenzirano
Odprti dostop
Plants provide unique opportunities to study the mechanistic basis and evolutionary processes of adaptation to diverse environmental conditions. Complementary laboratory and field experiments are ...important for testing hypotheses reflecting long-term ecological and evolutionary history. For example, these approaches can infer whether local adaptation results from genetic tradeoffs (antagonistic pleiotropy), where native alleles are best adapted to local conditions, or if local adaptation is caused by conditional neutrality at many loci, where alleles show fitness differences in one environment, but not in a contrasting environment. Ecological genetics in natural populations of perennial or outcrossing plants can also differ substantially from model systems. In this review of the evolutionary genetics of plant adaptation, we emphasize the importance of field studies for understanding the evolutionary dynamics of model and nonmodel systems, highlight a key life history trait (flowering time) and discuss emerging conservation issues.
Anthropogenic climate change has already altered the timing of major life-history transitions, such as the initiation of reproduction. Both phenotypic plasticity and adaptive evolution can underlie ...rapid phenological shifts in response to climate change, but their relative contributions are poorly understood. Here, we combine a continuous 38 year field survey with quantitative genetic field experiments to assess adaptation in the context of climate change. We focused on Boechera stricta (Brassicaeae), a mustard native to the US Rocky Mountains. Flowering phenology advanced significantly from 1973 to 2011, and was strongly associated with warmer temperatures and earlier snowmelt dates. Strong directional selection favoured earlier flowering in contemporary environments (2010–2011). Climate change could drive this directional selection, and promote even earlier flowering as temperatures continue to increase. Our quantitative genetic analyses predict a response to selection of 0.2 to 0.5 days acceleration in flowering per generation, which could account for more than 20 per cent of the phenological change observed in the long-term dataset. However, the strength of directional selection and the predicted evolutionary response are likely much greater now than even 30 years ago because of rapidly changing climatic conditions. We predict that adaptation will likely be necessary for long-term in situ persistence in the context of climate change.
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