Genetic response of a perennial grass to warm and wet environments interacts and is associated with trait means as well as plasticity.

The potential for rapid evolution is an important mechanism allowing species to adapt to changing climatic conditions. Although such potential has been largely studied in various short-lived organisms, to what extent we can observe similar patterns in long-lived plant species, which often dominate natural systems, is largely unexplored. We explored the potential for rapid evolution in Festuca rubra, a long-lived grass with extensive clonal growth dominating in alpine grasslands. We used a field sowing experiment simulating expected climate change in our model region. Specifically, we exposed seeds from five independent seed sources to novel climatic conditions by shifting them along a natural climatic grid and explored the genetic profiles of established seedlings after 3 years. Data on genetic profiles of plants selected under different novel conditions indicate that different climate shifts select significantly different pools of genotypes from common seed pools. Increasing soil moisture was more important than increasing temperature or the interaction of the two climatic factors in selecting pressure. This can indicate negative genetic interaction in response to the combined effects or that the effects of different climates are interactive rather than additive. The selected alleles were found in genomic regions, likely affecting the function of specific genes or their expression. Many of these were also linked to morphological traits (mainly to trait plasticity), suggesting these changes may have a consequence on plant performance. Overall, these data indicate that even long-lived plant species may experience strong selection by climate, and their populations thus have the potential to rapidly adapt to these novel conditions.

Plant effects on microbiome composition are constrained by environmental conditions in a successional grassland.

BACKGROUND: Below-ground microbes mediate key ecosystem processes and play a vital role in plant nutrition and health. Understanding the composition of the belowground microbiome is therefore important for maintaining ecosystem stability. The structure of the belowground microbiome is largely determined by individual plants, but it is not clear how far their influence extends and, conversely, what the influence of other plants growing nearby is. RESULTS: To determine the extent to which a focal host plant influences its soil and root microbiome when growing in a diverse community, we sampled the belowground bacterial and fungal communities of three plant species across a primary successional grassland sequence. The magnitude of the host effect on its belowground microbiome varied among microbial groups, soil and root habitats, and successional stages characterized by different levels of diversity of plant neighbours. Soil microbial communities were most strongly structured by sampling site and showed significant spatial patterns that were partially driven by soil chemistry. The influence of focal plant on soil microbiome was low but tended to increase with succession and increasing plant diversity. In contrast, root communities, particularly bacterial, were strongly structured by the focal plant species. Importantly, we also detected a significant effect of neighbouring plant community composition on bacteria and fungi associating with roots of the focal plants. The host influence on root microbiome varied across the successional grassland sequence and was highest in the most diverse site. CONCLUSIONS: Our results show that in a species rich natural grassland, focal plant influence on the belowground microbiome depends on environmental context and is modulated by surrounding plant community. The influence of plant neighbours is particularly pronounced in root communities which may have multiple consequences for plant community productivity and stability, stressing the importance of plant diversity for ecosystem functioning.

Global warming alters Himalayan alpine shrub growth dynamics and climate sensitivity.

Global climate change is having significant effects on plant growth patterns and mountain plants can be particularly vulnerable to accelerated warming. Rising temperatures are releasing plants from cold limitation, such as at high elevations and latitudes, but can also induce drought limitation, as documented for trees from lower elevations and latitudes. Here we test these predictions using a unique natural experiment with Himalayan alpine shrub Rhododendron anthopogon and its growth responses to changing climate over a large portion of its latitudinal and elevational ranges, including steep precipitation and temperature gradients. We determined growth dynamics during the last three decades, representing period of accelerated warming, using annual radial growth increments for nine populations growing on both wet and warm southern localities and drier and cold northern localities in the Himalayas along elevation gradients encompassing the lower and upper species range limits. A significant growth increase over past decades was observed after controlling for confounding effect of shrub age and microsites. However, the magnitude of increase varied among populations. Particularly, populations situated in the lower elevation of the northernmost (cold and dry) locality exhibited most substantial growth enhancement. The relationship between growth variability and climate varied among populations, with the populations from the coldest location displaying the strongest responsiveness to increasing minimum temperatures during July. Minimum temperatures of April and August were the most important factor limiting the growth across most populations. Potential warming-induced drought limitation had no significant impact on growth variation in any part of the species geographic range. Overall, our findings indicate that plant growth is continuously increasing in recent decades and growth-climate relationships are not consistent across populations, with populations from the coldest and wettest localities showing stronger responses. The observed patterns suggest that dwarf-shrubs benefit from ongoing warming, leading to increased shrubification of high elevation alpine ecosystems.

DNA methylation in the wild: epigenetic transgenerational inheritance can mediate adaptation in clones of wild strawberry (Fragaria vesca).

Due to the accelerating climate change, it is crucial to understand how plants adapt to rapid environmental changes. Such adaptation may be mediated by epigenetic mechanisms like DNA methylation, which could heritably alter phenotypes without changing the DNA sequence, especially across clonal generations. However, we are still missing robust evidence of the adaptive potential of DNA methylation in wild clonal populations. Here, we studied genetic, epigenetic and transcriptomic variation of Fragaria vesca, a predominantly clonally reproducing herb. We examined samples from 21 natural populations across three climatically distinct geographic regions, as well as clones of the same individuals grown in a common garden. We found that epigenetic variation was partly associated with climate of origin, particularly in non-CG contexts. Importantly, a large proportion of this variation was heritable across clonal generations. Additionally, a subset of these epigenetic changes affected the expression of genes mainly involved in plant growth and responses to pathogen and abiotic stress. These findings highlight the potential influence of epigenetic changes on phenotypic traits. Our findings indicate that variation in DNA methylation, which can be environmentally inducible and heritable, may enable clonal plant populations to adjust to their environmental conditions even in the absence of genetic adaptation.

Species phylogeny, ecology, and root traits as predictors of root exudate composition.

Root traits including root exudates are key factors affecting plant interactions with soil and thus play an important role in determining ecosystem processes. The drivers of their variation, however, remain poorly understood. We determined the relative importance of phylogeny and species ecology in determining root traits and analyzed the extent to which root exudate composition can be predicted by other root traits. We measured different root morphological and biochemical traits (including exudate profiles) of 65 plant species grown in a controlled system. We tested phylogenetic conservatism in traits and disentangled the individual and overlapping effects of phylogeny and species ecology on traits. We also predicted root exudate composition using other root traits. Phylogenetic signal differed greatly among root traits, with the strongest signal in phenol content in plant tissues. Interspecific variation in root traits was partly explained by species ecology, but phylogeny was more important in most cases. Species exudate composition could be partly predicted by specific root length, root dry matter content, root biomass, and root diameter, but a large part of variation remained unexplained. In conclusion, root exudation cannot be easily predicted based on other root traits and more comparative data on root exudation are needed to understand their diversity.

Response of Fragaria vesca to projected change in temperature, water availability and concentration of CO2 in the atmosphere.

The high rate of climate change may soon expose plants to conditions beyond their adaptation limits. Clonal plants might be particularly affected due to limited genotypic diversity of their populations, potentially decreasing their adaptability. We therefore tested the ability of a widely distributed predominantly clonally reproducing herb (Fragaria vesca) to cope with periods of drought and flooding in climatic conditions predicted to occur at the end of the twenty-first century, i.e. on average 4 °C warmer and with twice the concentration of CO2 in the air (800 ppm) than the current state. We found that F. vesca can phenotypically adjust to future climatic conditions, although its drought resistance may be reduced. Increased temperature and CO2 levels in the air had a far greater effect on growth, phenology, reproduction, and gene expression than the temperature increase itself, and promoted resistance of F. vesca to repeated flooding periods. Higher temperature promoted clonal over sexual reproduction, and increased temperature and CO2 concentration in the air triggered change in expression of genes controlling the level of self-pollination. We conclude that F. vesca can acclimatise to predicted climate change, but the increased ratio of clonal to sexual reproduction and the alteration of genes involved in the self-(in)compatibility system may be associated with reduced genotypic diversity of its populations, which may negatively impact its ability to genetically adapt to novel climate in the long-term.

Plant community stability is associated with a decoupling of prokaryote and fungal soil networks.

Soil microbial networks play a crucial role in plant community stability. However, we lack knowledge on the network topologies associated with stability and the pathways shaping these networks. In a 13-year mesocosm experiment, we determined links between plant community stability and soil microbial networks. We found that plant communities on soil abandoned from agricultural practices 60 years prior to the experiment promoted destabilising properties and were associated with coupled prokaryote and fungal soil networks. This coupling was mediated by strong interactions of plants and microbiota with soil resource cycling. Conversely, plant communities on natural grassland soil exhibited a high stability, which was associated with decoupled prokaryote and fungal soil networks. This decoupling was mediated by a large variety of past plant community pathways shaping especially fungal networks. We conclude that plant community stability is associated with a decoupling of prokaryote and fungal soil networks and mediated by plant-soil interactions.

Plant-soil interactions in the native range of two congeneric species with contrasting invasive success.

The aim of this study was to compare plant-soil interactions in the native range of two congeneric European species differing in their invasive success in the world: a globally invasive Cirsium vulgare and non-invasive C. oleraceum. We assessed changes in soil nutrients and soil biota following soil conditioning by each species and compared performance of plants grown in self-conditioned and unconditioned soil, from which all, some or no biota was excluded. The invasive species depleted more nutrients than the non-invasive species and coped better with altered nutrient levels. The invasive species had higher seedling establishment which benefited from the presence of unconditioned biota transferred by soil filtrate. Biomass of both species increased in soil with self-conditioned soil filtrate and decreased in soil with self-conditioned whole-soil inoculum compared to unconditioned filtrate and inoculum. However, the increase was smaller and the decrease greater for the invasive species. The invasive species allocated less biomass to roots when associated with harmful biota, reducing negative effects of the biota on its performance. The results show that in the native range the invasive species is more limited by self-conditioned pathogens and benefits more from unconditioned mutualists and thus may benefit more from loss of effectively specialized soil biota in a secondary range. Our study highlights the utility of detailed plant-soil feedback research in species native range for understanding factors regulating species performance in their native range and pinpointing the types of biota involved in their regulation.

Multiple introductions, polyploidy and mixed reproductive strategies are linked to genetic diversity and structure in the most widespread invasive plant across Southern Ocean archipelagos.

Biological invasions in remote areas that experience low human activity provide unique opportunities to elucidate processes responsible for invasion success. Here we study the most widespread invasive plant species across the isolated islands of the Southern Ocean, the annual bluegrass, Poa annua. To analyse geographical variation in genome size, genetic diversity and reproductive strategies, we sampled all major sub-Antarctic archipelagos in this region and generated microsatellite data for 470 individual plants representing 31 populations. We also estimated genome sizes for a subset of individuals using flow cytometry. Occasional events of island colonization are expected to result in high genetic structure among islands, overall low genetic diversity and increased self-fertilization, but we show that this is not the case for P. annua. Microsatellite data indicated low population genetic structure and lack of isolation by distance among the sub-Antarctic archipelagos we sampled, but high population structure within each archipelago. We identified high levels of genetic diversity, low clonality and low selfing rates in sub-Antarctic P. annua populations (contrary to rates typical of continental populations). In turn, estimates of selfing declined in populations as genetic diversity increased. Additionally, we found that most P. annua individuals are probably tetraploid and that only slight variation exists in genome size across the Southern Ocean. Our findings suggest multiple independent introductions of P. annua into the sub-Antarctic, which promoted the establishment of genetically diverse populations. Despite multiple introductions, the adoption of convergent reproductive strategies (outcrossing) happened independently in each major archipelago. The combination of polyploidy and a mixed reproductive strategy probably benefited P. annua in the Southern Ocean by increasing genetic diversity and its ability to cope with the novel environmental conditions.

Effect of DNA methylation, modified by 5-azaC, on ecophysiological responses of a clonal plant to changing climate.

Epigenetic regulation of gene expression is expected to be an important mechanism behind phenotypic plasticity. Whether epigenetic regulation affects species ecophysiological adaptations to changing climate remains largely unexplored. We compared ecophysiological traits between individuals treated with 5-azaC, assumed to lead to DNA demethylation, with control individuals of a clonal grass originating from and grown under different climates, simulating different directions and magnitudes of climate change. We linked the ecophysiological data to proxies of fitness. Main effects of plant origin and cultivating conditions predicted variation in plant traits, but 5-azaC did not. Effects of 5-azaC interacted with conditions of cultivation and plant origin. The direction of the 5-azaC effects suggests that DNA methylation does not reflect species long-term adaptations to climate of origin and species likely epigenetically adjusted to the conditions experienced during experiment set-up. Ecophysiology translated to proxies of fitness, but the intensity and direction of the relationships were context dependent and affected by 5-azaC. The study suggests that effects of DNA methylation depend on conditions of plant origin and current climate. Direction of 5-azaC effects suggests limited role of epigenetic modifications in long-term adaptation of plants. It rather facilitates fast adaptations to temporal fluctuations of the environment.

Time dynamics of stress legacy in clonal transgenerational effects: A case study on Trifolium repens.

Stress can be remembered by plants in a form of stress legacy that can alter future phenotypes of previously stressed plants and even phenotypes of their offspring. DNA methylation belongs among the mechanisms mediating the stress legacy. It is however not known for how long the stress legacy is carried by plants. If the legacy is long-lasting, it can become maladaptive in situations when parental-offspring environment do not match. We investigated for how long after the last exposure of a parental plant to drought can the phenotype of its clonal offspring be altered. We grew parental plants of three genotypes of Trifolium repens for five months either in control conditions or in control conditions that were interrupted with intense drought periods applied for two months in four different time slots. We also treated half of the parental plants with a demethylating agent (5-azacytidine, 5-azaC) to test for the potential role of DNA methylation in the stress memory. Then, we transplanted parental cuttings (ramets) individually to control environment and allowed them to produce offspring ramets for two months. The drought stress experienced by parents affected phenotypes of offspring ramets. The stress legacy resulted in enhanced number of offspring ramets originating from plants that experienced drought stress even 56 days before their transplantation to the control environment. 5-azaC altered transgenerational effects on offspring ramets. We confirmed that drought stress can trigger transgenerational effects in T. repens that is very likely mediated by DNA methylation. Most importantly, the stress legacy in parental plants persisted for at least 8 weeks suggesting that the stress legacy can persist in a clonal plant Trifolium repens for relatively long period. We suggest that the stress legacy should be considered in future ecological studies on clonal plants.

The role of plant-soil feedback in long-term species coexistence cannot be predicted from its effects on plant performance.

BACKGROUND: Despite many studies on the importance of competition and plants' associations with mutualists and pathogens on plant performance and community organization, the joint effects of these two factors remain largely unexplored. Even less is known about how these joint effects vary through a plant's life in different environmental conditions and how they contribute to the long-term coexistence of species. METHODS: We investigated the role of plant-soil feedback (PSF) in intra- and interspecific competition, using two co-occurring dry grassland species as models. A two-phase PSF experiment was used. In the first phase, soil was conditioned by the two plant species. In the second, we assessed the effect of soil conditioning, competition and drought stress on seedling establishment, plant growth in the first and second vegetation season, and fruit production. We also estimated effects of different treatments on overall population growth rates and predicted the species' potential coexistence. RESULTS: Soil conditioning played a more important role in the early stages of the plants' life (seedling establishment and early growth) than competition. Specifically, we found strong negative intraspecific PSF for biomass production in the first year in both species. Although the effects of soil conditioning persisted in later stages of plant's life, competition and drought stress became more important. Surprisingly, models predicting species coexistence contrasted with the effects on individual life stages, showing that our model species benefit from their self-conditioned soil in the long run. CONCLUSIONS: We provide evidence that the effects of PSF vary through plants' life stages. Our study suggests that we cannot easily predict the effects of soil conditioning on long-term coexistence of species using data only on performance at a single time as commonly done in PSF studies. We also show the importance of using as realistic environmental conditions as possible (such as drought stress experienced in dry grasslands) to draw reasonable conclusions on species coexistence.

DNA Methylation Can Mediate Local Adaptation and Response to Climate Change in the Clonal Plant Fragaria vesca: Evidence From a European-Scale Reciprocal Transplant Experiment.

The ongoing climate crisis represents a growing threat for plants and other organisms. However, how and if plants will be able to adapt to future environmental conditions is still debated. One of the most powerful mechanisms allowing plants to tackle the changing climate is phenotypic plasticity, which can be regulated by epigenetic mechanisms. Environmentally induced epigenetic variation mediating phenotypic plasticity might be heritable across (a)sexual generations, thus potentially enabling rapid adaptation to climate change. Here, we assessed whether epigenetic mechanisms, DNA methylation in particular, enable for local adaptation and response to increased and/or decreased temperature of natural populations of a clonal plant, Fragaria vesca (wild strawberry). We collected ramets from three populations along a temperature gradient in each of three countries covering the southern (Italy), central (Czechia), and northern (Norway) edges of the native European range of F. vesca. After clonal propagation and alteration of DNA methylation status of half of the plants via 5-azacytidine, we reciprocally transplanted clones to their home locality and to the other two climatically distinct localities within the country of their origin. At the end of the growing season, we recorded survival and aboveground biomass as fitness estimates. We found evidence for local adaptation in intermediate and cold populations in Italy and maladaptation of plants of the warmest populations in all countries. Plants treated with 5-azacytidine showed either better or worse performance in their local conditions than untreated plants. Application of 5-azacytidine also affected plant response to changed climatic conditions when transplanted to the colder or warmer locality than was their origin, and the response was, however, country-specific. We conclude that the increasing temperature will probably be the limiting factor determining F. vesca survival and distribution. DNA methylation may contribute to local adaptation and response to climatic change in natural ecosystems; however, its role may depend on the specific environmental conditions. Since adaptation mediated by epigenetic variation may occur faster than via natural selection on genetic variants, epigenetic adaptation might to some degree help plants in keeping up with the ongoing environmental crisis.

Rhizome trait scaling relationships are modulated by growth conditions and are linked to plant fitness.

BACKGROUND AND AIMS: Rhizomes are important organs allowing many clonal plants to persist and reproduce under stressful climates with longer rhizomes, indicating enhanced ability of the plants to spread vegetatively. We do not, however, know either how rhizome construction costs change with increasing length or how they vary with environmental conditions. METHODS: We analysed the rhizome length vs. mass scaling relationship, the plasticity in the scaling relationships, their genetic basis and how scaling relationships are linked to plant fitness. We used data from 275 genotypes of a clonal grass Festuca rubra originating from 11 localities and cultivated under four contrasting climates. Data were analysed using standard major axis regression, mixed-effect regression models and a structural equation model. KEY RESULTS: Rhizome construction costs increased (i.e. lower specific rhizome length) with increasing length. The trait scaling relationships were modulated by cultivation climate, and its effects also interacted with the climate of origin of the experimental plants. With increasing length, increasing moisture led to a greater increase in rhizome construction costs. Plants with lower rhizome construction costs showed significantly higher fitness. CONCLUSIONS: This study suggests that rhizome scaling relationships are plastic, but also show genetic differentiation and are linked to plant fitness. Therefore, to persist under variable environments, modulation in scaling relationships could be an important plant strategy.

Human activity strongly influences genetic dynamics of the most widespread invasive plant in the sub-Antarctic.

The link between the successful establishment of alien species and propagule pressure is well-documented. Less known is how humans influence the post-introduction dynamics of invasive alien populations. The latter requires studying parallel invasions by the same species in habitats that are differently impacted by humans. We analysed microsatellite and genome size variation, and then compared the genetic diversity and structure of invasive Poa annua L. on two sub-Antarctic islands: human-occupied Marion Island and unoccupied Prince Edward Island. We also carried out niche modelling to map the potential distribution of the species on both islands. We found high levels of genetic diversity and evidence for extensive admixture between genetically distinct lineages of P. annua on Marion Island. By contrast, the Prince Edward Island populations showed low genetic diversity, no apparent admixture, and had smaller genomes. On both islands, high genetic diversity was apparent at human landing sites, and on Marion Island, also around human settlements, suggesting that these areas received multiple introductions and/or acted as initial introduction sites and secondary sources (bridgeheads) for invasive populations. More than 70 years of continuous human activity associated with a meteorological station on Marion Island led to a distribution of this species around human settlements and along footpaths, which facilitates ongoing gene flow among geographically separated populations. By contrast, this was not the case for Prince Edward Island, where P. annua populations showed high genetic structure. The high levels of genetic variation and admixture in P. annua facilitated by human activity, coupled with high habitat suitability on both islands, suggest that P. annua is likely to increase its distribution and abundance in the future.

The importance of ecophysiological traits in response of Festuca rubra to changing climate.

Knowledge of the ability of plants to respond to climate change via phenotypic plasticity or genetic adaptation in ecophysiological traits and of the link of these traits to fitness is still limited. We studied the clonal grass Festuca rubra from 11 localities representing factorially crossed gradients of temperature and precipitation and cultivated them in growth chambers simulating temperature and moisture regime in the four extreme localities. We measured net photosynthetic rate, Fv /Fm , specific leaf area, osmotic potential and stomatal density and length and tested their relationship to proxies of fitness. We found strong phenotypic plasticity in photosynthetic traits and genetic differentiation in stomatal traits. The effects of temperature and moisture interacted (either as conditions of origin or growth chambers), as were effects of growth and origin. The relationships between the ecophysiological and fitness-related traits were significant but weak. Phenotypic plasticity and genetic differentiation of the species indicate the potential ability of F. rubra to adapt to novel climatic conditions. The most important challenge for the plants seems to be increasing moisture exposing plants to hypoxia. However, the plants have the potential to respond to increased moisture by changes in stomatal size and density and adjustments of osmotic potential. Changes in ecophysiological traits translate into variation in plant fitness, but the selection on the traits is relatively weak and depends on actual conditions. Despite the selection, the plants do not show strong local adaptation and local adaptation is thus likely not restricting species ability to adjust to novel conditions.

Quantifying patch-specific seed dispersal and local population dynamics to estimate population spread of an endangered plant species.

AIM: Habitat loss and fragmentation impose high extinction risk upon endangered plant species globally. For many endangered plant species, as the remnant habitats become smaller and more fragmented, it is vital to estimate the population spread rate of small patches in order to effectively manage and preserve them for potential future range expansion. However, population spread rate has rarely been quantified at the patch level to inform conservation strategies and management decisions. To close this gap, we quantify the patch-specific seed dispersal and local population dynamics of Minuartia smejkalii, which is a critically endangered plant species endemic in the Czech Republic and is of urgent conservation concern. LOCATION: Zelivka and Hrncíre, Czechia. METHODS: We conducted demographic analyses using population projection matrices with long-term demographic data and used an analytic mechanistic dispersal model to simulate seed dispersal. We then used information on local population dynamics and seed dispersal to estimate the population spread rate and compared the relative contributions of seed dispersal and population growth rate to the population spread rate. RESULTS: We found that although both seed dispersal and population growth rate in M. smejkalii were critically limited, the population spread rate depended more strongly on the maximal dispersal distance than on the population growth rate. MAIN CONCLUSIONS: We recommend conservationists to largely increase the dispersal distance of M. smejkalii. Generally, efforts made to increase seed dispersal ability could largely raise efficiency and effectiveness of conservation actions for critically endangered plant species.

Phenotypic plasticity masks range-wide genetic differentiation for vegetative but not reproductive traits in a short-lived plant.

Genetic differentiation and phenotypic plasticity jointly shape intraspecific trait variation, but their roles differ among traits. In short-lived plants, reproductive traits may be more genetically determined due to their impact on fitness, whereas vegetative traits may show higher plasticity to buffer short-term perturbations. Combining a multi-treatment greenhouse experiment with observational field data throughout the range of a widespread short-lived herb, Plantago lanceolata, we (1) disentangled genetic and plastic responses of functional traits to a set of environmental drivers and (2) assessed how genetic differentiation and plasticity shape observational trait-environment relationships. Reproductive traits showed distinct genetic differentiation that largely determined observational patterns, but only when correcting traits for differences in biomass. Vegetative traits showed higher plasticity and opposite genetic and plastic responses, masking the genetic component underlying field-observed trait variation. Our study suggests that genetic differentiation may be inferred from observational data only for the traits most closely related to fitness.

Evolutionary Rescue as a Mechanism Allowing a Clonal Grass to Adapt to Novel Climates.

Filing gaps in our understanding of species' abilities to adapt to novel climates is a key challenge for predicting future range shifts and biodiversity loss. Key knowledge gaps are related to the potential for evolutionary rescue in response to climate, especially in long-lived clonally reproducing species. We illustrate a novel approach to assess the potential for evolutionary rescue using a combination of reciprocal transplant experiment in the field to assess performance under a changing climate and independent growth chamber assays to assess growth- and physiology-related plant trait maxima and plasticities of the same clones. We use a clonal grass, Festuca rubra, as a model species. We propagated individual clones and used them in a transplant experiment across broad-scale temperature and precipitation gradients, simulating the projected direction of climate change in the region. Independent information on trait maxima and plasticities of the same clones was obtained by cultivating them in four growth chambers representing climate extremes. Plant survival was affected by interaction between plant traits and climate change, with both trait plasticities and maxima being important for adaptation to novel climates. Key traits include plasticity in extravaginal ramets, aboveground biomass, and osmotic potential. The direction of selection in response to a given climatic change detected in this study mostly contradicted the natural trait clines indicating that short-term selection pressure as identified here does not match long-term selection outcomes. Long-lived clonal species exposed to different climatic changes are subjected to consistent selection pressures on key traits, a necessary condition for adaptation to novel conditions. This points to evolutionary rescue as an important mechanism for dealing with climate change in these species. Our experimental approach may be applied also in other model systems broadening our understanding of evolutionary rescue. Such knowledge cannot be easily deduced from observing the existing field clines.

Maternal effects strengthen interactions of temperature and precipitation, determining seed germination of dominant alpine grass species.

PREMISE: Despite the existence of many studies on the responses of plant species to climate change, there is a knowledge gap on how specific climatic factors and their interactions regulate seed germination in alpine species. This understanding is complicated by the interplay between responses of seeds to the environment experienced during germination, the environment experienced by the maternal plant during seed development and genetic adaptations of the maternal plant to its environment of origin. METHODS: The study species (Anthoxanthum alpinum, A. odoratum) originated from localities with factorial combinations of temperature and precipitation. Seed germination was tested in conditions simulating the extreme ends of the current field conditions and a climate change scenario. We compared the performance of field-collected seeds with that of garden-collected seeds. RESULTS: A change to warmer and wetter conditions resulted in the highest germination of A. alpinum, while A. odoratum germinated the most in colder temperature and with home moisture. The maternal environment did have an impact on plant performance of the study species. Field-collected seeds of A. alpinum tolerated warmer conditions better than those from the experimental garden. CONCLUSIONS: The results demonstrate how knowledge of responses to climate change can increase our ability to understand and predict the fate of alpine species. Studies that aim to understand the germination requirements of seeds under future climates should use experimental designs allowing the separation of genetic differentiation, plasticity and maternal effects and their interactions, since all these mechanisms play an important role in driving species' germination patterns.