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2.
Ann Bot ; 2020 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-32016374

RESUMO

BACKGROUND AND AIMS: Plants experiencing contrasting environmental conditions may accommodate such heterogeneity by expressing phenotypic plasticity, evolving local adaptation or a combination of both. We investigated patterns of genetic differentiation and plasticity in response to drought in populations of the gypsum specialist Lepidium subulatum. METHODS: We created an outdoor common garden with rain-exclusion structures using 60 maternal progenies from four distinct populations that substantially differ in climatic conditions. We characterized fitness, life-history, and functional plasticity in response to two contrasting treatments that realistically reflect soil moisture variation in gypsum habitats. We also assessed neutral genetic variation and population structure using microsatellite markers. KEY RESULTS: In response to water stress, plants from all populations flowered earlier, increased allocation to root tissues and advanced leaf senescence, consistent with a drought escape strategy. Remarkably, these likely plastic responses were common to all populations, as shown by the lack of population by environment interaction (P × E) for almost all functional traits. This generally-common pattern of response was consistent with substantial neutral genetic variation and large differences in population trait means. However, such population-level trait variation was not related to climatic conditions at the sites of origin. CONCLUSIONS: Our results show that, rather than ecotypes specialized to local climatic conditions, these populations are composed of highly plastic, general-purpose genotypes in relation to climatic heterogeneity. The strikingly similar patterns of plasticity among populations, despite substantial site-of-origin differences in climate, suggest past selection on a common norm of reaction due to similarly high levels of variation within sites. It is thus likely that plasticity will have a prevalent role in the response of this soil specialist to further environmental change.

3.
Sci Data ; 7(1): 1, 2020 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-31896794

RESUMO

The dataset presented here was collected by the GenTree project (EU-Horizon 2020), which aims to improve the use of forest genetic resources across Europe by better understanding how trees adapt to their local environment. This dataset of individual tree-core characteristics including ring-width series and whole-core wood density was collected for seven ecologically and economically important European tree species: silver birch (Betula pendula), European beech (Fagus sylvatica), Norway spruce (Picea abies), European black poplar (Populus nigra), maritime pine (Pinus pinaster), Scots pine (Pinus sylvestris), and sessile oak (Quercus petraea). Tree-ring width measurements were obtained from 3600 trees in 142 populations and whole-core wood density was measured for 3098 trees in 125 populations. This dataset covers most of the geographical and climatic range occupied by the selected species. The potential use of it will be highly valuable for assessing ecological and evolutionary responses to environmental conditions as well as for model development and parameterization, to predict adaptability under climate change scenarios.

4.
Ecol Lett ; 22(9): 1472-1482, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31270929

RESUMO

Plant diversity fosters productivity in natural ecosystems. Biodiversity effects might increase agricultural yields at no cost in additional inputs. However, the effects of diversity on crop assemblages are inconsistent, probably because crops and wild plants differ in a range of traits relevant to plant-plant interactions. We tested whether domestication has changed the potential of crop mixtures to over-yield by comparing the performance and traits of major crop species and those of their wild progenitors under varying levels of diversity. We found stronger biodiversity effects in mixtures of wild progenitors, due to larger selection effects. Variation in selection effects was partly explained by within-mixture differences in leaf size. Our results indicate that domestication might disrupt the ability of crops to benefit from diverse neighbourhoods via reduced trait variance. These results highlight potential limitations of current crop mixtures to over-yield and the potential of breeding to re-establish variance and increase mixture performance.


Assuntos
Biodiversidade , Produtos Agrícolas/genética , Domesticação , Produtos Agrícolas/crescimento & desenvolvimento , Fenótipo , Melhoramento Vegetal
5.
Mol Ecol Resour ; 19(5): 1265-1277, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31232514

RESUMO

Most work on plant community ecology has been performed above ground, neglecting the processes that occur in the soil. DNA metabarcoding, in which multiple species are computationally identified in bulk samples, can help to overcome the logistical limitations involved in sampling plant communities belowground. However, a major limitation of this methodology is the quantification of species' abundances based on the percentage of sequences assigned to each taxon. Using root tissues of five dominant species in a semi-arid Mediterranean shrubland (Bupleurum fruticescens, Helianthemum cinereum, Linum suffruticosum, Stipa pennata and Thymus vulgaris), we built pairwise mixtures of relative abundance (20%, 50% and 80% biomass), and implemented two methods (linear model fits and correction indices) to improve estimates of root biomass. We validated both methods with multispecies mixtures that simulate field-collected samples. For all species, we found a positive and highly significant relationship between the percentage of sequences and biomass in the mixtures (R2  = .44-.66), but the equations for each species (slope and intercept) differed among them, and two species were consistently over- and under-estimated. The correction indices greatly improved the estimates of biomass percentage for all five species in the multispecies mixtures, and reduced the overall error from 17% to 6%. Our results show that, through the use of post-sequencing quantification methods on mock communities, DNA metabarcoding can be effectively used to determine not only species' presence but also their relative abundance in field samples of root mixtures. Importantly, knowledge of these aspects will allow us to study key, yet poorly understood, belowground processes.


Assuntos
Biota , Código de Barras de DNA Taxonômico/métodos , Metagenômica/métodos , Plantas/classificação , Plantas/genética , DNA de Plantas/genética , Raízes de Plantas/classificação , Raízes de Plantas/genética
6.
Ecol Evol ; 7(18): 7231-7242, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28944013

RESUMO

The effect of population size on population genetic diversity and structure has rarely been studied jointly with other factors such as the position of a population within the species' distribution range or the presence of mutualistic partners influencing dispersal. Understanding these determining factors for genetic variation is critical for conservation of relict plants that are generally suffering from genetic deterioration. Working with 16 populations of the vulnerable relict shrub Cneorum tricoccon throughout the majority of its western Mediterranean distribution range, and using nine polymorphic microsatellite markers, we examined the effects of periphery (peripheral vs. central), population size (large vs. small), and seed disperser (introduced carnivores vs. endemic lizards) on the genetic diversity and population structure of the species. Contrasting genetic variation (HE: 0.04-0.476) was found across populations. Peripheral populations showed lower genetic diversity, but this was dependent on population size. Large peripheral populations showed high levels of genetic diversity, whereas small central populations were less diverse. Significant isolation by distance was detected, indicating that the effect of long-distance gene flow is limited relative to that of genetic drift, probably due to high selfing rates (FIS = 0.155-0.887), restricted pollen flow, and ineffective seed dispersal. Bayesian clustering also supported the strong population differentiation and highly fragmented structure. Contrary to expectations, the type of disperser showed no significant effect on either population genetic diversity or structure. Our results challenge the idea of an effect of periphery per se that can be mainly explained by population size, drawing attention to the need of integrative approaches considering different determinants of genetic variation. Furthermore, the very low genetic diversity observed in several small populations and the strong among-population differentiation highlight the conservation value of large populations throughout the species' range, particularly in light of climate change and direct human threats.

7.
Nat Ecol Evol ; 1(3): 67, 2017 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-28812743

RESUMO

Climate change, land-use change, pollution and exploitation are among the main drivers of species' population trends; however, their relative importance is much debated. We used a unique collection of over 1,000 local population time series in 22 communities across terrestrial, freshwater and marine realms within central Europe to compare the impacts of long-term temperature change and other environmental drivers from 1980 onwards. To disentangle different drivers, we related species' population trends to species- and driver-specific attributes, such as temperature and habitat preference or pollution tolerance. We found a consistent impact of temperature change on the local abundances of terrestrial species. Populations of warm-dwelling species increased more than those of cold-dwelling species. In contrast, impacts of temperature change on aquatic species' abundances were variable. Effects of temperature preference were more consistent in terrestrial communities than effects of habitat preference, suggesting that the impacts of temperature change have become widespread for recent changes in abundance within many terrestrial communities of central Europe.

8.
Front Plant Sci ; 8: 843, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28603529

RESUMO

Habitat fragmentation, i.e., fragment size and isolation, can differentially alter patterns of neutral and quantitative genetic variation, fitness and phenotypic plasticity of plant populations, but their effects have rarely been tested simultaneously. We assessed the combined effects of size and connectivity on these aspects of genetic and phenotypic variation in populations of Centaurea hyssopifolia, a narrow endemic gypsophile that previously showed performance differences associated with fragmentation. We grew 111 maternal families sampled from 10 populations that differed in their fragment size and connectivity in a common garden, and characterized quantitative genetic variation, phenotypic plasticity to drought for key functional traits, and plant survival, as a measure of population fitness. We also assessed neutral genetic variation within and among populations using eight microsatellite markers. Although C. hyssopifolia is a narrow endemic gypsophile, we found substantial neutral genetic variation and quantitative variation for key functional traits. The partition of genetic variance indicated that a higher proportion of variation was found within populations, which is also consistent with low population differentiation in molecular markers, functional traits and their plasticity. This, combined with the generally small effect of habitat fragmentation suggests that gene flow among populations is not restricted, despite large differences in fragment size and isolation. Importantly, population's similarities in genetic variation and plasticity did not reflect the lower survival observed in isolated populations. Overall, our results indicate that, although the species consists of genetically variable populations able to express functional plasticity, such aspects of adaptive potential may not always reflect populations' survival. Given the differential effects of habitat connectivity on functional traits, genetic variation and fitness, our study highlights the need to shift the focus of fragmentation studies to the mechanisms that regulate connectivity effects, and call for caution on the use of genetic variation and plasticity to forecast population performance.

9.
J Hered ; 107(1): 42-50, 2016 01.
Artigo em Inglês | MEDLINE | ID: mdl-26324698

RESUMO

For organisms to adapt to future environments, they must both evolve appropriate functional responses and phenotypically express those responses under future climatic and CO2 conditions. We examined these 2 components of future adaptation in an invasive annual plant (Polygonum cespitosum) by performing a "resurrection" experiment under field conditions simulating a future environment. Resurrection experiments reveal recent evolution by comparing genotypes from natural populations sampled across a multigeneration interval. We collected genotypes from the same 3 North American populations in 1994 and 2005 and raised inbred lines from these collections under free air CO2 enrichment to examine functional and fitness traits expressed in hot, dry conditions at both ambient and elevated CO2 (N = 295 plants). The species has rapidly evolved in its introduced range to increase photosynthetic rate (collection year effect P ≤ 0.011) and delay senescence (P = 0.017) under full-sun, dry field conditions, but these adaptive changes were not expressed when the field environment included elevated CO2 (within-treatment year effect P ≥ 0.20 for both traits). Populations showed different levels of reproductive output and its genetic variance in these novel, stressful conditions. These findings illustrate constraints on evolutionary adaptation to predicted future conditions at both the species and population levels.


Assuntos
Adaptação Biológica/genética , Dióxido de Carbono/análise , Aptidão Genética , Espécies Introduzidas , Polygonum/genética , Meio Ambiente , Variação Genética , Genética Populacional , Genótipo , América do Norte , Fenótipo , Fotossíntese
10.
Oecologia ; 180(4): 1075-90, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26662734

RESUMO

Plants can respond to climate change by either migrating, adapting to the new conditions or going extinct. Relict plant species of limited distribution can be especially vulnerable as they are usually composed of small and isolated populations, which may reduce their ability to cope with rapidly changing environmental conditions. The aim of this study was to assess the vulnerability of Cneorum tricoccon L. (Cneoraceae), a Mediterranean relict shrub of limited distribution, to a future drier climate. We evaluated population differentiation in functional traits related to drought tolerance across seven representative populations of the species' range. We measured morphological and physiological traits in both the field and the greenhouse under three water availability levels. Large phenotypic differences among populations were found under field conditions. All populations responded plastically to simulated drought, but they differed in mean trait values as well as in the slope of the phenotypic response. Particularly, dry-edge populations exhibited multiple functional traits that favored drought tolerance, such as more sclerophyllous leaves, strong stomatal control but high photosynthetic rates, which increases water use efficiency (iWUE), and an enhanced ability to accumulate sugars as osmolytes. Although drought decreased RGR in all populations, this reduction was smaller for populations from the dry edge. Our results suggest that dry-edge populations of this relict species are well adapted to drought, which could potentially mitigate the species' extinction risk under drier scenarios. Dry-edge populations not only have a great conservation value but can also change expectations from current species' distribution models.


Assuntos
Adaptação Fisiológica , Mudança Climática , Secas , Ecossistema , Magnoliopsida/fisiologia , Fenótipo , Água/fisiologia , Aclimatação , Metabolismo dos Carboidratos , Clima , Magnoliopsida/metabolismo , Região do Mediterrâneo , Fotossíntese/fisiologia , Folhas de Planta/fisiologia , Estresse Fisiológico
11.
Ann N Y Acad Sci ; 1360: 101-19, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26457473

RESUMO

The introduced Asian plant Polygonum cespitosum has only recently become invasive in northeastern North America, spreading into sunny as well as shaded habitats. We present findings from a multiyear case study of this ongoing species invasion, drawing on field environmental measurements, glasshouse plasticity and resurrection experiments, and molecular genetic (microsatellite) data. We focus in particular on patterns of individual phenotypic plasticity (norms of reaction), their diversity within and among populations in the species' introduced range, and their contribution to its potential to evolve even greater invasiveness. Genotypes from introduced-range P. cespitosum populations have recently evolved to express greater adaptive plasticity to full sun and/or dry conditions without any loss of fitness in shade. Evidently, this species may evolve the sort of "general-purpose genotypes" hypothesized by Herbert Baker to characterize an "ideal weed." Indeed, we identified certain genotypes capable of extremely high reproductive output across contrasting conditions, including sunny, shaded, moist, and dry. Populations containing these high-performance genotypes had consistently higher fitness in all glasshouse habitats; there was no evidence for local adaptive differentiation among populations from sunny, shaded, moist, or dry sites. Norm of reaction data may provide valuable insights to invasion biology: the presence of broadly adaptive, high-performance genotypes can promote a species' ecological spread while providing the fuel for increased invasiveness to evolve.


Assuntos
Ecossistema , Espécies Introduzidas , Plantas Daninhas/crescimento & desenvolvimento , Polygonum/crescimento & desenvolvimento , Variação Genética/genética , Espécies Introduzidas/tendências , Plantas Daninhas/genética , Polygonum/genética
12.
AoB Plants ; 72015.
Artigo em Inglês | MEDLINE | ID: mdl-25862919

RESUMO

Little is known about how an introduced species may expand its ecological range, i.e. the set of local environmental conditions in which it can successfully establish populations. Delimiting this range of conditions is a methodological challenge, because it is impossible to sample all potential field locations for any species in a given region. Developing approaches to track ecological range over time could substantially contribute to understanding invasion dynamics. In this study, we use a previously established sampling strategy to document apparent changes across a 15-year time interval in the ecological range of the Asian annual Polygonum cespitosum Blume in northeastern North America, where the species has recently become invasive. Using a structured sample drawn from a large set of field populations, we determined the range of light, soil moisture and soil nutrient conditions that the species currently occupies in this region and the proportional distribution of individuals in differing types of microsite, and compared them with field measurements that were similarly determined 15 years earlier. Although in 1994 the species was absent from both high-light and flooded habitats, in 2009 P. cespitosum occurred in open as well as shaded habitats, across a wide range of moisture conditions. In 2009 the species also occupied a greater proportion of high-light microsites within field sites than in 1994. These findings suggest an expanded ecological range that, intriguingly, is consistent with the recent evolution in North American P. cespitosum populations of adaptive plasticity in response to high light. Possible non-evolutionary explanations for the change in field distribution are also considered.

13.
Ecol Lett ; 17(11): 1351-64, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25205436

RESUMO

Species are the unit of analysis in many global change and conservation biology studies; however, species are not uniform entities but are composed of different, sometimes locally adapted, populations differing in plasticity. We examined how intraspecific variation in thermal niches and phenotypic plasticity will affect species distributions in a warming climate. We first developed a conceptual model linking plasticity and niche breadth, providing five alternative intraspecific scenarios that are consistent with existing literature. Secondly, we used ecological niche-modeling techniques to quantify the impact of each intraspecific scenario on the distribution of a virtual species across a geographically realistic setting. Finally, we performed an analogous modeling exercise using real data on the climatic niches of different tree provenances. We show that when population differentiation is accounted for and dispersal is restricted, forecasts of species range shifts under climate change are even more pessimistic than those using the conventional assumption of homogeneously high plasticity across a species' range. Suitable population-level data are not available for most species so identifying general patterns of population differentiation could fill this gap. However, the literature review revealed contrasting patterns among species, urging greater levels of integration among empirical, modeling and theoretical research on intraspecific phenotypic variation.


Assuntos
Aclimatação/genética , Mudança Climática , Ecossistema , Modelos Biológicos , Animais , Simulação por Computador , Variação Genética , Genótipo , Fenótipo , Pinus/genética , Plantas/genética
14.
PLoS One ; 9(4): e93217, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24695495

RESUMO

Molecular markers can help elucidate how neutral evolutionary forces and introduction history contribute to genetic variation in invaders. We examined genetic diversity, population structure and colonization patterns in the invasive Polygonum cespitosum, a highly selfing, tetraploid Asian annual introduced to North America. We used nine diploidized polymorphic microsatellite markers to study 16 populations in the introduced range (northeastern North America), via the analyses of 516 individuals, and asked the following questions: 1) Do populations have differing levels of within-population genetic diversity? 2) Do populations form distinct genetic clusters? 3) Does population structure reflect either geographic distances or habitat similarities? We found low heterozygosity in all populations, consistent with the selfing mating system of P. cespitosum. Despite the high selfing levels, we found substantial genetic variation within and among P. cespitosum populations, based on the percentage of polymorphic loci, allelic richness, and expected heterozygosity. Inferences from individual assignment tests (Bayesian clustering) and pairwise FST values indicated high among-population differentiation, which indicates that the effects of gene flow are limited relative to those of genetic drift, probably due to the high selfing rates and the limited seed dispersal ability of P. cespitosum. Population structure did not reflect a pattern of isolation by distance nor was it related to habitat similarities. Rather, population structure appears to be the result of the random movement of propagules across the introduced range, possibly associated with human dispersal. Furthermore, the high population differentiation, genetic diversity, and fine-scale genetic structure (populations founded by individuals from different genetic sources) in the introduced range suggest that multiple introductions to this region may have occurred. High genetic diversity may further contribute to the invasive success of P. cespitosum in its introduced range.


Assuntos
Variação Genética/fisiologia , Espécies Introduzidas , Polygonum/genética , Humanos , Estados Unidos
15.
Ecology ; 94(11): 2464-74, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24400498

RESUMO

Maintaining high reproductive output in diverse conditions has consistently been found to promote invasiveness in introduced taxa. Following on this key observation, studies have compared the performance across environments of invasive vs. native congeners, and of introduced vs. native populations within invasive species. Performance differences among genotypes within introduced species have received far less attention, although such genetic variation could be critical to invasive potential. If an introduced species contains genotypes that can maintain high fitness across contrasting environments, such broadly adaptive, high-performance genotypes could promote and shape the species' immediate spread across multiple habitats. Furthermore, their presence could lead to the evolution of greater aggressiveness in the species, as these high performers increase in frequency. We investigated the existence and distribution of high-performance genotypes in Polygonum cespitosum, a newly invasive Asian annual. We raised 416 genotypes, collected from 14 North American populations, under resource-rich conditions to identify potential high-performance genotypes (the top 5% in total reproductive output). We then compared their fitness, life history, and functional traits to a random group of the remaining genotypes in three contrasting environments to ask the following: (1) Do consistently high-performance genotypes (i.e., genotypes with high relative fitness in diverse conditions) exist within introduced-range populations? (2) If so, do these high-performance genotypes possess distinctive life history and/or functional traits? (3) Do these genotypes occur in all populations or in only a subset of populations? Genotypes initially identified as high-performance in favorable conditions also had higher reproductive output in resource-limited environments. Their fitness advantage compared with control genotypes varied in magnitude from one environment to another but was significant within all three test environments. High-performance genotypes shared a developmental syndrome characterized by rapid and high germination, fast seedling growth, early reproductive onset, and high reproductive allocation, but they did not differ in other functional traits. P. cespitosum includes a subset of genotypes with accelerated development and significantly greater fitness in both favorable and stressful conditions. The nonrandom distribution of these high-performance genotypes among populations in the species' introduced range highlights the importance of genotypic and population-level variation for invasion dynamics.


Assuntos
Genótipo , Espécies Introduzidas , Polygonum/genética , Aptidão Genética , Variação Genética , Polygonum/classificação , Polygonum/fisiologia , Reprodução , Plântula
16.
PLoS One ; 7(9): e44955, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23028702

RESUMO

The ability to succeed in diverse conditions is a key factor allowing introduced species to successfully invade and spread across new areas. Two non-exclusive factors have been suggested to promote this ability: adaptive phenotypic plasticity of individuals, and the evolution of locally adapted populations in the new range. We investigated these individual and population-level factors in Polygonum cespitosum, an Asian annual that has recently become invasive in northeastern North America. We characterized individual fitness, life-history, and functional plasticity in response to two contrasting glasshouse habitat treatments (full sun/dry soil and understory shade/moist soil) in 165 genotypes sampled from nine geographically separate populations representing the range of light and soil moisture conditions the species inhabits in this region. Polygonum cespitosum genotypes from these introduced-range populations expressed broadly similar plasticity patterns. In response to full sun, dry conditions, genotypes from all populations increased photosynthetic rate, water use efficiency, and allocation to root tissues, dramatically increasing reproductive fitness compared to phenotypes expressed in simulated understory shade. Although there were subtle among-population differences in mean trait values as well as in the slope of plastic responses, these population differences did not reflect local adaptation to environmental conditions measured at the population sites of origin. Instead, certain populations expressed higher fitness in both glasshouse habitat treatments. We also compared the introduced-range populations to a single population from the native Asian range, and found that the native population had delayed phenology, limited functional plasticity, and lower fitness in both experimental environments compared with the introduced-range populations. Our results indicate that the future spread of P. cespitosum in its introduced range will likely be fueled by populations consisting of individuals able to express high fitness across diverse light and moisture conditions, rather than by the evolution of locally specialized populations.


Assuntos
Espécies Introduzidas , Fenótipo , Polygonum/anatomia & histologia , Polygonum/crescimento & desenvolvimento , Adaptação Fisiológica , Ecossistema , Ambiente Controlado , Evolução Molecular , Aptidão Genética , Luz , Polygonum/genética , Polygonum/fisiologia , Dinâmica Populacional , Plântula/anatomia & histologia , Plântula/genética , Plântula/crescimento & desenvolvimento , Plântula/fisiologia , Seleção Genética
17.
Am J Bot ; 98(7): e180-2, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21700804

RESUMO

PREMISE OF THE STUDY: We isolated and characterized microsatellite markers in Polygonum cespitosum Blume, an herbaceous annual plant species introduced into North America from Asia that has recently become invasive. METHODS AND RESULTS: A total of 12 polymorphic and 3 monomorphic loci were screened in 1-2 individuals from each of 20 populations from the introduced and native range, for a total of 24 samples. The number of alleles per locus in the polymorphic loci ranged from 3 to 9, and expected heterozygosity ranged from 0.156 to 0.838. CONCLUSIONS: These new loci will provide tools for examining genetic relatedness among introduced and native populations of this and other related species.


Assuntos
Técnicas Genéticas , Repetições de Microssatélites/genética , Polygonum/genética , Primers do DNA/genética , Testes Genéticos , Dados de Sequência Molecular
18.
Ann N Y Acad Sci ; 1206: 35-55, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20860682

RESUMO

Global change drivers create new environmental scenarios and selective pressures, affecting plant species in various interacting ways. Plants respond with changes in phenology, physiology, and reproduction, with consequences for biotic interactions and community composition. We review information on phenotypic plasticity, a primary means by which plants cope with global change scenarios, recommending promising approaches for investigating the evolution of plasticity and describing constraints to its evolution. We discuss the important but largely ignored role of phenotypic plasticity in range shifts and review the extensive literature on invasive species as models of evolutionary change in novel environments. Plasticity can play a role both in the short-term response of plant populations to global change as well as in their long-term fate through the maintenance of genetic variation. In new environmental conditions, plasticity of certain functional traits may be beneficial (i.e., the plastic response is accompanied by a fitness advantage) and thus selected for. Plasticity can also be relevant in the establishment and persistence of plants in novel environments that are crucial for populations at the colonizing edge in range shifts induced by climate change. Experimental studies show taxonomically widespread plastic responses to global change drivers in many functional traits, though there is a lack of empirical support for many theoretical models on the evolution of phenotypic plasticity. Future studies should assess the adaptive value and evolutionary potential of plasticity under complex, realistic global change scenarios. Promising tools include resurrection protocols and artificial selection experiments.


Assuntos
Evolução Biológica , Plantas/genética , Adaptação Biológica , Animais , Variação Genética , Humanos , Fenótipo
20.
Conserv Biol ; 24(1): 101-12, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20121845

RESUMO

Past and present pressures on forest resources have led to a drastic decrease in the surface area of unmanaged forests in Europe. Changes in forest structure, composition, and dynamics inevitably lead to changes in the biodiversity of forest-dwelling species. The possible biodiversity gains and losses due to forest management (i.e., anthropogenic pressures related to direct forest resource use), however, have never been assessed at a pan-European scale. We used meta-analysis to review 49 published papers containing 120 individual comparisons of species richness between unmanaged and managed forests throughout Europe. We explored the response of different taxonomic groups and the variability of their response with respect to time since abandonment and intensity of forest management. Species richness was slightly higher in unmanaged than in managed forests. Species dependent on forest cover continuity, deadwood, and large trees (bryophytes, lichens, fungi, saproxylic beetles) and carabids were negatively affected by forest management. In contrast, vascular plant species were favored. The response for birds was heterogeneous and probably depended more on factors such as landscape patterns. The global difference in species richness between unmanaged and managed forests increased with time since abandonment and indicated a gradual recovery of biodiversity. Clearcut forests in which the composition of tree species changed had the strongest effect on species richness, but the effects of different types of management on taxa could not be assessed in a robust way because of low numbers of replications in the management-intensity classes. Our results show that some taxa are more affected by forestry than others, but there is a need for research into poorly studied species groups in Europe and in particular locations. Our meta-analysis supports the need for a coordinated European research network to study and monitor the biodiversity of different taxa in managed and unmanaged forests.


Assuntos
Biodiversidade , Árvores , Europa (Continente)
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