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A meta-analysis of local adaptation in plants.

Leimu R, Fischer M - PLoS ONE (2008)

Bottom Line: We show that, overall, local plants performed significantly better than foreign plants at their site of origin: this was found to be the case in 71.0% of the studied sites.Furthermore, we found local adaptation much more common for large plant populations (>1000 flowering individuals) than for small populations (<1000 flowering individuals) for which local adaptation was very rare.Our results suggest that local adaptation is less common in plant populations than generally assumed.

View Article: PubMed Central - PubMed

Affiliation: Institute for Biochemistry and Biology, University of Potsdam, Potsdam, Germany. roosa.leimu@plants.ox.ac.uk

ABSTRACT
Local adaptation is of fundamental importance in evolutionary, population, conservation, and global-change biology. The generality of local adaptation in plants and whether and how it is influenced by specific species, population and habitat characteristics have, however, not been quantitatively reviewed. Therefore, we examined published data on the outcomes of reciprocal transplant experiments using two approaches. We conducted a meta-analysis to compare the performance of local and foreign plants at all transplant sites. In addition, we analysed frequencies of pairs of plant origin to examine whether local plants perform better than foreign plants at both compared transplant sites. In both approaches, we also examined the effects of population size, and of the habitat and species characteristics that are predicted to affect local adaptation. We show that, overall, local plants performed significantly better than foreign plants at their site of origin: this was found to be the case in 71.0% of the studied sites. However, local plants performed better than foreign plants at both sites of a pair-wise comparison (strict definition of local adaption) only in 45.3% of the 1032 compared population pairs. Furthermore, we found local adaptation much more common for large plant populations (>1000 flowering individuals) than for small populations (<1000 flowering individuals) for which local adaptation was very rare. The degree of local adaptation was independent of plant life history, spatial or temporal habitat heterogeneity, and geographic scale. Our results suggest that local adaptation is less common in plant populations than generally assumed. Moreover, our findings reinforce the fundamental importance of population size for evolutionary theory. The clear role of population size for the ability to evolve local adaptation raises considerable doubt on the ability of small plant populations to cope with changing environments.

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Evidence for local adaptation and effects of different plant and habitat characteristics.A) Effects of plant characteristics and B) of population characteristics on the effect size (Hedges' d). A positive effect size indicates better performance of local plants compared to foreign plants at a given site. Bars denote bias-corrected 95% confidence limits and the grey lines denote the pair-wise contrasts.
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pone-0004010-g003: Evidence for local adaptation and effects of different plant and habitat characteristics.A) Effects of plant characteristics and B) of population characteristics on the effect size (Hedges' d). A positive effect size indicates better performance of local plants compared to foreign plants at a given site. Bars denote bias-corrected 95% confidence limits and the grey lines denote the pair-wise contrasts.

Mentions: Local adaptation was independent of the plant or habitat characteristics considered in our study (Fig 3a, 3b). In our meta-analysis the strength and direction of the effect size did not differ between the considered categories of plant longevity (Qb = 0.138, df = 1, N = 36, P = 0.755), mating system (Qb = 1.666, df = 1, N = 31, P = 0.271), or clonality (Qb = 0.528, df = 1, N = 36, P = 0.491) (Fig 3a). Moreover, the strength and direction of the effect size did not depend on the measure of temporal constancy of the habitats (Qb = 0.051, df = 1, P = 0.784), on whether the sites had been selected randomly or because of specific habitat differences (Qb = 0.122, df = 1, N = 36, P = 0.743), or on whether the habitats were considered spatially heterogeneous or homogeneous by the authors (Qb = 0.213, df = 1, N = 36, P = 0.545) (Fig 3b). We found no difference in the strength and direction of the effect size between the reciprocal transplant studies and the experimental studies (Qb = 0.245, df = 1, N = 36, P = 0.614; d = −0.14, CI −0.22 to −0.06 and d = −0.18, CI −0.23 to −0.24, respectively). Also, none of these descriptors of life-history or habitat characteristics was related to how frequently the reaction norms crossed.


A meta-analysis of local adaptation in plants.

Leimu R, Fischer M - PLoS ONE (2008)

Evidence for local adaptation and effects of different plant and habitat characteristics.A) Effects of plant characteristics and B) of population characteristics on the effect size (Hedges' d). A positive effect size indicates better performance of local plants compared to foreign plants at a given site. Bars denote bias-corrected 95% confidence limits and the grey lines denote the pair-wise contrasts.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2602971&req=5

pone-0004010-g003: Evidence for local adaptation and effects of different plant and habitat characteristics.A) Effects of plant characteristics and B) of population characteristics on the effect size (Hedges' d). A positive effect size indicates better performance of local plants compared to foreign plants at a given site. Bars denote bias-corrected 95% confidence limits and the grey lines denote the pair-wise contrasts.
Mentions: Local adaptation was independent of the plant or habitat characteristics considered in our study (Fig 3a, 3b). In our meta-analysis the strength and direction of the effect size did not differ between the considered categories of plant longevity (Qb = 0.138, df = 1, N = 36, P = 0.755), mating system (Qb = 1.666, df = 1, N = 31, P = 0.271), or clonality (Qb = 0.528, df = 1, N = 36, P = 0.491) (Fig 3a). Moreover, the strength and direction of the effect size did not depend on the measure of temporal constancy of the habitats (Qb = 0.051, df = 1, P = 0.784), on whether the sites had been selected randomly or because of specific habitat differences (Qb = 0.122, df = 1, N = 36, P = 0.743), or on whether the habitats were considered spatially heterogeneous or homogeneous by the authors (Qb = 0.213, df = 1, N = 36, P = 0.545) (Fig 3b). We found no difference in the strength and direction of the effect size between the reciprocal transplant studies and the experimental studies (Qb = 0.245, df = 1, N = 36, P = 0.614; d = −0.14, CI −0.22 to −0.06 and d = −0.18, CI −0.23 to −0.24, respectively). Also, none of these descriptors of life-history or habitat characteristics was related to how frequently the reaction norms crossed.

Bottom Line: We show that, overall, local plants performed significantly better than foreign plants at their site of origin: this was found to be the case in 71.0% of the studied sites.Furthermore, we found local adaptation much more common for large plant populations (>1000 flowering individuals) than for small populations (<1000 flowering individuals) for which local adaptation was very rare.Our results suggest that local adaptation is less common in plant populations than generally assumed.

View Article: PubMed Central - PubMed

Affiliation: Institute for Biochemistry and Biology, University of Potsdam, Potsdam, Germany. roosa.leimu@plants.ox.ac.uk

ABSTRACT
Local adaptation is of fundamental importance in evolutionary, population, conservation, and global-change biology. The generality of local adaptation in plants and whether and how it is influenced by specific species, population and habitat characteristics have, however, not been quantitatively reviewed. Therefore, we examined published data on the outcomes of reciprocal transplant experiments using two approaches. We conducted a meta-analysis to compare the performance of local and foreign plants at all transplant sites. In addition, we analysed frequencies of pairs of plant origin to examine whether local plants perform better than foreign plants at both compared transplant sites. In both approaches, we also examined the effects of population size, and of the habitat and species characteristics that are predicted to affect local adaptation. We show that, overall, local plants performed significantly better than foreign plants at their site of origin: this was found to be the case in 71.0% of the studied sites. However, local plants performed better than foreign plants at both sites of a pair-wise comparison (strict definition of local adaption) only in 45.3% of the 1032 compared population pairs. Furthermore, we found local adaptation much more common for large plant populations (>1000 flowering individuals) than for small populations (<1000 flowering individuals) for which local adaptation was very rare. The degree of local adaptation was independent of plant life history, spatial or temporal habitat heterogeneity, and geographic scale. Our results suggest that local adaptation is less common in plant populations than generally assumed. Moreover, our findings reinforce the fundamental importance of population size for evolutionary theory. The clear role of population size for the ability to evolve local adaptation raises considerable doubt on the ability of small plant populations to cope with changing environments.

Show MeSH