Abstract：
OBJECTIVE: Elevation is a major factor shaping plant populations on a global scale. At the same time, reproductive traits play a major role in plant fitness. With increasing altitude and increasingly harsh conditions, decreases in pollinator visitation rates, sexual investment, seed set, and heterozygosity (due to increased selfing) are expected. In response, selection and/or phenotypic plasticity could lead to an increase in plants\' floral displays to increase their attractiveness to pollinators and compensates for the negative fitness impacts of reduced pollinator activity. A large body of literature tests these hypotheses at the among-species level, but empirical evidence at the population level (i.e., wihin-species), where adaptive change may occur, is still limited to species-specific studies. Unravelling the global patterns of change in the reproductive traits, flower visitation rates and heterozygosity of plant populations across variable environmental conditions, especially climate can help us to understand how species are able to cope with shifting conditions associated with global change, particularly in mountains. Here, we used meta-analytic approaches to assess the reproductive changes of plant populations in response to elevation on a global scale.
METHODS: We used a data set with 243 paired populations of plants at \'lower\' and \'higher\' elevations, spanning an elevation range of 0-4380 m asl and taken from 121 angiosperm species and 115 published studies. We analyzed changes in flower number, size and longevity, pollen production, flower visitation rate, seed set and expected heterozygosity.We then tested whether the observed patterns for each trait were dependent upon plant phylogeny and various ecogeographical factors and species traits.
RESULTS: We found no evidence of elevation having a global effect on the reproductive traits of angiosperm populations. This null global pattern was not affected by geograph or phylogenetics.
CONCLUSIONS: Our results suggest that changes in reproductive traits, flower visitation rates, and heterozygosity in plant populations across elevations are specific to each species and ecosystem. Hence, macroevolutionary (across species) and macroecological patterns of elevation of plant reproduction reported previously are apparently not simply the outcome of microevolutionary changes (within species). This apparent specificity of response across plant species poses difficulties in predicting the effects of global changes and, specifically, climatic changes, on the fate of plant species, populations, and communities.
METHODS: We used a data set with 243 paired populations of plants at \'lower\' and \'higher\' elevations, spanning an elevation range of 0-4380 m asl and taken from 121 angiosperm species and 115 published studies. We analyzed changes in flower number, size and longevity, pollen production, flower visitation rate, seed set and expected heterozygosity.We then tested whether the observed patterns for each trait were dependent upon plant phylogeny and various ecogeographical factors and species traits.
RESULTS: We found no evidence of elevation having a global effect on the reproductive traits of angiosperm populations. This null global pattern was not affected by geograph or phylogenetics.
CONCLUSIONS: Our results suggest that changes in reproductive traits, flower visitation rates, and heterozygosity in plant populations across elevations are specific to each species and ecosystem. Hence, macroevolutionary (across species) and macroecological patterns of elevation of plant reproduction reported previously are apparently not simply the outcome of microevolutionary changes (within species). This apparent specificity of response across plant species poses difficulties in predicting the effects of global changes and, specifically, climatic changes, on the fate of plant species, populations, and communities.
摘要：
目的：海拔是全球范围内影响植物种群的主要因素。同时,生殖性状在植物适体中起主要作用。随着海拔高度的增加和条件的日益恶劣，传粉媒介探视率下降，性投资,种子集，和杂合性(由于自交增加)是预期的。作为回应,选择和/或表型可塑性可能导致植物花卉展示的增加，以增加它们对传粉者的吸引力，并补偿传粉者活动减少的负面适应性影响。大量文献在物种间水平上检验了这些假设，但在人口层面的经验证据(即，wihin-species),在可能发生适应性变化的地方，仍然限于特定物种的研究。解开生殖性状变化的全球模式，不同环境条件下植物种群的花卉访问率和杂合性，特别是气候可以帮助我们了解物种如何应对与全球变化相关的变化条件，尤其是在山区。这里,我们使用荟萃分析方法在全球范围内评估植物种群对海拔升高的反应的生殖变化。
方法：我们使用了一个数据集，其中包含243个处于“较低”和“较高”海拔的成对植物种群，海拔范围为0-4380masl，取自121种被子植物和115项已发表的研究。我们分析了花数的变化，尺寸和寿命，花粉生产，花卉访问率,种子集和预期杂合度。然后，我们测试了每个性状的观察模式是否取决于植物系统发育以及各种生态地理因素和物种性状。
结果：我们没有发现升高对被子植物种群的生殖性状有整体影响的证据。这种无效的全球模式不受地理或系统发育的影响。
结论：我们的结果表明，生殖性状的变化，花卉访问率,不同海拔的植物种群的杂合性是每个物种和生态系统特有的。因此，先前报道的植物繁殖的宏观进化（跨物种）和宏观生态模式显然不仅仅是微观进化变化（物种内部）的结果。这种植物物种反应的明显特异性给预测全球变化的影响带来了困难，具体来说,气候变化,关于植物物种的命运，人口,和社区。
方法：我们使用了一个数据集，其中包含243个处于“较低”和“较高”海拔的成对植物种群，海拔范围为0-4380masl，取自121种被子植物和115项已发表的研究。我们分析了花数的变化，尺寸和寿命，花粉生产，花卉访问率,种子集和预期杂合度。然后，我们测试了每个性状的观察模式是否取决于植物系统发育以及各种生态地理因素和物种性状。
结果：我们没有发现升高对被子植物种群的生殖性状有整体影响的证据。这种无效的全球模式不受地理或系统发育的影响。
结论：我们的结果表明，生殖性状的变化，花卉访问率,不同海拔的植物种群的杂合性是每个物种和生态系统特有的。因此，先前报道的植物繁殖的宏观进化（跨物种）和宏观生态模式显然不仅仅是微观进化变化（物种内部）的结果。这种植物物种反应的明显特异性给预测全球变化的影响带来了困难，具体来说,气候变化,关于植物物种的命运，人口,和社区。
