Facilitative interactions do not wane with warming at high elevations in the Andes
Facilitative interactions do not wane with warming at high elevations in the Andes
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DOI：
10.1007/s00442-012-2316-x
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发表时间：
2012-10-01
期刊：
影响因子：
2.7
通讯作者：
Sierra-Almeida, Angela
中科院分区：
文献类型：
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作者：
Cavieres, Lohengrin A.;Sierra-Almeida, Angela
物种间的正相互作用在高山植物群落的结构和动态中起着重要的作用。人们知道，消极和积极相互作用之间的平衡会沿着空间和时间梯度发生变化，随着环境压力的增加，积极影响超过消极影响。因此，这种平衡可能会受到气候变化的影响。我们假设，温度的升高（全球变暖的情况下）应该减少的重要性，积极的相互作用，高山植物物种的生存和生长。为了验证这一假设，我们选择了生长在3,600 m.a.s.l.的护士垫物种Azorella madreporica内的本地草物种大麦的个体。在洛斯安第斯山脉（智利）进行，并在自然和温暖条件下进行了苗圃去除和幼苗存活实验。对于更温暖的条件，我们使用开顶式箱，这将温度提高了4 A摄氏度。经过两个生长季节，我们比较了护士去除对H的生存，生物量和光化学效率的影响。comosum个体在温暖和自然条件下。护士去除显着降低了H的生存，生物量和光化学效率。comosum，证明护士垫的促进作用。幼苗的存活率也提高了垫，即使在温暖的条件下。然而，温暖的条件下，只有部分减轻了护士删除的负面影响，这表明在温暖的条件下，缓冲垫的促进作用不会减弱。因此，促进相互作用是至关重要的性能和生存的高山物种，这些积极的相互作用将继续在未来的高高山栖息地的温暖条件下是重要的。
Positive interactions between species are known to play an important role in the structure and dynamics of alpine plant communities. The balance between negative and positive interactions is known to shift along spatial and temporal gradients, with positive effects prevailing over negative ones as the environmental stress increases. Thus, this balance is likely to be affected by climate change. We hypothesized that increases in temperature (a global warming scenario) should decrease the importance of positive interactions for the survival and growth of alpine plant species. To test this hypothesis, we selected individuals of the native grass species Hordeum comosum growing within the nurse cushion species Azorella madreporica at 3,600 m.a.s.l. in Los Andes (Chile), and performed nurse removal and seedling survival experiments under natural and warmer conditions. For warmer conditions, we used open-top chambers, which increased the temperature by 4 A degrees C. After two growing seasons, we compared the effect of nurse removal on the survival, biomass, and photochemical efficiency of H. comosum individuals under warmer and natural conditions. Nurse removal significantly decreased the survival, biomass, and photochemical efficiency of H. comosum, demonstrating the facilitative effects of nurse cushions. Seedling survival was also enhanced by cushions, even under warmer conditions. However, warmer conditions only partially mitigated the negative effects of nurse removal, suggesting that facilitative effects of cushions do not wane under warmer conditions. Thus, facilitative interactions are vital to the performance and survival of alpine species, and these positive interactions will continue to be important in the warmer conditions of the future in high-alpine habitats.