Slot Martijn, Kitajima Kaoru
Department of Biology, University of Florida, Gainesville, FL, 32611, USA.
Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Panama City, Republic of Panama.
Oecologia. 2015 Mar;177(3):885-900. doi: 10.1007/s00442-014-3159-4. Epub 2014 Dec 7.
Respiration is instrumental for survival and growth of plants, but increasing costs of maintenance processes with warming have the potential to change the balance between photosynthetic carbon uptake and respiratory carbon release from leaves. Climate warming may cause substantial increases of leaf respiratory carbon fluxes, which would further impact the carbon balance of terrestrial vegetation. However, downregulation of respiratory physiology via thermal acclimation may mitigate this impact. We have conducted a meta-analysis with data collected from 43 independent studies to assess quantitatively the thermal acclimation capacity of leaf dark respiration to warming of terrestrial plant species from across the globe. In total, 282 temperature contrasts were included in the meta-analysis, representing 103 species of forbs, graminoids, shrubs, trees and lianas native to arctic, boreal, temperate and tropical ecosystems. Acclimation to warming was found to decrease respiration at a set temperature in the majority of the observations, regardless of the biome of origin and growth form, but respiration was not completely homeostatic across temperatures in the majority of cases. Leaves that developed at a new temperature had a greater capacity for acclimation than those transferred to a new temperature. We conclude that leaf respiration of most terrestrial plants can acclimate to gradual warming, potentially reducing the magnitude of the positive feedback between climate and the carbon cycle in a warming world. More empirical data are, however, needed to improve our understanding of interspecific variation in thermal acclimation capacity, and to better predict patterns in respiratory carbon fluxes both within and across biomes in the face of ongoing global warming.
呼吸作用对植物的生存和生长至关重要，但随着温度升高，维持过程的成本增加，有可能改变叶片光合碳吸收与呼吸碳释放之间的平衡。气候变暖可能导致叶片呼吸碳通量大幅增加，这将进一步影响陆地植被的碳平衡。然而，通过热适应对呼吸生理进行下调可能会减轻这种影响。我们对从43项独立研究中收集的数据进行了荟萃分析，以定量评估全球陆地植物物种叶片暗呼吸对变暖的热适应能力。荟萃分析总共纳入了282个温度对比，代表了北极、北方、温带和热带生态系统中的103种草本植物、禾本科植物、灌木、树木和藤本植物。在大多数观测中，发现对变暖的适应会在设定温度下降低呼吸作用，无论其起源的生物群落和生长形式如何，但在大多数情况下，呼吸作用在不同温度下并非完全稳定。在新温度下发育的叶片比转移到新温度下的叶片具有更强的适应能力。我们得出结论，大多数陆地植物的叶片呼吸可以适应逐渐变暖，这有可能降低变暖世界中气候与碳循环之间正反馈的强度。然而，需要更多的实证数据来增进我们对热适应能力种间差异的理解，并更好地预测在持续全球变暖情况下生物群落内部和之间呼吸碳通量的模式。
