Zhou Shuang-Xi, Prentice I Colin, Medlyn Belinda E
Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia.
The New Zealand Institute for Plant and Food Research Ltd., Hawke's Bay, New Zealand.
Front Plant Sci. 2019 Jan 15;9:1965. doi: 10.3389/fpls.2018.01965. eCollection 2018.
Global climate change is expected to increase drought duration and intensity in certain regions while increasing rainfall in others. The quantitative consequences of increased drought for ecosystems are not easy to predict. Process-based models must be informed by experiments to determine the resilience of plants and ecosystems from different climates. Here, we demonstrate what and how experimentally derived quantitative information can improve the representation of stomatal and non-stomatal photosynthetic responses to drought in large-scale vegetation models. In particular, we review literature on the answers to four key questions: (1) Which photosynthetic processes are affected under short-term drought? (2) How do the stomatal and non-stomatal responses to short-term drought vary among species originating from different hydro-climates? (3) Do plants acclimate to prolonged water stress, and do mesic and xeric species differ in their degree of acclimation? (4) Does inclusion of experimentally based plant functional type specific stomatal and non-stomatal response functions to drought help Land Surface Models to reproduce key features of ecosystem responses to drought? We highlighted the need for evaluating model representations of the fundamental eco-physiological processes under drought. Taking differential drought sensitivity of different vegetation into account is necessary for Land Surface Models to accurately model drought responses, or the drought impacts on vegetation in drier environments may be over-estimated.
预计全球气候变化将使某些地区的干旱持续时间延长、强度增加，而其他地区的降雨量则会增加。干旱加剧对生态系统造成的量化后果并不容易预测。基于过程的模型必须通过实验来确定不同气候条件下植物和生态系统的恢复力。在此，我们展示了通过实验得出的量化信息是什么以及如何能够改进大规模植被模型中气孔和非气孔光合作用对干旱的响应表征。特别是，我们回顾了针对四个关键问题的文献答案：（1）短期干旱下哪些光合作用过程会受到影响？（2）来自不同水文气候的物种对短期干旱的气孔和非气孔响应有何不同？（3）植物是否会适应长期水分胁迫，中生和旱生物种在适应程度上是否存在差异？（4）纳入基于实验的特定植物功能类型的气孔和非气孔干旱响应函数是否有助于陆面模型再现生态系统对干旱响应的关键特征？我们强调了评估干旱条件下基本生态生理过程的模型表征的必要性。考虑到不同植被对干旱的敏感性差异，对于陆面模型准确模拟干旱响应是必要的，否则可能会高估干旱对较干燥环境中植被的影响。
