Meir Patrick, Mencuccini Maurizio, Dewar Roderick C
Research School of Biology, The Australian National University, Canberra, 2601, ACT, Australia.
School of Geosciences, The University of Edinburgh, Edinburgh, EH9 3FF, UK.
New Phytol. 2015 Jul;207(1):28-33. doi: 10.1111/nph.13382. Epub 2015 Mar 27.
Increased tree mortality during and after drought has become a research focus in recent years. This focus has been driven by: the realisation that drought-related tree mortality is more widespread than previously thought; the predicted increase in the frequency of climate extremes this century; and the recognition that current vegetation models do not predict drought-related tree mortality and forest dieback well despite the large potential effects of these processes on species composition and biogeochemical cycling. To date, the emphasis has been on understanding the causal mechanisms of drought-related tree mortality, and on mechanistic models of plant function and vegetation dynamics, but a consensus on those mechanisms has yet to emerge. In order to generate new hypotheses and to help advance the modelling of vegetation dynamics in the face of incomplete mechanistic understanding, we suggest that general patterns should be distilled from the diverse and as-yet inconclusive results of existing studies, and more use should be made of optimisation and probabilistic modelling approaches that have been successfully applied elsewhere in plant ecology. The outcome should inform new empirical studies of tree mortality, help improve its prediction and reduce model complexity.
干旱期间及之后树木死亡率上升已成为近年来的一个研究重点。这一重点的形成是由于：人们认识到与干旱相关的树木死亡率比之前认为的更为普遍；预计本世纪极端气候事件的频率会增加；以及认识到尽管这些过程对物种组成和生物地球化学循环有很大潜在影响，但当前的植被模型并不能很好地预测与干旱相关的树木死亡率和森林枯死。迄今为止，重点一直放在理解与干旱相关的树木死亡率的因果机制以及植物功能和植被动态的机理模型上，但尚未就这些机制达成共识。为了在对机理理解不完整的情况下产生新的假设并帮助推进植被动态建模，我们建议应从现有研究多样且尚无定论的结果中提炼出一般模式，并更多地使用已在植物生态学其他领域成功应用的优化和概率建模方法。其结果应能为树木死亡率的新实证研究提供信息，有助于改进对其的预测并降低模型复杂性。
