Tree defence and bark beetles in a drying world: carbon partitioning, functioning and modelling
Tree defence and bark beetles in a drying world: carbon partitioning, functioning and modelling
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DOI：
10.1111/nph.16173
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发表时间：
2019-10-08
期刊：
影响因子：
9.4
通讯作者：
Hartmann, Henrik
中科院分区：
文献类型：
--
作者：
Huang, Jianbei;Kautz, Markus;Hartmann, Henrik
近年来，干旱导致了昆虫引起的大规模树木死亡，对生态系统功能、大气过程、可持续资源和全球生物地球化学循环产生了严重后果。然而，干旱、树木防御和昆虫爆发之间的生理联系仍然不确定，这阻碍了我们在持续气候变化下准确预测树木死亡率的能力。在这里，我们提出了一个跨学科研究议程，以解决这些关键的知识差距。我们的框架包括田间操作、实验室实验以及昆虫和植被动态建模，并重点关注干旱如何影响针叶树和树皮甲虫之间的相互作用。我们以现有理论为基础，检验了几个关键假设：（1）树木碳投资在初级代谢物和次级代谢物之间存在权衡（例如生长与防御）； (2)次生代谢产物是树木防御树皮甲虫和相关微生物的主要成分之一； (3) 在当前模型中实施针叶树-树皮甲虫相互作用可以改善对气候变化中森林干扰的预测。我们的框架为解决当前大规模植被模型实施中的一个主要缺陷（昆虫引起的树木死亡率代表性不足）提供了指导。
Drought has promoted large-scale, insect-induced tree mortality in recent years, with severe consequences for ecosystem function, atmospheric processes, sustainable resources and global biogeochemical cycles. However, the physiological linkages among drought, tree defences, and insect outbreaks are still uncertain, hindering our ability to accurately predict tree mortality under on-going climate change. Here we propose an interdisciplinary research agenda for addressing these crucial knowledge gaps. Our framework includes field manipulations, laboratory experiments, and modelling of insect and vegetation dynamics, and focuses on how drought affects interactions between conifer trees and bark beetles. We build upon existing theory and examine several key assumptions: (1) there is a trade-off in tree carbon investment between primary and secondary metabolites (e.g. growth vs defence); (2) secondary metabolites are one of the main component of tree defence against bark beetles and associated microbes; and (3) implementing conifer-bark beetle interactions in current models improves predictions of forest disturbance in a changing climate. Our framework provides guidance for addressing a major shortcoming in current implementations of large-scale vegetation models, the under-representation of insect-induced tree mortality.