Friend or foe? The role of biotic agents in drought-induced plant mortality
Friend or foe? The role of biotic agents in drought-induced plant mortality
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DOI：
10.1007/s11258-021-01126-4
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发表时间：
2021-03-20
期刊：
影响因子：
1.7
通讯作者：
Fridley, Jason D.
中科院分区：
文献类型：
--
作者：
Griffin-Nolan, Robert J.;Mohanbabu, Neha;Fridley, Jason D.
植物死亡是一个受生物因素和非生物因素共同影响的复杂过程。近几十年来，广泛的死亡事件被归因于日益严重的干旱，这促使人们研究干旱导致死亡的生理机制，特别是水力故障。基于干旱的死亡机制进一步受到植物与邻近植物、害虫和微生物等生物群的相互作用的影响。在这篇综述中，我们重点介绍了一些最有影响力的论文，阐述了这些生物相互作用及其对植物死亡的影响。植物与植物的相互作用可以是积极的(促进)、中性的或消极的(竞争)，这取决于干旱强度和邻居身份。例如，林分规模死亡率可能随着断面积(竞争指数)的增加而增加。然而，林分的多样性很重要，因为更多样化的森林比物种稀少的森林遭受的干旱死亡更少。茂密的林木还增加了树皮甲虫的攻击频率，这可能会加剧干旱胁迫和死亡，特别是对于防御分配较低的快速生长物种。然而，在某些情况下，干旱胁迫可以减轻生物攻击，这取决于植物和害虫生理之间的反馈。最后，植物与有益微生物的相互作用可以提高抗旱性，降低死亡的可能性，甚至将植物分布扩大到更干燥的栖息地。我们的综述表明，需要在天然草本植物群落以及死亡机制较少了解的干燥热带生态系统中开展更多工作。总体而言，相对较少的研究直接将生物相互作用与死亡的生理机制联系起来。在植物死亡的预测模型中，需要同时处理生物相互作用和测量生理阈值(例如，木质部空化)，以完全代表生物相互作用。
Plant mortality is a complex process influenced by both biotic and abiotic factors. In recent decades, widespread mortality events have been attributed to increasing drought severity, which has motivated research to examine the physiological mechanisms of drought-induced mortality, particularly hydraulic failure. Drought-based mortality mechanisms are further influenced by plant interactions with biota such as neighboring plants, insect pests, and microbes. In this review, we highlight some of the most influential papers addressing these biotic interactions and their influence on plant mortality. Plant-plant interactions can be positive (facilitation), neutral, or negative (competition), depending on drought intensity and neighbor identity. For example, stand-scale mortality likely increases with basal area (an index of competition). However, the diversity of forest stands matters, as more diverse forests suffer less mortality from drought than species-poor forests. Dense forest stands also increase bark beetle attack frequency, which can exacerbate drought stress and mortality, particularly for fast-growing species with lower defense allocation. In some cases, however, drought stress can alleviate biotic attack, depending on feedbacks between plant and pest physiology. Finally, plant interactions with beneficial microorganisms can increase drought tolerance, reduce the likelihood of mortality, and even extend plant distributions into drier habitats. Our review suggests more work is needed in natural herbaceous plant communities as well as dry tropical ecosystems where mortality mechanisms are less understood. Overall, relatively few studies directly link biotic interactions with the physiological mechanisms of mortality. Simultaneous manipulations of biotic interactions and measurements of physiological thresholds (e.g., xylem cavitation) are needed to fully represent biotic interactions in predictive models of plant mortality.