Department of Biological Sciences, University of Illinois, Chicago, Illinois 60607; email:
Annu Rev Plant Biol. 2015;66:547-69. doi: 10.1146/annurev-arplant-043014-115540. Epub 2015 Jan 12.
Pest and pathogen disturbances are ubiquitous across forest ecosystems, impacting their species composition, structure, and function. Whereas severe abiotic disturbances (e.g., clear-cutting and fire) largely reset successional trajectories, pest and pathogen disturbances cause diffuse mortality, driving forests into nonanalogous system states. Biotic perturbations that disrupt forest carbon dynamics either reduce or enhance net primary production (NPP) and carbon storage, depending on pathogen type. Relative to defoliators, wood borers and invasive pests have the largest negative impact on NPP and the longest recovery time. Forest diversity is an important contributing factor to productivity: NPP is neutral, marginally enhanced, or reduced in high-diversity stands in which a small portion of the canopy is affected (temperate deciduous or mixed forests) but very negative in low-diversity stands in which a large portion of the canopy is affected (western US forests). Pests and pathogens reduce forest structural and functional redundancy, affecting their resilience to future climate change or new outbreaks. Therefore, pests and pathogens can be considered biotic forcing agents capable of causing consequences of similar magnitude to climate forcing factors.
虫害和病原体干扰在森林生态系统中普遍存在，影响其物种组成、结构和功能。虽然严重的非生物干扰（如砍伐和火灾）在很大程度上重置了演替轨迹，但虫害和病原体干扰会导致广泛的死亡，使森林进入非相似的系统状态。破坏森林碳动态的生物干扰要么减少要么增加净初级生产力（NPP）和碳储存，这取决于病原体的类型。与食叶昆虫相比，蛀木虫和入侵害虫对 NPP 的影响最大，恢复时间最长。森林多样性是生产力的一个重要贡献因素：在一小部分树冠受到影响（温带落叶林或混合林）的高多样性林分中，NPP 呈中性、略有增强或减少，但在大部分树冠受到影响（美国西部森林）的低多样性林分中，NPP 非常负面。虫害和病原体减少了森林的结构和功能冗余，影响了它们对未来气候变化或新爆发的恢复力。因此，虫害和病原体可以被视为能够造成与气候强迫因素相似程度的后果的生物强迫因素。
