Data from: Logging and fire regimes alter plant communities

Disturbances are key drivers of plant community composition, structure and function. Plant functional traits, including life forms and reproductive strategies are critical to the resilience and resistance of plant communities in the event of disturbance. Climate change and increasing anthropogenic disturbance are altering natural disturbance regimes, globally. When these regimes shift beyond the adaptive resilience of plant functional traits, local populations and ecosystem functions can become compromised. We tested the influence of multiple disturbances, of varying intensity and frequency, on the composition and abundance of vascular plant communities and their respective functional traits (life forms and reproductive strategies) in the wet sclerophyll, Mountain Ash Eucalyptus regnans forests of south-eastern Australia. Specifically, we quantified the effect of the type and number of disturbances (including fires, clearcut logging and salvage logging) on plant community composition. We found that clearcut and salvage logging and the number of fires significantly influenced plant community composition and functional traits. Specifically, multiple fires resulted in lower populations of species that depend on on-site seeding for persistence. This includes the common tree species, Eucalyptus regnans, Pomaderris aspera and Acacia dealbata. In contrast, clearcut and salvage logged sites supported abundant on-site seeder species. However, species that depend on resprouting by surviving individuals, such as common and keystone ‘tree ferns’ Dicksonia antarctica and Cyathea australis declined significantly. Our data have important implications for understanding the relationship between altered disturbance regimes and plant communities and the respective effects on ecosystem function. In a period of rapid global environmental change, with disturbances predicted to increase and intensify, it is critical to address the impact of altered disturbance regimes on biodiversity.

干扰是调控植物群落组成、结构与功能的核心驱动因子。植物功能性状（涵盖生活型与繁殖策略），是植物群落应对干扰时的恢复力与抗性的关键决定因素。当前，气候变化与日益加剧的人为干扰正在全球范围内重塑自然干扰格局。当此类格局突破植物功能性状的适应性恢复力阈值时，当地种群与生态系统功能便可能遭受损害。我们以澳大利亚东南部的山灰桉（Eucalyptus regnans）硬叶湿润林为研究对象，探究了不同强度、频率的多重干扰对维管植物群落的组成、丰度及其对应功能性状（生活型与繁殖策略）的影响。具体而言，我们量化了干扰类型与干扰频次（包括火灾、皆伐与灾后打捞采伐（salvage logging））对植物群落组成的作用效果。研究结果显示，皆伐、灾后打捞采伐以及火灾频次均显著影响植物群落组成与功能性状。具体来看，经历多次火灾的样地中，依赖原位结种延续种群的物种种群丰度显著降低，其中包含常见树种山灰桉（Eucalyptus regnans）、糙皮薄柱草（Pomaderris aspera）以及银叶金合欢（Acacia dealbata）。与之形成鲜明对比的是，皆伐与灾后打捞采伐的样地则孕育了大量原位结种物种。然而，依赖存活个体萌蘖更新的物种——比如常见的关键类群树蕨——软树蕨（Dicksonia antarctica）与澳洲桫椤（Cyathea australis）则出现了显著的种群衰退。本研究数据对于阐明改变后的干扰格局与植物群落间的关联，及其对生态系统功能的连锁效应具有重要参考价值。在全球环境快速变化、干扰事件预计愈发频繁与剧烈的当下，厘清干扰格局改变对生物多样性的影响已成为一项至关重要的课题。