Lloren Jed I, McCune J L
Department of Biological Sciences, University of Lethbridge, 4401 University Drive, Lethbridge, AB T1K 3M4 Canada.
Landsc Ecol. 2024;39(3):40. doi: 10.1007/s10980-024-01844-w. Epub 2024 Feb 16.
Anthropogenic and natural disturbances may interact synergistically, magnifying their individual effects on biodiversity. However, few studies have measured responses of ecological communities to multiple stressors at landscape scales.
We use a long-term dataset to test for synergistic effects of anthropogenic and natural disturbance on plant community diversity and composition in a large protected area.
We quantified changes in plant communities over two decades in 98 plots in Waterton Lakes National Park, Canada. Fifty-three plots burned in a wildfire in the interim. We modeled the effects of wildfire, proximity to trails or roads, and their interaction on changes in species richness, community composition, relative abundance of disturbance-associated species, and colonization by exotic species.
Interactions between wildfire and proximity to roads and trails affected all metrics except species richness. Only one interaction was synergistic: the relative abundance of disturbance-associated species following wildfire was magnified closer to recreational corridors. The other community metrics showed unexpected patterns. For example, plots with no exotic species in the baseline survey that burned in the wildfire were more likely to gain exotic species than unburned plots only when they were distant from recreational corridors.
Our study demonstrates interactive effects of natural and anthropogenic disturbance at landscape scales within a protected area. Plant community response to wildfire was influenced by proximity to recreational corridors, sometimes in surprising ways. As the frequency and severity of anthropogenic and natural disturbances both continue to rise, documenting the prevalence and magnitude of interactions between them is key to predicting long-term effects and designing mitigation strategies.
The online version contains supplementary material available at 10.1007/s10980-024-01844-w.
人为干扰和自然干扰可能会产生协同作用，放大它们对生物多样性的各自影响。然而，很少有研究在景观尺度上测量生态群落对多种压力源的响应。
我们使用一个长期数据集来测试人为干扰和自然干扰对一个大型保护区内植物群落多样性和组成的协同效应。
我们对加拿大沃特顿湖国家公园98个样地中二十多年间的植物群落变化进行了量化。在此期间，有53个样地发生了野火。我们模拟了野火、与步道或道路的距离及其相互作用对物种丰富度变化、群落组成、干扰相关物种的相对丰度以及外来物种定殖的影响。
野火与靠近道路和步道之间的相互作用影响了除物种丰富度之外的所有指标。只有一种相互作用是协同的：野火后干扰相关物种的相对丰度在靠近休闲走廊处被放大。其他群落指标呈现出意想不到的模式。例如，在基线调查中没有外来物种且发生了野火的样地，只有在远离休闲走廊时才比未燃烧的样地更有可能获得外来物种。
我们的研究证明了保护区内景观尺度上自然干扰和人为干扰的交互作用。植物群落对野火的响应受到与休闲走廊距离的影响，有时方式令人惊讶。随着人为干扰和自然干扰的频率和强度都持续上升，记录它们之间相互作用的普遍性和程度是预测长期影响和设计缓解策略的关键。
在线版本包含可在10.1007/s10980-024-01844-w获取的补充材料。
