Plant Ecology and Nature Conservation Group, Wageningen University, Wageningen, The Netherlands.
Ecology and Biodiversity Group, Department of Biology, Utrecht University, Utrecht, The Netherlands.
Glob Chang Biol. 2024 Aug;30(8):e17445. doi: 10.1111/gcb.17445.
Due to various human activities, including intensive agriculture, traffic, and the burning of fossil fuels, in many parts of the world, current levels of reactive nitrogen emissions strongly exceed pre-industrial levels. Previous studies have shown that the atmospheric deposition of these excess nitrogen compounds onto semi-natural terrestrial environments has negative consequences for plant diversity. However, these previous studies mostly investigated biodiversity loss at local spatial scales, that is, at the scales of plots of typically a few square meters. Whether increased atmospheric nitrogen deposition also affects plant diversity at larger spatial scales remains unknown. Here, using grassland plant community data collected in 765 plots, across 153 different sites and 9 countries in northwestern Europe, we investigate whether relationships between atmospheric nitrogen deposition and plant biodiversity are scale-dependent. We found that high levels of atmospheric nitrogen deposition were associated with low levels of plant species richness at the plot scale but also at the scale of sites and regions. The presence of 39% of plant species was negatively associated with increasing levels of nitrogen deposition at large (site) scales, while only 1.5% of the species became more common with increasing nitrogen deposition, indicating that large-scale biodiversity changes were mostly driven by "loser" species, while "winner" species profiting from high N deposition were rare. Some of the "loser" species whose site presence was negatively associated with atmospheric nitrogen deposition are listed as "threatened" in at least some EU member states, suggesting that nitrogen deposition may be a key contributor to their threat status. Hence, reductions in reactive nitrogen emissions will likely benefit plant diversity not only at local but also at larger spatial scales.
由于人类的各种活动，包括集约化农业、交通和化石燃料的燃烧，在世界许多地区，当前的活性氮排放水平远远超过了工业化前的水平。以前的研究表明，这些过量氮化合物在大气中的沉积对半自然陆地环境中的植物多样性产生了负面影响。然而，这些先前的研究大多在局部空间尺度上（即几个平方米的样方尺度上）调查了生物多样性的丧失。大气氮沉降是否也会对更大的空间尺度上的植物多样性产生影响还不得而知。在这里，我们使用了在欧洲西北部的 9 个国家的 153 个不同地点的 765 个样方中收集的草原植物群落数据，来研究大气氮沉降与植物生物多样性之间的关系是否具有尺度依赖性。我们发现，在样方尺度上，高水平的大气氮沉降与植物物种丰富度的降低有关，但在地点和区域尺度上也是如此。在大尺度（地点）上，有 39%的植物物种的存在与氮沉降的增加呈负相关，而只有 1.5%的物种随着氮沉降的增加而变得更加常见，这表明大尺度上的生物多样性变化主要是由“输家”物种驱动的，而从高氮沉降中受益的“赢家”物种则很少。一些与大气氮沉降呈负相关的物种的存在与地点呈负相关，被列为至少一些欧盟成员国的“受威胁”物种，这表明氮沉降可能是导致它们受到威胁的一个关键因素。因此，减少活性氮排放不仅会使植物多样性在局部，而且在更大的空间尺度上受益。
