Department of Biology, The Biological Museum, Lund University, Lund, Sweden.
Centre for Environmental and Climate Research, Lund University, Lund, Sweden.
Glob Chang Biol. 2018 Jun;24(6):2607-2621. doi: 10.1111/gcb.14031. Epub 2018 Jan 16.
Land-use changes, pollution and climate warming during the 20th century have caused changes in biodiversity across the world. However, in many cases, the environmental drivers are poorly understood. To identify and rank the drivers currently causing broad-scale floristic changes in N Europe, we analysed data from two vascular plant surveys of 200 randomly selected 2.5 × 2.5 km grid-squares in Scania, southernmost Sweden, conducted 1989-2006 and 2008-2015, respectively, and related the change in frequency (performance) of the species to a wide range of species-specific plant traits. We chose traits representing all plausible drivers of recent floristic changes: climatic change (northern distribution limit, flowering time), land-use change (light requirement, response to grazing/mowing, response to soil disturbance), drainage (water requirement), acidification (pH optimum), nitrogen deposition and eutrophication (N requirement, N fixation ability, carnivory, parasitism, mycorrhizal associations), pollinator decline (mode of reproduction) and changes in CO levels (photosynthetic pathway). Our results suggest that climate warming and changes in land-use were the main drivers of changes in the flora during the last decades. Climate warming appeared as the most influential driver, with northern distribution limit explaining 30%-60% of the variance in the GLMM models. However, the relative importance of the drivers differed among habitat types, with grassland species being affected the most by cessation of grazing/mowing and species of ruderal habitats by on-going concentration of both agriculture and human population to the most productive soils. For wetland species, only pH optimum was significantly related to species performance, possibly an effect of the increasing humification of acidic water bodies. An observed relative decline of mycorrhizal species may possibly be explained by decreasing nitrogen deposition resulting in less competition for phosphorus. We found no effect of shortage or decline of pollinating lepidopterans and bees.
在 20 世纪，土地利用变化、污染和气候变暖导致了全球生物多样性的变化。然而，在许多情况下，环境驱动因素还了解甚少。为了确定并排名目前导致北欧广泛的植物区系变化的驱动因素，我们分析了瑞典最南端斯科讷的 200 个随机选择的 2.5×2.5 公里网格方块的两个维管植物调查的数据，这两个调查分别于 1989-2006 年和 2008-2015 年进行，并将物种频率（表现）的变化与广泛的物种特异性植物特征相关联。我们选择了代表最近植物区系变化的所有可能驱动因素的特征：气候变化（北方分布极限、开花时间）、土地利用变化（光照需求、对放牧/修剪的反应、对土壤干扰的反应）、排水（水分需求）、酸化（pH 最佳值）、氮沉降和富营养化（氮需求、固氮能力、肉食性、寄生性、菌根关系）、传粉媒介减少（繁殖方式）和 CO2 水平变化（光合作用途径）。我们的结果表明，气候变暖以及土地利用的变化是过去几十年植物区系变化的主要驱动因素。气候变暖似乎是最具影响力的驱动因素，北方分布极限解释了 GLMM 模型中 30%-60%的方差。然而，驱动因素的相对重要性因生境类型而异，草原物种受放牧/修剪停止的影响最大，而荒地生境的物种则受农业和人口向最肥沃土壤集中的影响最大。对于湿地物种，只有 pH 最佳值与物种表现显著相关，这可能是酸性水体腐殖化增加的影响。观察到菌根物种相对减少可能是由于氮沉降减少导致对磷的竞争减少所致。我们没有发现传粉鳞翅目和蜜蜂短缺或减少的影响。
