Land-use intensification causes multitrophic homogenization of grassland communities
Land-use intensification causes multitrophic homogenization of grassland communities
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DOI：
10.1038/nature20575
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发表时间：
2016-12-08
期刊：
影响因子：
64.8
通讯作者：
Allan, Eric
中科院分区：
文献类型：
--
作者：
Gossner, Martin M.;Lewinsohn, Thomas M.;Allan, Eric
土地利用集约化是生物多样性丧失的主要驱动力（1，2）。随着当地物种多样性的减少，在更大的空间尺度上的生物同质化是保护的极大关注。生物同质化意味着β多样性（地点之间的组成差异）的减少。大多数研究都调查了局部（α）多样性（1，3）的损失，而忽视了更大空间尺度上的生物多样性损失。关于β多样性的研究集中于单一或少数几个生物群体（例如，参考文献4），因此不知道土地利用的集约化是否使地上和地下不同营养水平的群落均质化。在这里，我们表明，即使是适度增加当地土地利用强度（LUI）的微生物，植物和动物群体，地上和地下的生物同质化，这在很大程度上是独立的α多样性的变化。我们分析了一个独特的草原生物多样性数据集，其中包含属于12个营养组的4，000多种物种。LUI，特别是，高割草强度，有一致的影响β-多样性的各组，造成土壤微生物，真菌病原体，植物和节肢动物群落的同质化。这些影响是非线性的，β-多样性下降最强烈的过渡发生在广泛管理的中间强度草地。LUI倾向于降低地上群体的α多样性，而地下群体的α多样性增加。不同群体的α多样性之间的相关性，特别是植物和它们的消费者之间的相关性，在高LUI下变得较弱。这表明专业物种的损失，是生物同质化的进一步证据。土地利用指数对草原规模生物多样性的持续负面影响突出表明，广泛管理的草原对于保护多营养生物多样性和提供生态系统服务具有很高的价值。事实上，生物同质化而不是当地多样性的丧失可能是土地使用集约化的最严重后果。
Land-use intensification is a major driver of biodiversity loss(1,2). Alongside reductions in local species diversity, biotic homogenization at larger spatial scales is of great concern for conservation. Biotic homogenization means a decrease in beta-diversity (the compositional dissimilarity between sites). Most studies have investigated losses in local (alpha)-diversity(1,3) and neglected biodiversity loss at larger spatial scales. Studies addressing beta-diversity have focused on single or a few organism groups (for example, ref. 4), and it is thus unknown whether land-use intensification homogenizes communities at different trophic levels, above-and belowground. Here we show that even moderate increases in local land-use intensity (LUI) cause biotic homogenization across microbial, plant and animal groups, both above- and belowground, and that this is largely independent of changes in alpha-diversity. We analysed a unique grassland biodiversity dataset, with abundances of more than 4,000 species belonging to 12 trophic groups. LUI, and, in particular, high mowing intensity, had consistent effects on beta-diversity across groups, causing a homogenization of soil microbial, fungal pathogen, plant and arthropod communities. These effects were nonlinear and the strongest declines in beta-diversity occurred in the transition from extensively managed to intermediate intensity grassland. LUI tended to reduce local alpha-diversity in aboveground groups, whereas the alpha-diversity increased in belowground groups. Correlations between the alpha-diversity of different groups, particularly between plants and their consumers, became weaker at high LUI. This suggests a loss of specialist species and is further evidence for biotic homogenization. The consistently negative effects of LUI on landscape-scale biodiversity underscore the high value of extensively managed grasslands for conserving multitrophic biodiversity and ecosystem service provision. Indeed, biotic homogenization rather than local diversity loss could prove to be the most substantial consequence of land-use intensification.