Land abandonment and intensification diminish spatial and temporal β-diversity of grassland plants and herbivorous insects within paddy terraces

1. Although traditional land-use and management practices are known to enhance environmental heterogeneity in agricultural lands, loss of heterogeneity resulting from recent land-use changes can lead to spatiotemporal β-diversity losses (biotic homogenization). However, patterns and causes of β-diversity loss, especially at a within-field scale, have remained unexplored. 2. We examined β-diversity declines in plants, butterflies and orthopterans resulting from land abandonment and intensification in semi-natural grasslands on paddy margins at a within-field scale in relation to changes in disturbance frequency and surrounding landscapes by surveying eight abandoned, thirteen traditional and ten intensive paddy terraces. Three indices, the additive partitioning of species richness (βadd) and the turnover (βtu) and nestedness (βne) components of Jaccard dissimilarity of plants and herbivores, were used to evaluate different aspects of β-diversity. We hypothesized that biotic homogenizatio...

1. 尽管已有研究证实，传统土地利用与管理实践可提升农田的环境异质性，但近期土地利用变化引发的异质性丧失，会导致时空β多样性（β-diversity）损失，即生物均质化（biotic homogenization）。然而，β多样性丧失的格局与驱动机制，尤其是田块尺度内的相关规律，迄今仍未得到探索。2. 本研究聚焦稻田边际的半自然草地，通过实地调查8块撂荒、13块传统管理及10块集约化稻田梯田，结合干扰频率与周边景观的变化情况，探究了土地撂荒与集约化利用对田块尺度内植物、蝶类及直翅目昆虫β多样性的影响。研究选用三类指标以评估β多样性的不同维度：物种丰富度加性分解指数（βadd），以及植物与植食性动物雅卡尔相异度（Jaccard dissimilarity）的周转组分（βtu）与嵌套组分（βne）。我们提出假说：生物均质化……