Anthropogenic-driven species extinctions are radically changing the biosphere. Biological communities may become increasingly similar to or dissimilar from one another via the processes of biotic homogenisation or heterogenisation. A key question is how the conversion of native forests to agriculture may influence these processes by driving changes in the occurrence patterns of restricted-range endemic species versus wide-ranging generalists. We examined biotic homogenisation and heterogenisation in bird communities on the Southeast Asian islands of Borneo, Sulawesi, Seram, Buru, Talaud and Sangihe. Each island is characterised by high levels of avian endemism and unique spatial configuration of forest conversion to agriculture. Forest conversion to agriculture influenced the patterns of biotic homogenisation on five islands. Bird communities became increasingly dissimilar to forest reference communities relative to localised patterns of deforestation. Turnover led to species with larger global range-sizes dominating communities at the expense of island endemics and ecological specialists. Within islands, forest conversion did not result in clear changes to β-diversity, whereas between-island communities became increasingly similar with greater deforestation, implying that patterns of forest conversion profoundly affect biotic homogenisation. Our findings elucidate how continued conversion of forests is causing the replacement of endemic species by a small cohort of shared ubiquitous species with potentially strong negative consequences for ecosystem functioning and resilience. Halting reorganisation of the biosphere via the loss of range-restricted species and spread of wide-ranged generalists will require improved efforts to reduce the impacts of deforestation, particularly in regions with high endemism.

中文翻译：

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森林砍伐的严重程度介导岛屿群岛的生物同质化

人为驱动的物种灭绝正在从根本上改变生物圈。通过生物同质化或异质化的过程，生物群落可能变得越来越相似或彼此不同。一个关键问题是原生森林向农业的转变如何通过推动限制范围的特有物种与广泛的通才的发生模式的变化来影响这些过程。我们检查了婆罗洲、苏拉威西、塞拉姆、布鲁、塔劳德和桑吉赫等东南亚岛屿鸟类群落的生物同质化和异质化。每个岛屿的特点是高水平的鸟类特有性和独特的森林转化为农业的空间配置。森林转为农业影响了五个岛屿的生物同质化模式。相对于局部森林砍伐模式，鸟类群落与森林参考群落变得越来越不同。周转导致具有更大全球范围的物种以牺牲岛屿特有物种和生态专家为代价主导群落。在岛屿内，森林转化并未导致 β 多样性发生明显变化，而随着森林砍伐的增加，岛屿间的群落变得越来越相似，这意味着森林转化的模式深刻地影响了生物同质化。我们的研究结果阐明了森林的持续转变如何导致地方性物种被一小群共享的普遍存在的物种所取代，这些物种可能对生态系统功能和恢复力产生强烈的负面影响。