Data from: The importance of scattered trees for biodiversity conservation: a global meta-analysis

1. Scattered trees are thought to be keystone structures for biodiversity in landscapes worldwide. However, such trees have been largely neglected by researchers and their importance for biodiversity remains unclear. 2. We completed a global meta-analysis to quantify relationships between scattered trees and the species richness, abundance and composition of vertebrates, arthropods and plants. First, we tested whether areas near scattered trees support higher levels of species richness and abundance than nearby open areas. Second, we compared levels of species richness and abundance in matrix areas with scattered trees and areas embedded within nearby habitat patches. We also compared the composition of biological communities inhabiting habitat patches, open areas and areas with scattered trees. 3. A total of 62 studies contained suitable data for our quantitative analyses. The local abundance of arthropods, vertebrates and woody plants was 60-430% greater and overall species richness was 50-100% higher in areas with scattered trees than in open areas. Conversely, for herbaceous plants, there was no consistent relationship between species abundance and the occurrence of scattered trees, although species richness was, on average, 43% lower. 4. The abundance and richness of all taxonomic groups was similar in matrix areas supporting scattered trees and habitat patches, although the species richness of epiphytes was, on average, 50% higher in habitat patches. Communities inhabiting habitat patches were more similar in composition to the communities inhabiting areas with scattered trees, and less similar to the communities of open areas. 5. Synthesis and applications. Areas with scattered trees support greater levels of biodiversity than open areas, as well as communities that are more similar to those inhabiting habitat patches. Scattered trees can be regarded as keystone structures for vertebrates, arthropods and terrestrial plants in landscapes worldwide. The maintenance of scattered trees may be compatible with livestock grazing in some agricultural landscapes. Greater management effort and targeted, long-term policies are needed to retain or re-establish scattered trees in many farming landscapes in both forest and non-forest biomes around the world.04-May-20171. 散生树木（scattered trees）被认为是全球各类景观中维持生物多样性的关键结构（keystone structure）。然而，此类树木长期以来被研究者大幅忽视，其对生物多样性的重要性仍未明确。 2. 本研究开展了一项全球尺度的元分析（meta-analysis），以量化散生树木与脊椎动物（vertebrates）、节肢动物（arthropods）及植物的物种丰富度、多度和群落组成之间的关联。首先，我们验证了散生树木周边区域是否比邻近开阔区域拥有更高的物种丰富度与多度；其次，我们对比了带有散生树木的基质生境（matrix areas）与嵌入邻近栖息地斑块（habitat patches）内区域的物种丰富度及多度差异；此外，我们还比较了栖息于栖息地斑块、开阔区域及散生树木分布区域的生物群落组成差异。 3. 共计62项研究提供了适用于本定量分析的数据。相较于开阔区域，散生树木分布区域的节肢动物、脊椎动物及木本植物的本地多度提升了60%~430%，整体物种丰富度提升了50%~100%。与之相反，对于草本植物（herbaceous plants）而言，其物种多度与散生树木的存在并无一致关联，但其物种丰富度平均降低了43%。 4. 带有散生树木的基质生境与栖息地斑块内，所有生物类群的多度与丰富度均较为相近，不过附生植物（epiphytes）的物种丰富度在栖息地斑块内平均高出50%。栖息于栖息地斑块的生物群落，其组成与散生树木分布区域的群落更为相似，而与开阔区域的群落相似度较低。 5. 综合与应用 散生树木分布区域的生物多样性水平高于开阔区域，且其栖息的生物群落与栖息地斑块内的群落更为相似。散生树木可被视为全球各类景观中维持脊椎动物、节肢动物及陆生植物的关键结构。在部分农业景观中，保留散生树木可与畜牧放牧兼容。全球范围内的森林与非森林生物群系（biomes）中的多数农业景观，均需要加大管理投入并制定针对性的长期政策，以保留或重建散生树木。2017年5月4日