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...