Effects of compositional and configurational heterogeneity of the urban matrix on the species richness of woody plants in urban remnant forest patches

Context Urban remnant forest exists as patches scattered in an urban matrix. They are important sites for urban biodiversity conservation. Nevertheless, it is unclear how the properties of the urban matrix affect the biodiversity of remnant patches. Objective Using data surveyed from 30 urban remnant forest patches in Guiyang, China, we intended to find out whether heterogeneity of the urban matrix affects the species richness of woody plants in these patches significantly. Methods We used landscape indices calculated from land cover data to quantify compositional and configurational heterogeneity of the urban matrix. Then we analyzed the association between heterogeneity of the urban matrix and the species richness of woody plants in remnant forest patches using generalized linear regression models. Results A significant positive association between compositional heterogeneity of the urban matrix and the species richness of tree sapling/seedlings existed when the urbanization level of the urban matrix was high. Also, compositional heterogeneity of the urban matrix correlated significantly with the species richness of shrubs in patches when the change rate of urbanization level of the urban matrix was low. Configurational heterogeneity of the urban matrix could enhance the association between patch attributes and the species richness of tree sapling/seedlings and shrubs. Conclusions Heterogeneity of the urban matrix affected the woody plant diversity of the remnant forest patches through the interaction effects with patch attributes and the urbanization level of the urban matrix. We recommend including the management of heterogeneity of the urban matrix as an essential part of works to conserve biodiversity in urban remnant forest patches.

Automated summary

The heterogeneity of the urban matrix significantly affects the species richness of woody plants in remnant forest patches, particularly when the urbanization level is high. Compositional heterogeneity of the urban matrix is positively correlated with the species richness of tree sapling/seedlings, while it is significantly associated with the species richness of shrubs when the change rate of urbanization level is low. Configurational heterogeneity of the urban matrix can enhance the correlation between patch attributes and the species richness of tree sapling/seedlings and shrubs.