Urban tree cover improves breeding bird abundance across all public cemeteries in one of Europe's largest cities

Abstract

Urbanisation leads to the destruction and fragmentation of natural landscapes, significantly reducing biodiversity and impacting ecological functions and services. Green spaces within cities, particularly cemeteries, act as refuges for urban biodiversity and provide vital habitats for various ecological groups, such as birds. Understanding how both local and landscape factors influence biodiversity in urban cemeteries is essential to inform effective conservation efforts. This study assessed breeding bird abundance, richness, and diversity across all of Munich’s public cemeteries during May and June 2022. The influence of local variables (cemetery size and tree cover) and landscape variables (tree cover and road cover within a 1 km radius) was analysed using GIS. Surprisingly, none of these explanatory variables had a strong effect on species richness, diversity, or taxonomic diversity. This may indicate the need to examine other spatial scales or use different measures of urbanisation. However, bird abundance within fixed-radius point counts in the largest and most densely wooded cemeteries was approximately two thirds greater than in the smallest and least densely wooded cemeteries, indicating that both area and tree coverage are critical for supporting bird populations. These findings highlight trees as key habitat features in urban cemeteries, suggesting that tree conservation and health should be top priorities for urban green space management. This further supports the need to conserve urban trees for the multiple benefits they provide to human residents. Further research into the functional diversity of urban cemetery birds and the influence of cemetery tree age on these avian communities is recommended.