Dead wood resources vary across different types of urban green spaces and depend on property prices

Abstract

Dead wood provides important ecosystem services and has a positive effect on biodiversity. However, urban environments have limited resources of coarse woody debris (CWD). The presence of CWD depends on both progressive tree mortality and the frequency and intensity of CWD removal for safety or aesthetic reasons, which can lead to variations in CWD occurrence. The aim of this study was to assess the variation in the quantity and quality of CWD in urban green spaces and to assess the relationship between CWD resources and management policy, ownership, economic parameters and factors accelerating tree mortality. Fallen logs, dead standing trees and dead tree branches (DTB) were surveyed on 488 sample plots selected at random in the city of Kraków (Poland). Distance to the river, coverage of impervious surfaces, environmental pollution, property prices and types of green space were used to explain the variation in CWD resources. CWD occurred on 46% of the sample plots. DTB were the most frequent form of CWD (44% of plots), while dead standing trees were rare (4%) and fallen logs absent. The prevalence of CWD was the highest in forest remnants, followed by private gardens, urban parks, fallow land and small green patches. DTB were the most abundant in the forest remnants. In both forest remnants and private gardens, the probability of CWD occurrence decreased with increasing property prices. Management policy and economy rather than factors accelerating tree mortality are suggested as shaping CWD resources in urban green spaces. The article highlights the importance of DTB as the most widespread form of CWD and forest remnants as the type of green space having the most abundant resources of CWD. Sustainable management of CWD resources within urban green spaces and environmental education are needed to conserve biodiversity and maintain ecosystem services.