Urban biotope classification incorporates urban forest and green infrastructure for improved environmental land-use planning in Mexico City

Abstract

Urban forests are recognized worldwide as the most critical component of green infrastructure due to their capacity to provide various environmental goods and services. As cities continue to expand and their environmental problems intensify, there is a growing need for urban forests and green infrastructure to be better incorporated into strategic land-use planning, especially in developing cities. The first step in building an urban forest management plan is to capture characteristics of the urban forest and how these change across the built environment. Here, we used an urban biotope approach to classify urban forests and environmental characteristics in Mexico City. We sampled 500 fixed-area randomly stratified plots across the city to characterize urban forest structural and compositional variables. PCA and the broken-stick method were used to reduce the number of 25 urban forest variables down to five significant principal components that accounted for 78% of the data's cumulative variation. Ward's method helped classify biotopes into a hierarchical system with seven finer-level biotopes defined by urban forest characteristics (Dunn = 0.09, AC = 0.98), nested within two broader-level biotopes defined by forest canopy conditions (Silhouette = 0.59, AC = 0.99). A no-tree canopy biotope was extracted from sampling locations with no trees. The biotopes derived here can fundament biotope mapping, and support decision-making in urban forest planning, including the identification of available planting spaces, tree diversity targets, and canopy protection. Our work in Mexico City demonstrates how the biotope approach can be adapted and used to better incorporate urban forests and green infrastructure into future management planning for any city.