Measure what you manage? Comparing urban forest composition metrics used in research assessing carbon and avian outcomes of urban forest management

Abstract

Urban forests are multifunctional social-ecological systems that can contribute to both climate change mitigation and biodiversity conservation. However, management of urban forests for these objectives are often studied independently. Knowing which measures can be used to assess multiple objectives could enable integrated monitoring efforts and subsequently increase potentials for synergies in management. We compared the use of forest composition metrics in studies focused on carbon storage ( n = 109) and avian diversity ( n = 158) extracted from a published systematic literature map. Through qualitative content analysis, we developed a standardized set of 24 urban forest composition metrics spanning size, taxonomy, structure, tree characteristics, and presence of vegetation layer types. Analysis assessed frequency and co-occurrence of metrics for research assessing carbon or avian outcomes. Carbon-focused studies were dominated by a smaller and more restricted set of variables, with tree species composition and diameter measured in over 90% of studies. In contrast, avian studies used a broader and specialized suite of metrics, emphasizing different types of vegetation layers and diverse habitat features such as shrubs, cavities, and fruit resources. Co-occurrence analysis revealed tightly clustered measurement frameworks in carbon studies and somewhat more diffuse patterns in avian research. These results highlight how the same measures of urban forest composition have been and can be used to assess both avian and carbon management outcomes. Overlaps and gaps identified places where alignment in urban forest monitoring could improve the capacity to manage for multiple outcomes.

Citation

Bassett, Corinne G.; Liddell, Jessica; Ziter, Carly; Frei, Barbara. 2026. Measure what you manage? Comparing urban forest composition metrics used in research assessing carbon and avian outcomes of urban forest management. Environmental Research: Ecology. 5(4): 045004. 14 p. https://doi.org/10.1088/2752-664x/aeb67d.