Resumo

SAAVEDRA-ROMERO, L. de L. et al. Diversity, tree structure, and importance value index in an urban park in Mexico City. Polibotánica [online]. 2019, n.47, pp.25-37. ISSN 1405-2768.  https://doi.org/10.18387/polibotanica.47.3.

Urban trees are an essential component of all city´s facilities. The San Juan de Aragon Park (SJAP) in Mexico City, is considered a green area with environmental value; however, there is little research on the diversity and structure as a health indicator. The aims of the study were to adapt the Forest Health methodology for tree diversity and structure indicators (DSI) to assess SJAP current´s condition. A total of 28 circular sites (0.1 ha) were randomly established. For each tree, taxonomic identification, normal diameter (Nd) and total height (Th) were registered. Basal area (Ba), compound volume, crown surface as well as the Simpson, Berger-Parker, and an urban importance value index (UIVI) was determined. The Casuarinaceae, Proteaceae, Myrtaceae and Cupressaceae families were the most abundant with 69% of the total density. Average Nd, Th and Ba were 155 cm, 8.6 m, and 0.40 m2 ha-1, respectively. Simpson index was 0.85 representing a high dominance y low richness, Berger-Parker values (0.66) concentrates abundance in four species. The highest UIVI were obtained for Casuarina equisetifolia (31.98%), and Eucalyptus camaldulensis (19.96%). Tree diversity was low, similar to other urban green areas. The UIVI identifies species with the actual highest potential to provide ecosystem services due to their highest biomass and coverage.

Palavras-chave : urban forest; forest health; diversity indexes.