ORCHID DIVERSITY (Orchidaceae) IN TWO URBAN SITES IN THE STATE OF VERACRUZ, MEXICO

Abstract

Knowledge of urban orchids and their phorophytes is essential for conservation and education initiatives in these areas. The objective of this study was to assess the diversity of epiphytic orchids and identify their phorophytes at Postgraduate College Campus Córdoba (CPCC) and Paso Coyol Ecological Park (PEPC) in order to better understand the differences in their composition. The hypothesis was that the diversity of naturally established orchids would be higher in the less urbanized area, while the phorophytes would be mostly introduced trees. Orchids growing on phorophytes of the garden area (12 000 m²) of both sites were quantified from November 2019 to December 2021. The origin (endemic, native, or exotic) of the orchids and their phorophytes were determined. Simpson and Shannon-Weaver diversity indices were applied, and Whittaker curves were developed. A total of 13 419 orchid individuals were recorded, divided into 31 species, with 26 species reported in the CPCC and 17 in the PEPC. The Simpson and Shannon-Weaver indices showed that the diversity of epiphytic orchids was higher in the CPCC (1-D = 0.78) than in the PEPC (1-D = 0.41). In contrast, species dominance was lower in the CPCC (H = 2.6) than in the PEPC (H = 1.16). Whittaker curves showed that Catasetum integerrimum was the most abundant species in the CPPC and Platystele stenostachya in the PEPC. The CPCC had a greater level of diversity. Fifteen species of phorophytes were recorded in the CPCC and 10 in the PEPC, with a predominance of exotic species, while introduced species accounted for 70 % of the phorophytes found.