Evolução de nicho e evidências ecológicas e foliares em um gênero de bambus pigmeus (Piresia Swallen, Poaceae)

Abstract

This study investigates the ecological niches and leaf morphometric patterns of Piresia Swallen lineages, a genus of Neotropical herbaceous bamboos with a disjunct geographic distribution (Amazon and the Atlantic Forest of northeastern Brazil) of its species. Georeferenced data were collected from vouchers deposited in the main national and international collections, together with soil (Soilgrids) and bioclimatic (WorldClim) variables. Basal and median leaves were measured in all intact materials that could be identified from available photographs. The analyses included ecological niche overlap, geometric leaf morphometry, and comparison between data using the Mantel test. The results indicate that there is no direct correlation between environmental space and leaf shape and size. Ecological niches differ among lineages from different biomes, and the morphometric differences, although discrete, also reflect the geographic and phylogenetic disjunction between clades. Edaphic variables were identified as significant factors in the divergence of the lineages, suggesting that future investigations may include more detailed analyses of these variables. We also highlight the possibility of incipient speciation for some apparently cryptic lineages.