VEGETATION AND FLORA OF THE ISLANDS OF OHUIRA BAY, AHOME, SINALOA, PART OF THE APFF ISLANDS OF THE GULF OF CALIFORNIA.

Abstract

A study of flora and vegetation was conducted on six small islands in the Bahía de Ohuira, Topolobampo, Sinaloa. Soils on these islands are predominantly rocky, and the landscape is dominated by xerophytic scrub, with a clear prevalence of columnar cacti and Opuntia-dominated vegetation. At the coastal margins where islands meet the water, typical mangrove formations occur, as well as remnants of halophytic vegetation. The floristic inventory documented 152 plant species, arranged in 118 genera and 45 families. The richest families were Fabaceae (18 species), Cactaceae (16), Euphorbiaceae (13) and Poaceae (12); among the genera, Euphorbia stood out with six species, while Abutilon, Ipomoea and Opuntia each included four species. Regarding life-form categories, herbs (H) dominated, constituting 38.8 % of total species, followed by shrubs (Ar) at 26.97 % and climbers (Tr) at 11.84 %. The islands with the greatest floristic richness were Mazocahui (120 species), Mazocahui II (64 species) and Patos (54 species). Although this archipelago represents a relatively low number of plant spspecies, hin the Flora and Fauna Protection Area “Islas del Golfo de California, Sinaloa section”, it is distinguished by minimal deforestation, low tourism pressure, and a limited presence of invasive species (either exotic or introduced native species) with only 29 such species recorded. This study contributes to the knowledge of insular plant diversity in the Gulf of California and suggests that these islands, despite their relatively low species richness, still harbor comparatively intact plant communities, underscoring their ecological value and the need for their conservation.