Diversidad, estructura y cobertura del dosel arbóreo en dos tipos de bosque parque en el área protegida esteros y algarrobales del Río Uruguay

Forest and savanna ecosystems in Uruguay cover only a small portion of the country’s territory, but they play an important role due to their biodiversity and the ecosystem services they provide. The park forests of the western coast, associated with the Espinal Biogeographic Province, constitute floristically unique ecosystems within the national context and are highly vulnerable to changes in land use. The objective of this thesis was to study the tree diversity and structure of two types of park forests—dense and sparse—compare them with each other, and evaluate their association with the soil characteristics of their habitats. To achieve this objective, 10 plots (20x20 m) were established in the “Esteros y Algarrobales del Río Uruguay” protected area: 5 in a dense stratum on silty soils and 5 in a sparse stratum on alkaline soils. All trees with a diameter at breast height (DBH) greater than 2.5 cm were identified and measured. Soil samples were also collected from these plots and analyzed by members of the research team. A species list was compiled for each stratum, and diversity indices were calculated. Tree structure was studied, and the Importance Value Index (IVI) was calculated for each forest type. To compare diversity across strata, similarity indices were applied, species abundances were compared, and principal component analyses were conducted. Finally, to evaluate the diversity-soil association, principal component analyses and generalized regression models were performed. Species richness was similar between the two forest types studied, although their composition and structure were markedly different, as reflected in the low floristic similarity between the two communities. While Neltuma spp. and Vachellia caven predominate in the open stratum, Allophylus edulis, Scutia buxifolia, and Neltuma spp. stand out in the dense stratum. Soil was found to have a strong influence on the diversity of these forests, with pH and bulk density having a notable effect on species composition and abundance. The information generated in this study provides tools for the conservation and management of Uruguay’s park forests.