Tropical and subtropical agroecosystems
versão On-line ISSN 1870-0462
ESQUIVEL-MIMENZA, Humberto et al. Dispersed trees in pasturelands of cattle farms in a tropical dry ecosystem. Trop. subtrop. agroecosyt [online]. 2011, vol.14, n.3, pp.933-941. ISSN 1870-0462.
In many tropical cattle farms of Central America, farmers commonly retain trees in pastures to obtain timber and provide shade and fodder to cattle. However, little is known about the diversity, abundance, richness and species composition of dispersed trees in pastures of cattle farms in the dry tropics. Therefore, the objective of this study was to characterize and describe the pattern of tree cover dispersed in pastures of cattle farm systems assessing their roles in sustaining farm productivity. The study was conducted in 16 cattle farms in a tropical dry ecosystem in Costa Rica. A total of 5,896 trees, from 36 families and 99 species, were found dispersed in pastures (836 ha). Trees were present on 100% of the farms and in 85% of pastures and they occurred as individual trees (54%) and clustered (46%). The most abundant families are Bignonaceae, Sterculeaceae and Boraginaceae. The most common tree species were Tabebuia rosea (Bertol.) DC, Guazuma ulmifolia Lam, Cordia alliodora (Ruiz & Pav.) Oken and Acrocomia acule ata (Jacq.) Lodd. ex Mart, which together accounted for 60% of the total number of trees. Tree species with smaller crowns are found at higher densities than tree species with large crowns. Pastures mean crown cover was 7% (SE ± 0.54) and mean tree density was 8.1 trees ha-1 (SE ± 0.66). We conclude that farmers are managing a low tree diversity, cover (m2 ha-1) and density (trees ha-1) for fulfilling different farm needs that contribute to farm productivity but minimizing interference with pasture productivity.
Palavras-chave : Abundance; Diversity; Richness; Silvopastoralism; Tree cover.