Early recovery of subtropical dry forest in southwestern Puerto Rico

Abstract

Tree cover and species composition were surveyed in 1998, 2003, and 2010 after the elimination of grazing and fire on the lower 32 hectares of the Tinaja tract at Laguna Cartagena National Wildlife Refuge in south-western Puerto Rico. Surveys of the secondary subtropical dry forest showed that stems increased 3.9 times, trees 6.7 times, basal area 3.3 times, and biomass 4.4 times between 1998 and 2010. Notable differences occurred by site. Greater numbers of stems and trees, greater basal areas, and usually biomass were tallied on 10 plots along the southern boundary closer to residual tree cover than on the northern 22 plots in all three years of measurement. Four plots situated in arroyos and one plot along a fence-line also showed greater values when compared to the respective mean values for all 32 plots on lower Tinaja. Other major trends between 1998 and 2010 were: exotics increased from 70 to 84% of the trees; the ratio of stems to trees declined from 2.3. to 1.3; Leucaena leucocephala (Lam.) DeWit increases from 7 to 53% of the stems and from 14 to 64% of the trees; Pilosocereus royennii (L.) Byles and Rowley decreased from 10 to 2 % of the stems and from 7 to 1 % of the trees, largely due to attack by the cactus mealybug, Hypogeococcus pungens; and tree species richness increased from 30 to 34.

Citation

Weaver, Peter L. 2011. Early recovery of subtropical dry forest in southwestern Puerto Rico. Bois et Forets des Tropiques. No. 310(4): 11-23.