Chinea J.D.
Diversity and composition of tropical secondary forests recovering from large-scale clearing: results from the 1990 inventory in Puerto Rico
Sat, 07/30/2011 - 13:14 — ckassChinea, J. Danilo; Helmer, Eileen H. 2003. Diversity and composition of tropical secondary forests recovering from large-scale clearing: results from the 1990 inventory in Puerto Rico.. Forest Ecology and Management 180 :227-240.
Abstract:
The extensive recovery from agricultural clearing of Puerto Rican forests over the past half-century provides a good opportunity to study tropical forest recovery on a landscape scale. Using ordination and regression techniques, we analyzed forest inventory data from across Puerto Ricos moist and wet secondary forests to evaluate their species composition and whether the landscape structure of older forest affected tree species composition of recovering forests at this scale. Our results support conclusions from studies conducted in Puerto Rico at smaller scales and temperate forests at larger scales that timing of abandonment and land use history are of overwhelming importance in determining the species composition of recovering forests. Forest recovery is recent enough in Puerto Rico that previous land use is clearly evident in current species composition, and creates new forest communities. As demonstrated in other work, physical factors such as elevation and substrate co-vary with land use history, so that the species composition of the forest landscape results from the interplay between biophysical and socioeconomic forces over time. Our results also indicate that increasing the distance to the largest forest patches occurring in the landscape 12 years previous had a small negative impact on species richness but not species diversity or community composition.We conclude that land use history has as much influence in species composition as biophysical variables and that, at the scale of this study, there is no large influence of forest landscape structure on species diversity or composition.
Changes in the herbaceous and vine communities at the Bisley Experimental Watersheds, Puerto Rico, following Hurricane Hugo
Thu, 07/21/2011 - 20:10 — ckassChinea, Jesus D. 1999. Changes in the herbaceous and vine communities at the Bisley Experimental Watersheds, Puerto Rico, following Hurricane Hugo.. Can. J. For. Res. 29: 1433-1437 .
Abstract:
While herbaceous species and vines constitute a minor portion of the biomass in tropical closed forest
ecosystems, they account for a substantial portion of the diversity of these ecosystems and become more conspicuous
after natural disturbances. This study describes the changes in abundance and diversity of the herbs and vines during
5 years following Hurricane Hugo at the Bisley Experimental Watersheds, Puerto Rico. The cover of herbs, ferns, and
vine species was sampled within a 5-m2 area in 25 randomly chosen circular permanent plots within the 13 ha of these
watersheds. Sampling was done 12, 18, 36, 48, and 60 months after the hurricane. One year after the hurricane the
overall mean herbaceous cover in the watersheds was 55%. Four years later, the cover and species richness of herbs
and vines, but not ferns, had been significantly reduced. The only change in species diversity (H¢ ) was a significant
increase in ferns. These changes are explained in terms of the extent and spatial variability of the hurricane damage, as
well as changes in the tree component of this ecosystem.
An Annotated List of the Flora of the Bisley Area, Luquillo Experimental Forest, Puerto Rico 1987 to 1992
Thu, 07/21/2011 - 17:15 — ckassChinea, J. D., R. J. Beymer, C. Rivera, I. Sastre de Jesu´ s, and F.
N. Scatena. 1993. An annotated list of the flora of the Bisley
Area, Luquillo Experimental Forest, Puerto Rico 1987 to 1992.
General Technical Report SO-94:1–12. U.S. Department of Agriculture,
Southern Forest Experiment Station, New Orleans.
Abstract:
Known species of plants, including bryophytes and ferns, are listed
for the area of the Bisley experimental watershed area, a subtropical
wet forest in the Luquillo Mountains of northeastern Puerto
Rico.
The First five years in the reorganization of aboveground biomass and nutrient use following hurricane Hugo in the bisley Experimental Watersheds, luquillo Experimental Fortest, Puerto Rico
Thu, 07/21/2011 - 16:28 — ckassScatena, F. N. ; Moya, S.; Estrada, C; Chinea, J.D. 1996. The First five years in the reorganization of aboveground biomass and nutrient use following hurricane Hugo in the bisley Experimental Watersheds, luquillo Experimental Fortest, Puerto Rico. Biotropica 28(4) : 424-440.
Abstract:
Five years after Hurricane Hugo reduced the aboveground biomass by 50 percent in two forested watersheds in the Luquillo Experimental Forest of Puerto Rico, regeneration and growth of survivors had increased the aboveground biomass to 86 percent of the pre-hurricane value. Over the 5 yr, the net aboveground productivity averaged 21.6 Mg·ha-1·yr-1 and was faster than most plantations and secondary forests in the area. Woodfall and associated nutrient fluxes never attained pre-storm values but by the fifth yr, mean daily total litterfall, and N, P, K, Ca, and Mg fluxes in litterfall were 83, 74, 62, 98, 75, and 81 percent of their pre-disturbance values, respectively. Aboveground nutrient pools of these nutrients ranged from 102 to 161 percent of their pre-disturbance values and were larger after 5 yr because of higher nutrient concentrations in the regeneration compared to the older wood that it replaced. The following sequence of ecosystem reorganization during this first 5 yr period is suggested. An initial period of foliage production and crown development occurred as hurricane survivors re-leafed and herbaceous vegetation and woody regeneration became established. During this period, 75 to 92 percent of the nutrient uptake was retained in the aboveground vegetation and there was a relatively low rate of aboveground carbon accumulation per mole of nutrient cycled. This initial period of canopy development was followed by a peak in aboveground productivity that occurred as early successional species entered the sapling and pole stages. This period was followed by the establishment of the litterfall nutrient cycle and an increase in the net productivity per mole of nutrient cycled. During this 5 yr period, the Bisley forest had some of the lowest withinstand nutrient-use-efficiencies and some of the highest levels of aboveground productivity ever observed in the LEF. The study demonstrates that high levels of productivity and rapid rates of aboveground reorganization can be achieved with rapid within-system cycling and inefficient within-stand nutrient use.
