hurricane damage
Hurricane-induced nitrous oxide fluxes from a wet tropical forest
Wed, 07/27/2011 - 13:58 — ckassErickson HE, Ayala G (2004) Hurricane-induced nitrous oxide
fluxes from a wet tropical forest. Global Change Biology, 10,
1155–1162.
Abstract:
Hurricane activity is predicted to increase over the mid-Atlantic as global temperatures
rise. Nitrous oxide (N2O), a greenhouse gas with a substantial source from tropical soils,
may increase after hurricanes yet this effect has been insufficiently documented. On
September 21, 1998, Hurricane Georges crossed Puerto Rico causing extensive
defoliation. We used a before–after design to assess the effect of Georges on N2O
emissions, and factors likely influencing N2O fluxes including soil inorganic nitrogen
pools and soil water content in a humid tropical forest at El Verde, Puerto Rico.
Emissions of N2O up to 7 months post-Georges ranged from 5.92 to 4.26 ng cm2 h1 and
averaged five times greater than fluxes previously measured at the site. N2O emissions 27
months after the hurricane remained over two times greater than previously measured
fluxes. Soil ammonium pools decreased after Georges and remained low. The first year
after the hurricane, nitrate pools increased, but not significantly when compared against
a single measurement made before the hurricane. Soil moisture and temperature did not
differ significantly in the two sampling periods. These results suggest that hurricanes
increase N2O fluxes in these forests by altering soil N transformations and the relative
availabilities of inorganic nitrogen.
Forecasting hurricane-related disasters
Tue, 07/26/2011 - 15:52 — ckassAbstract:
The punch from hurricane-strength winds is quick. In the Caribbean, the storms whip across the
islands tearing out trees and shattering buildings. Monitoring hurricanes is a centuries-long
tradition. But with all hurricanes, and even with less formidable rain storms, comes the threat of
landslides and flooding to the hills and valleys on the islands' mountainous terrain.
To help emergency personnel evacuate regions at high risk to these secondary rain-induced
hazards, a consolidation of technology is needed, says Randall Updike of the U.S. Geological
Survey in Denver. He is working with colleagues at the USGS, along with scientists from the
National Oceanic and Atmospheric Association (NOAA) and NASA, to establish a united front on
forecasting landfall disasters from hurricanes in the Caribbean. UNESCO (United Nations
Educational, Scientific and Cultural Organization) and The World Meteorological Organization also
support the proposed idea, Updike added. Currently these organizations operate independently of
each other. Updike presented his proposal of bringing the groups together at the annual meeting of
the American Association for the Advancement of Science in Denver on Feb. 15.
Orchid-Phorophyte Relationships in a Forest Watershed in Puerto Rico
Fri, 07/22/2011 - 10:50 — ckassOrchid-Phorophyte Relationships in a Forest Watershed in Puerto Rico
Luis E. Migenis and James D. Ackerman
Journal of Tropical Ecology
Vol. 9, No. 2 (May, 1993), pp. 231-240
Abstract:
Orchid diversity, distribution and host specificity were examined in a tropical watershed in the Luquillo Experimental Forest of Puerto Rico. Eleven orchid species occur in the area. The low diversity is attributed to island isolation and large-scale hurricane disturbances. Pleurothallis ruscifolia and Maxillaria coccinea were by far the most abundant species in the area and occurred on the largest number of host species and host zones. None of the orchids were host specific or host zone specialists although preferences for hosts and vertical host zones were encountered. Only 8.2% of the 426 trees and shrubs and 24.4% of the 45 species surveyed were orchid phorophytes (= hosts). Examination of host distribution by diameter at breast height (DBH) showed that 80.5% were greater than 16 cm DBH. Orchid species in the area tend to occur on rough bark hosts, but their preferences are not statistically significant. Guarea guidonia (Meliaceae) and Dacryodes excelsa (Burseraceae) are the two most important orchid hosts in our study site comprising 62.9% of all host trees. Careful management of these two tree species is suggested, since these species may be crucial to the maintenance of orchid abundance and diversity in the area.
Fine Litterfall and Related Nutrient Inputs Resulting From Hurricane Hugo in Subtropical Wet and Lower Montane Rain Forests of Puerto Rico
Thu, 07/21/2011 - 21:18 — ckassFine Litterfall and Related Nutrient Inputs Resulting From Hurricane Hugo in Subtropical Wet and Lower Montane Rain Forests of Puerto Rico
D. Jean Lodge, F. N. Scatena, C. E. Asbury and M. J. Sanchez
Biotropica
Vol. 23, No. 4, Part A. Special Issue: Ecosystem, Plant, and Animal Responses to Hurricanes in the Caribbean (Dec., 1991), pp. 336-342
Abstract:
On 18 September 1989 Hurricane Hugo defoliated large forested areas of northeastern Puerto Rico. In two severely damaged subtropical wet forest sites, a mean of 1006-1083 g/m$^2$, or 419-451 times the mean daily input of fine litter (leaves, small wood, and miscellaneous debris) was deposited on the forest floor. An additional 928 g/m$^2$ of litter was suspended above the ground. A lower montane rain forest site received 682 times the mean daily fine litterfall. The concentrations of N and P in the hurricane leaf litter ranged from 1.1 to 1.5 and 1.7 to 3.3 times the concentrations of N and P in normal leaffall, respectively. In subtropical wet forest, fine litterfall from the hurricane contained 1.3 and 1.5-2.4 times the mean annual litterfall inputs of N and P, respectively. These sudden high nutrient inputs apparently altered nutrient cycling.
Fine Litterfall and Related Nutrient Inputs Resulting From Hurricane Hugo in Subtropical Wet and Lower Montane Rain Forests of Puerto Rico
Thu, 07/21/2011 - 20:57 — ckassFine Litterfall and Related Nutrient Inputs Resulting From Hurricane Hugo in Subtropical Wet and Lower Montane Rain Forests of Puerto Rico
D. Jean Lodge, F. N. Scatena, C. E. Asbury and M. J. Sanchez
Biotropica
Vol. 23, No. 4, Part A. Special Issue: Ecosystem, Plant, and Animal Responses to Hurricanes in the Caribbean (Dec., 1991), pp. 336-342
Abstract:
On 18 September 1989 Hurricane Hugo defoliated large forested areas of northeastern Puerto Rico. In two severely damaged subtropical wet forest sites, a mean of 1006-1083 g/m$^2$, or 419-451 times the mean daily input of fine litter (leaves, small wood, and miscellaneous debris) was deposited on the forest floor. An additional 928 g/m$^2$ of litter was suspended above the ground. A lower montane rain forest site received 682 times the mean daily fine litterfall. The concentrations of N and P in the hurricane leaf litter ranged from 1.1 to 1.5 and 1.7 to 3.3 times the concentrations of N and P in normal leaffall, respectively. In subtropical wet forest, fine litterfall from the hurricane contained 1.3 and 1.5-2.4 times the mean annual litterfall inputs of N and P, respectively. These sudden high nutrient inputs apparently altered nutrient cycling.
Ecological Consequences of Root Grafting in Tabonuco (Dacryodes excelsa) Trees in the Luquillo Experimental Forest, Puerto Rico
Thu, 07/21/2011 - 15:55 — ckassEcological Consequences of Root Grafting in Tabonuco (Dacryodes excelsa) Trees in the Luquillo Experimental Forest, Puerto Rico
Khadga Basnet, F. N. Scatena, Gene E. Likens and Ariel E. Lugo
Biotropica
Vol. 25, No. 1 (Mar., 1993), pp. 28-35
Abstract:
Root grafting was commonly found in tabonuco (Dacryodes excelsa Vahl), a dominant tree species of tabonuco forest in the subtropical wet forest of Puerto Rico. Over 60 percent of all stems and basal area of tabonuco occurred in unions, clumps of trees interconnected by root grafts. Self and intraspecific grafting were extensive, while interspecific grafting was not common in tabonuco trees. Seedlings and saplings did not show any grafting, probably because of their size or age. Grafted trees were taller and had a smaller crown/DBH ratio. Hurricane damage was significantly higher in isolated individual tabonuco trees than those in unions. Weak relationships between diameter class, area, and size of union, and inter-tree distances and the sum of the trunk circumferences of the two nearest neighbors suggested that a noncompetitive force such as root grafting was more important than competitive forces in maintaining the unions of tabonuco, and thus the forest community. A conceptual model of the costs and gains of tabonuco in unions is presented.
