Treesearch

Litter-induced pulses of nutrient availability could play an important role in the productivity and nutrient cycling of forested ecosystems, especially tropical forests. Tropical forests experience such pulses as a result of wet–dry seasonality and during major climatic events, such as strong El Niños. We hypothesized that (1) an increase in the quantity and quality of litter inputs would stimulate leaf litter production, woody growth, and leaf litter nutrient cycling, and (2) the timing and magnitude of this response would be influenced by soil fertility and forest age. To test these...

Data for trace gas fluxes (NOx, N2O, and CH4) from the Amazon and cerrado region are presented with focus on the processes of production and consumption of these trace gases in soils and how they may be changed because of land use changes in both regions. Fluxes are controlled by seaonality, soil moisture, soil texture, topography, and fine-root dynamics. Compared to Amazonian forests where the rapid cycling of nitrogen supports large emissions of N2O, nitrification rates and and soil emissions of N oxide gases in the cerrado region are very low. Several studies report CH4 consumption...

Selective logging is a major contributor to the social, economic, and ecological dynamics of Brazilian Amazonia. Logging activities have expanded from low-volume floodplain harvests in past centuries to high-volume operations today that take about 25 million m3 of wood from the forest each year. The most common high-impact conventional and often illegal logging practices result in major collateral forest damage, with cascading effects on ecosystem processes. Initial carbon losses and forest recovery rates following timber harvest are tightly linked to initial logging intensity, which...

From 1983 to 2008, the mean annual diameter growth (MAI) for 1,402 surviving stems of 62 species in the Cinnamon Bay watershed was 0.08¡À0.002 cm yr-1. Long-term MAI ranged from 0.02 cm yr-1 for Randia aculeata to 0.23 cm yr-1 for Inga laurina. Of the 30 species with ¡Ý8 surviving stems, eight averaged ¡Ý0.10 cm yr-1. Hurricane Hugo in 1989, Hurricane Marilyn in 1995, and a severe drought in 1994 and 1995 were the major climatic events during the 25-year measurement period. Plot dbh measurements provide useful information about stand structure, composition and dynamics, and for silvicultura...

The Cabezas de San Juan Natural Reserve (El Faro), an exposed peninsular area located in the Subtropical dry forest of northeastern Puerto Rico, was impacted by hurricanes Hugo (1989) and Georges (1998). From 1998 to 2008, a 0.10 ha plot was used to assess forest structure, species composition, and stem growth. During post-hurricane recovery, stem density, tree height, basal area, and aboveground woody biomass all increased on the plot. The 10-yr mean annual dbh (i.e., diameter at 1.4 m above the ground) growth was 0.11±0.00 cm yr-1 for the 181 stems of 16 species that survived the...

A previous study of tree productivity in the subtropical wet forest of the Luquillo Mountains of Puerto Rico was used to expose the frequency of 12 timber tree species to six different topographic sites, convex versus concave surface, lower versus upper slopes, and windward versus leeward aspects. All but one of the species are found in all six locations and the frequency of all have concentrations suggesting that if that is also where they grow best, they should be selected there for productivity, and should best be replanted there.

La ciencia, incluso la de Puerto Rico, aprende de muestras, su interpretación y extrapolación a situaciones más extensas. Las muestras de la naturaleza de Puerto Rico: las del suelo, la hojarasca, la sombra, la biomasa, los árboles, las aves, los reptiles y anfibios, o los insectos caracterizan los ecosistemas. [article in Spanish]

[article in Spanish] Puerto Rico consume muchos productos forestales costosos de importar. También tiene bosques extensos con maderas explotables. Además, existen condiciones físicas favorables para la producción de madera útil. No obstante, hoy día no se utiliza la madera de los bosques actuales ocurre la deforestación para cualquier fin. Los Bosques productivos de valor reconocido podrían reducir ese contratiempo y así reducir la sedimentación de los embalses, y la biodiversidad. La liberación de los árboles inmaduros maderables de árboles competidores podría adelantar una próxima cosecha.

This is a description of the composition of a forest in Puerto Rico almost unique in that it probably had not received human modification. It comes from a 1948 inventory of 4,570 hectares of what today is the El Yunque National Forest in the Luquillo Mountains. The inventory, preparatory to a forest management plan, was a search for sustainable level of timber volume utilization. The data presented are from 40 apparently undisturbed 1/10 ha samples out of 914 inventory plots along parallel transects. The description covers structure and composition of the two most prominent forest associati...