Treesearch

[1] To test whether plant species influence greenhouse gas production in diverse ecosystems, we measured wet season soil CO2 and N2O fluxes close to 300 large (>35 cm in diameter at breast height (DBH)) trees of 15 species at three clay‐rich forest sites in central Amazonia. We found that soil CO2 fluxes were 38% higher near large trees than at control sites >10 m away from any tree (P < 0.0001). After adjusting for large tree presence, a multiple linear regression of soil temperature, bulk density, and liana DBH explained 19% of remaining CO2 flux variability. Soil N2O fluxes adjacent to...

Timber extraction continues to add to vast cutover tropical forests. They are unattractive economically because of the loss of merchantable timber and the long delay foreseen for recovery. Despite this, wood in cutover tropical forests is in line to become more marketable as demand continues and old-growth forests become less accessible. In a cutover forest in Puerto Rico a well formed immature trees of timber species was found. They were ubiquitous, growing throughout the foothills of a mountain on both convex and concave land surfaces, on steep as well as low slopes, and exposed to...

Identifying the determinants of habitat quality for a species is essential for understanding how populations are limited and regulated. Spatiotemporal variation in moisture and its influence on food availability may drive patterns of habitat occupancy and demographic outcomes. Nonbreeding migratory birds in the neotropics occupy a range of habitat types that vary with respect to moisture. Using carbon isotopes and a satellite-derived measure of habitat moisture, we identified a moisture gradient across home ranges of radiotracked Northern Waterthrush (Seiurus noveboracensis). We used this...

Brazil, rural economic development, forest conservation, reduced impact loggin, sustainability, forest law, public lands

Herbivores and pathogens with acute host specificity may promote high tree diversity in tropical forests by causing distance- and density-dependent mortality of seedlings, but evidence is scarce. Although Lepidoptera larvae are the most abundant and host-specific guild of herbivores in these forests, their impact upon seedling distributions remains largely unknown. A Wrm test of the mechanism underpinning the Janzen–Connell hypothesis is dificult, even for a single tree species, because it requires more than just manipulating seeds and seedlings and recording their fates. Experimental...

What types of institutional configurations hold the most promise in fostering efforts for long-term amelioration of enduring environmental, social, and economic challenges facing the world’s forests? This chapter presents, and applies an analytical framework with which to review research findings and analyses that shed light on what appear to be the most promising institutional settings with which to address these drivers, ameliorate problems, and encourage responsible and sustainable forest management around the globe. Our framework focuses attention on the shift from government to...

We estimated financial returns and wood production costs in 2008 for the primary timber plantation species. Excluding land costs, returns for exotic plantations in almost all of South America e Brazil, Argentina, Uruguay, Chile, Colombia, Venezuela, and Paraguay e were substantial. Eucalyptus species returns were generally greater than those for Pinus species in each country, with most having Internal Rates of Return (IRRs) of 20% per year or more, as did teak. Pinus species in South America were generally closer to 15%, except in Argentina, where they were 20%. IRRs were less, but still...

Consumer demand for the premier neotropical luxury timber, big-leaf mahogany (Swietenia macrophylla), has driven boom-and-bust logging cycles for centuries, depleting local and regional supplies from Mexico to Bolivia. We revise the standard historic range map for mahogany in South America and estimate the extent to which commercial stocks have been depleted using satellite data, expert surveys, and sawmill processing center data from Brazil. We estimate an historic range of 278 million hectares spanning Venezuela to Bolivia, 57% of this in Brazil. Approximately 58 million hectares (21%)...