Treesearch

Secondary forests are becoming increasingly widespread in the tropics, but our understanding of how secondary succession affects carbon (C) cycling and C sequestration in these ecosystems is limited. We used a well-replicated 80-year pasture to forest successional chronosequence and primary forest in Puerto Rico to explore the relationships among litterfall, litter quality, decomposition, and soil C pools. Litterfall rates recovered rapidly during early secondary succession and averaged 10.5 (± 0.1 SE) Mg/ha/y among all sites over a 2-year period. Although forest plant community composition...

Current information on land cover, forest type and forest structure for the Virgin Islands is critical to land managers and researchers for accurate forest inventory and ecological monitoring. In this study, we use cloud free image mosaics of panchromatic sharpened Landsat ETM+ images and decision tree classification software to map land cover and forest type for the Virgin Islands, illustrating a low cost, repeatable mapping approach. Also, we test if coarse-resolution discrete lidar data that are often collected in conjunction with digital orthophotos are useful for mapping forest...

We have developed three land use regions for Puerto Rico: Urban, Suburban, and Rural (Gould et al. 2008; Martinuzzi et al. 2007). These three regions can also be considered urban, densely-populated rural, and sparsely-populated rural or as urban and wildland with a wildland-urban interface. The suburban use is the most dynamic in terms of population growth and land cover change. Developed surfaces refer to built-up and non-vegetated areas that result from human activity. These areas were identified using remote sensing techniques to analyze a mosaic of Landsat ETM+ satellite images from...

The landscape units map of Puerto Rico represents climatic, substrate, and topographic variation by integrating six climatic zones (Ewel and Whitmore 1973), six distinct substrates (Bawiec 2001, USGS 2005), five topographic positions or landforms (Martinuzzi et al. 2007), and prominent lakes and rivers (USGS 2005). Substrates were a simplified set of Bawiec’s (2001) twelve geologic terrane units and include cretaceous and tertiary limestone deposits, alluvium and other unconsolidated quaternary deposits, intrusive and extrusive volcanic formations and volcaniclastic sedimentary deposits...

This map shows the distribution of developed land cover in Puerto Rico (Martinuzzi et al. 2007). Developed land cover refers to urban, built-up and non-vegetated areas that result from human activity. These typically include built structures, concrete, asphalt, and other infrastructure. The developed land cover was estimated using Landsat 7 ETM+ satellite images pan sharpened to a spatial resolution of 15 meter. Multiple Landsat ETM+ images, ranging from the years 2000 to 2003, were used to create a mosaic of the island. The Iterative Self-Organizing Data Analysis Technique (ISODATA)...

This map shows the distribution of high and low density developed lands in Puerto Rico (Martinuzzi et al. 2007). The map was created using a mosaic of Landsat ETM+ images that range from the years 2000 to 2003. The developed land cover was classified using the Iterative Self-Organizing Data Analysis Technique (ISODATA) unsupervised classification (ERDAS 2003). Developed land cover refers to urban, built-up and non-vegetated areas that result from human activity. These typically include built structures, concrete, asphalt, and other infrastructure. The developed cover was divided into high...

requires producer nations to certify that exported supplies were obtained in a manner non-detrimental to the species’ survival in its role in the ecosystem. Non-detriment findings based on annual export quotas should verify that current harvest rates are sustainable with respect to total commercial stocks. In order to assess this impact, a method for converting export quality sawnwood volumes to numbers of standing trees is used to estimate the number of mahogany trees and forest area required to produce the original and revised 2007 export quotas set by Peru, correcting for systematic...

Quantification of the downed woody materials that comprise forest fuels has gained importance in Caribbean forest ecosystems due to the increasing incidence and severity of wildfires on island ecosystems. Because large-scale assessments of forest fuels have rarely been conducted for these ecosystems, forest fuels were assessed at 121 US Department of Agriculture forest service inventory plots on Puerto Rico, Vieques, and the US Virgin Islands. Results indicated that fuel loadings averaged 24.05 Mg ha1 in 2004–2006. Forest litter decreased from wetter to drier forest life zones. These...

This article is in Spanish. During an inventory to assess avian biodiversity among the critical watersheds that flow into the Pacific from Nicaragua, we captured a hybrid Vermivora chrysoptera (“Golden-winged Warbler”) with V. pinus (“Blue-winged Warbler”) known as Brewster’s Warbler (V. leucobronchialis). The capture ocurred on November 30, 2007 in dry forest (elevation c. 500m above see level) approximately 25 km from Managua. To the best of our knowledge this is the first recorded sighting documented with photos and morphometric data.

Forest fragmentation affects the heterogeneity of accumulated fuels by increasing the diversity of forest types and by increasing forest edges. This heterogeneity has implications in how we manage fuels, fire, and forests. Understanding the relative importance of fragmentation on woody biomass within a single climatic regime, and along climatic gradients, will improve our ability to manage forest fuels and predict fire behavior. In this study we assessed forest fuel characteristics in stands of differing moisture, i.e., dry and moist forests, structure, i.e., open canopy (typically...