Treesearch

Environmental and past land use controls on tree species assemblages on the Commonwealth of Puerto Rico and the U.S. Virgin Islands were characterized to determine whether biophysical factors or land-use history has been more important in determining the species composition of secondary tropical forests after large-scale forest clearing for agriculture, widespread species introduction, and landscape-scale forest fragmentation. Post-deforestation, secondary forest assemblages are comprehensively described, both as broad general assemblages and island-specific variations by calculating...

Rapid deforestation in the Brazilian Amazon, caused by economic, social, and policy factors, has focused global and national attention on protecting this valuable forest resource. In response, Brazil reformed its federal forest laws in 2006, creating new regulatory, development, and incentive policy instruments and institutions. Federal forestry responsibilities are maintained within the ministry of the environment; its regulatory agency responsibilities are divided among three different branches of the agency; many powers are delegated to states and municipalities; and a new private...

Red- breasted Blackbird Sturnella militaris is extensively distributed through northern South America, Panama, Costa Rica and Trinidad6. Generally, it is considered ‘common’ throughout its range and, thus, is of Least Concern in terms of conservation and management needs3. The species is associated with open country, including moist grasslands and open agricultural areas, e.g., rice, row crops, and monocultures1, facilitating latitudinal, longitudinal1 and altitudinal expansion7.

The response of local economies to the globalization process can have a large effect on population and land-use dynamics. In countries with a high population density and relatively high levels of education, the globalization process has resulted in a shift in the local economy from agriculture to manufacturing, technology, and service sectors. This shift in the economy has impacted land-use dynamics by decreasing agricultural lands, increasing urban growth, and in some cases, increasing forest cover. This process of economic and forest transition has been well documented in Puerto Rico for...

With a total landmass of 276 km2 , Ometepe is the world’s largest island within a fresh-water lake—Lake Nicaragua, also known as Lake Cocibolca—the same lake that the Spanish conquerors called a “fresh water sea” because of its sheer size. Ometepe, which means “two hills” in the native “náhuatl” language, is aptly named since the island is comprised of two volcanoes separated by a narrow strip of land. The largest, Concepción, an active volcano towering 1,610 m above sea level, is located in the northern half of the island. The smaller, inactive Maderas volcano, with a maximum height of...

Not only has Nicaragua been largely overlooked in studies of avian distribution and ecology, general information on species richness is scarce and often outdated. Countrywide species lists range from 644 to 69510,20, much lower than for neighbouring countries13,27. A recent study added three new country records, Green Ibis Mesembrinibis cayennensis, Purple-throated Fruitcrow Querula purpurata and Tropical Mockingbird Mimus gilvus, and made important distributional records of several species31. In addition, Cooper’s Hawk Accipiter cooperii was reported for the first time in Nicaragua, when...

Owing to Nicaragua’s long history of geological discontinuity between northern and southern landmasses, the northern and southern range limits of several species terminate within its borders. Three unique and highly diverse ecological regions (Atlantic and Pacific slopes, Central highlands15) have resulted, reinforcing Nicaragua’s importance in the study of geographical distribution, abundance and the spatio- temporal dynamics of Central American birds, especially given accelerating global climate change.

Este mapa representa la cobertura desarrollada en Puerto Rico (Martinuzzi et al. 2007). Cobertura desarrollada se define aqui como areas urbanas, construidas y sin vegetacion, que resultan de actividad humana. Tipicamente, estas incluyen estructuras construidas, concreto, asfalto, u otra infraestructura. La cobertura desarrollada se creo mediante el analisis de imagenes de satelite Landsat ETM+, de los años 2000 al 2003, preprocesadas a una resolucion de 15 metros. Las imagenes se utilizaron para construer un mosaico de Puerto Rico. Para crear la cobertura desarrollada, el mosaico fue...

Este mapa demuestra la distribución de terrenos de alta y baja densidad de desarrollo urbano en Puerto Rico (Martinuzzi et al. 2007). El mapa fue creado mediante el analisis de un mosaico de imagenes de satelite Landsat ETM+ de los años 2000 – 2003. La clasificacion no supervisada ISODATA (“Iterative Self-Organizing Data Analysis Technique”) (ERDAS 2003) fue utilizada para crear una cobertura desarrollada de Puerto Rico. Cobertura desarrollada se define aqui como areas urbanas, construidas y sin vegetacion, que resultan de actividad humana. Tipicamente, estas incluyen estructuras construida...