Treesearch

The purpose of this paper is to call attention to the importance of epiphytes in understanding how global atmospheric changes impact tropical forests. The Luquillo Experimental Forest (LEF), like other peaks in the Caribbean, intercepts at least five major global weather systems: (1) trade winds originating in the Azores; (2) tropical depressions and hurricanes originating in western Africa; (3) northern cold fronts originating in the polar regions of North America; and systems originating (4) in the Pacific and (5) the Amazon basin. Each of these "global airsheds" has a particular return...

Fifteen species of Lepidoptera occurred in large numbers in spring and early summer after the passage of Hurricane Hugo over the north-east of Puerto Rico. Spodoptera eridania (Noctuidae) was the most common of the larvae and fed on 56 plant species belonging to 31 families. All the Lepidoptera fed on early successional vegetation. Some of the plants represent new host plants for these species. The outbreaks appeared to be based on the flush of new foliage that developed in the Luquillo Mountains after the passage of the hurricane. The end of the S. eridania outbreak was concurrent with...

Plantations of multi-purpose tree species can play an important role in restoring productivity, ecosyste~ 2n stability, and biological diversity to degraded tropical lands. The present study, conducted at a degraded coastal pasture site in Puerto Rico, compares 4.5-year-old Aibizia lebbek (L.) Benth. plantation stands and adjacent control areas with respect to biomass production, understorey species diversity and nutrient storage patterns within vegetation, forest floor organic matter, and mineral soil compartments. Mineral soil (0-20 cm depth) organic carbon (OC) and total nitrogen (TN)...

We investigate the relationship between immigration and internal labor movements in the US. Wedding the literatures on immigration and internal migration, we develop a mobility model linking these various flows on the basis of occupational status of worker, producction and institutional relations in the economy, and economic restructuring.