Treesearch

Annual precipitation on the Caribbean island of Puerto Rico has decreased steadily during the twentieth century, on average by 16%. The reduced rainfall manifested itself in the form of regular water rationings for millions of inhabitants during the 1990's. This chapter examines the link between the reduction in precipitation and the land-cover change using a combination of energy balance measurements and meso-scale atmospheric modeling. The explanation of the reducation in precipitation proved to be different than expected. Based on measurements made earlier over rain forest and pasture...

The structure and function of forest ecosystems often change along altitudinal gradients in the tropics, culminating in short-stature, low-productivity cloud forests at the uppermost elevations. Field data and literature values were used to examine patterns in nitrogen mineralization on tropical mountains and to discuss the potential for nitrogen limitation to net primary productivity. Few trends in net nitrogen mineralization within and across elevation gradients in the tropics were found, and rates were generally comparable to those found in tropical forests at low elevations. Gross...

Although soil resources are widely considered as a major factor that reduces the productivity, stature, and diversity of tropical montane cloud forests (TMCF), systematic comparisons of soil resources within and between TMCF are lacking. This study combines published reports on TMCF soils with new data on the soils and forest structure of the Luquillo Mountains in Puerto Rico to assess the current state of knowledge regarding global and local-scale variation in TMCF soils. At the global scale, soils from 33 TMCF sites and over 150 pedons are reviewed. Compared to soils in humid lowland...

Abstract: The ultimate goal of many international and transnational attempts to address global problems is to influence domestic policymaking processes rather than simply to constrain or modify the external behaviour of states. This chapter reviews existing scholarship on the impacts that global forest governance arrangements have had on domestic policymaking processes and decisions. We apply a framework that distinguishes ‘economic globalisation’ – the phenomenon of increasing economic integration – from ‘internationalisation’, in which international and transnational pressures influence...

Between 10 July and 25 October 2001, fog interception (CWI) by a Puerto Rican elfin cloud forest at 970 m.a.s.l. was studied. Values of CWI were estimated from the wet-canopy water budget as the sum of throughfall, stemflow, and interception loss, minus rainfall corrected for the effect of slope. CWI was also estimated from throughfall measurements during periods fog-only. Timing and duration of fog were measured using a wire harp that was protected against rainfall. Estimated rates of CWI correlated significantly (p

BACKGROUND: Species number, functional traits, and phylogenetic history all contribute to characterizing the biological diversity in plant communities. The phylogenetic component of diversity has been particularly difficult to quantify in species-rich tropical tree assemblages. The compilation of previously published (and often incomplete) data on evolutionary relationships of species into a composite phylogeny of the taxa in a forest, through such programs as Phylomatic, has proven useful in building community phylogenies although often of limited resolution. Recently, DNA barcodes have...