The Puerto Rico Tropical Cloud Forest Symposium: Introduction and Workshop Synthesis

Abstract

It is becoming increasingly recognized that the cloud forests of tropical mountains are high on the list of the world's most threatened ecosystems. In many countries or regions, their rate of loss exceeds that of the lowland tropical rain forests that have received much public concern. Perhaps 90 percent of these tropical montane cloud forests (TMCFs) in the northern Andes have been lost. During the symposium, for which this publication is the proceedings, visual evidence presented by Dr. Alwyn Gentry and others, and the verbal descriptions given by many participants, attested to the loss not only for the Andes, but for all parts of the world where TMCF occurs. The original estimate (and it was only an estimate) given by Persson (1974) of 50 million ha of cloud forests was probably on the high side. He suggested that TMCF constituted one-quarter of montane and sub montane rain forest. We believe that TMCF is being lost at a rate considerably in excess of that of the muchabused, but much-publicized, lowland tropical rain forest. Indeed the first paper (Doumenge et al.) that follows indicates that annual forest loss in tropical hills and mountains is 1.1 percent compared with 0.8 percent for all forests of the tropics. Those on isolated volcanic mountains, especially where occurring on small oceanic islands, are particularly vulnerable, and their loss is a serious concern. Cutting of forest for firewood or for charcoal production, and conversion to agricultural uses (mainly grazing) are the principal villains. However, the threats and damaging activities are many. They will be discussed in this synthesis and in many of the papers that follow. L. S. Hamilton et al. (eds.), Tropical Montane Cloud Forests

Composição florística da vegetação altimontana do distrito de Monte Verde (Camanducaia, MG), Serra da Mantiqueira Meridional, Sudeste do Brasil

“…Gêneros neotropicais, austral-antárticos e pantropicais, indicadores de formações florestais de altitude, como Chusquea, Drimys, Ilex e Weinmannia estiveram presentes no estrato arbóreo da Floresta Altimontana em Monte Verde (Giulietti & Pirani 1987;Gentry 1995;Hamilton et al 1995). Abutilon, Escallonia, Macropeplus, Myrceugenia e Symplocos são outros gêneros arbóreos neotropicais, austral-antárticos ou pantropicais com espécies restritas e indicadoras de florestas altimontanas das Regiões Sul ou Sudeste brasileiros (Meireles et al 2008;Scheer et al 2011).…”

Regional long-term climate change (1950-2000) in the midtropical Atlantic and its impacts on the hydrological cycle of Puerto Rico

“…The liquid water mixing ratio (g kg −1 ) contains the amount, in total mass, of cloud droplets and raindrops per kilogram of dry air, and therefore accounts for the two completely nonfrozen cloud microphysics hydrometeors in the atmospheric regional model cloud module that indicate the cloud formation and rain development process in the tropics. It has been reported that changes in wind patterns and vertical wind motions should also produce changes in cloud base heights, an important parameter in tropical montane cloud forests [Hamilton et al, 1993;Bruijnzeel and Proctor, 1993;Still et al, 1999;Nair et al, 2003;Ray et al, 2006;Lawton et al, 2011]. A montane cloud forest is defined as a tropical or subtropical moist forest in elevated terrain in which the cloud base is persistently or seasonally at or below the vegetation canopy level.…”

“…[27] These results for accumulated precipitation are of particular importance for small island states, mainly because tropical rain and montane cloud forests provide much of the natural resources, including fresh water, consumed in these countries [Hamilton et al, 1993;Bruijnzeel and Proctor, 1993;Franco et al, 1997;Pounds et al, 1999;Still et al, 1999;Lawton et al, 2011]. Therefore, it is equally important that the results for accumulated precipitation differences be compared with other data sets.…”

Tree Community Composition and Aboveground Biomass in a Secondary Atlantic Forest, Serra Do Mar State Park, São Paulo, Brazil

“…Furthermore, these environmental conditions lead to the accumulation of large quantities of organic matter (SOETHE et al, 2008). In general, montane forests have higher density of individuals, lower diversity of species and families and, vascular and avascular epiphytic, compared with other tropical forests at lower altitudes (HAMILTON et al, 1995;LIEBERMAN et al, 1996). Alves et al (2010) found an increase of aboveground biomass along of altitudinal gradient in the Ombrophilous Dense Atlantic Forest, as well as litter accumulation and carbon and nitrogen stocks, both above and below ground .…”