On the definition of ecological species groups in tropical rain forests

Vegetatio ◽  
1988 ◽  
Vol 75 (1-2) ◽  
pp. 81-86 ◽  
Author(s):  
M. D. Swaine ◽  
T. C. Whitmore

Author(s):  
Randall A. Kramer ◽  
Carel P. van Schaik

Tropical rain forests are disappearing rapidly as a result of increasing human encroachment. During the past century, tropical rain forests have been reduced to about half of their original area. And the rate of deforestation is accelerating, fueled by population growth in developing countries and resource demands in the developed countries. The remaining forests are subject to increasingly intensive human use. Deforestation, fragmentation, and exploitation cause a plethora of problems, including soil erosion; siltation of rivers, lakes, and estuaries; increased flooding and droughts; release of carbon dioxide and other greenhouse gases into the atmosphere; and loss of species. In recent years, these problems have become the subject of international concern. This book focuses on the loss of biodiversity in tropical rain forests and on the role of protected areas in stemming the loss. This chapter examines the meaning of biodiversity and the history of the park movement in the tropics. What began as protection of habitat through the exclusion of people has transformed into sustainable use of biological resources. This new emphasis provides local control of important resources and greater income, but does it conserve habitat and species? We will argue that a renewed focus on protected areas as the primary storehouse of biodiversity is needed. We will also make the case for a focus on the tropical rain forest biome and will conclude with an overview of the rest of the book. In its strict sense, biodiversity refers to the “variety and variability among living organisms and the ecological complexes in which they occur” (Office of Technology Assessment, U.S. Congress, 1987:3). This definition can be extended both downward to cover genetic variability within a species and upward to include habitat and ecosystem diversity. practical terms, however, biodiversity is most profitably expressed as species diversity (weighted for rarity, endemism, and taxonomic distinctiveness, if necessary) at the landscape level (see chapter 6). We adopt this definition of biodiversity. During the past few years, attempts to link rain forest protection with sustainable development have led to a noticeable expansion of the meaning of the phrase “biodiversity conservation.”





2016 ◽  
Vol 083 (02) ◽  
Author(s):  
Amanda Beckrich




2012 ◽  
Vol 28 (5) ◽  
pp. 437-443 ◽  
Author(s):  
Terrence P. McGlynn ◽  
Evan K. Poirson

Abstract:The decomposition of leaf litter is governed, in part, by litter invertebrates. In tropical rain forests, ants are dominant predators in the leaf litter and may alter litter decomposition through the action of a top-down control of food web structure. The role of ants in litter decomposition was investigated in a Costa Rican lowland rain forest with two experiments. In a mesocosm experiment, we manipulated ant presence in 50 ambient leaf-litter mesocosms. In a litterbag gradient experiment, Cecropia obtusifolia litter was used to measure decomposition rate constants across gradients in nutrients, ant density and richness, with 27 separate litterbag treatments for total arthropod exclusion or partial arthropod exclusion. After 2 mo, mass loss in mesocosms containing ants was 30.9%, significantly greater than the 23.5% mass loss in mesocosms without ants. In the litter bags with all arthropods excluded, decomposition was best accounted by the carbon: phosphorus content of soil (r2 = 0.41). In litter bags permitting smaller arthropods but excluding ants, decomposition was best explained by the local biomass of ants in the vicinity of the litter bags (r2 = 0.50). Once the microarthropod prey of ants are permitted to enter litterbags, the biomass of ants near the litterbags overtakes soil chemistry as the regulator of decomposition. In concert, these results support a working hypothesis that litter-dwelling ants are responsible for accelerating litter decomposition in lowland tropical rain forests.



2009 ◽  
Vol 12 (5) ◽  
pp. 385-394 ◽  
Author(s):  
Natalia Norden ◽  
Robin L. Chazdon ◽  
Anne Chao ◽  
Yi-Huei Jiang ◽  
Braulio Vílchez-Alvarado


2005 ◽  
Vol 21 (2) ◽  
pp. 237-241 ◽  
Author(s):  
Tomoaki Ichie ◽  
Tanaka Kenta ◽  
Michiko Nakagawa ◽  
Kaori Sato ◽  
Tohru Nakashizuka

Some tree species exhibit large year-to-year variation in seed production, a phenomenon known as masting (Kelly 1994, Kelly & Sork 2002). Even in tropical rain forests, in which the climate is suitable for plant growth all year round with little seasonal variation (Whitmore 1998), there are many reports of masting (Appanah 1993, Hart 1995, Newbery et al. 1998, Newstrom et al. 1994, Wheelwright 1986). In particular, Dipterocarpaceae, the dominant family in lowland mixed dipterocarp forests in South-East Asia, undergo mast fruiting following mass-flowering with strong interspecific synchronization in aseasonal western Malesia (Appanah 1985, 1993; Ashton 1989, Ashton et al. 1988, Curran et al. 1999, Janzen 1974, Medway 1972, Sakai et al. 1999, Whitmore 1998, Wood 1956). In mixed-dipterocarp forests, dipterocarp species contribute more than 70% of the canopy biomass (Bruenig 1996, Curran & Leighton 2000). Masting of dipterocarp species is therefore likely to have a major impact on animal populations, and also on the nutrient cycle in such forest ecosystems by causing fluctuations in the availability of resources (Sakai 2002).





1997 ◽  
Vol 45 (4) ◽  
pp. 439-450 ◽  
Author(s):  
R.G.A. Boot

Tropical rain forests are rich in plant and animal species. The sustainable extraction of non-timber forest products has been advocated as a strategy to best conserve this diversity. However, the development and implementation of such exploitation systems, which aim to reconcile conservation and economic development, are still hampered by the lack of information on the biological sustainability of these systems, the impact of these exploitation systems on the biological diversity and the insufficient knowledge of the role of forest products in the household economy of forest dependent people and hence their prospects for economic development. Whether the exploitation of non-timber forest products from tropical rain forests is sustainable or not is still open to question, but data presently available on the biological, social and economic aspects of these extraction systems point at an interesting question: does diversity come at a price? Namely, low density of conspecifics, and thus products, and hence low productivity for those involved in the collection of forest resources. The paper will further discuss whether domestication of forest species provides an alternative for some of these species. Species are part of a complex ecosystem and their functioning is partly depended on the presence of other species in the system. The attributes of the species which have to be taken into account in order to make domestication of forest species successful are considered. Finally, the paper returns to the question of how to reconcile conservation and use of tropical rain forests. It will present a case for domesticating the forest instead of the species or, in other words, changing the forest composition without changing its structure and functioning, and maintaining acceptable levels of biodiversity.



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