| Signatura:||Biblioteca OET: 574.26420913 B615. |
| Autor:|| Wright, Stuart Joseph; Orians, Gordon H, [ed.]; Dirzo, Rodolfo, [ed.]; Cushman, J.H, [ed.]. |
| Dirección:|| Smithsonian Tropical Research Institute, Apartado 2072, Balboa, PA E-mail: firstname.lastname@example.org E-mail: email@example.com. |
| Título: ||
Ecological Studies, no. 122. Plant species diversity and ecosystem functioning in tropical forests. Diversidad de especies de plantas y funcionamiento del ecosistema en bosques tropicales. |
| P.imprenta: || p. 11-31. Año 1996. Editorial Berlin, Springer-Verlag, DE. |
| Descriptores:|| PLANTS. |
BIODIVERSITY; TROPICAL FOREST.
PANAMA; PUERTO RICO; CARIBBEAN; COSTA RICA; CENTRAL AMERICA.
BARRO COLORADO NATURE MONUMENT; TURRIALBA (CANTON); AREA DE CONSERVACION CORDILLERA VOLCANICA CENTRAL.
| Resumen: ||Introduction: Ecosystem processes emerge from the capture, transfer, and loss of energy and nutrients by biological species. It has been clearly established that both the presence of particular species and also the total number of species involved can influence emergent ecosystem processes. Keystone species such as predators that prey selectively on competitive dominants or plants that fruit during seasons of scarcity can have profound effects on entire ecosystems and have been identified in a wide range of habitats from the rocky intertidal to tropical forests (Paine 1966; Terborgh 1986). In contrast, evidence that the total number of species present influences ecosystem functioning has been limited to laboratory microcosms (Naeem et al. 1994) and to relatively species-poor grasslands (McNaughton 1993; Tilman and Downing 1994). In this chapter, the question is asked whether the total number of plant species present affects some components of ecosystem functioning in tropical forests. Tropical forests include the most floristically diverse habitats on the planet. Although it is well established that species richness influences processes in species-poor ecosystems, the effect of an increase from perhaps 50 tree species per hectare in a dry tropical forest to more than 300 tree species per hectare in a wetter forest is uncertain. Uncertainty also remains over when, where, and how species composition affects ecosystem functioning. This chapter addresses the relationship between plant species diversity and ecosystem productivity and stability. In the introductory chapter to this volume, Orians et al. provide a more complete catalog of ecosystem processes. Here consideration is limited to productivity and stability because the relationship between tropical forest plant species diversity and other ecosystem properties has been reviewed elsewhere (Vitousek and Hooper 1993) and is explored in subsequent chapters in this book. To avoid ambiguity, the definitions of diversity, stability, and associated terms (Table 2.1) are adopted from Pimm (1984), where they are more fully developed. Mechanisms that relate species diversity and ecosystem processes are explored, then productivity with different plant species diversities is compared. Finally the stability of paleoforests followed through time after major perturbations is evaluated for modern tropical forests|