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Registros recuperados: 8.909 | |
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Elmqvist, Thomas; Stockholm University; thomase@system.ecology.su.se; Wall, Maria; Stockholm University; fredwall@club-internet.fr; Berggren, Anna-Lena; Stockholm University; Anna-Lena.Berggren@o.lst.se; Blix, Lisa; Stockholm University; lisa.blix@lrf.se; Rinman, Ulrika; Stockholm University; ulrika.rinman@sjv.se. |
In disturbed rain forests, large, living remnant trees may be of significant importance for postdisturbance reorganization either directly, by producing large quantities of seeds, or indirectly, by attracting vertebrate seed dispersers. In addition, remnant trees may also be important in providing a favorable microhabitat for seedlings of late-successional species. This study focused on the role of large remnant trees (> 40 cm dbh) in patterns of regeneration after cyclone and fire damage in the Tafua and Falealupo Rain Forest Preserves, Savaií, Samoa. At Tafua, 10 large trees at each of two sites (one site burned in 1990) were investigated with regard to numbers of species and densities of plants from three different size classes at... |
Tipo: Peer-Reviewed Reports |
Palavras-chave: Biological legacies; Cyclone; Fire; Rain forest; Remnant trees; Reorganization; Vertebrate dispersal.. |
Ano: 2001 |
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Dominy, Nathaniel J; University of Hong Kong; njdominy@hkusua.hku.hk; Duncan, Brean; Dynamac Corporation, Kennedy Space Center; DuncaBW@kscems.ksc.nasa.gov. |
Since the completion of the Navstar Global Positioning System (GPS) in 1995, the integration of GPS and Geographical Information Systems (GIS) technology has expanded to a great number of ecological and conservation applications. In tropical rain forest ecology, however, the technology has remained relatively neglected, despite its great potential. Notwithstanding cost, this is principally due to (1) the difficulty of quality satellite reception beneath a dense forest canopy, and (2) a degree of spatial error unacceptable to fine-scale vegetation mapping. Here, we report on the technical use of GPS/GIS in the rain forest of Kibale National Park, Uganda, and the methodology necessary to acquire high-accuracy spatial measurements. We conclude that the... |
Tipo: Peer-Reviewed Reports |
Palavras-chave: Kibale National Park; Uganda; Biodiversity conservation; Canopy interference; Differential correction; Frugivores; Geographic information systems; Global positioning system; Seed dispersal; Spatial ecology; Tropical rain forest; Vegetation mapping. |
Ano: 2001 |
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Cane, James H; USDA-ARS; jcane@biology.usu.edu. |
Few studies directly address the consequences of habitat fragmentation for communities of pollinating insects, particularly for the key pollinator group, bees (Hymenoptera: Apiformes). Bees typically live in habitats where nesting substrates and bloom are patchily distributed and spatially dissociated. Bee studies have all defined habitat fragments as remnant patches of floral hosts or forests, overlooking the nesting needs of bees. Several authors conclude that habitat fragmentation is broadly deleterious, but their own data show that some native species proliferate in sampled fragments. Other studies report greater densities and comparable diversities of native bees at flowers in some fragment size classes relative to undisrupted habitats, but find... |
Tipo: Peer-Reviewed Reports |
Palavras-chave: Apoidea; Bees; Conservation; Diversity; Habitat fragmentation; Land-use change; Pollination; Pollinator; Statistics; Taxonomy. |
Ano: 2001 |
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Packer, Laurence; York University; bugsrus@yorku.ca; Owen, Robin; Mount Royal College and University of Calgary; rowen@mtroyal.ab.ca. |
We reviewed the theory of conservation genetics, with special emphasis on the influence of haplodiploidy and other aspects of bee biology upon conservation genetic parameters. We then investigated the possibility that pollinator decline can be addressed in this way, using two meta-analytical approaches on genetic data from the Hymenoptera and the Lepidoptera. First, we compared levels of heterozygosity between the orders. As has been found previously, the haplodiploid Hymenoptera had markedly lower levels of genetic variation than the Lepidoptera. Bees had even lower levels, and bumble bees, in particular, often seemed almost monomorphic genetically. However, the statistically confounding effects of phylogeny render detailed interpretation of such data... |
Tipo: Peer-Reviewed Reports |
Palavras-chave: Bumble bees; Effective population size; Gene flow; Haplodiploidy; Heterozygosity; Hymenoptera; Lepidoptera; Meta-analysis; Pollinator decline; Population fragmentation; Population genetics. |
Ano: 2001 |
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Roubik, David Ward; Smithsonian Tropical Research Institute; roubikd@tivoli.si.edu. |
Plant-pollinator systems inherently possess wide variation that limits the applicability of surveys on population dynamics or diversity. Stable habitats are scarcely studied, whereas dynamics in unprotected habitats are less predictable or more compromised by exotic organisms (Apis, in the case of bee surveys). An extensively replicated, long-term study of orchid-bees (Euglossini) was made in protected tropical moist forest in Panama. Over 47,000 bees were recorded in 124 monthly censuses employing 1952 counts. No aggregate trend in abundance occurred (from 1979 to 2000), although four individual species declined, nine increased, 23 showed no change, and species richness was stable. No rare or parasitic species showed decreasing trends, while the most... |
Tipo: Peer-Reviewed Reports |
Palavras-chave: ENSO; Euglossini; Abundance variability; Bees; Census techniques; Diversity; Pollinators; Trends; Tropical- temperate comparisons. |
Ano: 2001 |
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Schiller, Andrew; Clark University; aschille@black.clarku.edu; Hunsaker, Carolyn T; Pacific Southwest Research Station, USDA Forest Service; carolyn.hunsaker/psw_fresno@fs.fed.us; Kane, Michael A; University of Tennessee, Knoxville; mkane1@utk.edu; Wolfe, Amy K; Oak Ridge National Laboratory; ami@ornl.gov; Dale, Virginia H; Oak Ridge National Laboratory; vhd@ornl.gov; Suter, Glenn W; U.S. Environmental Protection Agency, NCEA; suter.glenn@epamail.epa.gov; Russell, Clifford S; Vanderbilt University; cliff.russell@vanderbilt.edu; Pion, Georgine; Vanderbilt University;; Jensen, Molly H; ;; Konar, Victoria C; ;. |
Ecological assessments and monitoring programs often rely on indicators to evaluate environmental conditions. Such indicators are frequently developed by scientists, expressed in technical language, and target aspects of the environment that scientists consider useful. Yet setting environmental policy priorities and making environmental decisions requires both effective communication of environmental information to decision makers and consideration of what members of the public value about ecosystems. However, the complexity of ecological issues, and the ways in which they are often communicated, make it difficult for these parties to fully engage such a dialogue. This paper describes our efforts to develop a process for translating the indicators of... |
Tipo: Peer-Reviewed Reports |
Palavras-chave: Common language; Communication; Decision making; Ecological indicators; Ecological monitoring; Environmental assessments; Environmental values; Public input. |
Ano: 2001 |
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Registros recuperados: 8.909 | |
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