Results 171 to 180 of about 486,429 (206)

Field water-turnover rates of three Gerbillurus species

Journal of Arid Environments, 1990
Comparative water-turnover rates of Gerbillurus tytonis, G. p. paeba and G. setzeri were determined in the field at different seasons and localities. All species are omnivorous, selecting food opportunistically. During March there was no significant difference in water flux among species, although water flux decreased with body size. Water flux of
Colleen T. Downs, M.R. Perrin
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Species turnover on elevational gradients in small rodents

Global Ecology and Biogeography, 2005
ABSTRACTAim  The elevational gradients of species richness have been well documented; however, studies about species turnover (i.e. beta diversity) in such gradients are limited. We aimed to evaluate the relationship between species turnover and elevation in rodents, and particularly to assess two assumptions at the local scale: (1) species turnover is
José Luis Mena, Ella Vázquez‐Domínguez   +1 more
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Species turnover does not rescue biodiversity in fragmented landscapes

Nature
Habitat fragmentation generally reduces biodiversity at the patch scale (α diversity)1. However, there is ongoing debate about whether such negative effects can be alleviated at the landscape scale (γ diversity) if among-patch diversity (β diversity) increases as a result of fragmentation2-6. This controversial view has not been rigorously tested. Here
Thiago Gonçalves-Souza, Jonathan M. Chase, Nick M. Haddad, Maurício H. Vancine, Raphael K. Didham, Felipe L. P. Melo, Marcelo A. Aizen, Enrico Bernard, Adriano G. Chiarello, Deborah Faria, Heloise Gibb, Marcelo G. de Lima, Luiz F. S. Magnago, Eduardo Mariano-Neto, André A. Nogueira, André Nemésio, Marcelo Passamani, Bruno X. Pinho, Larissa Rocha-Santos, Rodolpho C. Rodrigues, Nathalia Vieira Hissa Safar, Bráulio A. Santos, Alejandra Soto-Werschitz, Marcelo Tabarelli, Marcio Uehara-Prado, Heraldo L. Vasconcelos, Simone Vieira, Nathan J. Sanders   +27 more
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Species Turnover and Seedling Recruitment in Limestone Grasslands

Oikos, 1992
Species turnover and germination were analysed in the Veronica spicata-Avenula pratensis limestone grassland community. Species turnover was estimated on the basis of presence/absence of species in fifty 10×10 cm permanent plots during the period 1986 to 1989.
Graciela Rusch, Eddy van der Maarel
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Plant species persistence and turnover on small Bahamian islands

Oecologia, 2003
I conducted surveys of the plant species occupying 136 small islands in the Exuma Cays and 58 small islands near Andros, Bahamas. Most species occurred on relatively few islands, and most islands contained relatively few species. Identities of the most common species differed between the two archipelagos.
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Species Turnover and the Regulation of Trophic Structure

Annual Review of Ecology and Systematics, 1997
Trophic structure, the partitioning of biomass among trophic levels, is a major characteristic of ecosystems. Most studies of the forces that shape trophic structure emphasize either “bottom-up” or “top-down” regulation of populations and communities.
Mathew A. Leibold, Jonathan M. Chase, Jonathan B. Shurin, Amy L. Downing   +3 more
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Turnover rate of molecular species of sphingomyelin in rat brain

Neurochemical Research, 1981
Turnover rate of individual molecular species of sphingomyelin of adult rat brain myelin and microsomal membranes was determined after an intracerebral injection of 100 microCi of [C3H3]choline. Myelin and microsomal membrane sphingomyelins were isolated from the rest of the lipids.
F N, LeBaron, S, Sanyal, F B, Jungalwala
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Hepatic Bile Pigment Excretion and Erythrocyte Turnover in Various Species

Veterinary Clinical Pathology, 1980
SummaryEndogenous bile pigment excretory rates have now been recorded in fifteen species, and the following review briefly compares the excretion per unit of body weight in animals of varying sizes, attempts to determine if any correlation exists between bile flow and endogenous pigment excretion and discusses bile pigment excretion in relation to mean
C E, Cornelius, M L, Bruss
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Trends in aquatic macrophyte species turnover in Northern Ireland — which factors determine the spatial distribution of local species turnover?

Global Ecology and Biogeography, 2004
ABSTRACTAim The study examined qualitative predictions of ecological theories in relation to the spatial distribution of species turnover of aquatic macrophytes, through the following parameters: (1) distance between lakes (2) chemical conditions of the lakes (3) chemical differences between the lakes, and (4) the lake size.Location 562 lakes dispersed
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Light-induced Mass Turnover in a Mono-species Community of Mixotrophs

Journal of Theoretical Biology, 2002
We formulate a simple model for growth of a facultative photoautotroph with chemoheterotrophic capabilities. The organism is described by zero, one or three reserve components, and one structural component, all taken to be generalized compounds.
Kooijman, S.A.L.M., Dijkstra, H.A., Kooi, B.W.   +2 more
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