Results 251 to 260 of about 220,261 (288)

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 Vazquez-Dominguez
exaly   +2 more sources

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
Einar Heegaard
exaly   +2 more sources

SCALE DEPENDENCE IN THE SPECIES-RICHNESS–PRODUCTIVITY RELATIONSHIP: THE ROLE OF SPECIES TURNOVER

Ecology, 2004
Recent research in aquatic systems suggests that productivity-richness re- lationships change with spatial scale and that species turnover (i.e., spatial and temporal variation in species composition) plays an important role in generating this scale depen- dence.
David R Chalcraft, , Melinda D Smith
exaly   +2 more sources

Succession: Similarities of Species Turnover Rates

Science, 1973
The rate coefficients for species turnover (the proportion of species lost per unit time) for successional communities decrease as the communities approach some equilibrium state. This observation makes it possible to determine the parameters of a two-parameter model which quantifies the time variation of successional changes in the second derivative.
H H, Shugart, J M, Hett
openaire   +2 more sources

Species richness and species turnover in a successional heathland

Applied Vegetation Science, 2001
Abstract. Changes in species richness and species turnover during secondary succession following experimental disturbance were studied in eight permanent plots in a species‐rich dry heathland in the southern part of the Czech Republic. The treatments applied were sod‐cutting, burning, cutting of above‐ground biomass, and control.
Milan Chytrý, Iva Sedláková, Lubomír Tichý   +2 more
openaire   +1 more source

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
openaire   +1 more source

Temporal species turnover in amphibian and reptile species assemblages

2022
Es ist gut dokumentiert, dass Ölpalmplantagen durch einen deutlich geringeren Artenreichtum gekennzeichnet sind und eine deutlich differenzierte Artenzusammensetzung aufweisen als tropische Regenwälder. Über die zeitliche Dynamik oder Stabilität von Artengemeinschaften in Ölpalmplantagen, im Vergleich zu Wäldern, ist jedoch sehr wenig bekannt.
openaire   +1 more source

The Distribution of Bird Species in the New World: Patterns in Species Turnover

Oikos, 1996
Spatial patterns of species richness are most often analysed at large scales by covering the area in question with a grid and comparing the richness of different squares. This method ignores species turnover across squares, or beta diversity, which has the potential either to reduce or to exaggerate richness patterns demonstrated using grid ...
Tim M. Blackburn, Kevin J. Gaston
openaire   +1 more source

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
openaire   +2 more sources

Species Turnover Rates on Islands: Dependence on Census Interval

Science, 1977
Measurements of species turnover in island bird communities demonstrate two trends with increasing census interval t : (i) Apparent turnover rates T decrease greatly with t , and (ii) the coefficient of variation of T decreases asymptotically to
J M, Diamond, R M, May
openaire   +2 more sources