نتایج جستجو برای: richness margalef

تعداد نتایج: 20862  

ژورنال: مرتع 2022
, ,

Abstract Background and objectives: Prediction of species richness and diversity patterns are used to develop conservation strategies for biodiversity under regional and global environmental changes. Since modeling the distribution of plant species can provide useful and important information about identifying and introducing potential habitats of plant species, and also few studies have been ...

1997
W. K. W. Li Paul Dickie Brian Irwin Edward Horne Glen Harrison

The concept and methods of ecological diversity in communities were applied to phytoplankton categorized by flow cytometric measurements related to size and chlorophyll content. Each cytometric signature was condensed to single numerical values indicative of diversity and evenness. Measurements pooled from studies disparate in temporal and spatial scales indicated greater chlorophyll biomass an...

2003
JUSTIN P. WRIGHT ALEXANDER S. FLECKER CLIVE G. JONES

There is considerable interest in determining whether the species richness of communities is determined by forces controlling dispersal into patches that operate at the landscape scale, or forces controlling persistence that act at the local scale. Understanding the relative importance of these two classes of factors in controlling within-patch species richness is particularly important when pa...

2006
Catherine H. Graham Robert J. Hijmans

Aim Maps of species richness are the basis for applied research and conservation planning as well as for theoretical research investigating patterns of richness and the processes shaping these patterns. The method used to create a richness map could influence the results of such studies, but differences between these methods have been insufficiently evaluated. We investigate how different metho...

2007
Boris R. Krasnov Georgy I. Shenbrot Irina S. Khokhlova Robert Poulin

Aim We searched for signs of the ‘bottom-up’ diversity effect in the association between fleas (Siphonaptera) and their small mammalian hosts (Rodentia, Insectivora and Lagomorpha). We asked (1) whether a strong dependence of flea species richness on host species richness is characteristic for both Palaeoarctic and Nearctic realms; (2) if yes, whether the ratio of host species per flea species ...

2012
SOPHIA QIAN NIU MICHAEL P. FRANCZYK JASON H. KNOUFT

1. Local assemblage structure, from a deterministic perspective, is presumably dictated by the regional species pool as well as regulated by local factors. We examined the relationships of the regional species pool and local hydrological characteristics to local species richness of North American freshwater fishes using data sets collected during the National Water Quality Assessment program co...

2016
Krithi K. Karanth Vishnupriya Sankararaman Shashank Dalvi Arjun Srivathsa Ravishankar Parameshwaran Sushma Sharma Paul Robbins Ashwini Chhatre

Wildlife Conservation Society, New York, NY, USA, Centre for Wildlife Studies, Bangalore, India, 3 Environmental Science and Policy, Nicholas School of the Environment, Duke University, Durham, NC, USA, 4 India Program, Wildlife Conservation Society, Bangalore, India, Department of Wildlife Ecology and Conservation, School of Natural Resources and Environment, University of Florida, Gainesville...

2004
MANUEL A. GRAÇA PAULO PINTO RUI CORTES NUNO COIMBRA SIMONE OLIVEIRA MANUELA MORAIS MARIA JOÃO CARVALHO

We analysed the spatial patterns in macroinvertebrate taxon richness and abundance at two scales: sampling unit and basin. We sampled 12 stream sites in three zones of Portugal, differing in climate geomorphology and water chemistry. At a sampling unit scale, substratum organic matter content, depth and the dominant size of substratum particles were correlated with numbers of taxa and individua...

2014
Steve Wathen James H. Thorne Andrew Holguin Mark W. Schwartz

Evidence for significant losses of species richness or biodiversity, even within protected natural areas, is mounting. Managers are increasingly being asked to monitor biodiversity, yet estimating biodiversity is often prohibitively expensive. As a cost-effective option, we estimated the spatial and temporal distribution of species richness for four taxonomic groups (birds, mammals, herpetofaun...

Journal: :The Journal of animal ecology 2011
Dale G Nimmo Simon G James Luke T Kelly Simon J Watson Andrew F Bennett

1. Patterns of species richness often correlate strongly with measures of energy. The more individuals hypothesis (MIH) proposes that this relationship is facilitated by greater resources supporting larger populations, which are less likely to become extinct. Hence, the MIH predicts that community abundance and species richness will be positively related. 2. Recently, Buckley & Jetz (2010, Jour...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید