نتایج جستجو برای: physical habitat

تعداد نتایج: 715969  

Over the last five years, restoration and rehabilitation projects in saline and alkaline rangelands at north of Golestan Province in Iran through plantation of Lycium depressum Stock. have not achieved any success. One reason behind this lies in the lack of knowledge about relations between the soil and plant. This study aimed at assessing and comparing soil physiochemical characteristics insid...

Journal: :PLoS ONE 2008
Martin Hromada Marcin Antczak Thomas J. Valone Piotr Tryjanowski

Animals often settle near competitors, a behavior known as social attraction, which belies standard habitat selection theory. Two hypotheses account for these observations: individuals obtain Allee benefits mediated by the physical presence of a competitor, or they use successfully settled individual as a source of information indicating the location of high quality habitat. We evaluated these ...

Journal: :Journal of environmental quality 2007
Thomas Heatherly Matt R Whiles Todd V Royer Mark B David

The influence of specific stressors, such as nutrient enrichment and physical habitat degradation, on biotic integrity requires further attention in Midwestern streams. We sampled 53 streams throughout Illinois and examined relationships between macroinvertebrate community structure and numerous physicochemical parameters. Streams were clustered into four major groups based on taxa dissimilarit...

Journal: :BMC Public Health 2009
Nicola W Burton Michele Haynes Lee-Ann M Wilson Billie Giles-Corti Brian F Oldenburg Wendy J Brown Katrina Giskes Gavin Turrell

BACKGROUND Little is known about the patterns and influences of physical activity change in mid-aged adults. This study describes the design, sampling, data collection, and analytical plan of HABITAT, an innovative study of (i) physical activity change over five years (2007-2011) in adults aged 40-65 years at baseline, and (ii) the relative contribution of psychological variables, social suppor...

2014
T. K. WILDING B. BLEDSOE N. L. POFF J. SANDERSON

Dams and water diversions can dramatically alter the hydraulic habitats of stream ecosystems. Predicting how water depth and velocity respond to flow alteration is possible using hydraulic models, such as Physical Habitat Simulation (PHABSIM); however, such models are expensive to implement and typically describe only a short length of stream (10m). If science is to keep pace with development, ...

Journal: :Environmental management 2004
S Mazeika P Sullivan Mary C Watzin W Cully Hession

Scientists have long assumed that the physical structure and condition of stream and river channels have pervasive effects on biological communities and processes, but specific tests are few. To investigate the influence of the stream-reach geomorphic state on in-stream habitat and aquatic macroinvertebrate communities, we compared measures of habitat conditions and macroinvertebrate community ...

2006
Alison L. Green

The continuous reef tract on the semi-exposed side of Lizard Island, northern Great Barrier Reef, can be divided into 6 habitat zones, which are distinctly different in terms of their physical (depth, slope and wave exposure) and biological characteristics (percentage of living cover, percentage cover of each substratum type, substratum diversity and complexity). Sixty-four labrid species were ...

2013
Melinda A. Coleman

With marine protected areas being established worldwide there is a pressing need to understand how the physical setting in which these areas are placed influences patterns of dispersal and connectivity of important marine organisms. This is particularly critical for dynamic and complex nearshore marine environments where patterns of genetic structure of organisms are often chaotic and uncoupled...

Journal: :Journal of fish biology 1997
Prenda Armitage Grayston

Patterns of habitat use by fish assemblages in two chalk streams in southern England were examined to identify species preferences with respect to major habitat gradients. Both study sites, although differing in some physical habitat characteristics, mainly channel width, water temperature and instream cover, could be arranged similarly along a continuum extending from erosional to depositional...

2005
Ricard V. Solé Frederic Bartumeus Javier G. P. Gamarra J. G. P. Gamarra

Rainforests biodiversity is sustained by the three-dimensional structure of their canopy which provides a wide range of physical microenvironments. Given the dynamic nature of the forest, the recognition of stable vertical layers or strata in the canopy is controversial. The spatial characterisation of potential habitats of understory species is not straightforward due to the complex structure ...

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