نتایج جستجو برای: physical habitat

تعداد نتایج: 715969  

Journal: :The Journal of the Acoustical Society of America 2003
Brian S Nelson

Attenuation over distance in natural habitat is often difficult to predict when measured without respect to sound frequency. The physical-acoustic structure of Florida scrub habitat is described and both attenuation and reliability of attenuation are measured as a function of sound frequency, over several distances, speaker elevations, and microphone elevations. The spatial context of sound pro...

2005

In order to minimize the impacts on fish of human activities such as logging, agriculture, and urbanization, managers must understand and be able to accurately monitor how these activities affect fish habitat. Specifically, it is necessary to understand what habitat factors are affected, what habitat factors are limiting to fish abundance, how these factors interact with each other and which ar...

2015
Alex Rattray Daniel Ierodiaconou Tim Womersley

*Correspondence: Daniel Ierodiaconou, Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Princes Hwy., Warrnambool, VIC 3280, Australia e-mail: [email protected] The new found ability to measure physical attributes of the marine environment at high resolution across broad spatial scales has driven the rapid evolution of benthic habitat mapping as a fi...

2008
JASON JONES

The study of habitat use and selection in birds has a long tradition (Grinnell 1917, Kendeigh 1945, Svardson 1949, Hild6n 1965; Block and Brennan 1993). Early habitat-selection theory was characterized by correlative models of habitat characteristics and species abundance (MacArthur and Pianka 1966, Verner et al. 1986, Rosenzweig 1991), which subsequently evolved into models that involved densi...

2011
David D. Huff Steven T. Lindley Polly S. Rankin Ethan A. Mora

The green sturgeon (Acipenser medirostris) is a highly migratory, oceanic, anadromous species with a complex life history that makes it vulnerable to species-wide threats in both freshwater and at sea. Green sturgeon population declines have preceded legal protection and curtailment of activities in marine environments deemed to increase its extinction risk. Yet, its marine habitat is poorly un...

Journal: :Ecological applications : a publication of the Ecological Society of America 2011
Christy R Violin Peter Cada Elizabeth B Sudduth Brooke A Hassett David L Penrose Emily S Bernhardt

Streams, as low-lying points in the landscape, are strongly influenced by the stormwaters, pollutants, and warming that characterize catchment urbanization. River restoration projects are an increasingly popular method for mitigating urban insults. Despite the growing frequency and high expense of urban stream restoration projects, very few projects have been evaluated to determine whether they...

2005

Plans and policies are enhanced by information generated in Step 1, which involves analyzing the role that wetlands play in landscape processes. Landscape processes both maintain and interact with wetlands and the functions they perform. Landscape processes can include physical processes such as those that maintain hydrology and the physical stability of shorelines; chemical processes such as t...

2002
MATTHEW R. DARE WAYNE A. HUBERT KENNETH G. GEROW

—We assessed habitat availability and habitat use by subadult cutthroat trout Oncorhynchus clarki and brown trout Salmo trutta during a four-stage flow manipulation in the Shoshone River, Wyoming, to determine how the physical characteristics of a medium-size river and the habitat use and movement patterns of subadult trout change in response to declining discharge. Discharge was reduced from 2...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - دانشکده منابع طبیعی 1391

in this study, the effects of oleothermal modification on physical and mechanical peroperties of fir wood (abeis sp.) blocks were examined. at first, some blocks of fir wood with 5 × 20 × 120 cm dimensions were prepared. the blocks were treated in soybean oil. the effects of 3 factors such as treatments temperature (180and 200 °c), holding time (12 and 15 h) and initial moisture content of wood...

سالاروند, مرضیه, عرفانزاده, رضا, کوچ, یحیی,

This study aimed to compare plant species diversity indices (diversity and richness) and some physico-chemical properties of soil among forest, ecotone and rangeland habitats. Vegetation sampling was done randomly at each habitat. One dominant community was selected in each habitat and one key area was distinguished in each community and 8×1m2 plots were randomly established in each key area. I...

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