نتایج جستجو برای: environmental ecosystems

تعداد نتایج: 405619  

2013
Florian Altermatt Mathew Seymour Nicolas Martinez

Aim Spatial dynamics and habitat connectivity affect community composition and diversity in many ecosystems. For many decades, diversity patterns in riverine ecosystems were thought to be related to local environmental conditions. Recent theoretical work, however, suggests that diversity in rivers is strongly affected by dispersal along the dendritic landscape structure and that environmental c...

2014
Angel Borja

INTRODUCTION The study of marine ecosystems has become a hot research topic in recent times. In fact, the number of manuscripts including the words “marine ecosystems” published since 1970 has immensely increased reaching between 1100 and 1500 articles per year in the past five years (Figure 1). Based on the keywords used in these manuscripts, the most frequent topics can be grouped into: (i) m...

M. Pourafrasyabi Z. Ramezanpour

Phytoplanktons are the first bio- indicators of pollution in aquatic ecosystems. Phytoplankton assemblage and aquatic ecosystems are always influenced by environmental factors therefore these environmental changes and threats must be understood in any ecosystem. Phytoplankton are inexpensive and readily available bio- indicators. In the present study, phytoplankton were used to study the Sefid ...

Dina Askarizadeh Mohammad Hassan Jouri, Mohammad Mahdavi, Vahid Rahimi

Mountainous rangeland ecosystems have a highly delicate position in ecologic areabecause of severe environmental conditions and having wildlife and livestock. Knowing andrealizing the biotic and abiotic components, which have an interaction with each other in thisecosystem, perform the most important role in to desirable management of it. The systematicmanagement is one of the managing features...

2013
William J. Ripple Aaron J. Wirsing Christopher C. Wilmers Mike Letnic

Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR 97331, USA b School of Environmental and Forest Sciences, University of Washington, Seattle, WA 98195, USA Environmental Studies Department, University of California, Santa Cruz, CA 95064, USA Australian Rivers, Wetlands and Landscapes Centre, School of Biological, Earth and Environmental Sciences, University of...

Journal: :health in emergencies and disasters quarterly 0
mehrdad farrokhi department of health in disasters and emergencies, university of social welfare & rehabilitation sciences, tehran, iran. zahra abbasi dolatabadi department of critical care nursing, school of nursing and midwifery, tehran university of medical sciences, tehran, iran. shahrzad pakjouei department of health in disasters and emergencies, university of social welfare & rehabilitation sciences, tehran, iran. vahideh pouyesh department of nursing, faculty of nursing and midwifery, iranshahr university of medical sciences, sistan and baluchestan, iran.

background: environment and its ecosystems are affected by various natural and man-made disasters. the environmental management in disasters tries to protect ecosystems, sustain development, reduce disaster risk, and adapt to or decrease the impact of climate change. this study aimed to investigate the impact of disasters on the environment and methods of reducing these effects. materials and m...

Arash Karami Javad Mirzaei,

Plant diversityis essential to maintain the health of planet's ecosystems. Conservation of biodiversity is necessary for the ecological stability and productivity in natural ecosystems. The aim of this research was to study the biodiversity and richness of plant species (including trees, shrubs and grasses) related to the environmental factors (soil and physiography) in the forests of Zagros, w...

Ahmad Pahlavanravi Einollah Rouhi Moghaddam, Khalil Amoozadeh

Objective: The aim of this study is to provide a management plan for the Sykan watershed of Darre shahr city located in Ilam province using GIS in land use planning. Methods: For land using of Sykan watershed of Ilam province with about 9 hectares area, map of classes, elevation, percent slope, geographical aspects, soil characteristics, vegetation density and the final map units were combined ...

Ahmad Pahlavanravi Einollah Rouhi Moghaddam, Khalil Amoozadeh

Objective: The aim of this study is to provide a management plan for the Sykan watershed of Darre shahr city located in Ilam province using GIS in land use planning. Methods: For land using of Sykan watershed of Ilam province with about 9 hectares area, map of classes, elevation, percent slope, geographical aspects, soil characteristics, vegetation density and the final map units were combined ...

Journal: :Molecular ecology 2010
Ivan P Edwards Donald R Zak

The Agaricomycotina are a phylogenetically diverse group of fungi that includes both saprotrophic and mycorrhizal species, and that form species--rich communities in forest ecosystems. Most species are infrequently observed, and this hampers assessment of the role that environmental heterogeneity plays in determining local community composition and in driving beta-diversity. We used a combinati...

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