نتایج جستجو برای: 17 wetlands in gilan

تعداد نتایج: 17018721  

Journal: :Bulletin of entomological research 2010
J O Lundström Y Brodin M L Schäfer T Z Persson Vinnersten O Ostman

Species richness and species turn-over of Chironomidae was studied in irregularly flooded wetlands of the River Dalälven flood-plains in central Sweden. The chironomid fauna, sampled with emergence traps in six wetlands over six summers, contained as much as 135 species, and the cumulative species curves indicated that the regional species pool contain several more species. Recurrent irregular ...

Journal: :Environmental management 2004
Manuel Ortega Josefa Velasco Andrés Millán Cristina Guerrero

The main goal of the present study was to develop an ecological integrity index for littoral wetland management and conservation in semiarid Mediterranean areas that have been highly impacted by agriculture, including the selection of pressure and state indicators at landscape and wetlands scales that reflect the status, condition, and trends of wetlands ecosystems. We used a causality framewor...

2009
Andrea Ghermandi Jeroen C.J.M. van den Bergh Luke M. Brander Henri L.F. de Groot Paulo A.L.D. Nunes

The values of goods and services provided by natural and constructed wetlands are examined through a meta-analysis of 418 observations of the economic value of 186 wetlands. Water quality improvement, non-consumptive recreation, and provision of natural habitat and biodiversity turn out to be highly valued services. Substitution effects are observed through the negative correlation between valu...

2009
Chang - gyun Lee

Since the mid 1990s, constructed wetlands have been increasingly used as a lowenergy ‘green’ technique, in the treatment of wastewater and stormwater, driven by the rising cost of fossil fuels and increasing concern about climate change. Among various applications of these wetlands, a significant area is the removal of nitrogenous pollutants to protect the water environment and to enable effect...

Journal: :IJAGR 2011
Evelyn Brister Elizabeth Hane Karl Korfmacher

Ecological data from land surveys from 1811 for the 100,000-acre Connecticut Tract in western New York were transcribed and then analyzed using ArcGIS and IDRISI GIS software. The surveys contained both witness tree data and line descriptions, which were analyzed for species composition and community type. Results illustrate that many changes have occurred in species composition. Possible cause...

Journal: :Journal of environmental quality 2011
Melanie D Harrison Peter M Groffman Paul M Mayer Sujay S Kaushal Tamara A Newcomer

Riparian wetlands have been shown to be effective "sinks" for nitrate N (NO3-), minimizing the downstream export of N to streams and coastal water bodies. However, the vast majority of riparian denitrification research has been in agricultural and forested watersheds, with relatively little work on riparian wetland function in urban watersheds. We investigated the variation and magnitude of den...

The objective of this study was to isolate halophilic bacteria with the ability to produce intracellular or extracellular L-asparaginase. A total number of 120 halophilic bacteria were isolated from 17 different saline habitats of Iran including salt lakes, wetlands, brine springs and deserts. Among these, 68 were able to grow in the presence of 1.5 M NaCl and 52 demonstrated the ability to gro...

Journal: :J. Geographic Information System 2011
Meenu Rani Pavan Kumar Manoj Yadav R. S. Hooda

Wetlands, the transitional zones that occupy an intermediate position between dry land and open water, regulate the flow of water and nutrients, thereby facilitating optimum functioning of the physical and biological cycles of nature. To conserve and manage wetland resources, it is important to invent and monitor wetlands and their adjacent uplands. Wetlands are most productive ecosystems besid...

2005
MICHAEL J. RUBBO JOSEPH M. KIESECKER

Amphibians commonly use wetlands for breeding habitat, and given the concern about their ongoing global declines, the effects of urbanization on the breeding distribution of amphibians need to be quantified. Thus, we conducted a survey of the larval amphibian community in central Pennsylvania (U.S.A.) wetlands along an urbanization gradient. Wetlands in urban areas had less surrounding forest a...

2014
Alisa L. Gallant Shannon G. Kaya Lori White Brian Brisco Mark F. Roth Walt Sadinski

Wetlands provide ecosystem goods and services vitally important to humans. Land managers and policymakers working to conserve wetlands require regularly updated information on the statuses of wetlands across the landscape. However, wetlands are challenging to map remotely with high accuracy and consistency. We investigated the use of multitemporal polarimetric synthetic aperture radar (SAR) dat...

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