نتایج جستجو برای: playa wetland

تعداد نتایج: 11151  

Journal: :Environmental science & technology 2014
Dale W Daniel Loren M Smith David A Haukos Lacrecia A Johnson Scott T McMurry

Watershed cultivation and subsequent soil erosion remains the greatest threat to the service provisioning of playa wetlands in the High Plains. The U.S. Department of Agriculture's (USDA) Conservation Reserve Program (CRP) plants perennial vegetation cover on cultivated lands including playa watersheds, and therefore, the program influences sediment deposition and accumulation in playas. Our ob...

2002
LOREN M. SMITH DAVID A. HAUKOS

There are 25,000–30,000 playa wetlands in the intensively cultivated Southern Great Plains of the United States. Knowledge of area and watershed influences on wetland flora are needed to guide their conservation. We surveyed plant-community composition in 224 playas over 360,000 km 2 and examined the relationships of species richness and diversity (Shannon’s) to playa area and watershed disturb...

Journal: :Geochemical Transactions 2007
Ian M Power Siobhan A Wilson James M Thom Gregory M Dipple Gordon Southam

BACKGROUND This study provides experimental evidence for biologically induced precipitation of magnesium carbonates, specifically dypingite (Mg5(CO3)4(OH)2.5H2O), by cyanobacteria from an alkaline wetland near Atlin, British Columbia. This wetland is part of a larger hydromagnesite (Mg5(CO3)4(OH)2.4H2O) playa. Abiotic and biotic processes for magnesium carbonate precipitation in this environmen...

2004
JA Dini

South Africa has begun developing a wetland inventory program, coordinated on a national scale and employing a standardised methodology and classification system. In order to facilitate the mapping phase of the inventory and enhance the value of data gathered, a classification system for South Africa’s wetlands has been developed. This is based on the Cowardin system used by the United States N...

2004
Steven Goldsmith LOREN M. SMITH MATTHEW J. GRAY ABIGAIL QUARLES

Although amphibians are the dominant vertebrate inhabiting playa wetlands during spring and summer in the Southern Great Plains, little is known about their diet and role in playa trophic structure. Because new metamorphs are more numerous than other terrestrial life stages of amphibians, we describe the diets of recently (,2 weeks) metamorphosed Great Plains toad (Bufo cognatus), barred tiger ...

Journal: :desert 2010
gh.r zehtabian m.k kianian a. salehpour jam

abstract soil, is a reclamable and sustainable source. it is the basis of survival and it’s implication, should be performed on the basis of productivity identification according to scientific and technical rules, we can protect this valuable source, and increase it’s productivity and usage. nowdays, saline soils cover nearly 14.6% of the country area. study areas (kashan’ playa) have saline an...

Journal: :Journal of environmental management 2009
J Herrero C Castañeda

The small playa-lakes and other saline wetlands of Monegros, scattered over a dry area with winter cereal monoculture, are threatened by the settlement of new irrigation districts and other kinds of human pressure. Enforcing the protection rules of European Union in these valuable habitats requires, first, their delimitation and monitoring. This article shows how these tasks can be undertaken u...

2004
MATTHEW J. GRAY LOREN M. SMITH ROBERTO BRENES

Anthropogenic disturbance of landscapes surrounding wetlands is considered a factor in local and global amphibian declines. Few data exist on the effects of agricultural cultivation of wetland watersheds on amphibians, and results from previous studies are contradictory. Our objective was to test the effects of general anthropogenic land use (cultivation vs. grassland) on the demographics of se...

Journal: :Wetlands Ecology and Management 2021

Freshwater wetlands located in dryland environments are characterised by high evapotranspiration rates and frequent periods of desiccation, which strongly influence the water chemistry solute budgets these systems. The transpiration groundwater, especially trees, is an important mechanism through can lose water. This process lead to groundwater salinization precipitation substantial quantities ...

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