نتایج جستجو برای: desert journal
تعداد نتایج: 155408 فیلتر نتایج به سال:
Vegetation phenology in temperate grasslands is highly sensitive to climate change. However, it is still unclear how the timing of vegetation phenology events (especially for autumn phenology) is altered in response to climate change across different grassland types. In this study, we investigated variations of the growing season start (SOS) and end (EOS), derived from Moderate Resolution Imagi...
Arid desert ecosystems of the western United States are particularly susceptible to climate change and climate variability. Plants and animals in this region live near their physiological limits for water and temperature stress. Slight changes in temperature or precipitation regimes or a change in the frequency and magnitude of extreme climatic events could therefore substantially alter the com...
The sugar-flotation-sieving (SFS) and Baermann-funnel (BF) methods were compared for nematode extraction efficiency. The SFS method recovered nematodes from more trophic groups whereas greater total numbers of individuals were recovered by BF. In a test to validate the efficiency of SFS, virtually 100% of the nematodes added to desert soil prior to extraction were recovered by four consecutive ...
Many island communities exhibit a highly nonrandom pattern of species composition in which smaller biotas contain successive subsets of the species in richer ones. Here, we examine the composition of continental communities to see whether this 'nested subset' pattern holds and, if so, to determine its spatial scale and environmental correlates. Granivorous rodent assemblages at 202 sites in Gre...
Food, like water, is in short supply in the desert. We report a specialized mechanism used by a desert mouse for surviving prolonged food shortages. The key element of this adaptation is a large reduction in resting metabolism. After about 2 weeks of restricted food intake (50% of normal), the desert mouse "switched down" its resting metabolism and was able to survive and maintain its weight in...
4-Coumarate:CoA ligase (4CL) genes are critical for the biosynthesis of plant phenylpropanoids. Here we identified 20 4CL genes in the genomes of two desert poplars (Populus euphratica and P. pruinosa) and salt-sensitive congener (P. trichocarpa), but 12 in Salix suchowensis (Salix willow). Phylogenetic analyses clustered all Salicaceae 4CL genes into two clades, and one of them (corresponding ...
OBJECTIVE There exist no prospectively generated analyses of the type and frequency of medical incidents in desert settings. We created a database of every illness and injury during 6 field seasons in the Gobi Desert in order to optimize expedition medical and safety planning. METHODS Every incident presenting to the expeditions' physicians, regardless of type, magnitude, treatment, or outcom...
INTRODUCTION The United States Department of Agriculture (USDA) describes a food desert as an urban neighborhood or rural town without ready access to fresh, healthy, and affordable food. An estimated 2.3 million rural Americans live in food deserts. One goal of the USDA is to eliminate food deserts. However, at a time when some food deserts are being eliminated, hundreds of grocery stores are ...
Patterns of spatial variation in biological diversity represent one of the central themes in modern biogeography and ecology (Rosenzweig, 1995; Gaston & Williams, 1996). Much of the knowledge about these patterns available to date is based strictly on studies of free-living organisms (Rosenzweig, 1995), whereas patterns of parasite diversity have until now attracted Ramon Science Center and Mit...
[1] Soil sulfates are present in arid and hyperarid environments on Earth and have been found to be abundant in soils on Mars. Examination of soil gypsum from the Atacama Desert, Chile, the Mojave Desert, United States, and Al-Jafr Basin, Jordan, revealed endolithic cyanobacteria communities just below the surface of soil gypsum samples. Optical and scanning electron microscope observations of ...
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