We conducted a 5-year study on the impact of nutrients, depending on stream and season. grazing on stream-channel bare ground and erosion, and a © CSA 3-year study of cattle-trail erosion on intermittent stream channels draining grazed oak (Quercus)-woodland 450. Correlations of stocking with the cryptogamic soil watersheds. These studies were conducted on the San crust of a semi-arid rangeland...

Shrubs and subshrubs can tolerate wider ranges of moisture stresses in both soil and air than other plant life forms, and thus represent greater nonlinearity and uncertainty in ecosystem physiology. The objectives of this paper are to model shrub/subshrub stomatal conductance by synthesizing the field leaf gas exchanges data of 24 species in China, in order to detect the differences between dec...

BACKGROUND Although semi-arid and arid regions account for about 40% of terrestrial surface of the Earth and contain approximately 10% of the global soil organic carbon stock, our understanding of soil organic carbon dynamics in these regions is limited. METHODOLOGY/PRINCIPAL FINDINGS A field experiment was conducted to compare soil organic carbon dynamics between a perennial grass community ...

Fodder shrubs are highly attractive to farmers as protein supplements for their dairy cows because they require little or no cash. Nor do they require land as they are grown along boundaries, pathways, and across the contour to curb soil erosion. But like many agroforestry and natural resource management practices, fodder shrubs are “knowledge intensive”, that is, they require considerable skil...

Facilitation of tree regeneration by nurse shrubs that offer protection against large herbivores is an important driver of wood-pasture dynamics. Here we asked whether the response to facilitation by nurse shrubs depends on the grazing resistance of the protégé saplings. We experimentally tested the protective effects of the thorny Rosa rubiginosa on browsing frequency, survival, and biomass ch...

Current control practices are discussed for the California ground squirrel (Spermophilus beecheyi) which is considered a major rodent pest to agriculture. The primary control options are poison baits, burrow fumigation and trapping. The effectiveness of baits and fumigants is linked closely with the squirrel's annual life cycle, hence knowledge of their cycle is essential. The elements of the s...

We develop a simple, analytical model for canopy resistance to canopy–atmosphere gas exchange that is well suited for incorporation into regional-scale land-surface parameterizations. This model exploits the conservative nature of canopy light-use efficiency (LUE) in carbon assimilation that is observed within broad categories of plant species. The model paradigm assumes that under standard env...

in order to estimate the relationship between forage quality and preference value of plant species for raini goats(capra aegagrus hircus), a field study was carried out on raini goats’ grazing behavior in some desert habitats.crude protein (as the most important factor affecting forage quality) of all plant species was measured at twophenological stages (spring and summer, 2010) in the dry rang...

interrupting the processes which control ecosystem resources has dramatic impacts on the rangeland conditions. to protect ecosystems and landscape, it needs to understand the ecosystem processes which regulate the ecosystem resources. as main components of ecosystems, patches and inter-patches play important roles in energy and materials cascade. ecologically, functional parameters such as stab...

This paper aims to provide guidance to ecologists with limited experience in spatial analysis to help in their choice of techniques. It uses examples to compare methods of spatial analysis for ecological field data. A taxonomy of different data types is presented, including pointand area-referenced data, with and without attributes. Spatially and non-spatially explicit data are distinguished. T...