نتایج جستجو برای: grasslands
تعداد نتایج: 6042 فیلتر نتایج به سال:
Rangeland ecosystems cover approximately one-third of the land area in the United States and half of the land area of California. This large land area, coupled with the propensity of grasses to allocate a considerable proportion of their photosynthate belowground, leads to high soil carbon (C) sequestration potential. Annual grasslands typical of the Mediterranean climates of the western United...
BACKGROUND To assess population persistence of species living in heterogeneous landscapes, the effects of habitat on reproduction and survival have to be investigated. METHODOLOGY/PRINCIPAL FINDINGS We used a matrix population model to estimate habitat-specific population growth rates for a population of northern wheatears Oenanthe oenanthe breeding in farmland consisting of a mosaic of disti...
BACKGROUND By the end of this century, the potential climate-biome of the southern Kenai Peninsula is forecasted to change from transitional boreal forest to prairie and grasslands, a scenario that may already be playing out in the Caribou Hills region. Here, spruce (Picea × lutzii Little [glauca × sitchensis]) forests were heavily thinned by an outbreak of the spruce bark beetle (Dendroctonus ...
In Switzerland, the traditional three-stage grassland farming system consists of grazed or cut grasslands along a gradient from lowland to alpine elevations. We measured carbon dioxide (CO2) fluxes at three grassland sites (400, 1000, 2000 m elevation) and estimated carbon sequestration for two years (2006 and 2007). Grasslands at higher elevations (>1000 m), managed at lower intensities, exhib...
*The impact of various agricultural practices on soil biodiversity and, in particular, on arbuscular mycorrhizal fungi (AMF), is still poorly understood, although AMF can provide benefit to plants and ecosystems. Here, we tested whether organic farming enhances AMF diversity and whether AMF communities from organically managed fields are more similar to those of species-rich grasslands or conve...
The natural vegetation of Southern Brazil's coastal region includes grasslands formations that are poorly considered in conservation policy, due to the lack of knowledge about these systems. This study reports results from a regional-scale survey of coastal grasslands vegetation along a 536 km gradient on southern Brazil. We sampled 16 sites along the coastal plain with 15 plots (1 m²) per site...
The grasslands of Inner Mongolia are not only the source of the necessary resources for the survival and development of herdsmen, but also represent a significant green ecological barrier in North C hina. Coal-mining production is important in maintaining GDP growth in Inner Mongolia. However, overexploitation has created serious problems, such as pollution of the environment and significant de...
Although temporal heterogeneity is a well-accepted driver of biodiversity, effects of interannual variation in land-use intensity (LUI) have not been addressed yet. Additionally, responses to land use can differ greatly among different organisms; therefore, overall effects of land-use on total local biodiversity are hardly known. To test for effects of LUI (quantified as the combined intensity ...
BACKGROUND The changes in land use and land cover have a strong effect on the total soil organic carbon, its fractions and its overall soil health. This study carried out in Olesharo Catchment, Kenya, was to quantify the differences in total organic carbon (TOC), particulate organic carbon (POC), mineral organic carbon (MOC) and carbon management index (CMI) among four land use types: grassland...
The success or failure of many organisms to respond to the challenges of habitat destruction and a warming climate lies in the ability of plant species to disperse between isolated habitats or to migrate to new ranges. European semi-natural grasslands represent one of the world’s most species-rich habitats at small scales, but agricultural intensification during the 20th century has meant that ...
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