نتایج جستجو برای: vegetation degradation
تعداد نتایج: 196873 فیلتر نتایج به سال:
Exclosure studies have been used to great advantage in the Hawaiian Islands to evaluate and demonstrate impacts of alien vertebrate herbivores upon native vegetation. Information presented for 50 exclosures, mostly on Hawaii and Maui, shows a wide range of vegetation responses. In most situations, native biota hold their own or increase following removal of vertebrate damage, but the chance of ...
The contribution of understorey vegetation (UVEG) to forest ecosystem biomass and carbon (C) across diverse forest types has, to date, eluded quantification at regional and national scales. Efforts to quantify UVEG C have been limited to field-intensive studies or broad-scale modelling approaches lacking field measurements. Although large-scale inventories of UVEG C are not common, speciesand c...
The Amazon basin is characterized by a strong interplay between the atmosphere and vegetation. Anthropogenic land use and land cover change (LULCC) affects vegetation and the exchange of energy and water with the atmosphere. Here we have assessed potential LULCC impacts on climate and natural vegetation dynamics over South America with a regional Earth system model that also accounts for vegeta...
Vegetation biomass is a crucial ecological variable for understanding the evolution and potential future changes of the climate system. Vegetation biomass is a larger global store of carbon than the atmosphere, and changes in the amount of vegetation biomass already affect the global atmosphere by being a net source of carbon, and having the potential either to sequester carbon in the future or...
In recent years, the degradation of Amazon forest has been target studies at global level to identify elements and factors influencing this process. Thus, study had as objective vegetation during years El Niño Southern Oscillation (ENSO) phenomenon in State Amazonas. We used remote sensing data, typologies, weather from 14 conventional stations located Evapotranspiration images obtained MODIS G...
Chengde city is located in the agro-pastoral transitional zone in northern China near the capital city of Beijing, which has experienced large-scale ecological construction in the past three decades. This study quantitatively assessed the environmental changes in Chengde through observation records of water resources, water environment, atmospheric environment, and vegetation activity and inves...
Roads and cities represent huge sources of degradation for adjacent ecosystems regarding nutrient cycling, energy, water flow and species composition. In this study we test the hypothesis that distance from roads and cities is associated with habitat loss and fragmentation in the caatinga vegetation--a dry forest to scrub vegetation that covers ca. 736,000 km2 of northeast Brazil. The study sit...
Degradation of chlorobenzoic acids (e.g., products of microbial degradation of PCB) by strains of microorganisms isolated from PCB contaminated soils was assessed. From seven bulk-soil isolates two strains unique in ability to degrade a wider range of chlorobenzoic acids than others were selected, individually and even in a complex mixture of 11 different chlorobenzoic acids. Such a feature is ...
Assessing how environmental changes affect the distribution and dynamics of vegetation and animal populations is becoming increasingly important for terrestrial ecologists to enable better predictions of the effects of global warming, biodiversity reduction or habitat degradation. The ability to predict ecological responses has often been hampered by our rather limited understanding of trophic ...
Overgrazing has caused vegetation destruction and soil degradation in Leymus chinensis grassland, the widely distributed type of grassland in northern China. To restore the degraded ecosystem, grazing exclusion was implemented in 1979, 1999, and 2004. However, changes in the vegetation and soil organic carbon (SOC) in different years of grazing exclusion have not been thoroughly elucidated. Thi...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید