نتایج جستجو برای: vegetation type
تعداد نتایج: 1384618 فیلتر نتایج به سال:
Basic information on where nonnative plant species have successfully invaded is lacking. We assessed the vulnerability of 22 vegetation types (25 sets of four plots in nine study areas) to nonnative plant invasions in the north-central United States. In general, habitats with high native species richness were more heavily invaded than species-poor habitats, low-elevation areas were more invaded...
Vegetation productivity is an essential variable in ecosystem functioning. Vegetation dynamics of dryland ecosystems are most strongly determined by water availability and consequently by rainfall and there is a need to better understand how water limited ecosystems respond to altered rainfall amounts and variability. This response is partly determined by the vegetation functional response to r...
Ecotones represent locations where vegetation change is likely to occur as a result of climate and other environmental changes. Using a model of an ecotone vulnerable to such future changes, we estimated the resilience of the ecotone to disturbances. The specific ecotone is that between two different vegetation types, salinity-tolerant and salinity-intolerant, along a gradient in groundwater sa...
Introduction Otitis media with effusion is the fluid in the middle ear with no signs or symptoms of acute ear infection. Objective This study aims to research the frequency of serous otitis media in patients referred to the pediatric clinic between 3-16 years of age without any active ear, nose, and throat complaints. Methods This study included 589 children patients (280 boys, 309 girls; mean ...
Microbial biomass phosphorus (MBP) is one of the most active forms of phosphorus (P) in soils. MBP plays an important role in the biogeochemical P cycle. To explore MBP distribution and its relationship with other factors, the MBP and rhizosphere soil P concentrations and fractions in six vegetation zones on the eastern slope of Gongga Mountain in SW China were investigated. The MBP distributio...
The presence and identity of Cu-complexing ligands in soil solution strongly affects biogeochemistry, bioavailability and the fate of Cu in soils. In this study, we compared the influence of heavy metal pollution, vegetation and soil type on the amount and characterization of ligands able to form ternary complexes with Cu in soil solution. For separation and characterization, we applied immobil...
The turbidity of lakes is generally considered to be a smooth function of their nutrient status. However, recent results suggest that over a range of nutrient concentrations, shallow l&es can have two alternative equilibria: a clear state dominated by nquatic vegetation, and a turbid state characterized by high algal biomass. This bi-stability has important implications for the possibilities of...
vegetation cover as the main factor affecting the water erosion plays an important role in preventingsoil loss. to this end, for better understanding the impact of vegetation cover on soil erosion andsediment yield over the major existing geological formations in the summer rangelands of balade inthe mazandaran province, rainfall simulation studies have been carried out using a portable rainfal...
Sagebrush (Artemisia spp.) communities constitute the largest temperate semidesert in North America and provide important rangelands for livestock and habitat for wildlife. Remote sensing methods might provide an efficient method to monitor sagebrush communities. This study used airborne LiDAR and field data to measure vegetation heights in five different community types at the Reynolds Creek E...
Knowledge and protection of natural plant assemblages are key objectives of the California Native Plant Society (CNPS). The CNPS Vegetation Program has a floristic classification system to define and map vegetation in the state, including rare and common vegetation. Rare vegetation represents important and distinctive assemblages of biodiversity, and over 60% of the described vegetation allianc...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید