نتایج جستجو برای: grasslands
تعداد نتایج: 6042 فیلتر نتایج به سال:
On a Flemish sandy loam soil, cut and grazed swards were compared at different levels of mineral nitrogen (N) fertilization. Economically optimal N fertilization rates were 400 (or more) and 200 kg N ha yr on cut and grazed swards respectively. Considering the amounts of residual soil nitrate-N in autumn, these N rates also met the current Flemish legal provisions, i.e. no more than 90 kg ha ni...
1. Grasslands in the Temperate Zone: Distribution and History 2. Characteristics of Old Temperate Grassland Ecosystems 2.1 Grazing and Cutting Regimes 2.2 Nutrients 2.3 Area Size and Networks 2.4 Dynamic Land Use 2.5 Species Richness/Biodiversity 3. Present and Future Policy to Manage Old Temperate Grasslands 3.1 Modern Agriculture and Traditional Temperate Grasslands 3.2 Avoidance of Eutrophic...
When males of a species follow different reproductive strategies in different habitats, one might expect the strategy adopted to maximize fitness payoffs under particular ecological conditions. Striped mice (Rhabdomys pumilio) males in the moist grasslands of South Africa follow a roaming mating strategy, visiting several receptive females, and do not participate in parental care. In contrast, ...
Fire is a globally distributed disturbance that impacts terrestrial ecosystems and has been proposed to be a global "herbivore." Fire, like herbivory, is a top-down driver that converts organic materials into inorganic products, alters community structure, and acts as an evolutionary agent. Though grazing and fire may have some comparable effects in grasslands, they do not have similar impacts ...
two species of pratylenchoides recovered from the grasslands in sabalan region and one species recovered from natural habitats of tehran are illustrated based on morphological, morphometric and molecular characters. the first species, p. crenicauda is characterized mainly by its lip region with three-four annuli, lateral field with four incisures areolated throughout the length and having rod s...
A significant recovery of food plants preferred by introduced deer (Cervus elaphus) occurred between 1969 and 1984 on 57 permanent plots in the alpine grasslands of northern Fiordland. During this period the deer population was reduced markedly by hunters operating from helicopters. Deer showed a strong preference for grasslands characterised by Chionochloa pallens and large-leaved herbs. These...
Discriminating and mapping the C3 and C4 composition of grasslands in the northern Great Plains, USA
Article history: Received 30 October 2006 Received in revised form 25 March 2007 Accepted 26 March 2007 There is uncertainty about the extent and distribution of grasslands following the C3 and C4 photosynthetic pathways. Since these grasses have an asynchronous seasonal profile it should be possible to estimate and map the C3–C4 composition of grasslands from multitemporal remote sensing image...
Understanding the temperature sensitivity (Q 10) of soil organic matter (SOM) decomposition is important for predicting soil carbon (C) sequestration in terrestrial ecosystems under warming scenarios. Whether Q 10 varies predictably with ecosystem succession and the ways in which the stoichiometry of input SOM influences Q 10 remain largely unknown. We investigate these issues using a grassland...
Patch-burn grazing is a management framework that promotes heterogeneity in grasslands, similar to the structure grasslands birds evolved inhabiting. Published studies on patch-burn grazing have been conducted on large, contiguous grasslands and only one of these studies has investigated the reproductive success of grassland birds. We assessed the effects of patch-burn grazing (grazing, one thi...
Marginal croplands, such as those in the Conservation Reserve Program (CRP), have been suggested as a source of biomass for biofuel production. However, little is known about the composition of plant species on these conservation grasslands or their potential for ethanol production. Our objective was to assess the potential of CRP and other conservation grasslands for biofuel production, descri...
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