نتایج جستجو برای: grazing
تعداد نتایج: 15163 فیلتر نتایج به سال:
to clarify fermentative alterations in the large intestine (hindgut) during grazing, fecal alcohol and volatile fatty acids (vfas) concentrations were evaluated in 30 dairy heifers. the heifers were kept in pasture growing mixed grass herbage from spring (mid may) until october, and their rectal feces were collected periodically. concentrations of ethanol, methanol and isopropanol were increase...
In grazed habitats is a tradeoff between competition (decreases with the grazing intensity) and disturbance (increases). This may give tradeoffs between plant life stages. The seed production can be assumed to decrease at high disturbance intensities because of herbivory of reproductive organs, but also at high levels of competition (low grazing intensity) because of resource limitation. The es...
Observations of wild boar damage to alpine grazing pastures in Romania's Carpathian Mountains were collected using photographs of the slopes from vantage points. We mapped the rooted areas and then used GIS software to estimate the relative proportions of the total grazing areas visible in the photographs that were damaged by wild boar. The amounts of damage from our two demonstration pastures ...
introduction:changes caused by grazing on range ecosystem are generally assessed based on the soil conditions and vegetation. livestock as one of the major elements in range land ecosystems has different effects on different parts of this ecosystem. one of these impacts is excessive livestock grazing capacity which can have different effects on soils and plants in various intensities. materials...
The effect of cattle grazing on the soil nematode and protozoan communities, and on microbial biomass, was measured in Israel’s northern highlands. Three grazing areas were compared: (1) with 1 1 cow ha 1 y ; (2) 0 55 cow ha 1 y ; and (3) control—no grazing for almost 18 years. Soil samples were collected from the upper 10 cm level of each area (n1⁄4 24), in autumn, before the onset of the rain...
Three grass species, Agropyron desertorum (Agde) and Agropyron elongatum (Agel) and recently, Bromus tomentellus (Brto) are mainly used for range improvement as mixed seeding in semi-arid areas of Iran. Because there is little information about management of these grasses, this study was conducted at the Sisab Research Station in northern Iran to evaluate their responses to grazing management a...
Species relative abundance have closely related to ecological niche of plant communities. The broader specie ecological niche for food sources the greater relative abundance of plant species. Species abundance distributions models can be are divided into two groups Statistical and biological models. In this study we aimed to investigate how animal grazing (Long time grazing exclusion, Grazing a...
Forage production of rangelands differs during different times of grazing season and in the same month of different years. In range management projects, grazing capacity calculated once during the grazing season, which coincides with the maximum production of rangeland species. This may cause more livestock entry into the rangeland during the grazing season, leading to more degradation. Th...
Mountainous landscapes in Central Zagros are mainly used as grazing rangelands to feed animals and are heavily degraded. Overgrazing may impose a negative effect on rangeland productivity and sustainability through significant changes in soil properties. Soil nitrogen (N) mineralization is one of the key biological processes that might be affected by biotic and abiotic factors including range g...
Grazing by large herbivores may negatively affect bird populations. This is of great conservation concern in areas with intensive sheep grazing. Sheep management varies substantially between regions, but no study has been performed in less intensively grazed systems. In a fully replicated, landscape scale experiment with three levels of sheep grazing, we tested whether the abundance and diversi...
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