نتایج جستجو برای: tolerance to grazing
تعداد نتایج: 10646507 فیلتر نتایج به سال:
this study conducted to investigate the effects of grazing in a short-term stocking system on the water-soluble carbohydrates (wsc) and nitrogen (n) reserves of permanent parts of bromus tomentellus, cephalaria kotschyi and ferula haussknekhtii in saral rangelands. a key area was selected with a permanent exclosure area and two temporary exclosure areas. root excavation was conducted at six to ...
Many biodiversity experiments have demonstrated that plant diversity can stabilize productivity in experimental grasslands. However, less is known about how diversity-stability relationships are mediated by grazing. Grazing is known for causing species losses, but its effects on plant functional groups (PFGs) composition and species asynchrony, which are closely correlated with ecosystem stabil...
In some plant species the whole shoot is occasionally removed, as a result of specialist herbivory, grazing, mowing, or other causes. The plant can adapt to defoliation by allocating more to tolerance and less to growth and defense. Plant tolerance to defoliation (TOL1) is typically measured as the ratio between the average dry weight of a group of damaged plants and a control group of undamage...
Research was conducted on the effects of rotational grazing (RG) compared to continuous grazing (CG) on the behavior of cattle grazing on rangelands. Different livestock den&tics in the RG treatments were created by varying the size of paddocks in a 4651a, U-paddock, cell deaigntd RG treatment stocked at a rate of 3.6 ha/cow/yr. Paddock sizes of 30 and lo-ha were used to simulate RG with 14 (RG...
Short-term changes (5 years) in canopy cover, species composition and forage production were studied under protection from grazing and grazed condition in 19 range sites in Fereydan region, Isfahan province. In this study, density, canopy cover and forage production data were obtained from quadrates inside and outside exclosures in the spring of 1983. These parameters were studied again in 1988...
Evaluating the possible relationships between vegetation and environmental characteristics can assist managers to identify effective factors influencing plants establishment and to characterize various vegetation communities. This study was aimed to evaluate the effects of long term grazing exclusion ( more than 33 years) and the controlled grazing system (resting – rotation grazing system) on ...
Considering the importance of plant diversity and to evaluate the effect of grazing pressure on species richness and structure of plant communities, this experiment was conducted at Golestan National Park and its surrounding areas in the north east of Iran. Sampling was conducted in intact and abandoned habitats and habitats under seasonal and heavy grazing, using Modified Whitaker Plot in 1, 1...
Livestock grazing can be used as a key management tool for maintaining healthy ecosystems. However, the effectiveness of using grazing to modify habitat for species of conservation concern depends on how the grazing regime is implemented. Timing of grazing is one grazing regime component that is less understood than grazing intensity and grazer identity, but is predicted to have important impli...
Changes in commodity pricing and environmental concerns are changing animal agriculture throughout the United States. Adopting multispecies grazing as an alternative production system could result in improved forage utilization, increased animal performance, and reduced production costs, and thereby improve the financial stability of livestock operations. This study focused on the Silver Spur R...
We studied five lower forest–grassland ecotones in the Darhad Valley in northern Mongolia and investigated the effects of 20th Century grazing regimes and changes in grazing management on ecotone dynamics at a local scale. A total of 2968 Siberian larch (Larix sibirica) trees were cored and tree-age distribution was constructed to determine 20th Century tree establishment. Tree age and location...
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