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Rangeland Degradation (rangeland + degradation)
Selected AbstractsEffect of seed coating on plant growth and soil conditions: A preliminary study for restoration of degraded rangeland in the Qinghai,Tibetan Plateau, ChinaGRASSLAND SCIENCE, Issue 3 2010Yingchun Liu Abstract Rangeland degradation is a significant problem in the Qinghai,Tibetan Plateau, China. Restoration of the degraded rangelands through reseeding is being undermined by poor seedling growth under adverse soil moisture and nutrition conditions. Accordingly, seeds of Italian ryegrass (Lolium multiflorum) and Chinese milk vetch (Astragalus sinicus) were coated with a mixture of hygroscopic and plant-derived polysaccharide gums and alga powder (Phaeocystis sp. necolon-1), and inoculated with spores of microorganisms (Aspergillus sp. and Streptomyces sp.), serving as coating mixture decomposers, in order to improve rhizosphere moisture and nutrition. In a growth chamber simulating spring climate on the Plateau, seedling emergence of the coated seeds was 60,80 and 48,82%, respectively, for the two plant species in comparison to 38 and 24% for the uncoated seeds, which was due to moisture being supplied by the coat. In the outdoor pots with soil texture and moisture conditions similar to those of the degraded rangelands on the Plateau, dry weight of the plants from the coated seeds was 109,184 and 118,156 mg plant,1 for the respective plant species, while that of the plants from uncoated seeds was 18,20 and 10,11 mg plant,1. The number of Rhizobium sp. nodules on Chinese milk vetch plants from the coated seeds was 21,25 plant,1 while 0,2 in plants from uncoated seeds. Enhancement of plant growth was caused by increased activity of soil microbes. Plant growth on the soil after sampling plants from the coated seeds was also enhanced, indicating sustainability of improvement of soil conditions. Thus seed coating with hygroscopic nutrient-source materials and inoculation with microorganism spores as slow decomposers of the coating materials is a promising method for restoring degraded rangelands. [source] Short-Term and Long-Term Effects of Soil Ripping, Seeding, and Fertilization on the Restoration of a Tropical RangelandRESTORATION ECOLOGY, Issue 2010David Kinyua Rangeland degradation is a serious problem in semiarid Africa. Extensive areas of bare, compacted, nutrient-poor soils limit the productivity and biodiversity of many areas. We conducted a set of restoration experiments in which all eight combinations of soil tilling, fertilization, and seeding with native perennial grasses were carried out in replicated plots. After 6 months, little aboveground biomass was produced in plots without tilling, regardless of seeding or fertilization. Tilling alone tripled plant biomass, mostly of herbaceous forbs and annual grasses. Perennial grasses were essentially limited to plots that were both tilled and seeded. The addition of fertilizer had no significant additional effects. After 7 years, vegetation had declined, but there were still large differences among treatments. After 10 years, one tilled (and seeded) plot had reverted to bare ground, but the other tilled plots still had substantial vegetation. Only one seeded grass (Cenchrus ciliaris) was still a contributor to total cover after 10 years. We suggest that restoration efforts on these soils be directed first to breaking up the surface crust, and second to the addition of desirable seed. A simple ripping trial inspired by this experiment showed considerable promise as a low-cost restoration technique. [source] Rangeland degradation is poised to cause Africa's first recorded avian extinctionANIMAL CONSERVATION, Issue 3 2009C. N. Spottiswoode Abstract Rangeland degradation by livestock threatens several restricted-range species, but is largely overlooked by conservation biologists. The Sidamo lark Heteromirafra sidamoensis, confined to the Liben Plain grassland in southern Ethiopia, is critically endangered by bush encroachment, permanent settlement and agricultural conversion. Its global range was previously estimated at 760 km2, but in 2007,2008 available habitat covered<35 km2. Density estimates from multi-model inference analysis of distance transect data provided a global population estimate of 90,256 adults (possibly with a serious sex-ratio bias towards males). Logistic regression models of habitat selection showed that males preferentially occurred in areas of grassland with greater cover of medium-length grass (5,15 cm), less cover of bare ground and fewer bushes. Habitat transects extending outward from its core range revealed massive and rapid bush encroachment, corroborating information from semi-structured interviews. The survival of both local Borana pastoralism and this species , mainland Africa's likeliest first avian extinction , depends on restoring seasonal patterns of grazing, resisting agricultural conversion of grasslands, reversing fire suppression policies and clearing bush. [source] China's Rangelands under Stress: A Comparative Study of Pasture Commons in the Ningxia Hui Autonomous RegionDEVELOPMENT AND CHANGE, Issue 2 2000Peter Ho China's economic reforms have exacerbated the problems of over-grazing and desertification in the country's pastoral areas. In order to deal with rangeland degradation, the Chinese government has resorted to nationalization, or semi-privatization. Since the implementation of rangeland policy has proved very difficult, however, experiments with alternative rangeland tenure systems merit our attention. In Ningxia, in northwest China, local attempts have been undertaken to establish communal range management systems with the village as the basic unit of use and control. Some of these management regimes are under severe stress, due to large-scale digging for medicinal herbs in the grasslands. This digging has resulted in serious conflicts between Han and Hui Muslim Chinese, during which several farmers have been killed. It is against this backdrop that this article explores the institutional dynamics of range management in two different villages. [source] Integrating local and scientific knowledge for adaptation to land degradation: Kalahari rangeland management optionsLAND DEGRADATION AND DEVELOPMENT, Issue 3 2007M. S. Reed Abstract Despite numerous assessments of the sensitivity and resilience of drylands to degradation, there has been little research into the way affected communities innovate and adapt in response to land degradation. This paper shows how local and scientific knowledge can be combined to identify rangeland management strategies to reduce or adapt to land degradation. To achieve this, we have developed and applied a four-stage social learning approach based on stakeholder participation in three degradation ,hotspots' in communal rangelands of the Kalahari, Botswana. This approach aims to collate, evaluate and apply both scientific and local knowledge on rangeland degradation and management options. First, current practice and possible management options were identified from the literature. Second, a series of semi-structured interviews with rangeland users identified local knowledge of strategies to reduce and adapt to land degradation. Third, these options were discussed and evaluated with rangeland stakeholders in focus groups held across each study region. Finally, the outputs from these focus groups were used to produce rangeland assessment guides for each region that provided management options agreed to be locally relevant by both researchers and local stakeholders. The study found that the majority of strategies reported in the literature were not suitable for use by pastoralists in the Kalahari. However, many of the strategies suggested by stakeholders could only be applied effectively under common property regimes, giving impetus to the growing literature encouraging institutional reform to strengthen common property management regimes. The research stimulated a social learning process that combined knowledge from local stakeholders (both pastoralists and extension workers) with the scientific knowledge of researchers to provide a range of management options that could help land managers reduce or adapt to land degradation. By combining participatory research with insights from scientific literature in this way, more relevant results were provided than either approach could have achieved alone. Copyright © 2007 John Wiley & Sons, Ltd. [source] | |||||||||||||