Impact of enclosure management on soil properties and microbial biomass in a restored semi-arid rangeland, Kenya

Rangeland degradation is a serious problem throughout sub-Saharan Africa and its restoration is a challenge for the management of arid and semi-arid areas. In Lake Baringo Basin of Kenya, communities and individual farmers are restoring indigenous vegetation inside enclosures in an effort to combat severe land degradation and address their livelihood problems. This study evaluated the impact of enclosure management on soil properties and microbial biomass, being key indicators of soil ecosystem health. Six reseeded communal enclosures using soil embankments as water-harvesting structures and strictly regulated access were selected, varying in age from 13 to 23 years. In six private enclosures, ranging from 3 to 17 years in age, individual farmers emulated the communal enclosure strategy and restored areas for their exclusive use. Significant decreases in bulk density, and increases in the soil organic carbon, total nitrogen and microbial biomass contents and stocks were found in the enclosures as compared with the degraded open rangeland. In the private enclosures, the impact of rehabilitation on the soil quality was variable, and soil quality was in general lower than that obtained under communal management. The significant increase of absolute stocks of carbon, nitrogen and microbial biomass compared to the degraded open rangeland indicates the potential for the restoration of soil quality through range rehabilitation. Over-sowing with indigenous legume fodder species could improve total nitrogen content in the soil and nutritional value of the pastures as well.

Effects of vegetation differences in relocated Utah prairie dog release sites

Utah prairie dogs have been extirpated in 90% of their historical range. Because most of the population occurs on private land, this threatened species is continually in conflict with land-owners due to burrowing. The Utah Division of Wildlife Resources has been relocating Utah prairie dogs from private to public land since the 1970s, but relocations have been largely unsuccessful due to high mortality. Utah prairie dogs were relocated in 2010 and 2011 from the golf course in Cedar City, Utah to two prepared sites near Bryce Canyon National Park, Utah. Vegetation transects were established at each site to determine if there was a correlation between site vegetation composition and structure, and Utah prairie dog survival at relocation sites. The vegetation at the two sites was significantly different. One site had significantly less grass cover, more invasive plant cover, and rockier soils. The sites also had different soil structures and long-term Utah prairie dog retention rates. Newly established burrows were clustered rather than randomly distributed. Utah prairie dogs appeared to avoid placing burrows in areas with tall vegetation and rocky soils. More research is needed to determine how site selection determines longterm retention and colonization of a relocation site.

Maintaining Sustainability and Resilience in Rangeland Ecosystems

Rangelands contribute to human well-being worldwide.However,its fragile ecosystems are threatened due to inappropriate management that has been leading to its degradation in African rangelands in general and in Ethiopian rangelands in particular.Rangeland degradation is attributable to both natural and anthropogenic causes.Restoring degraded areas by replanting using native species is one of the most promising sustainable rangeland management tools to fight the degradation in the rangelands and enhance resilience in the face of environmental shocks.Restoration improves vegetation cover and biomass yield and enhances other ecosystem services.Native drought-tolerant species have produced promising rehabilitation outcomes and have been recommended for the restoration of degraded rangeland areas.Replanting using native species remains a viable sustainable management option to enhance resilience in the face of environmental shocks.Therefore,to maintain the sustainability and resilient rangeland ecosystems,comprehensive approaches and strategies suitable for rangelands need to be revitalized,developed,strengthened and promoted.

Artificial Management Improves Soil Moisture, C, N and P in an Alpine Sandy Meadow of Western China

Regeneration of degraded grassland ecosystems is a significant issue in restoration ecology globally. To understand the effects of artificial management measures on alpine meadows, we surveyed topsoil properties including moisture, organic carbon (SOC), nitrogen (N), and phosphorus (P) contents five years after fencing and fencing + reseeding management practices in a sandy meadow in the eastern Qinghai-Tibetan Plateau, northwestern China. Both the fencing and fencing + reseeding management practices significantly increased soil moisture storage, SOC, total N, available N, total P, and available P, as compared to the unmanaged control. Fencing plus reseeding was more effective than fencing alone for improving soil C, N, and P contents. These suggested that rehabilitation by reseeding and fencing generally had favorable effects on the soil properties in degraded sandy alpine meadows, and was an effective approach for restoration of degraded meadow ecosystems of the Qinghai-Tibetan Plateau.

Grassland management practices in Chinese steppes impact productivity, diversity and the relationship

Grasslands are crucial parts of the terrestrial ecosystem, with an extremely high differentiation of productivity and diversity across spatial scales and land use patterns. The practices employed to manage grassland,such as grazing, haymaking, fertilization or reseeding, can improve the grassland condition. This study focuses on the changes in productivity and diversity and the relationship between them as affected by management practices.Productivity and diversity have unequivocally been altered in response to different management practices. When grazing intensity of a typical steppe increased from 1.5 to 9 sheep per hectare, both productivity and diversity declined.Higher grazing intensity(6 to 9 sheep per hectare)accelerated loss of diversity because of lower productivity.Productivity was significantly improved but diversity was lost by fertilizing. N fertilization also reduced the sensitivity of diversity to productivity. A similar response was found in mown grassland with increased productivity and diversity but their relationship was negatively affected.Mowing also slowed down the decline in diversity as productivity increased. Reseeding purple-flowered alfalfa led to an increased diversity, while yellow-flowered alfalfa increased productivity significantly. The negative productivity-diversity relationship was transformed to a positive one by reseeding alfalfa. These results enhance understanding of how productivity, diversity and their relationships change in response to altered grassland management practices, and support an integrated approach for improving both productivity and diversity.

Reducing test-data volume and test-power simultaneously in LFSR reseeding-based compression environment

This paper presents a new test scheme based on scan block encoding in a linear feedback shift register （LFSR） reseeding-based compression environment.Meanwhile,our paper also introduces a novel algorithm of scan-block clustering.The main contribution of this paper is a flexible test-application framework that achieves significant reductions in switching activity during scan shift and the number of specified bits that need to be generated via LFSR reseeding.Thus,it can significantly reduce the test power and test data volume.Experimental results using Mintest test set on the larger ISCAS＇89 benchmarks show that the proposed method reduces the switching activity significantly by 72%-94%and provides a best possible test compression of 74%-94%with little hardware overhead.