Study on the Degradation Trend of Ryegrass-White Clover Artificial Grassland

[Objective] The study aimed to explore the degradation law and trend of artificial grassland. [Method] Taking the ryegrass （Lolium perenne） - white clover （ Trifolium repens） artificial grassland in Maiping Township, Guizhou Province as the research object, the grassland vegetation of 40 quadrate from different areas （area around the sheep shed, hilltop, hillside, flatland at the foot of the hill） were analyzed by comparing the dominance and richness index. [ Result] Degradation of different degrees appeared in various areas of this artificial grassland. To be specific, the degradation of grassland around the sheep shed was not serious for less consumption by the sheep; however, the areas on the hilltop and hillside degenerated to the grassland types of dallis grass （ Paspalum dilatatum Poir. ） -Indian lovegrass （ Eragrostis pilosa） and dallis grass - cogongrass [ Imperata cylindrica （ Linn. ） Beauv. ], respectively, and the area at the foot of the hill degenerated to the grassland type dominated by garland chrysanthetnum （ Chrysanthemum coronarium L. ） and knotgrass （ Paspalum distichum L. ）. [ Conclusion ] This study provided a basis for grassland improvement as well as the efficient and sustainable utilization of grazing-type artificial grassland in South China.

How to Build Artificial Grassland in the Cold and Semi-Arid Regions? ——A Case Study in Naqu

Construction of artificial grassland is a key factor to solve the shortage of grass and forage balance in cold and semi-arid areas of high plateau,and it is the key measure to ensure the sustainable development of grassland animal husbandry in this area. At present,the artificial grassland construction is neither reasonable nor scientific,which restricts the healthy and rapid development of artificial grassland in the cold and semi-arid areas of high plateau. In this research,with Naqu Area in Tibet as a case,problems and current status in construction process of artificial grassland are analyzed in cold and semi-arid areas of high plateau. Suitable artificial forage species in Nagqu are elaborated,and recommendations for the construction and development of artificial grassland are discussed.

Response of Artificial Grassland Carbon Stock to Management in Mountain Region of Southern Ningxia, China

Grassland is a major carbon sink in the terrestrial ecosystem. The dynamics of grassland carbon stock profoundly influence the global carbon cycle. In the published literatures so far, however, there are limited studies on the long-term dynamics and influential factors of grassland carbon stock, including soil organic carbon. In this study, spatial-temporal substitution method was applied to explore the characteristics of Medicago sativa L. （alfalfa） grassland biomass carbon and soil organic carbon density （SOCD） in a loess hilly region with different growing years and management patterns. The results demonstrated that alfalfa was the mono-dominant community during the cutting period （viz. 0-10 year）. Community succession began after the abandonment of alfalfa grassland and then the important value of alfalfa in the community declined. The artificial alfalfa community abandoned for 30 years was replaced by the S. bungeana community. Accordingly, the biomass carbon density of the clipped alfalfa showed a significant increase over the time during 0-10 year. During 0-30 year, the SOCD from 0-100 cm of the soil layer of all 5 management patterns increased over time with a range between 5.300 ± 0.981 kg/m2 and 12.578 ± 0.863 kg/m2. The sloping croplands had the lowest SOCD at 5.300 ± 0.981 kg/m2 which was quite different from the abandoned grasslands growing for 30 years which exhibited the highest SOCD with 12.578 ± 0.863 kg/m2. The ecosystem carbon density of the grassland clipped for 2 years increased 0.1 kg/m2 compared with the sloping cropland, while that of the grassland clipped for 10 years substantially increased to 10.30 ± 1.26 kg/m2. Moreover, the ecosystem carbon density for abandoned grassland became 12.62± 0.50 kg/m2 at 30 years. The carbon density of the grassland undisturbed for l0 years was similar to that of the sloping cropland and the grassland clipped for 2 years. Different management patterns imposed great different effects on the accumulation of biomass carbon on artificial grasslands, whereas the ecosystem carbon density of the grassland showed a slight increase from the clipping to abandonment of grassland in general.

Management of re‐established artificial grasslands via grazing or fencing: Effects on plant and soil properties

Background:Revegetation is widely used in degraded grassland restoration.However,the responses of grassland plant and soil properties to fencing(FC)and grazing(GZ)remain poorly understood,especially the vegetation–soil coupling coordination(C_(d))mechanism.This study explored single and interactive responses of vegetation and soil properties under FC and GZ after revegetation.Methods:A field experiment with FC and GZ treatments was conducted in Loess Plateau reconstructed grassland,with degraded grassland as the control(CK).Plant and soil properties and C_(d) were analyzed using the analytic hierarchy process(AHP)and principal component analysis(PCA).Results:The order of soil comprehensive evaluation(SCE)was GZ>FC>CK,while that of vegetation comprehensive evaluation(VCE)was FC>GZ>CK.The C_(d) of CK was 0.39(mild imbalance),while the values of FC and GZ were 0.57 and 0.54,respectively(little coordination).The VCE/SCE of FC was 1.48(soil lag type),and the values of GZ and CK were 0.69 and 0.35,respectively(vegetation lag and vegetation loss type,respectively).Conclusions:Both GZ and FC improved C_(d) and facilitated recovery.However,degraded grasslands should be restored via moderate grazing for sustainable ecological and economic development.

Analysis of Characteristics of Grazed Artificial Pastures in the South of Guizhou

＂Ryegrass, orchard grass, Festuca arundinacea and Trifolium repens＂ were researched in Dushan County, Guizhou Province, in order explore grass characteristics by different grazing methods in seasons. The results show that grass community height in different groups was of little differences（P0.05）; the group of moderate grazing in spring, summer and autumn dominated in grass cover; grass density showed insignificant variations among different treatment groups（P0.05） and in the groups of heavy grazing in spring and autumn and moderate grazing in summer and of moderate grazing in spring, summer and autumn, grass community density was higher compared with the other groups（P0.05）; as for above-ground biomass, the group of moderate grazing in spring and autumn and heavy grazing in summer and of moderate grazing in spring, summer and autumn dominated.

Current Distribution of Vegetation Resources in Yunnan-Guizhou Plateau and Mechanism Research of Its Effects on Rocky Desertification Process

Yunnan-Guizhou Plateau is the core area of the rocky desertification in the Chinese southwest Karst regions, and the existing studies are very limited to describe the process of rocky desertification quantitatively. The vegetation resources are applied as the key indicators in quantitative description of the degree of rocky desertification damage, and the previous methods using only remote sensing datasets are not competent to distinguish the detailed information of vegetation type, coverage and patch fragmentation on a large scale. Previous research shows that the technology of unmanned aerial vehicle and the estimation software of fraction vegetation coverages and patches could be accurately and rapidly to exploit vegetation resource information. In this project, current distribution of vegetation resources in Yunnan-Guizhou Plateau was clarified to reveal the influence mechanism of the rocky desertification. The control factors of rocky desertification distribution and the driving reasons of its dynamic changes were explained by the data of terrain, climate, population, economics and policy. Therefore, it could get the current distribution of vegetation resources in Yunnan-Guizhou Plateau, especially the grassland resources could be updated, which could not provide research foundations and scientific implications for resolving the rocky desertification, but also could provide valuable background information for the programs of restoring ecological environment and increasing local people's income in Yunnan-Guizhou Plateau.

Benefits of Pasture Construction for Comprehensive Agricultural Development in Duolun Agro-pasturage Ecotone of Inner Mongolia

The agro-pasturage ecotone in northern China is not only an important green ecosystem barrier but also an important economic belt. However, the extensive operation manner and harsh natural surroundings lead to the grassland degradation, low agricultural productivity and people living in poverty. In our study, the result has shown that the aboveground biomass and economic benefits of improved grassland, artificial perennial grassland and silage farmland have been increased greatly. Therefore, the development and construction of high-yield silage farmland and artificial perennial grassland in agro-pasturage ecotone not only increase the economic benefits but also protect the ecological environment.