Land degradation, caused by water erosion. closely related to inherent vulnerabilities of itseco-environment in South China. Spatial variation of land degradation from top to foot of a slope wasmainly induced by diffe...Land degradation, caused by water erosion. closely related to inherent vulnerabilities of itseco-environment in South China. Spatial variation of land degradation from top to foot of a slope wasmainly induced by differentiation of surface materials and their erodibility, nutrient and moisture dueto downslope variation of land erosion. It was showed by comparing maps of land degradationbetween the 1950s and the 1980s that changes of land degradation varied from one area to anotherbecause of differences of human activities, including land reclamation and vegetation depletion.展开更多
The soil and water conservation practices of ecological restoration(ER),fish scale pit(FP),furrow and ridge tillage across the slope(FR),shrub strips(SS),and vegetation-covered ridge(VR)are characteristic of the Jixin...The soil and water conservation practices of ecological restoration(ER),fish scale pit(FP),furrow and ridge tillage across the slope(FR),shrub strips(SS),and vegetation-covered ridge(VR)are characteristic of the Jixing small watershed of the low mountain and hilly region of Jilin Province,Northeast China.This study aims to elucidate the effects of soil and water conservation practices on soil conditions after the short-term implementation of practices.Soil samples were collected from five soil and water conservation sites(ER,FP,FR,SS,and VR)and two controls(BL and CT)to investigate their properties.To evaluate the influence of soil and water conservation practices on soil quality,an integrated quantitative index,soil quality index(QI),was developed to compare the soil quality under the different soil and water conservation practices.The results show that not all soil and water conservation practices can improve the soil conditions and not all soil properties,especially soil organic carbon(SOC),can be recovered under soil and water conservation practice in short-term.Moreover,the QI in the five soil and water conservation practices and two controls was in the following order:ER>VR>BL>FR>CT>SS>FP.ER exhibited a higher soil quality value on a slope scale.In the low mountain and hilly region of Northeast China,ER is a better choice than the conversion of farmlands to planted grasslands and woodlands early in the soil and water conservation program.展开更多
Measures taken according to experimental ecology and ecological engineering to modify environment of the subtropical hilly regions of southern China, cultivated grasslands of Chinese lespedeza (Lespedeza cuneata) and ...Measures taken according to experimental ecology and ecological engineering to modify environment of the subtropical hilly regions of southern China, cultivated grasslands of Chinese lespedeza (Lespedeza cuneata) and broadleaf paspalum (Paspalum wettsteinii) were raised. The sown pastures replaced the degraded grasslands of shrub-herb and herb growths of low-productivity in order to improve the degenerated ecosystem of the region. Some early stage ecological restoration measures and processes to ensure the grassland reconstruction were adopted.Results show that the soil productivity could be raised to provide yield of Chinese lespedeza to 12160 kg/hm^2 and of broadleaf paspalum to 17690 kg/hm^2 in the first year of cultivation, and to 13400 kg/hm^2 of the former, 20750 kg/hm^2 of the latter in the second year, an increase of 2.61~5.16 times of the yield of the previous degraded pastures. The solar energy utilization efficiency increased from 0.14% to 0.64% with the Chinese lespedeza grassland and to 0.93% with the broadleaf paspalum in the first year, then to 0.68% with the former and 1.01% with the latter in the second year. The output of energy, nitrogen and phosphorus were manifold of those of the degraded grassland. Effects in the second year were still better. The cultivated grassland prevented soil erosion efficiently by restoring vegetation, thickening the vegetation coverage, and establishing better above- and under-ground vegetation construction. The amount of soil erosion in the first year was deducted by about three quarters of that of the previous half-barren grassland. Soil erosion in the second year was cut by 51.77% in the Chinese lespedeza plot and 61.47% in the broadleaf paspalum grassland compared to the extent of soil erosion in the previous year.Compared to the former grassland, the newly cultivated pastures boasted higher soil pH value, richer amount of organic matter, total N, total P and available nutrients of the soil, as well as increased activities of catalase, acid phosphatase and urease, though the soil total K content and the activity of polyphenol oxidase were not regularly effected. Intensive cultivation and management ensures the soil qualities of the grassland. More organic carbon was fixed in the pasture with the increased vegetative cover. The soil organic carbon increased by 23% in the Chinese lespedeza pasture and 27% in the broadleaf paspalum one due to more organic matter input into the soil and the friendly environment conditions.Much more economic benefits have been gained in the reconstructed pasture. There is a payoff of RMB 5015.73 yuan/hm^2 with the Chinese lespedeza grassland and 5755.80 yuan/hm^2 with the broadleaf paspalum one in the first year, and RMB 8940.07 yuan/hm^2 of the former, and 9330.36 yuan/hm^2 of the latter in the second year. The input/output is 2.09 and 2.60 in the first year, and 7.15 and 7.39 in the second year, respectively.展开更多
文摘Land degradation, caused by water erosion. closely related to inherent vulnerabilities of itseco-environment in South China. Spatial variation of land degradation from top to foot of a slope wasmainly induced by differentiation of surface materials and their erodibility, nutrient and moisture dueto downslope variation of land erosion. It was showed by comparing maps of land degradationbetween the 1950s and the 1980s that changes of land degradation varied from one area to anotherbecause of differences of human activities, including land reclamation and vegetation depletion.
基金Under the auspices of Foundation of State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau(No.10501-1210)National Natural Science Foundation of China(No.31101606)+1 种基金Basic Scientific Research Operating Expenses of Jilin University(No.200903377)National Key Projects in National Science&Technology Program during the 12th Five-Year Plan Period of China(No.2011BAD16B10-3,2012BAD04B02-3)
文摘The soil and water conservation practices of ecological restoration(ER),fish scale pit(FP),furrow and ridge tillage across the slope(FR),shrub strips(SS),and vegetation-covered ridge(VR)are characteristic of the Jixing small watershed of the low mountain and hilly region of Jilin Province,Northeast China.This study aims to elucidate the effects of soil and water conservation practices on soil conditions after the short-term implementation of practices.Soil samples were collected from five soil and water conservation sites(ER,FP,FR,SS,and VR)and two controls(BL and CT)to investigate their properties.To evaluate the influence of soil and water conservation practices on soil quality,an integrated quantitative index,soil quality index(QI),was developed to compare the soil quality under the different soil and water conservation practices.The results show that not all soil and water conservation practices can improve the soil conditions and not all soil properties,especially soil organic carbon(SOC),can be recovered under soil and water conservation practice in short-term.Moreover,the QI in the five soil and water conservation practices and two controls was in the following order:ER>VR>BL>FR>CT>SS>FP.ER exhibited a higher soil quality value on a slope scale.In the low mountain and hilly region of Northeast China,ER is a better choice than the conversion of farmlands to planted grasslands and woodlands early in the soil and water conservation program.
文摘Measures taken according to experimental ecology and ecological engineering to modify environment of the subtropical hilly regions of southern China, cultivated grasslands of Chinese lespedeza (Lespedeza cuneata) and broadleaf paspalum (Paspalum wettsteinii) were raised. The sown pastures replaced the degraded grasslands of shrub-herb and herb growths of low-productivity in order to improve the degenerated ecosystem of the region. Some early stage ecological restoration measures and processes to ensure the grassland reconstruction were adopted.Results show that the soil productivity could be raised to provide yield of Chinese lespedeza to 12160 kg/hm^2 and of broadleaf paspalum to 17690 kg/hm^2 in the first year of cultivation, and to 13400 kg/hm^2 of the former, 20750 kg/hm^2 of the latter in the second year, an increase of 2.61~5.16 times of the yield of the previous degraded pastures. The solar energy utilization efficiency increased from 0.14% to 0.64% with the Chinese lespedeza grassland and to 0.93% with the broadleaf paspalum in the first year, then to 0.68% with the former and 1.01% with the latter in the second year. The output of energy, nitrogen and phosphorus were manifold of those of the degraded grassland. Effects in the second year were still better. The cultivated grassland prevented soil erosion efficiently by restoring vegetation, thickening the vegetation coverage, and establishing better above- and under-ground vegetation construction. The amount of soil erosion in the first year was deducted by about three quarters of that of the previous half-barren grassland. Soil erosion in the second year was cut by 51.77% in the Chinese lespedeza plot and 61.47% in the broadleaf paspalum grassland compared to the extent of soil erosion in the previous year.Compared to the former grassland, the newly cultivated pastures boasted higher soil pH value, richer amount of organic matter, total N, total P and available nutrients of the soil, as well as increased activities of catalase, acid phosphatase and urease, though the soil total K content and the activity of polyphenol oxidase were not regularly effected. Intensive cultivation and management ensures the soil qualities of the grassland. More organic carbon was fixed in the pasture with the increased vegetative cover. The soil organic carbon increased by 23% in the Chinese lespedeza pasture and 27% in the broadleaf paspalum one due to more organic matter input into the soil and the friendly environment conditions.Much more economic benefits have been gained in the reconstructed pasture. There is a payoff of RMB 5015.73 yuan/hm^2 with the Chinese lespedeza grassland and 5755.80 yuan/hm^2 with the broadleaf paspalum one in the first year, and RMB 8940.07 yuan/hm^2 of the former, and 9330.36 yuan/hm^2 of the latter in the second year. The input/output is 2.09 and 2.60 in the first year, and 7.15 and 7.39 in the second year, respectively.
