Degradation of land/water ecotones in China is a serious problem and it is often neglected by people. The types of ecotone degradation are described and analyzed. The degradation of land/water ecotones enhanced the wa...Degradation of land/water ecotones in China is a serious problem and it is often neglected by people. The types of ecotone degradation are described and analyzed. The degradation of land/water ecotones enhanced the water quality reduction, bank erosion, desasters such as landslide, flood and drought, biodiversity reduction, lost of fertilized lands, decrease of the resource value of water scenic beauty and many others. The paper analyzes how these problems are related with each other.展开更多
Young elm trees belt-pumpkin strip intercropping was studied to solve the actual problem of resource losses in the large barren area resulted from reconverting cultivated land into forest in the agro-pastoral ecotone ...Young elm trees belt-pumpkin strip intercropping was studied to solve the actual problem of resource losses in the large barren area resulted from reconverting cultivated land into forest in the agro-pastoral ecotone in northern China. The final objective was to realize effective utilization of the barren land with both ecological improvement and economic development. Field experiments were conducted together with laboratory analysis. The results indicated that the soil moisture level was remarkably increased in young elm trees belt-pumpkin strip intereropping because the pumpkin vines covered the gap between pumpkin planting-furrow and elm trees belt. The water use efficiency of the intercropping system was increased by 23.7-163.3% as compared with the single cropping. Elm trees belt-pumpkin strip intercropping changed the sequential succession trend of the grasses growing in the gap of the pumpkin planting-furrow. The annual grasses become the dominant vegetation. The nutritive value as fodder and yield of the annual grasses were also increased remarkably. The biomass of pumpkin, elm trees and grasses under intercropping increased by 24.4, 28.4 and 144.4%, respectively, as compared with those under single cropping. The land use efficiency was increased by 132%. It was also indicated that the soil erosion from the intercropping land was not increased due to pumpkin plantation. The differences in the soil erosion among intercropped area, elm trees belt and pumpkin strip with single cropping were not remarkable. Therefore, it was concluded that young elm trees belt-pumpkin strip intercropping is an effective way to utilize the barren land between the young elm trees belt and realize synergistic enhancement of ecological benefit and economic profit.展开更多
Based on explicating the definition of ecotone, this paper discussed emphatically the distribution and features of joint zone between land and water, transition zone between mountains and plains, and intersection zone...Based on explicating the definition of ecotone, this paper discussed emphatically the distribution and features of joint zone between land and water, transition zone between mountains and plains, and intersection zone between agricultural and animal husbandry regions. The geographic environment of the three ecotones were evaluated, their developing tendency predicted and the corresponding measures to be taken in the 21st century pointed out.展开更多
Nutrient retention capacity by the land/water ecotone soil of Lake Baiyangdian was studied by means of simulation in situ. The results from column experiments suggested that the standard capacity for phosphorus adsorp...Nutrient retention capacity by the land/water ecotone soil of Lake Baiyangdian was studied by means of simulation in situ. The results from column experiments suggested that the standard capacity for phosphorus adsorption be less than P14 mg·kg -1 soil in order to meet the lake water quality regulation (P 0.1 mg·L -1 ). Thus the 9,333 hectares of ecotone around the lake could retain 1,245 tons phosphorus in the upper 50-cm soil without degrading the water quality. The amount was nearly 24 times large as that of taken by annual reed harvesting. The maximum capacity for phosphorus was measured as P 774 mg·kg -1 soil. The isothermal equation of phosphorus was also obtained. It was found that temperature had a significant effect on the transformation of nitrogen, and higher temperature would accelerated the nitrification rate. Nitrogen retention was conducted by the microbial activities in the soil and the uptake through aquatic vegetation. The research will benefit for better utilization of local ecotone and design of the planning project which aims to water eutrophication control.展开更多
文摘Degradation of land/water ecotones in China is a serious problem and it is often neglected by people. The types of ecotone degradation are described and analyzed. The degradation of land/water ecotones enhanced the water quality reduction, bank erosion, desasters such as landslide, flood and drought, biodiversity reduction, lost of fertilized lands, decrease of the resource value of water scenic beauty and many others. The paper analyzes how these problems are related with each other.
基金supported by the National Key Technologies R&D Program of China during the 11th Five-Year Plan period(2006BAD15B05)the Science and Technology R&D Project of Hebei Province,China(06220901D)
文摘Young elm trees belt-pumpkin strip intercropping was studied to solve the actual problem of resource losses in the large barren area resulted from reconverting cultivated land into forest in the agro-pastoral ecotone in northern China. The final objective was to realize effective utilization of the barren land with both ecological improvement and economic development. Field experiments were conducted together with laboratory analysis. The results indicated that the soil moisture level was remarkably increased in young elm trees belt-pumpkin strip intereropping because the pumpkin vines covered the gap between pumpkin planting-furrow and elm trees belt. The water use efficiency of the intercropping system was increased by 23.7-163.3% as compared with the single cropping. Elm trees belt-pumpkin strip intercropping changed the sequential succession trend of the grasses growing in the gap of the pumpkin planting-furrow. The annual grasses become the dominant vegetation. The nutritive value as fodder and yield of the annual grasses were also increased remarkably. The biomass of pumpkin, elm trees and grasses under intercropping increased by 24.4, 28.4 and 144.4%, respectively, as compared with those under single cropping. The land use efficiency was increased by 132%. It was also indicated that the soil erosion from the intercropping land was not increased due to pumpkin plantation. The differences in the soil erosion among intercropped area, elm trees belt and pumpkin strip with single cropping were not remarkable. Therefore, it was concluded that young elm trees belt-pumpkin strip intercropping is an effective way to utilize the barren land between the young elm trees belt and realize synergistic enhancement of ecological benefit and economic profit.
文摘Based on explicating the definition of ecotone, this paper discussed emphatically the distribution and features of joint zone between land and water, transition zone between mountains and plains, and intersection zone between agricultural and animal husbandry regions. The geographic environment of the three ecotones were evaluated, their developing tendency predicted and the corresponding measures to be taken in the 21st century pointed out.
文摘Nutrient retention capacity by the land/water ecotone soil of Lake Baiyangdian was studied by means of simulation in situ. The results from column experiments suggested that the standard capacity for phosphorus adsorption be less than P14 mg·kg -1 soil in order to meet the lake water quality regulation (P 0.1 mg·L -1 ). Thus the 9,333 hectares of ecotone around the lake could retain 1,245 tons phosphorus in the upper 50-cm soil without degrading the water quality. The amount was nearly 24 times large as that of taken by annual reed harvesting. The maximum capacity for phosphorus was measured as P 774 mg·kg -1 soil. The isothermal equation of phosphorus was also obtained. It was found that temperature had a significant effect on the transformation of nitrogen, and higher temperature would accelerated the nitrification rate. Nitrogen retention was conducted by the microbial activities in the soil and the uptake through aquatic vegetation. The research will benefit for better utilization of local ecotone and design of the planning project which aims to water eutrophication control.
