The vast area of farmland was abandoned at downstream of the Shiyang River because of decreased water recourse. To ensure the ecological safety of Minqin Oasis and to provide management basis for the abandoned land, s...The vast area of farmland was abandoned at downstream of the Shiyang River because of decreased water recourse. To ensure the ecological safety of Minqin Oasis and to provide management basis for the abandoned land, soil physical properties were observed and studied. The authors analyzed land with abandonment time of 1 year, 2 years, 3 years, 4 years, 5 years, 8 years, 15 years, 24 years and 31 years. Samples were took at the 0-40 cm layer of soil to measure the bulk density, porosity and grain composition of soil in the different abandoned lands. Results showed that the tendency of clay content was decreasing, conversely, the fine sand increased at the layer of 0-10 cm of different abandoned lands.The changes of grain content reached a peak at the fourth year after the land was abandoned, then varied slightly. The variation of grain content of abandoned land was obvious with the extension of the abandonment year. The soil bulk density decreased and porosity increased with the extension of the abandonment year. The difference of porosity and soil bulk density at the range of 0-40 cm of different abandoned land decreased after the land abandoned for 3 years. The quality of soil was decreased, while the soil permeability was improved. The soil physical properties changed obviously in 3 to 4 years after abandonment, so it is the key time for land management.展开更多
[Objective] The aim was to explore physical properties and community characteristics of abandoned lands in different years in Minqin Oasis, downstream of the Shiyang River, [Method] The evolution of environment and pl...[Objective] The aim was to explore physical properties and community characteristics of abandoned lands in different years in Minqin Oasis, downstream of the Shiyang River, [Method] The evolution of environment and plant community characteristics in different abandoned lands were analyzed after abandonment for 1, 2, 3, 4, 5, 8, 15, 24 and 31 years, and the plant community characteristics, water content, bulk density, porosity and mechanical composition of soil in the different a- bandoned lands were also researched in the Minqin Oasis, downstream of the Shiyang River. [Result] Plant of 32 species spread over 14 family live through fifty years appeared in abandoned lands in the study area. Shrubs was 6 species, herbs was 26 species among them, which were 18.75%, 81.25% respectively. The goose- foot family （6 species）, the composite family（4 species）,the grass family（4 species）, caltrop family（3 species） were 53.13% among them. Within the range of 0-40 cm of different abandoned Land, the soil moisture content showed a trend of first increase and then decrease with the increase of soil depth changes in soil bulk density and porosity of less obvious. In the range of 0-40 cm soil depth, the largest proportion of fine sand, followed by silt and clay and the smallest proportion of coarse sand in every plot, but the proportion of the each silt size varies little with the years aban- doned. [Conclusion] The research provides references for vegetation reconstruction and eco-environment construction in abandoned lands in downstream of Shiyang River.展开更多
基金Supported by National Natural Science Foundation of China"Research of soil system evolvement rule and its driving mechanism of abandoned farmland in the Middle and lower Shiyang River"(41161049)"Research of Dynamic Change and Ecological Effects of groundwater by Human intervention in downstream of the Shiyang River"(31260129)~~
文摘The vast area of farmland was abandoned at downstream of the Shiyang River because of decreased water recourse. To ensure the ecological safety of Minqin Oasis and to provide management basis for the abandoned land, soil physical properties were observed and studied. The authors analyzed land with abandonment time of 1 year, 2 years, 3 years, 4 years, 5 years, 8 years, 15 years, 24 years and 31 years. Samples were took at the 0-40 cm layer of soil to measure the bulk density, porosity and grain composition of soil in the different abandoned lands. Results showed that the tendency of clay content was decreasing, conversely, the fine sand increased at the layer of 0-10 cm of different abandoned lands.The changes of grain content reached a peak at the fourth year after the land was abandoned, then varied slightly. The variation of grain content of abandoned land was obvious with the extension of the abandonment year. The soil bulk density decreased and porosity increased with the extension of the abandonment year. The difference of porosity and soil bulk density at the range of 0-40 cm of different abandoned land decreased after the land abandoned for 3 years. The quality of soil was decreased, while the soil permeability was improved. The soil physical properties changed obviously in 3 to 4 years after abandonment, so it is the key time for land management.
基金Supported by National Natural Science Foundation of China(31560128,31360203,31260201,31460223,31460134)
文摘[Objective] The aim was to explore physical properties and community characteristics of abandoned lands in different years in Minqin Oasis, downstream of the Shiyang River, [Method] The evolution of environment and plant community characteristics in different abandoned lands were analyzed after abandonment for 1, 2, 3, 4, 5, 8, 15, 24 and 31 years, and the plant community characteristics, water content, bulk density, porosity and mechanical composition of soil in the different a- bandoned lands were also researched in the Minqin Oasis, downstream of the Shiyang River. [Result] Plant of 32 species spread over 14 family live through fifty years appeared in abandoned lands in the study area. Shrubs was 6 species, herbs was 26 species among them, which were 18.75%, 81.25% respectively. The goose- foot family （6 species）, the composite family（4 species）,the grass family（4 species）, caltrop family（3 species） were 53.13% among them. Within the range of 0-40 cm of different abandoned Land, the soil moisture content showed a trend of first increase and then decrease with the increase of soil depth changes in soil bulk density and porosity of less obvious. In the range of 0-40 cm soil depth, the largest proportion of fine sand, followed by silt and clay and the smallest proportion of coarse sand in every plot, but the proportion of the each silt size varies little with the years aban- doned. [Conclusion] The research provides references for vegetation reconstruction and eco-environment construction in abandoned lands in downstream of Shiyang River.
