THE Loess Plateau of Shaanxi Province has traditionally been a poverty-stricken area.Local farmers would grow grains like winter wheat and spring corn,and every July,August,and September plow the fields and collect ra...THE Loess Plateau of Shaanxi Province has traditionally been a poverty-stricken area.Local farmers would grow grains like winter wheat and spring corn,and every July,August,and September plow the fields and collect rain water.The plateau featured desolate scenery with dry,powdery,wind-blown soil,with barely a trace of green.展开更多
The Tibetan Plateau is vital for animal husbandry in China,and relies heavily on its natural grasslands.However,grassland degradation,increasing livestock numbers,and uneven grazing practices are exacerbating the gras...The Tibetan Plateau is vital for animal husbandry in China,and relies heavily on its natural grasslands.However,grassland degradation,increasing livestock numbers,and uneven grazing practices are exacerbating the grass-livestock imbalance.Cultivated grasslands are a key strategy to address this issue.In this review,we evaluate the current status,challenges,and suggestions for developing and managing Tibetan Plateau cultivated grasslands.While discernible advancements have been made in the cultivated grasslands in this region,persistent challenges exist.These challenges stem from issues like low awareness and enthusiasm among farmers and herders,uneven cultivated grassland distribution,and limited scientific and technological contributions.Based on these challenges,we propose strengthening the promotion of artificial forage,implementing a rationalized grassland layout,and improving the scientific and technological contributions to forage species selection,sowing,management,and storage.In summary,cultivated grasslands in the Tibetan Plateau offer promising prospects but still face significant challenges.Overcoming these obstacles will require innovative approaches to unlock the full potential of cultivated grasslands in this unique ecological niche.展开更多
The nitrogen changes and the nitrogen mass balance in a free water surface flow constructed wetland （CW） using the four-year monitoring data from 2008 to 2012 were estimated. The CW was composed of six cells in seri...The nitrogen changes and the nitrogen mass balance in a free water surface flow constructed wetland （CW） using the four-year monitoring data from 2008 to 2012 were estimated. The CW was composed of six cells in series that include the first settling basin （Cell 1）, aeration pond （Cell 2）, deep marsh （Cell 3）, shallow marsh （Cell 4）, deep marsh （Cell 5） and final settling basin （Cell 6）. Analysis revealed that the NH4＋-N concentration decreased because of ammonification which was then followed by nitrification. The NO4＋-N and NO4＋-N were also further reduced by means of microbial activities and plant uptake during photosynthesis. The average nitrogen concentration at the influent was 37,819 kg/year and approximately 45% of that amount exited the CW in the effluent. The denitrification amounted to 34% of the net nitrogen input, whereas the accretion of sediment was only 7%. The biomass uptake of plants was able to retain only 1% of total nitrogen load. In order to improve the nutrient removal by plant uptake, plant coverage in four cells （i.e., Cells 1, 3, 4 and 5） could be increased.展开更多
文摘THE Loess Plateau of Shaanxi Province has traditionally been a poverty-stricken area.Local farmers would grow grains like winter wheat and spring corn,and every July,August,and September plow the fields and collect rain water.The plateau featured desolate scenery with dry,powdery,wind-blown soil,with barely a trace of green.
基金The Central Government Leading Project for Tibetan Science and Technology Development(XZ202202YD0028C)The Entrusted Project ofthe Development Research Center,National Forestry and Grassland Administration(JYC-2022-0053)The Natural Science Foundation of Tibet(XZ202201ZR0063G).
文摘The Tibetan Plateau is vital for animal husbandry in China,and relies heavily on its natural grasslands.However,grassland degradation,increasing livestock numbers,and uneven grazing practices are exacerbating the grass-livestock imbalance.Cultivated grasslands are a key strategy to address this issue.In this review,we evaluate the current status,challenges,and suggestions for developing and managing Tibetan Plateau cultivated grasslands.While discernible advancements have been made in the cultivated grasslands in this region,persistent challenges exist.These challenges stem from issues like low awareness and enthusiasm among farmers and herders,uneven cultivated grassland distribution,and limited scientific and technological contributions.Based on these challenges,we propose strengthening the promotion of artificial forage,implementing a rationalized grassland layout,and improving the scientific and technological contributions to forage species selection,sowing,management,and storage.In summary,cultivated grasslands in the Tibetan Plateau offer promising prospects but still face significant challenges.Overcoming these obstacles will require innovative approaches to unlock the full potential of cultivated grasslands in this unique ecological niche.
基金supported by a grant (Code#413-111-004) from Eco Innovation Project funded by the Ministry of Environment of the Korean government
文摘The nitrogen changes and the nitrogen mass balance in a free water surface flow constructed wetland （CW） using the four-year monitoring data from 2008 to 2012 were estimated. The CW was composed of six cells in series that include the first settling basin （Cell 1）, aeration pond （Cell 2）, deep marsh （Cell 3）, shallow marsh （Cell 4）, deep marsh （Cell 5） and final settling basin （Cell 6）. Analysis revealed that the NH4＋-N concentration decreased because of ammonification which was then followed by nitrification. The NO4＋-N and NO4＋-N were also further reduced by means of microbial activities and plant uptake during photosynthesis. The average nitrogen concentration at the influent was 37,819 kg/year and approximately 45% of that amount exited the CW in the effluent. The denitrification amounted to 34% of the net nitrogen input, whereas the accretion of sediment was only 7%. The biomass uptake of plants was able to retain only 1% of total nitrogen load. In order to improve the nutrient removal by plant uptake, plant coverage in four cells （i.e., Cells 1, 3, 4 and 5） could be increased.
