青藏高原是我国重要的草本沼泽分布区,该地区草本沼泽对于东亚生态安全及碳循环具有重要的意义。植被净初级生产力(NPP)是反映生态系统固碳能力的重要指标,气候变化能够显著影响植被NPP。在全球气候变化背景下,青藏高原草本沼泽植被NPP...青藏高原是我国重要的草本沼泽分布区,该地区草本沼泽对于东亚生态安全及碳循环具有重要的意义。植被净初级生产力(NPP)是反映生态系统固碳能力的重要指标,气候变化能够显著影响植被NPP。在全球气候变化背景下,青藏高原草本沼泽植被NPP的时空变化及对气候响应机理尚不明确。利用2000―2020年NPP数据和气象数据,对青藏高原草本沼泽植被NPP的时空变化及其对气候变化的响应进行分析。研究表明:青藏高原草本沼泽植被NPP多年平均值为122.80 g C/m^(2),在2000—2020年青藏高原草本沼泽植被年NPP总体呈现显著增加趋势(0.79 g C m^(-2)a^(-1)),其中增加趋势最为显著的地区集中于研究区北部。研究发现青藏高原草本沼泽植被NPP主要受年均气温影响,年均降水对青藏高原草本沼泽植被NPP的影响并不显著。在不同季节,夏季和秋季升温均能够显著增加沼泽植被NPP,其中夏季夜晚最低温升高对青藏高原草本沼泽植被生长的促进作用比白天最高温升高更显著。在全球昼夜不对称增温背景下,未来模拟青藏高原草本沼泽植被NPP时,需重点关注白天和夜晚温度变化对草本沼泽植被生长的不同影响。研究结果有助于评估青藏高原草本沼泽植被固碳潜力,并为青藏高原沼泽生态保护提供科学依据。展开更多
乡村振兴是解决农业、农村、农民“三农”问题的重大战略举措,电子商务助农是实现乡村振兴的有力抓手。农村电子商务通过产业、政策、基础设施建设路径为支持“三农”问题的优化提供了有力的保障。农村电子商务推动了农产品品牌建设、...乡村振兴是解决农业、农村、农民“三农”问题的重大战略举措,电子商务助农是实现乡村振兴的有力抓手。农村电子商务通过产业、政策、基础设施建设路径为支持“三农”问题的优化提供了有力的保障。农村电子商务推动了农产品品牌建设、农业产业结构结构优化及产业融合、降低了交易成本,增加了农民收入,提高了农民生活水平。目前我国农村电子商务发展存在区域间发展不平衡、农产品安全溯源体系不健全,电商人才短缺,基础设施建设缺乏连续性等问题,应当采取适当的措施消除电子商务助农障碍,强化其助力乡村振兴的功能。Rural revitalization is a major strategic measure to solve the problems of agriculture, rural areas and farmers, and e-commerce in helping agriculture is a powerful starting point for rural revitalization. Rural e-commerce provides a strong guarantee to support the optimization of the issues related with agriculture, farmer and rural area through industry, policy and infrastructure construction paths. Rural e-commerce has promoted the brand building of agricultural products, the optimization of agricultural industrial structure and industrial integration, reduced transaction costs, increased farmers’ income, and improved farmers’ living standards. At present, there are problems in the development of rural e-commerce in China, such as unbalanced inter-regional development, imperfect safety traceability system of agricultural products, shortage of e-commerce talents, lack of continuity of infrastructure construction, etc. Appropriate measures should be taken to eliminate obstacles to e-commerce to help agriculture and strengthen its function of helping rural revitalization.展开更多
文摘青藏高原是我国重要的草本沼泽分布区,该地区草本沼泽对于东亚生态安全及碳循环具有重要的意义。植被净初级生产力(NPP)是反映生态系统固碳能力的重要指标,气候变化能够显著影响植被NPP。在全球气候变化背景下,青藏高原草本沼泽植被NPP的时空变化及对气候响应机理尚不明确。利用2000―2020年NPP数据和气象数据,对青藏高原草本沼泽植被NPP的时空变化及其对气候变化的响应进行分析。研究表明:青藏高原草本沼泽植被NPP多年平均值为122.80 g C/m^(2),在2000—2020年青藏高原草本沼泽植被年NPP总体呈现显著增加趋势(0.79 g C m^(-2)a^(-1)),其中增加趋势最为显著的地区集中于研究区北部。研究发现青藏高原草本沼泽植被NPP主要受年均气温影响,年均降水对青藏高原草本沼泽植被NPP的影响并不显著。在不同季节,夏季和秋季升温均能够显著增加沼泽植被NPP,其中夏季夜晚最低温升高对青藏高原草本沼泽植被生长的促进作用比白天最高温升高更显著。在全球昼夜不对称增温背景下,未来模拟青藏高原草本沼泽植被NPP时,需重点关注白天和夜晚温度变化对草本沼泽植被生长的不同影响。研究结果有助于评估青藏高原草本沼泽植被固碳潜力,并为青藏高原沼泽生态保护提供科学依据。
文摘乡村振兴是解决农业、农村、农民“三农”问题的重大战略举措,电子商务助农是实现乡村振兴的有力抓手。农村电子商务通过产业、政策、基础设施建设路径为支持“三农”问题的优化提供了有力的保障。农村电子商务推动了农产品品牌建设、农业产业结构结构优化及产业融合、降低了交易成本,增加了农民收入,提高了农民生活水平。目前我国农村电子商务发展存在区域间发展不平衡、农产品安全溯源体系不健全,电商人才短缺,基础设施建设缺乏连续性等问题,应当采取适当的措施消除电子商务助农障碍,强化其助力乡村振兴的功能。Rural revitalization is a major strategic measure to solve the problems of agriculture, rural areas and farmers, and e-commerce in helping agriculture is a powerful starting point for rural revitalization. Rural e-commerce provides a strong guarantee to support the optimization of the issues related with agriculture, farmer and rural area through industry, policy and infrastructure construction paths. Rural e-commerce has promoted the brand building of agricultural products, the optimization of agricultural industrial structure and industrial integration, reduced transaction costs, increased farmers’ income, and improved farmers’ living standards. At present, there are problems in the development of rural e-commerce in China, such as unbalanced inter-regional development, imperfect safety traceability system of agricultural products, shortage of e-commerce talents, lack of continuity of infrastructure construction, etc. Appropriate measures should be taken to eliminate obstacles to e-commerce to help agriculture and strengthen its function of helping rural revitalization.
