China＇ s state planned land use system, including regulations such as setting planned quotas for land use, basic cropland preservation, and pursuing a balance between the conversion of arable land into non-agricultur...China＇ s state planned land use system, including regulations such as setting planned quotas for land use, basic cropland preservation, and pursuing a balance between the conversion of arable land into non-agricultural use and the supplement of new agricultural land, has substantially constrained the economic growth of industrial provinces in China. This article explores the innovative reforms adopted by Zhejiang Province through land development rights （LDR） transfer within a locality and LDR trading across localities. We argue that there is a ＂Zhejiang model of LDR transferring and trading,＂ which, we believe, has significant implications not only for fostering an efficiency-enhancing market for land development rights and agricultural land preservation, but also for optimal use of land and a more balanced regional development. One important policy issue relating to China＇s rural land system is that under China＇ s land requisition system, farmers are usually under compensated for urban land-taking.展开更多
浙江省是大鲵的主要历史分布地之一,分析其潜在适生区对该物种保护具有现实指导意义。本研究综合考虑海拔、水源、坡度等多项因子,结合有效的大鲵分布点,利用最大熵(maximum entropy, MaxEnt)模型预测浙江省大鲵的适宜栖息地。结果显示:...浙江省是大鲵的主要历史分布地之一,分析其潜在适生区对该物种保护具有现实指导意义。本研究综合考虑海拔、水源、坡度等多项因子,结合有效的大鲵分布点,利用最大熵(maximum entropy, MaxEnt)模型预测浙江省大鲵的适宜栖息地。结果显示:MaxEnt模型10次重复运行训练集的平均曲线下面积(area under the curve, AUC)为0.913,说明预测结果可靠且准确性高。影响大鲵栖息地分布的主要环境因子包括坡向(aspect)、等温性(bio3)、坡度(slope)、海拔(elevation)和年温差(bio7),其次为温度季节性(bio4)、最冷季度平均温度(bio11)和最冷季降水量(bio19),其余因子的影响较小且不显著。在当前年份的气候情景下,大鲵在浙江省的高适宜区面积为2.14万km2,约占浙江省面积的20.30%,主要集中于浙江省西南部地区(丽水南部地区以及温州西南部),西部地区也有零星分布;中适宜区面积约占浙江省面积的12.31%,次适宜区占38.46%,分布于浙江省中部地区;不适宜区主要集中于浙江省东北部地区(杭州东北部、嘉兴、绍兴)。模型结果表明,大鲵的适宜栖息地在浙江省内呈现较为集中的分布,主要集中于西南部的山地区域。展开更多
基金the China National Science Foundation (70633002)the Chinese Ministry of Science+3 种基金Technology Key Technologies R&D Program (2006 BAJI1B06)the Chinese Academy of Science Innovation project (KSCX2-YW-N-039)the Lincoln Institute of LPolicy for generous financial support
文摘China＇ s state planned land use system, including regulations such as setting planned quotas for land use, basic cropland preservation, and pursuing a balance between the conversion of arable land into non-agricultural use and the supplement of new agricultural land, has substantially constrained the economic growth of industrial provinces in China. This article explores the innovative reforms adopted by Zhejiang Province through land development rights （LDR） transfer within a locality and LDR trading across localities. We argue that there is a ＂Zhejiang model of LDR transferring and trading,＂ which, we believe, has significant implications not only for fostering an efficiency-enhancing market for land development rights and agricultural land preservation, but also for optimal use of land and a more balanced regional development. One important policy issue relating to China＇s rural land system is that under China＇ s land requisition system, farmers are usually under compensated for urban land-taking.
文摘浙江省是大鲵的主要历史分布地之一,分析其潜在适生区对该物种保护具有现实指导意义。本研究综合考虑海拔、水源、坡度等多项因子,结合有效的大鲵分布点,利用最大熵(maximum entropy, MaxEnt)模型预测浙江省大鲵的适宜栖息地。结果显示:MaxEnt模型10次重复运行训练集的平均曲线下面积(area under the curve, AUC)为0.913,说明预测结果可靠且准确性高。影响大鲵栖息地分布的主要环境因子包括坡向(aspect)、等温性(bio3)、坡度(slope)、海拔(elevation)和年温差(bio7),其次为温度季节性(bio4)、最冷季度平均温度(bio11)和最冷季降水量(bio19),其余因子的影响较小且不显著。在当前年份的气候情景下,大鲵在浙江省的高适宜区面积为2.14万km2,约占浙江省面积的20.30%,主要集中于浙江省西南部地区(丽水南部地区以及温州西南部),西部地区也有零星分布;中适宜区面积约占浙江省面积的12.31%,次适宜区占38.46%,分布于浙江省中部地区;不适宜区主要集中于浙江省东北部地区(杭州东北部、嘉兴、绍兴)。模型结果表明,大鲵的适宜栖息地在浙江省内呈现较为集中的分布,主要集中于西南部的山地区域。
