为明晰不同放牧强度下内蒙古典型草原土壤有机碳(Soil organic carbon,SOC)的分布特征及其影响因素,本试验以内蒙古锡林郭勒正镶白旗典型草原为研究对象,针对不同放牧强度下的0~50 cm土层的SOC、全碳(Soil total carbon,STC)、全氮(Soil...为明晰不同放牧强度下内蒙古典型草原土壤有机碳(Soil organic carbon,SOC)的分布特征及其影响因素,本试验以内蒙古锡林郭勒正镶白旗典型草原为研究对象,针对不同放牧强度下的0~50 cm土层的SOC、全碳(Soil total carbon,STC)、全氮(Soil total nitrogen,STN)、全磷(Soil total phosphorus,STP)、土壤含水量(Soil water content,SWC)、土壤pH值(pH)、土壤容重(Soil bulk density,SBD)以及植物地上生物量(Aboveground biomass,AGB)等指标进行了测定和分析。结果表明:SOC含量在不同放牧强度下均随土层深度的增加而逐渐降低,0~10 cm的SOC含量均最高。在无牧、中度放牧和重度放牧条件下,自0~50 cm土层,SOC含量分别下降了7%,17%和8%;中度放牧显著提高了0~30 cm的SOC含量,且0~10 cm的SOC含量提升最多,增幅为11%;放牧对SOC含量的影响随土层深度的增加而降低,土层越深放牧的影响越弱;不同放牧强度改变了SOC与环境因子的关系,随着放牧强度的增加,SOC的影响因素从AGB和SWC逐步转向土壤养分和土壤物理性质。研究表明:在放牧持续时间较短时,中度放牧更有利于典型草原SOC的积累和转化。重度放牧虽未显著降低SOC含量,但已呈现碳流失风险,需通过控制放牧强度优先保护表层碳库。展开更多
Dear Editor,This letter investigates the problem of multi-dimension formation tracking(MDFT)for the cross-domain unmanned systems,including several interconnected agents,namely,unmanned aerial vehicles(UAVs)and unmann...Dear Editor,This letter investigates the problem of multi-dimension formation tracking(MDFT)for the cross-domain unmanned systems,including several interconnected agents,namely,unmanned aerial vehicles(UAVs)and unmanned surface vehicles(USVs).We assume that each agent suffers from by the mixed constraints on its velocity,control input and Euler angle.Solving the MDFT problem implies that 1)The virtual state of each USV is determined in the earth coordinate by expanding its 2D work space to the 3D space.展开更多
文摘为明晰不同放牧强度下内蒙古典型草原土壤有机碳(Soil organic carbon,SOC)的分布特征及其影响因素,本试验以内蒙古锡林郭勒正镶白旗典型草原为研究对象,针对不同放牧强度下的0~50 cm土层的SOC、全碳(Soil total carbon,STC)、全氮(Soil total nitrogen,STN)、全磷(Soil total phosphorus,STP)、土壤含水量(Soil water content,SWC)、土壤pH值(pH)、土壤容重(Soil bulk density,SBD)以及植物地上生物量(Aboveground biomass,AGB)等指标进行了测定和分析。结果表明:SOC含量在不同放牧强度下均随土层深度的增加而逐渐降低,0~10 cm的SOC含量均最高。在无牧、中度放牧和重度放牧条件下,自0~50 cm土层,SOC含量分别下降了7%,17%和8%;中度放牧显著提高了0~30 cm的SOC含量,且0~10 cm的SOC含量提升最多,增幅为11%;放牧对SOC含量的影响随土层深度的增加而降低,土层越深放牧的影响越弱;不同放牧强度改变了SOC与环境因子的关系,随着放牧强度的增加,SOC的影响因素从AGB和SWC逐步转向土壤养分和土壤物理性质。研究表明:在放牧持续时间较短时,中度放牧更有利于典型草原SOC的积累和转化。重度放牧虽未显著降低SOC含量,但已呈现碳流失风险,需通过控制放牧强度优先保护表层碳库。
基金supported in part by the National Natural Science Foundation of China(62073301,62373162,62473349,U24A20268,62233007)the Shenzhen Science and Technology Program(JCYJ20240813114007010).
文摘Dear Editor,This letter investigates the problem of multi-dimension formation tracking(MDFT)for the cross-domain unmanned systems,including several interconnected agents,namely,unmanned aerial vehicles(UAVs)and unmanned surface vehicles(USVs).We assume that each agent suffers from by the mixed constraints on its velocity,control input and Euler angle.Solving the MDFT problem implies that 1)The virtual state of each USV is determined in the earth coordinate by expanding its 2D work space to the 3D space.
