This study focuses on the vulnerability of soil carbon storage and the ecological restoration processes in karst regions.Given that land-use changes significantly influence the stability and functionality of soil carb...This study focuses on the vulnerability of soil carbon storage and the ecological restoration processes in karst regions.Given that land-use changes significantly influence the stability and functionality of soil carbon pools,this study investigated the vertical and temporal dynamics of soil organic carbon(SOC)and its labile fractions under five land-use types in a fragile karst region of Guizhou,China.Soil samples from five depths(0–100 cm)were collected in 2019 and 2020 from agricultural land,abandoned land,shrubland,and middle-aged and over-mature Pinus massoniana forests.Analyses showed that SOC,readily oxidizable organic carbon(ROOC),and watersoluble organic carbon(WSOC)decreased significantly with depth(P<0.001).Mean SOC was 10.51 g·kg^(-1),with the highest topsoil content in agricultural land(13.24–15.14 g·kg^(-1)).Shrubland exhibited the highest surface carbon sequestration efficiency,indicated by a Carbon Management Index(CMI)of 149.37 in the 0–20 cm layer and higher carbon pool activity(L=1.31 at 0–40 cm).Redundancy analysis identified total potassium,total phosphorus,and ROOC as key factors governing CMI variability(97.75%variance explained).The results advocate for stratified land management promoting shrubland for surface carbon sequestration and adopting reduced tillage in agriculture to enhance carbon retention in karst ecosystems.展开更多
基金the financial support from the National Natural Science Foundation of China(Projects No.32360379 and No.32360007)the Guizhou Provincial Department of Science and Technology Guizhou Provincial Basic Research Program of Natural Science(Project No.qjhe-MS[2025]211)+1 种基金the Guizhou Provincial Postgraduate Research Fund(Project No.2024YJSKYJJ230)the PhD Project of Guizhou Normal University(Project No.2019BS003)。
文摘This study focuses on the vulnerability of soil carbon storage and the ecological restoration processes in karst regions.Given that land-use changes significantly influence the stability and functionality of soil carbon pools,this study investigated the vertical and temporal dynamics of soil organic carbon(SOC)and its labile fractions under five land-use types in a fragile karst region of Guizhou,China.Soil samples from five depths(0–100 cm)were collected in 2019 and 2020 from agricultural land,abandoned land,shrubland,and middle-aged and over-mature Pinus massoniana forests.Analyses showed that SOC,readily oxidizable organic carbon(ROOC),and watersoluble organic carbon(WSOC)decreased significantly with depth(P<0.001).Mean SOC was 10.51 g·kg^(-1),with the highest topsoil content in agricultural land(13.24–15.14 g·kg^(-1)).Shrubland exhibited the highest surface carbon sequestration efficiency,indicated by a Carbon Management Index(CMI)of 149.37 in the 0–20 cm layer and higher carbon pool activity(L=1.31 at 0–40 cm).Redundancy analysis identified total potassium,total phosphorus,and ROOC as key factors governing CMI variability(97.75%variance explained).The results advocate for stratified land management promoting shrubland for surface carbon sequestration and adopting reduced tillage in agriculture to enhance carbon retention in karst ecosystems.
文摘目的 探讨不同人工耳蜗植入年龄听障儿童术后言语能力发展规律,以及植入年龄对术后言语能力的影响。方法 将1258例儿童根据人工耳蜗植入年龄分为6组:组(1)植入年龄6~12个月,组(2)13~24个月,组(3)25~36个月,组(4)37~48个月,组(5)49~60个月,组(6)61~72个月。在开机时、开机后6、12、24、36、48和60个月采用有意义使用言语量表(meaningful use of speech scale,MUSS)对6组儿童进行言语能力评估。结果 组(1)~(3)的MUSS得分率在开机后0~48个月呈显著增长趋势(P<0.05);组(4)~(5)在开机后0~36个月呈快速增长(P<0.05);组(6)在开机后0~24个月呈显著增长(P<0.05);其余评估阶段呈较慢增长(P>0.05)。结论 MUSS问卷是评价人工耳蜗植入儿童言语能力行之有效的方法,不同植入年龄儿童的言语产出能力总体趋势相同,但又各有特点,3岁前植入者的言语能力增长速度快且持续时间长;3岁后植入者虽然早期言语能力较3岁前植入者得分高,但言语能力增长速度较3岁前植入者慢且快速增长期持续短,有必要早期进行人工耳蜗植入。
