土地利用-气候因子对岩溶区水生生态系统代谢调控研究  

Research on the Metabolic Regulation of Aquatic Ecosystems in Karst Areas by Land Use–Climate Factors

作　　者：赵宇豪 曾思博 刘再华[1] 贺海波[1] 石亮星 邵明玉 ZHAO Yuhao;ZENG Sibo;LIU Zaihua;HE Haibo;SHI Liangxing;SHAO Mingyu(State Key Laboratory of Environmental Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081,China;University of Chinese Academy of Sciences,Beijing 100049,China;School of Geographical Sciences,Southwest University,Chongqing 400715,China)

机构地区：[1]中国科学院地球化学研究所环境地球化学国家重点实验室,贵阳550081 [2]中国科学院大学,北京100049 [3]西南大学地理科学学院,重庆400715

出　　处：《地球与环境》2025年第1期14-25,共12页Earth and Environment

基　　金：国家自然科学基金重点项目(42130501);喀斯特湖库生物泵的碳施肥及其碳增汇和富营养化缓解效应(42130501);2021年贵州省补助资金(GZ2021SIG);岩溶区不同土地利用下生物泵稳碳–固碳效应对比研究(42307070)。

摘　　要：岩溶区地表水生生态系统代谢是岩溶区乃至全球碳循环的重要影响过程,目前岩溶区水生代谢相关的碳通量对全球变化的响应机制尚不明确。本研究通过普定岩溶水碳模拟试验场由不同土地利用控制的岩溶地下水–地表水系统,开展水生生物池代谢过程以及相关碳通量连续监测和模型计算,揭示岩溶水生生态系统净生产力(NEP)与气候以及土地利用的耦合关系。结果表明:(1)不同土地利用控制地表水水生生态系统NEP在季节和昼夜尺度上皆呈现出显著差异,其中裸岩控制下地表水的NEP季节变化范围为–1.02~0.60 g C/(m^(2)·d)、裸土为–0.18~0.59 g C/(m^(2)·d)、耕地为0.60~0.87 g C/(m^(2)·d)、草地为0.38~0.74 g C/(m^(2)·d);(2)水生生态系统NEP对气候变化的响应存在季节性差异,辐射强度主导夏秋季水生生态系统NEP变化,春、冬季表现为风速主导NEP变化,同时降雨对水生生态系统NEP的影响在春季明显小于其他季节;(3)不同土地利用控制下,地表水生生态系统NEP年均值呈现明显差异,表现为裸岩[–10.95 t C/(km^(2)·a)]<裸土[127.75 t C/(km^(2)·a)]<草地[229.95 t C/(km^(2)·a)]<耕地[266.45 t C/(km^(2)·a)]。本研究表明土地利用变化是岩溶地表水NEP的重要控制因子,土地覆被条件改善促进了碳酸盐岩的溶蚀以及地下水的DIC输入,地表水在DIC施肥后NEP显著上升,水生生态系统从异养转为自养型;土地覆被条件差的岩溶地表水生生态系统NEP受控气温、降雨,覆被条件较好的则受控辐射。这些发现将为岩溶区地表水碳通量的计算与管理提供依据。The metabolism of surface aquatic ecosystems is an important influencing carbon cycling process in karst areas and even globally.Currently,the response mechanism of carbon flux related to aquatic metabolism in karst areas to global change is unclear.This study investigates the coupling relationship between net productivity(NEP),climate,and land use in karst water surface water systems controlled by different land uses at the Puding Karst Water-Carbon Simulation Test Site.The metabolic processes of aquatic ponds and related carbon fluxes are continuously monitored and model calculations are carried out to reveal the net productivity(NEP)of karst aquatic ecosystems.The results showed that:(1)There were significant differences in NEP of surface water aquatic ecosystems under different land use controls at both seasonal and day-night scales.The seasonal variation range of NEP of surface water under bare rock control was–1.02-0.60 g C/(m^(2)·d),bare soil was–0.18-0.59 g C/(m^(2)·d),cultivated land was 0.60-0.87 g C/(m^(2)·d),and grassland was 0.38-0.74 g C/(m^(2)·d);(2)The response of NEP in aquatic ecosystems to climate change varies seasonally,with radiation intensity dominating NEP changes in summer and autumn,and wind speed dominating NEP changes observed in spring and winter.At the same time,the impact of rainfall on NEP in aquatic ecosystems is significantly smaller in spring than in other seasons;(3)Under different land use controls,there are significant differences in the annual mean NEP of surface aquatic ecosystems,manifested as bare rock[–10.95 t C/(km^(2)·a)]<bare soil[127.75 t C/(km^(2)·a)]<grassland[229.95 t C/(km^(2)·a)]<cultivated land[266.45 t C/(km^(2)·a)].This study indicates land use is an important control factor for NEP in karst surface water.Improving land cover conditions promotes carbonate dissolution and DIC input of groundwater.After DIC fertilization,NEP in surface water significantly increases,and aquatic ecosystems shift from heterotrophic to autotrophic.These findings will

关 键 词：土地利用变化 气候变化 碳酸盐风化 碳汇 水生生态系统 

分 类 号：P593[天文地球—地球化学] X142[天文地球—地质学]