The critical zone(CZ) represents the intersection of the biosphere with the atmosphere, hydrosphere and lithosphere.Understanding the hydrological processes and human impact factors on the CZ is fundamental to sustain...The critical zone(CZ) represents the intersection of the biosphere with the atmosphere, hydrosphere and lithosphere.Understanding the hydrological processes and human impact factors on the CZ is fundamental to sustainable water resources management for agroforestry. Transpiration(T) is an important component of terrestrial evapotranspiration(ET), and understanding the time lag(TL) between vegetation transpiration and meteorological factors can improve our knowledge of the mechanisms of vegetation adaptability to a changing environment. However, the controlling factors on the TL remain poorly understood. Therefore, the objective of this study is identifying the temporal dynamics of key controlling factors on the TL, using a typical deciduous broad-leaved tree species(Zenia insigins Chun) of CZ in subtropical humid karst regions. This species is used as an example to explore the characteristics of the TL between SF(sap flow) and hydro-meteorological forcing. Sap flow in these 6 trees was monitored using the thermal dissipation probes(TDP). Results showed that:(1) the peak of diurnal sap flow generally lagged behind PAR but preceded Ta(air temperature), RH(relative humidity) and VPD(vapor pressure deficit), with the mean TL of-67.4 min(PAR), 90.5 min(Ta), 91.6 min(RH) and 92.9 min(VPD), respectively;(2) TL had no significant relationships with the daily mean meteorological factors and soil moisture, but was highly(R^2>0.66) correlated to CRs(changing rates of meteorological factors) in the morning;(3) At seasonal scale, the sap flow rate and TL both were controlled by the seasonality of precipitation and temperature. Overall, the seasonality of the TL was caused by plants' high water loss and strongly active physiological response in hot seasons, leading to close stomata earlier than in cold seasons;(4) The reason why CRs proposed can explain the TL better than mean values of metrological factors is that the CRs considered the distribution and change processes of metrological factors in the daytime. This study may b展开更多
基岩风化层作为地球关键带的主要组成部分,联系其上层土壤水分变动和地下水补给,在陆地表层生态水文循环中扮演着重要角色.为阐明地球关键带中基岩风化层生态水文的研究进展,本文回顾了Web of Science(WOS)核心合集数据库和中国知网(CN...基岩风化层作为地球关键带的主要组成部分,联系其上层土壤水分变动和地下水补给,在陆地表层生态水文循环中扮演着重要角色.为阐明地球关键带中基岩风化层生态水文的研究进展,本文回顾了Web of Science(WOS)核心合集数据库和中国知网(CNKI)学术期刊数据库中收录的相关文献,计量可视化了当前的研究热点,总结了基岩风化层生态水文潜在的影响途径,展望了未来潜在的研究热点.结果表明,基岩风化层生态水文研究呈现地质学、水资源科学、环境科学与生态学及工程学等多学科交叉且基础理论丰富的特点;基岩风化层生态水文效应既包含了自身特性差异,也涵盖对土壤水分再分配、地下水补给排泄调节和植物生长调控等外部扰动;基岩风化层生态水文潜在影响途径可能是通过阻碍土壤水分入渗流失和补给地下水来调节季节性缺水、中微小型动物活动加剧岩石风化提高水分贮存空间、植被根系贴附岩层并结合菌根菌丝参与水养传输等多种方面.本文以期为深化地球关键带科学,拓展生态水文研究领域和鉴别植被恢复选址的合理性提供参考.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 41571130073 & 41501042)the Youth Innovation Team Project of ISA, CAS (Grant No. 2017QNCXTD_XXL)the CAS Interdisciplinary Innovation Team
文摘The critical zone(CZ) represents the intersection of the biosphere with the atmosphere, hydrosphere and lithosphere.Understanding the hydrological processes and human impact factors on the CZ is fundamental to sustainable water resources management for agroforestry. Transpiration(T) is an important component of terrestrial evapotranspiration(ET), and understanding the time lag(TL) between vegetation transpiration and meteorological factors can improve our knowledge of the mechanisms of vegetation adaptability to a changing environment. However, the controlling factors on the TL remain poorly understood. Therefore, the objective of this study is identifying the temporal dynamics of key controlling factors on the TL, using a typical deciduous broad-leaved tree species(Zenia insigins Chun) of CZ in subtropical humid karst regions. This species is used as an example to explore the characteristics of the TL between SF(sap flow) and hydro-meteorological forcing. Sap flow in these 6 trees was monitored using the thermal dissipation probes(TDP). Results showed that:(1) the peak of diurnal sap flow generally lagged behind PAR but preceded Ta(air temperature), RH(relative humidity) and VPD(vapor pressure deficit), with the mean TL of-67.4 min(PAR), 90.5 min(Ta), 91.6 min(RH) and 92.9 min(VPD), respectively;(2) TL had no significant relationships with the daily mean meteorological factors and soil moisture, but was highly(R^2>0.66) correlated to CRs(changing rates of meteorological factors) in the morning;(3) At seasonal scale, the sap flow rate and TL both were controlled by the seasonality of precipitation and temperature. Overall, the seasonality of the TL was caused by plants' high water loss and strongly active physiological response in hot seasons, leading to close stomata earlier than in cold seasons;(4) The reason why CRs proposed can explain the TL better than mean values of metrological factors is that the CRs considered the distribution and change processes of metrological factors in the daytime. This study may b
文摘基岩风化层作为地球关键带的主要组成部分,联系其上层土壤水分变动和地下水补给,在陆地表层生态水文循环中扮演着重要角色.为阐明地球关键带中基岩风化层生态水文的研究进展,本文回顾了Web of Science(WOS)核心合集数据库和中国知网(CNKI)学术期刊数据库中收录的相关文献,计量可视化了当前的研究热点,总结了基岩风化层生态水文潜在的影响途径,展望了未来潜在的研究热点.结果表明,基岩风化层生态水文研究呈现地质学、水资源科学、环境科学与生态学及工程学等多学科交叉且基础理论丰富的特点;基岩风化层生态水文效应既包含了自身特性差异,也涵盖对土壤水分再分配、地下水补给排泄调节和植物生长调控等外部扰动;基岩风化层生态水文潜在影响途径可能是通过阻碍土壤水分入渗流失和补给地下水来调节季节性缺水、中微小型动物活动加剧岩石风化提高水分贮存空间、植被根系贴附岩层并结合菌根菌丝参与水养传输等多种方面.本文以期为深化地球关键带科学,拓展生态水文研究领域和鉴别植被恢复选址的合理性提供参考.
