关键词: 时空分异, 分析尺度, 景观格局脆弱度, 南四湖湿地, 空间统计学

Abstract: Hydraulic redistribution (HR) is a passive movement process of water between different soil parts via plant root systems, driven by water potential gradients in the rootsoil interface. Now, HR has been observed in approximately 120 species that involve in a wide variety of ecosystems and a wide range of life forms. Empirical and modeling estimates of the average amount of water moved by HR span nearly two orders of magnitude, from 0.04 to 1.3 mm·d^-1 in the empirical literature, and from 0.1 to 3.23 mm·d^-1 in the modeling literature. The applicative techniques of HR measurements include soil moisture, isotopic labeling and sap flow methods. Each of the measurement techniques of HR has defects and uncertainty about test results, due to the lack of the comparison of the various methods. The soil connection model of HR has been widely applied, but other models, including the physical processesbased big root model, mesoscale moisture dynamic model and dynamic root profile model, have not been promoted for their complex structures and numerous parameters. In the future, quantifying the magnitude and understanding the mechanism of HR are still the difficulties of this subject.

Key words: landscape pattern vulnerability, spatial statistics, analysis scale, Nansihu Lake wetland, temporal-spatial differentiation.