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Titel |
Connecting ecohydrology and hydropedology in desert shrubs: stemflow as a source of preferential flow in soils |
VerfasserIn |
Xiao-Yan Li, Zhi-Peng Yang, Yue-Tan Li, Henry Lin |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1027-5606
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Digitales Dokument |
URL |
Erschienen |
In: Hydrology and Earth System Sciences ; 13, no. 7 ; Nr. 13, no. 7 (2009-07-14), S.1133-1144 |
Datensatznummer |
250011936
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Publikation (Nr.) |
copernicus.org/hess-13-1133-2009.pdf |
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Zusammenfassung |
Ecohydrology and hydropedology are two emerging fields
that are interconnected. In this study, we demonstrate stemflow hydrology
and preferential water flow along roots in two desert shrubs (H. scoparium and S. psammophila) in the south
fringe of Mu Us sandy land in North China. Stemflow generation and
subsequent movement within soil-root system were investigated during the
growing seasons from 2006 to 2008. The results indicated that the amount of
stemflow in H. scoparium averaged 3.4% of incident gross rainfall with a range of
2.3–7.0%, while in S. psammophila stemflow averaged 6.3% with a range of
0.2–14.2%. Stemflow was produced from rainfall events with total amount
more than 1 mm for both shrubs. The average funneling ratio (the ratio of
rainfall amount delivered to the base of the tree to the rainfall that would
have reached the ground should the tree were not present) was 77.8 and 48.7
for H. scoparium and S. psammophila, respectively, indicating that branches and stems were fully
contributing to stemflow generation and thereby provided sources of water
for possible preferential flow into deeper soil layer. Analysis of
Rhodamine-B dye distribution under the shrubs showed that root channels were
preferential pathways for the movement of most stemflow water into the soil.
Distribution of soil water content under the shrubs with and without
stemflow ascertained that stemflow was conducive to concentrate and store
water in deeper layers in the soil profiles, which may create favorable soil
water conditions for plant growth under arid conditions. Accordingly, a
clear linkage between aboveground ecohydrology and belowground hydropedology
in the desert shrubs is worth noticing, whereby an increase in stemflow
would result in an increase in soil hydrologic heterogeneity. |
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