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| Titel |
The impact of broadleaved woodland on water resources in lowland UK: I. Soil water changes below beech woodland and grass on chalk sites in Hampshire |
| VerfasserIn |
J. Roberts, P. Rosier |
| 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 ; 9, no. 6 ; Nr. 9, no. 6 (2005-12-31), S.596-606 |
| Datensatznummer |
250007140
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| Publikation (Nr.) |
 copernicus.org/hess-9-596-2005.pdf |
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| Zusammenfassung |
| The possible effects of broadleaved woodland on recharge to the UK Chalk
aquifer have led to a study of evaporation and transpiration from beech
woodland (Black Wood) and pasture (Bridgets Farm), growing in shallow soils
above chalk in Hampshire. Eddy correlation measurements of energy balance
components above both the forest and the grassland enabled calculation of
latent heat flux (evaporation and transpiration) as a residual. Comparative
measurements of soil water content and soil water potential in 9 m profiles
under both forest and grassland found changes in soil water content down to 6
m at both sites; however, the soil water potential measurements showed upward
movement of water only above a depth of about 2 m. Below this depth, water
continued to drain and the soil water potential measurements showed downward
movement of water at both sites, notwithstanding significant negative soil
water potentials in the chalk and soil above. Seasonal differences occur in
the soil water content profiles under broadleaved woodland and grass. Before
the woodland foliage emerges, greater drying beneath the grassland is offset
in late spring and early summer by increased drying under the forest. Yet,
when the change in soil water profiles is at a maximum, in late summer, the
profiles below woodland and grass are very similar. A comparison of soil
water balances for Black Wood and Bridgets Farm using changes in soil water
contents, local rainfall and evaporation measured by the energy balance
approach allowed drainage to be calculated at each site. Although seasonal
differences occurred, the difference in cumulative drainage below broadleaved
woodland and grass was small. |
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