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| Titel |
Sap flow measurements to determine the transpiration of facade greenings |
| VerfasserIn |
Marie-Therese Hölscher, Thomas Nehls, Gerd Wessolek |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250086911
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| Publikation (Nr.) |
 EGU/EGU2014-853.pdf |
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| Zusammenfassung |
| Facade greening is expected to make a major contribution to the mitigation of the urban
heat-island effect through transpiration cooling, thermal insulation and shading of vertical
built structures. However, no studies are available on water demand and the transpiration of
urban vertical green. Such knowledge is needed as the plants must be sufficiently watered,
otherwise the posited positive effects of vertical green can turn into disadvantages when
compared to a white wall.
Within the framework of the German Research Group DFG FOR 1736 "Urban Climate and
Heat Stress" this study aims to test the practicability of the sap flow technique for
transpiration measurements of climbing plants and to obtain potential transpiration rates for
the most commonly used species.
Using sap flow measurements we determined the transpiration of Fallopia baldschuanica,
Parthenocissus tricuspidata and Hedera helix in pot experiments (about 1 m high)
during the hot summer period from August 17th to August 30th 2012 under indoor
conditions.
Sap flow measurements corresponded well to simultaneous weight measurement on a daily
base (factor 1.19). Fallopia baldschuanica has the highest daily transpiration rate
based on leaf area (1.6 mm d-1) and per base area (5.0 mm d-1). Parthenocissus
tricuspidata and Hedera helix show transpiration rates of 3.5 and 0.4 mm d-1 (per base
area). Through water shortage, transpiration strongly decreased and leaf temperature
measured by infrared thermography increased by 1 K compared to a well watered
plant.
We transferred the technique to outdoor conditions and will present first results for
facade greenings in the inner-city of Berlin for the hottest period in summer 2013. |
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