Cite as:
Strobl, S.; Cueva Ortiz, E.; Silva, B.; Knuesting, J.; Schorch, M.; Scheibe, R.; Bendix, J. &amp; Beck, E. (2017): <b>Water relations and photosynthetic water use efficiency as indicators of slow climate change effects on trees in a tropical mountain forest in South Ecuador</b>. <i>Ecological Indicators </i> <b>83</b>, 550–558.

Resource Description

Title: Water relations and photosynthetic water use efficiency as indicators of slow climate change effects on trees in a tropical mountain forest in South Ecuador
FOR816dw ID: 297
Publication Date: 2017-12-01
License and Usage Rights:
Resource Owner(s):
Individual: Simone Strobl
Individual: E. Cueva Ortiz
Individual: Brenner Silva
Individual: Johannes Knuesting
Individual: Michael Schorch
Individual: Renate Scheibe
Individual: Jörg Bendix
Individual: Erwin Beck
The effects of an increasing moisture on trees of the tropical species-rich mountain rain forest in the South<br/> Ecuadorian Andes was investigated, using the daily total water consumption (TWC) and the instantaneous<br/> water use ef?ciency (WUE, ratio of photosynthetic CO2 uptake per water loss by transpiration) as eco-<br/> physiological indicators. Two canopy and one sub-canopy tree species, (Vismia tomentosa, Clusiaceae, an<br/> as of yet unknown Lauracee, and Spirotheca rosea, Bombacaceae) were the experimental objects. Seasonal<br/> changes as well as a long-term (18 months) trend of increasing precipitation caused an inverse reaction<br/> of the TWC of the trees. Because of a rather unlimited water supply to the trees from a permanently high<br/> water content of the soil, transpiration followed mainly the atmospheric demand of water vapor, and<br/> increasing moisture hence reduced water loss by transpiration. It was hypothesized that in spite of the<br/> reduction in transpiratory water loss photosynthetic carbon acquisition would be not or less affected<br/> due to an increase in water use ef?ciency. Concomitant measurements of photosynthetic net CO2 uptake<br/> showed the expected increase of WUE in V. tomentosa and S. rosea, but no clear reaction of the Lauracee.<br/> Accompanying measurements of stem extension growth con?rmed an undiminished growth of V. tomen-<br/> tosa and S. rosea but showed also suspended growth of the Lauracee during the wettest months. While<br/> TWC can be continuously monitored with the heat dissipation technique, WUE is determined by leaf<br/> porometry in campaigns for which access to the canopy is required. Simultaneous recordings of the gas<br/> exchange of leaves at 4 different positions in the crown of one of the experimental trees (V. tomentosa)<br/> showed the usability of the trait WUE in combination with the total daily water consumption as indicator<br/> set for assessing the response of trees to a subtly changing climate. However, not all tree species appear<br/> as likewise useful indicator trees
| South Ecuador | tree water relations |
Literature type specific fields:
Journal: Ecological Indicators
Volume: 83
Page Range: 550–558
Metadata Provider:
Individual: Jörg Bendix
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