CO2exchange of CAM exhibiting suceulents in the southern Namib desert in relation to microclimate and water stress
✍ Scribed by D. J. Willert; E. Brinckmann; B. M. Eller; B. Scheitler
- Publisher
- Springer
- Year
- 1983
- Tongue
- English
- Weight
- 532 KB
- Volume
- 4
- Category
- Article
- ISSN
- 0166-8595
No coin nor oath required. For personal study only.
✦ Synopsis
The responses of CO2 exchange and overnight malate accumulation of leaf and stem succulent CAM-plants to water stress and the particular climatic conditions of fog and f6hn in the southern Namib desert have been investigated. In most of the investigated CAM plants a long term water stress gradually attenuated any uptake of external CO 2 and led to CO2 release throughout day and night. No CAM-idling was observed. Rainfall or irrigation immediately restored daytime CO 2 uptake while the recovery of the nocturnal CO2 uptake was delayed. Dawn peak of photosynthesis was only found in well watered plants but was markedly reduced by the short term water stress of a f6hn-storm. Morning fog with its higher diffuse light intensity compared with clear days increased photosynthetic CO 2 uptake considerably. Even in well watered plants nocturnal CO: uptake and malate accumulation were strongly affected by f6hn indicating that the water vapour pressure deficit during the night determines the degree of acidification.