|Water isotopes in desiccating lichens
|Hartard, B.; Cuntz, M.; Máguas, C.; Lakatos, M.
|Cryptogams; d18O discrimination; Isotope equilibration; Modelling; Vapour; Water exchange
|The stable isotopic composition of water is routinely used as a tracer to study water exchange processes in vascular plants and ecosystems. To date, no study has focussed on isotope processes in non-vascular, poikilohydric organisms such as lichens and bryophytes. To understand basic isotope exchange processes of non-vascular plants, thallus water isotopic composition was studied in various green-algal lichens exposed to desiccation. The study indicates that lichens equilibrate with the isotopic composition of surrounding water vapour. A model was developed as a proof of concept that accounts for the specific water relations of these poikilohydric organisms. The approach incorporates first their variable thallus water potential and second a compartmentation of the thallus water into two isotopically distinct but connected water pools. Moreover, the results represent first steps towards the development of poikilohydric organisms as a recorder of ambient vapour isotopic composition.
|Persistent UFZ Identifier
|Hartard, B., Cuntz, M., Máguas, C., Lakatos, M. (2009):
Water isotopes in desiccating lichens
Planta 231 (1), 179 - 193