Publication details
Ecophysiological study of Antarctic lichens using manipulated environment approach
| Authors | |
|---|---|
| Year of publication | 2007 |
| Type | Article in Proceedings |
| Conference | Critical Issues and Research Priorities for the IPY and 2007-2009. 6th PNRA Meeting on Antarctic Biology |
| MU Faculty or unit | |
| Citation | |
| Field | Botany |
| Keywords | lichens; James Ross Island; open top chambers |
| Description | A brief overview of ecophysilogical studies on lichens, performed by the Czech group at the James Ross Island is given. For field studies, an open top chamber (OTC) approach was used to study the impact of elevated air tempretarure on lichens. One OTC was located close to the seashore, the other three OTCs were located at the top of table mountains at the altitude of about 350 m a.s.l. (meseta). While the seashore OTC was dominated by moss species with limited number of lichens on them, the OTCs at the meseta were dominated exclusively by lichen species Usnea antarctica and Umbilicaria decussata. The aim of OTCs installations is to study changes in community structure inside OTCs due to elevated air and soil temperature. To monitor the likely changes in species composition, distribution and production with time of exposition, detailed phytosociological record was taken. A set of temperature and relative air humidity sensors was installed in control plots and OTCs. Temperature and RH data were collected (datalogger, EMS, CZ) in 30 minute interval. The results from the first season (spring 2007) showed that both air and soil temperature were increased in OTC and related to prevailing weather. Samples of typical representatives of lichen flora were collected in the field and measured in the laboratory (J.G. Mendel station, James Ross Island). Responses to dehydration and low-temperature photoinhibition were evaluated using chlorophyll fluorescence imaging technique (fluorometer HFC-010, Photon Systems Instruments, CZ). It was found for Caloplaca sp., Umbilicaria decussata, Usnea antarctica, Leptogium menzeisii and other lichen species, that in spite of interspecific differences, primary photosynthetic processes in lichens are well adapted to extremes and perturbations in environmental factors. It was also shown that capacity of photoprotective mechanisms is sufficient to assure full recovery from severe wet-state photoinhibition of lichen thalli in terms of hours. |