ACCLIMATION OF LEAF DARK RESPIRATION TO TEMPERATURE IN ALPINE AND LOWLAND PLANT-SPECIES

Acclimation to temperature in terms of dark respiration by leaves is a missing link in current efforts to predict the effects of global warming on plant communities. We studied the acclimation of plants from alpine or lowland areas and asked two questions: (1) do plants acclimate to a change in temperature and does acclimation depend on the plants' origin; and (2) have alpine plants adapted to low temperatures by respiring faster than lowland plants at any given temperature? Nineteen alpine and corresponding lowland species, collected in Switzerland, were grown at 10 and 20 degrees C for 5 weeks. Night-time leaf dark respiration rates were measured at the growth temperature of each plant. Acclimation patterns ranged from full to no acclimation. Full acclimation to temperature, defined as the equality between respiration measured at 20 degrees C of plants grown at 20 degrees C and respiration measured at 10 degrees C of plants grown at 10 degrees C, occurred in only three our of 19 species. Dark respiration of leaves was stimulated by a 10 K warming, but on average, by about 50% less than predicted by the instantaneous temperature response, i.e. Q(10). Acclimation did nor depend on the alpine or lowland origin of the plant, but rather on its genus. Prostrate alpine plants displayed the lowest acclimation potential. We conclude that predictions at the community level cannot be made based on single species because of the variety observed in the respiration responses. (C) 1995 Annals of Botany Company