Photosynthetic Response to Temperature and Moisture Stress of Three Timberline Meadow Species

The photosynthetic response to temperature and moisture stress of three dominants of the west, moist, and dry meadows of the central Sierra Nevada was determined. The wet meadows are relatively cold; the dry meadows, warm and the moist meadows, intermediate. The photosynthetic response to moisture stress parallels the natural distribution with Carex exserta of the dry meadows being least sensitive, Potentilla breweri of the moist meadows intermediate, and Calamagrostis breweri of the wet meadows most sensitive. The photosynthetic response to temperature also parallels the natural distributions. Calamagrostis photosynthesis more efficiently at lower temperatures than Carex or Potentilla.