Seasonal carbon isotope discrimination in a grassland community
- 1 January 1991
- journal article
- Published by Springer Science and Business Media LLC in Oecologia
- Vol. 85 (3), 314-320
- https://doi.org/10.1007/bf00320605
Abstract
Grassland communities of arid western North America are often characterized by a seasonal increase in ambient temperature and evaporative demand and a corresponding decline in soil moisture availability. As the environment changes, particular species could respond differently, which should be reflected in a number of physiological processes. Carbon isotope discrimination varies during photosynthetic activity as a function of both stomatal aperture and the biochemistry of the fixation process, and provides an integrated measure of plant response to seasonal changes in the environment. We measured the seasonal course of carbon isotope discrimination in 42 grassland species to evaluate changes in gas exchange processes in response to these varying environmental factors. The seasonal courses were then used to identify community-wide patterns associated with life form, with phenology and with differences between grasses and forbs. Significant differences were detected in the following comparisons: (1) Carbon isotope discrimination decreased throughout the growing season; (2) perennial species discriminated less than annual species; (3) grasses discriminated less than forbs; and (4) early flowering species discriminated more than the later flowering ones. These comparisons suggested that (1) species active only during the initial, less stressful months of the growing season used water less efficiently, and (2) that physiological responses increasing the ratio of carbon fixed to water lost were common in these grassland species, and were correlated with the increase in evaporative demand and the decrease in soil moisture.Keywords
This publication has 18 references indexed in Scilit:
- Patterns of water use and the tissue water relations in the dioecious shrub, Salix arctica: the physiological basis for habitat partitioning between the sexesOecologia, 1989
- Stable isotopesPublished by Springer Science and Business Media LLC ,1989
- Correlation between the Carbon Isotope Discrimination in Leaf Starch and Sugars of C3 Plants and the Ratio of Intercellular and Atmospheric Partial Pressures of Carbon DioxidePlant Physiology, 1988
- Correlations between carbon isotope ratio and microhabitat in desert plantsOecologia, 1988
- Leaf carbon isotope ratios of plants from a subtropical monsoon forestOecologia, 1987
- Leaf carbon isotope and mineral composition in subtropical plants along an irradiance clineOecologia, 1986
- Carbon Isotope Discrimination measured Concurrently with Gas Exchange to Investigate CO2 Diffusion in Leaves of Higher PlantsFunctional Plant Biology, 1986
- Cold desertPublished by Springer Science and Business Media LLC ,1985
- Isotopic Composition of Plant Carbon Correlates With Water-Use Efficiency of Wheat GenotypesFunctional Plant Biology, 1984
- Effect of salinity and humidity on δ13C value of halophytes—Evidence for diffusional isotope fractionation determined by the ratio of intercellular/atmospheric partial pressure of CO2 under different environmental conditionsOecologia, 1982