Growth, photosynthesis, and resource investment for vegetative and reproductive modules of artemisia tridentata
- Washington State Univ., Pullman (United States)
Growth of vegetative and reproductive structures in Artemisia tridentata is temporally separated during the growing season; vegetative growth occurs during spring and early summer when soil moisture is most abundant, while reproductive growth occurs during summer and fall when soil moisture may be limiting. Vegetative and reproductive structures may exhibit contrasting efficiencies of resource acquisition and investment resulting from temporal differences in resource availability. The effect of water stress on growth, photosynthesis, and resource investment for vegetative and reproductive modules of Artemisia tridentata was examined by applying supplemental water. No differences were observed in vegetative biomass in the two watering treatments. Growth of vegetative structures occurred in the spring when water was not limiting, and shrubs in both treatments exerted little stomatal control over water loss. Conversely, supplemental watering increased reproductive growth. Shrubs conserved water during summer by abscising leaves and lowering stomatal conductance potential and increases in evaporative demand. In florescences are capable of positive photosynthetic rates comparable to vegetative leaves. Water stress did not alter tissue construction costs or carbon and nitrogen contents for either vegetative or reproductive modules. Resource limitations were reflected in the efficiency of water use during tissue construction; floral leaves and floral heads of shrubs not receiving supplemental water were produced with higher water-use efficiency. Conservative use of water during production of vegetative modules would offer no advantage because neighboring species are also most active at this time. Reproductive growth in A. tridentata occurs during summer when neighboring species are largely dormant, and so efficient use of water may allow development of reproductive structures to continue throughout the summer even with limited supplies of water. 66 refs., 8 figs., 3 tabs.
- DOE Contract Number:
- FG06-89ER75522
- OSTI ID:
- 6442962
- Journal Information:
- Ecology; (United States), Vol. 74:5; ISSN 0012-9658
- Country of Publication:
- United States
- Language:
- English
Similar Records
Effects of CO{sub 2} and rhizosphere temperature on growth of Artemisia tridentata, Sitanion hystrix, and Stipa thurberiana
Mount St. Helens ash: recreating its effects on the steppe environment and ecophysiology. [Artemisia tridentata; Lupinus sulphureus]