Effect of Manipulation of Water and Nitrogen Supplies on the Quantitative Phenology of Larrea tridentata (Creosote Bush) in the Sonoran Desert of California
Sharifi MR, Meinzer FC, Nilsen ET, Rundel PW, Virginia RA, Jarrell WM, Herman DJ, Clark PC. 1988. Effect of Manipulation of Water and Nitrogen Supplies on the Quantitative Phenology of Larrea tridentata (Creosote Bush) in the Sonoran Desert of California. American Journal of Botany. 75(8):1163-1174
Two years of water and nitrogen augmentation experiments on Larrea tridentata (creosote bush)w erec arriedo ut in a southernC alifornianw armd esertw ashp lantc ommunity.T reatments consisted of control (C), water (W), water and soil nitrogen (W + SN), and soil nitrogen (SN). Quantitative phenological data and microclimatic measurements were collected prior to the onset of and during the growth period and treatments. Predawn and midday water potentials were lower in nonirrigatedt han irrigatedi ndividuals.L eaf conductancew as higheri n irrigated than in nonirrigated shrubs, with a maximum difference of 1 cm s^-1 observed in July 1984 under relatively low vapor pressure deficit conditions. Leaf production rates were significantly higheri n the irrigated( W andW + SN) treatmentst hani n the nonirrigated(C and SN) treatments in 1984. Addition of soil nitrogen caused no increased in vegetative growth rates in 1984. In 198 5, a drier year, there was only minimal growth during the spring and summer growth periods in the nonirrigatedt reatments,w hile the W and W + SN treatmentsr esultedi n significantly higherl eaf and shoot growthr ates. Growthr ates in 1985 were significantlyh igheri n the W + SN treatment than in the W treatment. Reproductive growth was higher in the nonirrigated than the irrigated treatments, with the lowest reproductive activity noted in the W treatment
- Type
- Journal Article
- Authors
- Sharifi, M.; Meinzer, F.; Nilsen, E.; Rundel, P.; Virginia, R.; Jarrell, W.; Herman, D.; Clark, P.
- Units
- JOTR
- Keywords
- California, Larrea tridentata (Creosote bush), Microclimate, nitrogen augmentation, Phenology, Plant Communities, Sonoran Desert, water augmentation