Foliar uptake of fog in coastal California shrub species
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Understanding plant water uptake is important in ecosystems that experience periodic drought. In many Mediterranean-type climates like coastal California, plants are subject to significant drought and wildfire disturbance. During the dry summer months, coastal shrub species are often exposed to leaf wetting from overnight fog events. This study sought to determine whether foliar uptake of fog occurs in shrub species and how this uptake affects physiology and fuel condition. In a controlled greenhouse experiment, dominant California shrub species were exposed to isotopically labeled fog water and plant responses were measured. Potted plants were covered at the base to prevent root uptake. The deuterium label was detected in the leaves of four out of five species and in the stems of two of the species. While there was a minimal effect of foliar water uptake on live fuel moisture, several species had lower xylem tension and greater photosynthetic rates after overnight fog treatments, especially Salvia leucophylla. Coastal fog may provide a moisture source for many species during the summer drought, but the utilization of this water source may vary based on foliar morphology, phenology and plant water balance. From this study, it appears that drought-deciduous species (Artemisia californica and Salvia leucophylla) benefit more from overnight fog events than evergreen species (Adenostoma fasciculatum, Baccharis pilularis and Ceanothus megacarpus). This differential response to fog exposure among California shrub species may affect species distributions and physiological tolerances under future climate scenarios.
KeywordsFoliar water uptake Fog Stable isotopes Shrubs California Live fuel moisture
Many thanks to Dr. Carla D’Antonio and the UCSB Greenhouse for logistical and financial support, Dr. Carla D’Antonio, Dr. Max Moritz, Dr. Chris Still and Dr. Dar Roberts for helpful comments on an earlier version of this manuscript, and Dr. Todd Dawson, Dr. Stefania Mambelli and the Center for Stable Isotope Biogeochemistry at UC Berkeley for guidance and facilities. This project was funded by National Science Foundation Doctoral Dissertation Improvement Grant Award #1311605 and supported by the Isotope Inter-University Training for Continental-scale Ecology Fellowship, University of Utah.
Author contribution statement
NCE conceived, designed, and executed this study and wrote the manuscript. No other person is entitled to authorship.
- Anderson HE (1982) Aids to determining fuel models for estimating fire behavior. General technical report INT-122 Ogden, UT: USDA forest service, intermountain forest and range experiment station pp 22Google Scholar
- Benzing DH, Burt KM (1970) Foliar permeability among twenty species of the Bromeliaceae. Bull Torrey Bot Club, pp 269–279Google Scholar
- Bradstock RA, Williams JE, Gill AM (eds) (2002) Flammable Australia: the fire regimes and biodiversity of a continent. Cambridge University Press, CambridgeGoogle Scholar
- Brown MB, Forsythe AB (1974) Robust tests for equality of variances. J Am Stat Assoc 69:64–367Google Scholar
- Cole ES (2005). Root and whole plant growth responses to soil resource heterogeneity in coastal dune shrubs of California. PhD dissertation, University of California, Santa Barbara, USAGoogle Scholar
- Countryman CM, Dean WA (1979). Measuring moisture content in living chaparral: A field user’s manual. General technical report PSW-36 Berkeley, CA: USDA, forest service pacific southwest forest and range experiment station pp 27Google Scholar
- Filonczuk MK, Cayan DR, Riddle LG (1995) Variability of marine fog along the California coast. Scripps Institution of Oceanography, San DiegoGoogle Scholar
- Hanes TL (1977) California chaparral. In: Barbour MG, Major J (eds) Terrestrial vegetation of California. Wiley, New York, pp 417–470Google Scholar
- Hiatt C, Fernandez D, Potter C (2012) Measurements of fog water deposition on the California Central Coast. Atmos Clim Sci 2:525Google Scholar
- LACFD (Los Angeles County Fire Department) (2015) Fire weather/fire danger program. http://www.fire.lacounty.gov/forestry-division/fire-weather-report/. Accessed 17 Dec 2015
- Lekson V, Holmlund HI, Davis SD, Nakamatsu NA, Burns AM (2015) Comparative foliar water uptake and leaf hydrophobicity among eight species of California ferns. Pepperdine University, MalibuGoogle Scholar
- Martin RE, Gordon DA and Gutierrez MA (1994) Assessing the flammability of domestic and wildland vegetation. In: 12th conference on fire and forest meteorology. Society of American Forestry, Bethesda. pp 796Google Scholar
- Nobs MA (1963) Experimental studies on species relationship in Ceanothus, vol 623. Carnegie Institution of Washington, Washington, D.CGoogle Scholar
- Skierucha W (2000) Accuracy of soil moisture measurement by TDR technique. Int Agrophysics 14:417–426Google Scholar
- Whelan RJ (1995) The ecology of fire. Cambridge University Press, CambridgeGoogle Scholar
- Williams AP (2009) Tree rings, climate variability, and coastal summer stratus clouds in the western United States. PhD thesis, University of California, Santa BarbaraGoogle Scholar
- Wright CD (1928) An ecological study of Baccharis pilularis. MS thesis, University of California, Berkeley, California, USAGoogle Scholar