How Waterlogged Microsites Help an Annual Plant Persist Among Salt Marsh Perennials
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Annual plants that coexist among perennial dominants might persist in microsites that are stressful to their competitors. In Californian salt marshes, where cover of annual and perennial Salicornia species are negatively correlated, we hypothesized that waterlogged depressions support the annual (Salicornia bigelovii) but not the region’s dominant perennial (Salicornia virginica). In a large restoration site, S. virginica cover was low in naturally formed pools, and our 10-cm depressions decreased its cover by approximately 30% compared to the controls. S. bigelovii grew taller and produced more flowers in waterlogged sites with low soil redox potential, and it completed its life cycle in the 5-cm-deep depressions that we created. Experimentally reducing S. virginica canopy cover in shallow depressions also increased the survival of the annual. In the greenhouse, rhizosphere oxidation was indicated as a mechanism for tolerating waterlogging, as S. bigelovii elevated the soil redox potential by 50 mV more than S. virginica did. Also, in the greenhouse, S. bigelovii seedlings actually suppressed the growth of S. virginica seedlings under increased flooding. We conclude that waterlogged microsites help sustain S. bigelovii in Californian salt marshes and that this increasingly rare plant could be managed by adding shallow depressions to restoration sites.
KeywordsDepressions Microtopography Restoration Tidal pools Salicornia bigelovii Salicornia virginica Topographic heterogeneity
- Adam, P. 1990. Salt marsh ecology. New York, NY: Cambridge University Press.Google Scholar
- Armstrong, W. 1982. Waterlogged soilsIn Environment and plant ecology, ed. New York, NY: Wiley.Google Scholar
- Bonin, C. 2007. Plant traits explain abundance rank in salt marsh vegetation. M.S. Thesis, University of Wisconsin, Madison, Wisconsin.Google Scholar
- Cantilli, J. F. 1989. Sulfide phytotoxicity in salt marshes. M.S. Thesis, San Diego State University, San Diego, California.Google Scholar
- Chapman, V. J. 1974. Salt marshes and salt deserts of the world. Lehre, Germany: J. Cramer.Google Scholar
- Drew, M. C., and L. H. Stolzy. 1991. Growth under oxygen stressIn Plant roots: the hidden half, eds. , A. Eshel, and U. KafkafiNew York: Marcel Dekker.Google Scholar
- Larkin, D. J., G. Vivian-Smith, and J. B. Zedler. 2006. Topographic heterogeneity theory and ecological restorationIn Foundations of Restoration Ecology, eds. , M. Palmer, and J. B. Zedler, 144–164. Washington, DC: Island Press.Google Scholar
- Lindig-Cisneros, R., and J. B. Zedler. 2002. Halophyte recruitment in a salt marsh restoration site. Estuaries 25: 1174–1183.Google Scholar
- Morzaria-Luna, H. N. 2005. Determinants of plant species assemblages in the California marsh plain: Implication for restoration of ecosystem function. Ph.D. Dissertation, University of Wisconsin, Madison, Wisconsin.Google Scholar
- Neuenschwander, L. F., T. H. Thorsted Jr., and R. J. Vogl. 1979. The salt marsh and transitional vegetation of Bahia de San Quintin. Bulletin of the Southern California Academy of Sciences 78: 163–182.Google Scholar
- Ranwell, D. S. 1972. Ecology of salt marshes and sand dunes. London, England: Chapman and Hall.Google Scholar
- SCWRP (Southern California Wetland Recovery Project). 2007. http://www.scwrp.org.
- Sullivan, G., J. Callaway, and J.B. Zedler. 2007. Biodiversity effects among 32 salt marsh assemblages are largely due to species. Ecological Monographs in press.Google Scholar
- Valiela, I., J. M. Teal, C. Cogswell, J. Hartman, S. Allen, R. van Etten, and D. Goehringer. 1985. Some long-term consequences of sewage contamination in salt marsh ecosystemsIn Ecological considerations in wetlands treatment of municipal wastewaters, eds. , E. R. Kaynor, S. Pelczarski, and J. Benforado, 301–316. New York: Van Nostrand Reinhold.Google Scholar
- Varty, A. K. 2007. The role of waterlogged refuges in the persistence of an annual plant in a perennial-dominated salt marsh. M. S. Thesis, University of Wisconsin, Madison, Wisconsin.Google Scholar
- Wetzel, R. G. 1983. Limnology, second edition. New York, NY: Harcourt Brace College Publishers.Google Scholar
- Winfield, T. P. 1980. Dynamics of nitrogen and carbon in a southern California salt marsh. Ph.D. Dissertation, University of California Riverside and San Diego State University, San Diego, California.Google Scholar
- Zedler, J. B., and J. M. West. 2007. Declining diversity in natural and restored salt marshes: A 30-year study of Tijuana Estuary. Restoration Ecology in press. DOI 10.1111/j.1526-100X.2007.00268.x.