Plant Ecology

, Volume 183, Issue 1, pp 157–170

Contrasting demographies and persistence of rare annual plants in highly variable environments

  • Laurel R. Fox
  • Heather N. Steele
  • Karen D. Holl
  • Margaret H. Fusari


Spatial and temporal variation in critical life history traits differ markedly between two co-occurring, rare and endangered annual plants, Gilia tenuiflora arenaria and Chorizanthe pungens pungens, that have restricted, but overlapping geographic distributions in coastal habitats of central California, USA. Environmental variation was extreme during the 6-year study (1997–2002), with the greatest differences between an intense wet, warm El Niño year (1998), followed by a very dry, cool La Niña (1999). Both species have similar increases in adult survival and seed set with wetter, warmer weather in spring, but they differed in other traits: more Gilia germinated in years with high rainfall and temperature, while more Chorizanthe germinated in dry, cooler years; Gilia abundance increased with the number of years since the previous large El Niño event, while Chorizanthe abundance declined; and Gilia abundance was independent of the previous year’s seed set, while Chorizanthe density was directly related to the previous year’s seed set. The strong negative associations of Chorizanthe abundance with warm, wet weather and with time since the previous El Niño probably reflect the particular sequence of annual weather patterns from 1997 through 2002, especially the extremes in 1998 and 1999. Since it germinates readily in most years under a wide range of winter conditions and does not develop a long-lived seed bank, Chorizanthe seedling abundance reflects recent additions and depletions of its seed bank, rather than prevailing weather, per se. In contrast, Gilia seeds may remain in the seed bank for many years, until relatively rare winter conditions trigger significant germination. These species-specific demographies enhance persistence and coexistence of these species, but the mechanisms differ from each other and from those described for annuals in other highly variable environments.

Key words:

Chorizanthe Coexistence Demography Gilia Rare plants Variable environments 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Aziz S., Khan M.A. (1995). Role of disturbance on the seed bank and demography of Leucis urticifolia (Labiate) populations in a maritime sub-tropical desert of Pakistan. International Journal of Plant Science 156: 834–840CrossRefGoogle Scholar
  2. Baskin C.C., Baskin J.M. (1998). Seeds: Ecology, Biogeography, and Evolution of Dormancy and Germination. Academic Press, San DiegoGoogle Scholar
  3. Baskin J.M., Baskin C.C. (1992). Seed dormancy pattern and seed reserves as adaptations of the endemic winter annual Lesquerella lescurii (Brassicaceae) to its floodplain habitat. Natural Areas Journal 12:184–190Google Scholar
  4. Bevill R.L., Louda S.M. (1999). Comparisons of related rare and common species in the study of plant rarity. Conservation Biology 13:493–498CrossRefGoogle Scholar
  5. Chesson P. (2000). Mechanisms of maintenance of species diversity. Annual Review of Ecology and Systematics. 31: 343–366CrossRefGoogle Scholar
  6. Chesson P.L. (1986). Environmental variation and the coexistence of species. In: Diamond J., Case T.J. (eds) Community Ecology. Harper and Row. New York, USA. pp. 240–256Google Scholar
  7. Chesson P., Huntly N. (1997). The roles of harsh and fluctuating conditions in the dynamics of ecological communities. American Naturalist 150: 519–553CrossRefPubMedGoogle Scholar
  8. Chesson P.L., Murdoch W.W. (1986). Aggregation of risk relationships among host-parasitoid models. American Naturalist 127:696–715CrossRefGoogle Scholar
  9. Chesson P.L., Warner R.R. (1981). Environmental variability promotes coexistence in lottery competitive systems. American Naturalist 117:923–943CrossRefGoogle Scholar
  10. Clauss M.J., Venable D.L. (2000). Seed germination in desert annuals: an empirical test of adaptive bet hedging. American Naturalist 155:168–186PubMedCrossRefGoogle Scholar
  11. Doak D.F., Thomson D.M., Jules E.S. (2002). PVA for Plants Understanding the demographic consequences of seed banks for population health. In: Beissinger S., McCullough D. (eds) Population Viability Analysis. University of Chicago Press, Chicago. pp. 312–337Google Scholar
  12. Dorell-Canepa J. (1994). Population biology of Gilia tenuiflora ssp. arenaria (Polemoniaceae). M.S. San Jose State University, San Jose, CaliforniaGoogle Scholar
  13. Dupre W.R. (1990). Quaternary geology of the Monterey Bay region, California. In: Garrison R.E., Greene H.G., Hicks K.R., Weber G.E., Wright T.L. (eds.). Geology and Tectonics of the Central California Coast Region, San Francisco to Monterey. American Association of Petroleum Geologists, Bakersfield CA, pp. 185–191Google Scholar
  14. Fox L.R., Holl K., Fusari M. (1998). Habitat management on capped landfills Report. Department of Defense, U.S. Army Corps of Engineers Army National Defense Center for Environmental Excellence. Concurrent Technologies Corporation, Johnstown PAGoogle Scholar
  15. Freund R.J., Littell R.C. (1986). SAS System for Regression. SAS Institute Inc., Cary, NCGoogle Scholar
  16. Hair J.F., Anderson R.E., Tatham R.L., Black W.C. (1998). Multivariate Data Analysis, 5th edition. Prentice Hall, Upper Saddle River, New Jersey, USAGoogle Scholar
  17. Hairston N.G. Jr, Ellner S. and Kearns C.M. (1996). Overlapping generations: the storage effect and the maintenance of biotic diversity. In: Rhoades O.E., Chesser R.K. and Smith M.H. (eds) Population Dynamics in Ecological Space and Time. University of Chicago Press, Chicago, pp. 109–145Google Scholar
  18. Hedges L.V., Gurevitch J., Curtis P.S. (1999). The meta-analysis of response ratios in experimental ecology. Ecology 80:1150–1156CrossRefGoogle Scholar
  19. Kalisz S., McPeek M.A. (1992). Demography of an age-structured annual resampled projection matrices, elasticity analyses, and seed bank effects. Ecology 73:1082–1093CrossRefGoogle Scholar
  20. Kalisz S., McPeek M.A. (1993). Extinction dynamics, population growth, and seed banks. Oecologia 95: 314–320CrossRefGoogle Scholar
  21. Kane D. (2000). Germination cues for the endangered annual Gilia tenuiflora ssp. arenaria: an experimental study. BS. University of California, Santa CruzGoogle Scholar
  22. Kluse J., Doak D.F. (1999). Demographic performance of a rare California endemic, Chorizanthe pungens var hartwegiana (Polygonaceae). American Midland Naturalist 142:244–256CrossRefGoogle Scholar
  23. Littell R.C., Milliken G.A., Stroup W.W., Wolfinger R.D. (1996). SAS System for Mixed Models. SAS Institute Inc., Cary NC USAGoogle Scholar
  24. Menges E.S. (2000). Population viability analyses in plants: challenges and opportunities. Trends in Ecology & Evolution 15:51–56CrossRefGoogle Scholar
  25. Monson R.K.J., Schultz E.-D., Freund M., Heilmeir J. (1994). The influence of nitrogen availability on carbon and nitrogen storage in the biennial Cirsium vulgare (Savi) Ten. II. The cost of nitrogen storage. Plant Cell and Environment 17:1133–1141CrossRefGoogle Scholar
  26. Pacala S.W., Silander J.A., Jr. (1987). Neighborhood interference among velvet leaf, Abutilon theophrasti, and pigweed, Amaranthus retroflexus. Oikos. 48:217–224CrossRefGoogle Scholar
  27. Pake C.E., Venable D.L. (1996). Seed banks in desert annuals: implications for persistence and coexistence in variable environments. Ecology 77:1427–1435CrossRefGoogle Scholar
  28. Pantastico-Caldas M., Venable D.L. (1993). Competition in two species of desert annuals along a topographic gradient. Ecology 74:2192–2203CrossRefGoogle Scholar
  29. Phillipi T. (1993). Bet-hedging germination of desert annuals: beyond the first year. American Naturalist 142:474–487CrossRefGoogle Scholar
  30. Pierce N. (2001). Germination ecology of the endangered annual, sand gilia, Gilia tenuiflora ssp. arenaria: effects of several abiotic factors. BA. University of California, Santa CruzGoogle Scholar
  31. Tuljapurkar S. (1990). Delayed reproduction and fitness in variable environments. Proceedings National Academy of Sciences 87:1139–1143PubMedCrossRefGoogle Scholar
  32. Venable D.L., Pake C.E., Caprio A.C. (1993). Diversity and coexistence of Sonoran desert winter annuals. Plant Species Biology 8:207–216CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, Inc. 2005

Authors and Affiliations

  • Laurel R. Fox
    • 1
  • Heather N. Steele
    • 1
    • 3
  • Karen D. Holl
    • 2
  • Margaret H. Fusari
    • 2
  1. 1.Department of Ecology and Evolutionary BiologyUniversity of CaliforniaSanta CruzUSA
  2. 2.Department of Environmental StudiesUniversity of CaliforniaSanta CruzUSA
  3. 3.c/o Dr. Matthew Kohn, Department of Geological SciencesUniversity of South CarolinaColumbiaUSA

Personalised recommendations