Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

The Demography of the Short-Lived Perennial Halophyte Spergularia Maritima in a Sea-Shore Meadow in South-Western Sweden

Anders Telenius
Journal of Ecology
Vol. 81, No. 1 (Mar., 1993), pp. 61-73
DOI: 10.2307/2261224
Stable URL: http://www.jstor.org/stable/2261224
Page Count: 13
  • Read Online (Free)
  • Download ($18.00)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
The Demography of the Short-Lived Perennial Halophyte Spergularia Maritima in a Sea-Shore Meadow in South-Western Sweden
Preview not available

Abstract

1. This paper summarizes a 9-year field study of the demography of Spergularia maritima growing in a sea-shore meadow in south-western Sweden, emphasizing the influence of competition and abiotic factors on mortality and reproduction. 2. Fifteen thousand individuals (3000 adults and 12 000 seedlings) were recorded. Between 1981 and 1989 the size of the population declined by almost 75% from a density of c. 110 established plants $m^{-2}$, primarily due to the effect of two successive cold winters in the middle of the decade. The average probability of a seed becoming established and growing into another mature plant was 0.002. 3. The population was strongly hierarchically structured both by age and by size. The average longevity of the established plants was estimated to be 2 years but individuals more than 10 years old were found. Although most of the plants that attained the adult stage developed only one or a few shoots, some plants developed up to seven shoots even in their first season. The largest individual consisted of 21 shoots. Only one-third of the population flowered simultaneously at any one time, and even after reaching the age of 5 years c. 20% of the individuals had not yet flowered. 4. The shape of the survivorship curve conforms to Deevey type III. Increasing vegetation density negatively affected the survivorship of seedlings, but the most marked effect was that of between-year variation in climate and hydrology, which profoundly influenced both survivorship and reproduction at all stages of the life cycle. 5. An experiment to determine the influence of freezing and submersion on winter survivorship showed severe effects of the combination of low temperature and absence of an insulating snow cover.

Page Thumbnails

  • Thumbnail: Page 
61
    61
  • Thumbnail: Page 
62
    62
  • Thumbnail: Page 
63
    63
  • Thumbnail: Page 
64
    64
  • Thumbnail: Page 
65
    65
  • Thumbnail: Page 
66
    66
  • Thumbnail: Page 
67
    67
  • Thumbnail: Page 
68
    68
  • Thumbnail: Page 
69
    69
  • Thumbnail: Page 
70
    70
  • Thumbnail: Page 
71
    71
  • Thumbnail: Page 
72
    72
  • Thumbnail: Page 
73
    73