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.

Distribution of Thalli in a Population of the Epiphytic Lichen Lobaria oregana and a Model of Population Dynamics and Production

Frederick M. Rhoades
The Bryologist
Vol. 86, No. 4 (Winter, 1983), pp. 309-331
DOI: 10.2307/3243243
Stable URL: http://www.jstor.org/stable/3243243
Page Count: 23
  • Read Online (Free)
  • Download ($10.00)
  • 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.
Distribution of Thalli in a Population of the Epiphytic Lichen Lobaria oregana and a Model of Population Dynamics and Production
Preview not available

Abstract

Data on weight-class distribution, growth rate and asexual propagule (lobule) release are used to analyze populations of the nitrogen-fixing lichen Lobaria oregana in old-growth Douglas fir canopies of western Oregon. A life-table model prepared from observed data is used to produce an estimate of net annual production of biomass, and to analyze the response of a population of this lichen to possible environmental perturbations. The weight-class distribution is similar in each of four trees studied and at different levels within the trees, but differed among the different components of the trees. Survivorship curves (log survivorship versus estimated thallus age) are similar for populations in all trees studied. Estimated net annual production is 31.1% of the standing crop of Lobaria oregana biomass. Mathematical manipulation of matrix formulations of the life-table model indicates that populations would be stable if they recruited 10% of the lobules released each year. In such a configuration, the model population returns to its original size and distribution within 30 years following a simulated storm that removes 90% of the largest thalli and momentarily increases lobule production.

Page Thumbnails

  • Thumbnail: Page 
[309]
    [309]
  • Thumbnail: Page 
310
    310
  • Thumbnail: Page 
311
    311
  • Thumbnail: Page 
312
    312
  • Thumbnail: Page 
313
    313
  • Thumbnail: Page 
314
    314
  • Thumbnail: Page 
315
    315
  • Thumbnail: Page 
316
    316
  • Thumbnail: Page 
317
    317
  • Thumbnail: Page 
318
    318
  • Thumbnail: Page 
319
    319
  • Thumbnail: Page 
320
    320
  • Thumbnail: Page 
321
    321
  • Thumbnail: Page 
322
    322
  • Thumbnail: Page 
323
    323
  • Thumbnail: Page 
324
    324
  • Thumbnail: Page 
325
    325
  • Thumbnail: Page 
326
    326
  • Thumbnail: Page 
327
    327
  • Thumbnail: Page 
328
    328
  • Thumbnail: Page 
329
    329
  • Thumbnail: Page 
330
    330
  • Thumbnail: Page 
331
    331