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.

Extreme Preformation in Alpine Polygonum viviparum: An Architectural and Developmental Analysis

Pamela K. Diggle
American Journal of Botany
Vol. 84, No. 2 (Feb., 1997), pp. 154-169
Stable URL: http://www.jstor.org/stable/2446077
Page Count: 16
  • Read Online (Free)
  • Download ($12.00)
  • 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.
Extreme Preformation in Alpine Polygonum viviparum: An Architectural and Developmental Analysis
Preview not available

Abstract

Preformation, the initiation of organs one or more years prior to maturation and function, is reported to be common and crucial for plant survival in arctic and alpine environments, yet the phenomenon is remarkably little studied. In order to understand the role of preformation in the ecology and evolution of tundra species, this investigation takes a developmental and architectural approach to the analysis of plant growth and reproduction in the alpine perennial Polygonum viviparum L. Analyses show that the extent and duration of preformation in P. viviparum are extraordinary. Four years are required for each leaf and inflorescence to progress from initiation to functional and structural maturity. This single salient feature of development has profound consequences for basic architecture, dynamics of resource allocation, and the timing of plant responses to environmental variation. As a consequence of the protracted duration of leaf and inflorescence development, five cohorts of primordia, initiated in successive years, are borne simultaneously by an individual plant. In the year prior to maturation leaves reach 30% of their maximum size, and the maximum potential reproductive output of each inflorescence is determined. Thus, developmental processes that affect final morphology and resource allocation occur at least 1 yr before functional maturity. From the developmental and architectural models constructed for P. viviparum, a 1-yr delay in measurable plant responses to environmental variation is predicted. The models also apply generally to arctic and alpine species and provide a mechanistic explanation for observed patterns of productivity at the community and ecosystem scale.

Page Thumbnails

  • Thumbnail: Page 
154
    154
  • Thumbnail: Page 
155
    155
  • Thumbnail: Page 
156
    156
  • Thumbnail: Page 
157
    157
  • Thumbnail: Page 
158
    158
  • Thumbnail: Page 
159
    159
  • Thumbnail: Page 
160
    160
  • Thumbnail: Page 
161
    161
  • Thumbnail: Page 
162
    162
  • Thumbnail: Page 
163
    163
  • Thumbnail: Page 
164
    164
  • Thumbnail: Page 
165
    165
  • Thumbnail: Page 
166
    166
  • Thumbnail: Page 
167
    167
  • Thumbnail: Page 
168
    168
  • Thumbnail: Page 
169
    169