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.

Edge Effects in Central Amazonian Forest Fragments

Jay R. Malcolm
Ecology
Vol. 75, No. 8 (Dec., 1994), pp. 2438-2445
Published by: Wiley
DOI: 10.2307/1940897
Stable URL: http://www.jstor.org/stable/1940897
Page Count: 8
  • Download ($42.00)
  • Subscribe ($19.50)
  • Cite this Item
Edge Effects in Central Amazonian Forest Fragments
Preview not available

Abstract

Current descriptive models of edge effects describe little more than the relationship between perimeter and area. A more realistic model, one that incorporates the additive nature of edge effects, is presented and tested. The total edge effect at a location within a patch is modelled as the sum of edge effects at points along the edges of the patch, weighted by the distances from the edge points to the location. At four sites in the central Amazon @?80 km north of Manaus, Brazil, I measured vertical stratification of foliage in three primary forest habitats: (1) continuous forest close to linear edges, (2) 10-ha forest fragments, and (3) 1-ha forest fragments. Foliage thickness (foliage density along a vertical line) was scored in six height intervals (0-2, 2-5, 5-10, 10-20, 20-30, and 30-40 m). With decreasing distance from a linear edge, understory (0-5 m) foliage thickness increased and overstory (10-30 m) foliage thickness decreased, and the relationship between foliage thickness and distance to the edge agreed with that predicted by the model. Using parameter estimates obtained from the "best fit" of the model to these data from linear edges, understory and overstory thickness in 1- and 10-ha fragments was predicted. Foliage thickness varied extensively among fragments, but agreed quite closely with that predicted by the model, and the additive model performed better than a curvilinear non-additive one.

Page Thumbnails

  • Thumbnail: Page 
2438
    2438
  • Thumbnail: Page 
2439
    2439
  • Thumbnail: Page 
2440
    2440
  • Thumbnail: Page 
2441
    2441
  • Thumbnail: Page 
2442
    2442
  • Thumbnail: Page 
2443
    2443
  • Thumbnail: Page 
2444
    2444
  • Thumbnail: Page 
2445
    2445