Tree invasion into a mountain-top meadow in the Oregon Coast Range, USA
Article first published online: 24 FEB 2009
1992 IAVS - the International Association of Vegetation Science
Journal of Vegetation Science
Volume 3, Issue 4, pages 485–494, August 1992
How to Cite
Magee, T. K. and Antos, J. A. (1992), Tree invasion into a mountain-top meadow in the Oregon Coast Range, USA. Journal of Vegetation Science, 3: 485–494. doi: 10.2307/3235805
- Issue published online: 24 FEB 2009
- Article first published online: 24 FEB 2009
- Received 16 September 1991; Revision received 21 February 1992; Accepted 1 March 1992.
- Abies procera;
- Establishment microsite;
- Recruitment pattern;
- Tree invasion
- Hitchcock & Cronquist (1973)
Abstract. The grassy meadow on the top of Marys Peak, in the Oregon Coast Range, is being invaded, primarily along the margins, by Abies procera. To examine vegetation and environmental changes across the forest-meadow transition and to evaluate factors affecting tree invasion, belt transects were established at 10 sites. Correlations of environmental variables with ordination axes from Detrended Correspondence Analysis suggest that the sites were distributed along a moisture gradient. Although the sites varied considerably in species composition and environment, tree invasion of the meadow was occurring at all sites. Reduction in abundance of the dense herbaceous vegetation of the meadow is required before the small seedlings of Abies procera can become established. Almost all tree invasion of the meadow occurs in the narrow forest-meadow ecocline because trees at the edge of the forest reduce the cover of herbaceous plants in the adjacent meadow. On some sites, above average snow accumulations further reduce vigor of meadow vegetation and increase tree establishment. On the driest sites wet summers facilitate tree establishment. Infrequent fires, which remove the fire sensitive Abies procera, are probably required to reverse the slow but persistent trend of forest expansion and ultimately maintain the meadow.