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Tree invasion into a mountain‐top meadow in the Oregon Coast Range, USA
Author(s) -
Magee Teresa K.,
Antos Joseph A.
Publication year - 1992
Publication title -
journal of vegetation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 115
eISSN - 1654-1103
pISSN - 1100-9233
DOI - 10.2307/3235805
Subject(s) - transect , vegetation (pathology) , detrended correspondence analysis , range (aeronautics) , ordination , ecology , herbaceous plant , belt transect , environmental science , abundance (ecology) , plant community , geography , ecological succession , biology , medicine , materials science , pathology , composite material
. 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.