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• 1. [Article] The phytosociology of some vine maple communities in the Marys Peak watershed

  A study was undertaken in the Marys Peak watershed with the following objectives. First, a classification of the major plant communities was carried out. Second, some of the ecological features of Acer ...

  Citation × Citation Citation Abstract Copy Title: The phytosociology of some vine maple communities in the Marys Peak watershed Author: Anderson, Howard George A study was undertaken in the Marys Peak watershed with the following objectives. First, a classification of the major plant communities was carried out. Second, some of the ecological features of Acer circinatum that account for its distribution within these communities were determined. The following plant communities are described: Corylus californica/Bromus vulgaris (CB) Acer circinatum/Gaultheria shallon Corylus californica - Holodiscus discolor (AGs) subtype Tsuga heterophylla/Xerophyllum tenax (AGx) subtype Holodiscus discolor/Gaultheria shallon (HG) Acer circinatum/Polystichum munitum (AP) Oxalis oregana (O) The CB community is confined to south aspects below 1,400 feet along Rock Creek. Pseudotsuga menziesii, Corylus californica and Bromus vulgaris are the usual dominant species in each of the tree, shrub and herb layer respectively. The AGs is found below 1,800 feet, Pseudotsuga, Acer circinatum and Gaultheria shallon are the dominants in each layer. The AGx is a higher elevation counterpart of the AGs found between 1,800 and 3,200 feet. It has similar dominant species to the AGs but species composition is different. The presence of Taxus brevifolia, Tsuga heterophylla and Xerophyllum tenax distinguish this from the AGs. The HG is essentially confined to south slopes between 1,000 and 1,800 feet. Pseudotsuga, Holodiscus discolor and Gaultheria are the dominants. The AP community is restricted to steep north slopes where downslope movement of seepage water occurs. Layer dominants include Tsuga and/or Thuja plicata, Acer circinatum and Polystichum munitum. The O community occurs above 2,500 feet on the north slope of Marys Peak. Species dominants in the old- growth forest include Tsuga and Oxalis oregana. The shrub layer is represented by occasional Tsuga. Differences in response of Acer circinatum to environmental factors are noted between communities. Height, stem diameter, density, canopy coverage, growth form and bryophyte coverage of Rock and Griffith Creeks. The steep slope and the time factor have been effective barriers to the upslope encroachment of vine maple. In the O community vine maple is confined to restricted niches where light is not limiting but it can never become extensively established in the adjacent forest because of the insufficient light intensity and the slowness of spread of the species. This latter feature is an important limitation since the spread of vine maple is quickly arrested during the relatively short time interval between a catastrophic removal of the overstory and re-establishment of the coniferous species. Title: The phytosociology of some vine maple communities in the Marys Peak watershed Author: Anderson, Howard George A study was undertaken in the Marys Peak watershed with the following objectives. First, a classification of the major plant communities was carried out. Second, some of the ecological features of Acer circinatum that account for its distribution within these communities were determined. The following plant communities are described: Corylus californica/Bromus vulgaris (CB) Acer circinatum/Gaultheria shallon Corylus californica - Holodiscus discolor (AGs) subtype Tsuga heterophylla/Xerophyllum tenax (AGx) subtype Holodiscus discolor/Gaultheria shallon (HG) Acer circinatum/Polystichum munitum (AP) Oxalis oregana (O) The CB community is confined to south aspects below 1,400 feet along Rock Creek. Pseudotsuga menziesii, Corylus californica and Bromus vulgaris are the usual dominant species in each of the tree, shrub and herb layer respectively. The AGs is found below 1,800 feet, Pseudotsuga, Acer circinatum and Gaultheria shallon are the dominants in each layer. The AGx is a higher elevation counterpart of the AGs found between 1,800 and 3,200 feet. It has similar dominant species to the AGs but species composition is different. The presence of Taxus brevifolia, Tsuga heterophylla and Xerophyllum tenax distinguish this from the AGs. The HG is essentially confined to south slopes between 1,000 and 1,800 feet. Pseudotsuga, Holodiscus discolor and Gaultheria are the dominants. The AP community is restricted to steep north slopes where downslope movement of seepage water occurs. Layer dominants include Tsuga and/or Thuja plicata, Acer circinatum and Polystichum munitum. The O community occurs above 2,500 feet on the north slope of Marys Peak. Species dominants in the old- growth forest include Tsuga and Oxalis oregana. The shrub layer is represented by occasional Tsuga. Differences in response of Acer circinatum to environmental factors are noted between communities. Height, stem diameter, density, canopy coverage, growth form and bryophyte coverage of Rock and Griffith Creeks. The steep slope and the time factor have been effective barriers to the upslope encroachment of vine maple. In the O community vine maple is confined to restricted niches where light is not limiting but it can never become extensively established in the adjacent forest because of the insufficient light intensity and the slowness of spread of the species. This latter feature is an important limitation since the spread of vine maple is quickly arrested during the relatively short time interval between a catastrophic removal of the overstory and re-establishment of the coniferous species. Close