The biology of rarity: Conservation of bryophytes and lichens
Martin, Erin P. , McCune, Bruce , Geiser, Linda .
Variation in the occurrence of rare epiphytic lichens of the western Oregon Cascades..
We examined factors related to representation of rare epiphytic lichens across a broad geographic band along the west slope of the Cascades in Oregon. Supporting this objective, we also described variation in lichen communities and its relationship to environment and past disturbance. We used lichen community data collected in 309 plots by the USDA Forest Service Pacific Northwest Air Program. We obtained environmental variables relating to geographic position, climate, stand structure, species richness, and air quality for each plot. We created variables to describe ecological and functional roles of lichen species, old growth association and rarity. Major gradients in lichen community composition, summarized by non-metric multidimensional scaling (NMS), were related to the environmental and species trait variables. NMS found a three dimensional solution which explained 83.4% of the variation lichen community composition. Axis 1 represents the strongest gradient in lichen community composition. It is related to elevation, annual temperature, and air quality. Axis 2 is related to Northing position, species richness, and species rarity, while axis 3 is associated with stand age. Rare species increased in the southern portion of our study area in plots at mid elevations, with warmer annual temperatures and higher lichen species diversity. The positive association between lichen species richness and species rarity indicates that a “coarse filter” management approach using species diversity should be successful in preserving many, but not necessarily all, rare lichen species.
1 - Pacific Northwest Region Air Program, Siuslaw National Forest, 4077 SW Research Way, Corvallis, Oregon, 97339, USA
2 - Oregon State University, Department of Botany and Plant Pathology, 2082 Cordley Hall, Corvallis, Oregon, 97331-2902, USA
non-metric multidimensional scaling
Presentation Type: Symposium
Location: Ballroom 3 (Cliff Lodge)
Date: Monday, August 2nd, 2004
Time: 10:00 AM