Mountain fen distribution, types and restoration priorities, San Juan Mountains, Colorado, USA

Abstract

Mountain fens are vital ecosystems for habitat, biodiversity, water and carbon cycling, but there is little comprehensive information on their distribution, abundance or condition in any region of the western U.S. Our study objectives were to: 1) evaluate fen distribution, abundance and characteristics in the San Juan Mountains of Colorado, 2) quantify disturbances, and 3) prioritize restoration needs of fens. We mapped 624 fens in 37 watersheds and collected field data on 182 of these fens. We estimated that approximately 2,000 fens occur in the San Juan Mountains, primarily in the subalpine zone at an average elevation of 3,288 m. Fens ranged from 0.2 to 20.5 ha in size, peat thickness ranged between 0.40 to \u3e 4.00 m, and surface slope ranged from 0-21%. Groundwater pH ranged from 3.1-7.6 and Ca+2 from 1-341 mg/L, reflecting the diverse geochemistry of watershed parent materials. We identified 188 vascular and 63 bryophyte taxa, and classified the 309 sampled stands into 20 plant communities that formed along complex hydrogeomorphic and geochemical gradients. The majority of fens were in excellent condition; however 10% of our sampled fens had high to very high restoration potential due to impacts from roads, mining, and ditching. © Society of Wetland Scientists 2010