Restoring the vegetation of mined peatlands in the southern Rocky Mountains of Colorado, USA

South Park is a high-elevation, semi-arid, treeless intermountain basin in central Colorado. A few extreme rich fens occur on the western margin and i n the center of South Park where regional and local groundwater flow system s discharge to the ground surface. Over the past 40 years there has been ex tensive peat mining in these fens, but restoration methods have yet to be d eveloped and successfully applied. The first part of this study compared th e naturally reestablished vegetation on six mined peatlands with six pristi ne sites, while the second part of the study tested different revegetation techniques in 27 plots with varying depths to the water table. The six mine d sites had only 30 plant species as compared with 122 species in the unmin ed sites; 43% of the species in the mined sites were not present in the und isturbed fens. Even after 40 years the sedges and willows that dominate the undisturbed sites were largely absent on the mined sites. The revegetation experiments seeded eight species, transplanted Carex aquatilis (water sedg e) seedlings, transplanted rhizomes from six species, and transplanted four species of willow cuttings. Of the eight species seeded, only Triglochin m aritima (arrowgrass) germinated and established seedlings. C. aquatilis see dlings, rhizome transplants of C. aquatilis, Kobresia simpliciuscula (elk s edge), and Juncus arcticus (arctic rush), and willow cuttings all had diffe ring patterns of survival with respect to the annual maximum height of the water table. These results indicate that the dominant species can be succes sfully reintroduced to mined surfaces with the appropriate hydrologic condi tions, but human intervention will be necessary to rapidly re-establish the se species. The slow rate of peat accumulation means that restoration of th e mined fens will require hundreds, if not thousands, of years.