Alpine Wetland Soil Development, Colorado

Alpine wetland soils differ significantly from lowland wetland soils because they typically do not exhibit extreme reducing conditions even when flooded throughout the growing season and producing wetland vegetation. Lack of reducing conditions leads to their classification as Oxyaquic Cryepts and Gelepts rather than Cryaquepts. Groundwater flow is impeded in areas there solifluction causes buried soils which then fosters reducing conditions. Soil profiles were excavated and plants were surveyed at 26 locations in wet alpine tundra on Niwot Ridge, Colorado. Ten subgroups of soils were classified. Statistical analyses show positive but weak correlation between plant communities and underlying soil classification and characteristics. Bare ground indicates Entisols and Pedicularis groenlandica is a strong indicator of Terric Cryofibrists. Soils have an acidic pH (A: 4.1-5.1; B: 4.6-6.0) and mainly skeletal loam texture in the subhorizons. O horizons are mainly fibric. No clay films were identified. This study proposes a development sequence for alpine wetland soils from Gelorthent to Oxyaquic Humicryept to Cryofibrist.