Effects of human disturbance and cryoturbation on soil iron and organic matter distributions and on carbon storage at high elevations in the Cairngorm Mountains, Scotland

Abstract

Soil profiles were sampled at 43 sites on granitic parent material at altitudes ranging from 970 to 1300 m in the Cairngorm Mountains, Scotland. Many soils under undisturbed vegetation showed evidence of iron and organic matter translocation with distinctive Bh or Bs horizons. Approximately 50% of the sites sampled had no or partial vegetation cover, due either to human activity (trampling) or active geomorphic processes such as cryoturbation on patterned ground. Exposed cols and summit ridges were most heavily affected by trampling with extensive areas of path development and some erosion. Trampling was principally associated with loss of the upper soil horizons and cryoturbation processes with disturbance of horizon development. Median total organic matter at the vegetated sites ranged from 4.8 to 22.0 kg m −2 with a median of 9.5 kg m −2. There was significantly less total organic matter at the unvegetated sites with median of 4.6 kg m −2 and range from 1.5 to 11.9 kg m −2. There was little difference in total organic matter between sites where vegetation disturbance was due to human trampling or to cryoturbation.