Vehicle Perturbation Effects upon a Tundra Soil‐Plant System: I. Effects on Morphological and Physical Environmental Properties of the Soils

Abstract

AbstractChanges obtaining in the soil abiotic physical environment due to tracked‐vehicle disturbance were determined in Tundra soils near Barrow, Alaska. The study was a contribution of the U.S.I.B.P., Tundra Biome Program.Six years following the scarring of the tundra surface by several years of infrequent passage by tracked‐vehicles (Weasel), the soils within the track had higher bulk densities and temperatures, accelerated and deeper thaw, and lower moisture percentages than undisturbed soil. Soil morphology was little altered except for direct physical alteration of surface organic horizons and a slight increase in mottling of mineral horizons in all but the wetter portions of the track. The intensity of alteration and associated environmental changes were related to the degree of evident disturbance (the amount of visible damage to the vegetative cover and soil surface) which, in turn, were related to differences in the natural drainage of the soils along the tracks; disturbance being greater, the poorer the natural drainage.The study indicated that a slight amount of disturbance to the tundra surface may be beneficial in terms of increased productivity and nutrient content of vegetation (see Part II of this paper). On the other hand, heavy disturbance can result in severe damage to the tundra system due to subsidence and erosion preventing the revegetation of the disturbed areas.