Soil formation and erosion in the Murree Hills, northeast Pakistan

Abstract

Soils at altitudes ranging from 700 to 3000 m in the Murree Hills of northeast Pakistan have been examined in terms of pedogenesis and erosion. Organic accumulation varies with vegetation type and density, and the level of biological activity in the soil. Weathering is evidenced by iron release and dissolution of calcareous materials, but the development of weathering-differentiated soil profiles is limited due to slope instability and restricted water availability. Profile differentiation in terms of translocation of fines and sesquioxides is limited probably for the same reasons and also, at lower altitudes, because of alkaline conditions. The soils are classified as Entisols and Inceptisols, with more acid forms predominating above about 2000 m and alkaline forms below this altitude. Rates of soil erosion are estimated to be around 150 t ha −1 y −1 on average in higher altitude areas of recent deforestation, and around 50–75 t ha −1 y −1 in areas of overgrazing at lower altitude. Susceptibility to erosion is high due to steep slopes, high silt and/or fine sand contents and low organic matter contents. Erosion control is being attempted by replanting the lower areas and by policing illegal felling of the higher, forested areas, but these measures have met with limited success to date due to topographic and administrative difficulties.