Impact of Cattle Grazing on Degradation of Mountain Pastelands in South-East of Kazakhstan
Abstract
This study examines the degradation of mountain pastures in southeastern Kazakhstan due to overgrazing and other human impacts. Soil degradation progresses more slowly than vegetation changes, but its effects are severe, with a reduction in silty and dusty fractions to 30% and an increase in sandy fractions, which lowers water retention and makes the soil more vulnerable to erosion. As a result, key pasture grasses like cereals (Poaceae) and legumes (Fabaceae) are being replaced by inedible and toxic plants with deep root systems. Pasture productivity varies seasonally, with total biomass yield at 0.42 0.05 t/ha in spring, peaking at 1.28± 0.40 t/ha in summer, and declining to 0.36± 0.007 t/ha in autumn, while the edible portion follows a similar pattern, ranging from 0.31 0.01 t/ha in spring to 0.97 0.28 t/ha in summer and 0.28 0.021 t/ha in autumn. The proportion of weeds and poisonous plants remains high throughout the year (22–25%), indicating a progressive transformation of the plant community under grazing pressure. Field studies confirm significant shifts in vegetation, with nutritious forage species being replaced by unpalatable and invasive plants. These changes threaten biodiversity and pasture sustainability, emphasizing the urgent need for rotational grazing and sustainable management practices to restore degraded pastures and ensure long-term productivity for livestock farming in Kazakhstan.