Soil degradation was found in first generation of Dahurian larch (Larix gmelinii (Rupr) Rupr.) plantations in northern China and also in plantations of other larch species such as Larix olgensis and Larix leptolepis in the same area. Soil degradation in pure larch plantations may be exacerbated in the second rotation under continuous cropping and was accompanied by obvious concomitant decrease in tree growth. A study on nutrient cycling revealed that poor quality of larch litter, which decomposed very slowly, was a key factor leading to soil degradation and decline in tree growth in pure larch plantations. The accumulation of forest floor litter in ∼20-year-old pure larch stands was 23-28 ton ha - 1 and this was higher than 9-16 ton ha - 1 in virgin mixed Korean pine/ broad-leaf forests. Larch litter took 4.4 years to mineralise, whereas angiosperm litter (ash, birch and poplar) in a pure larch stand took only 0.9-2.4 years. The progressive accumulation of litter on the forest floor acted as a heat-isolating layer which inhibited thermal conduction and decreased soil temperature and limited soil microbial activities. Consequently, degradation of soil fertility occurred and this was exacerbated after two or more rotations under continuous cropping. The role of the understorey vegetation was significant in nutrient recycling and maintaining sustainable soil fertility in larch plantations. A low-cost, effective way to prevent soil degradation in pure larch plantations is to develop mixed stands formed either by creating a mixture with broad-leaved trees or by introducing understorey vegetation (herbs and shrubs). Large areas of man-made, pure larch stands should be replaced by many small patches of different, uneven-age stands and crop rotation with different tree species should be adopted instead of continuous larch cropping.