Arbuscular mycorrhizae and soil enzymatic activities as modulated by grazing and plant species in a semiarid grassland

In this study, plant species and soil chemistry were the two key factors determining the composition of AMF communities, while grazing intensity had no direct effect. Available potassium and total nitrogen, as well as alkaline phosphatase and urease enzymatic activities were significantly increased by higher dung and urine at the heavily grazed site, while mycorrhizal root colonization was decreased by the lower grazing intensity. In addition, root colonization varied between the plant species, and was highest in S. hohenackeriana, which was most sensitive to grazing.