Effect of grazing intensity on plant–soil C:N:P stoichiometry within a
desert grassland under long-term grazing
Abstract
Background and aims High-intensity grazing in Mongolian grasslands has
led to the general deterioration of biodiversity and ecosystem
functioning. Abundant evidence shows that grazing affects the structure
and function of grassland ecosystems, especially under overgrazing.
Methods We examined the effects of three grazing intensities (0, 1.92,
and 3.08 sheep ha-1 a-1) on plant commu-nities, plant and soil C, N and
P contents, and plant and soil C:N:P stoichiometry in a desert grassland
in different years. Results Grazing did not affect plant coverage,
richness, or N:P, and the plant community biomass, litter bio-mass and
C:N and C:P were highest under a zero grazing intensity. Soil C:N
changed with the year and grazing intensity. However, soil C:P and N:P
were higher in 2018 than in 2016 and 2017. Conclusions Our study
suggested that grazing promoted the flow of N between plants and the
soil, especially at 3.08 sheep ha-1 a-1. Under grazing stress, plants
maintained the potential for compensatory growth. Further-more, N was
shown to be the limiting fertilizer component for plants growing in this
area among the three grazing intensities.