Grazing Affects the Ecological Stoichiometry of the Plant-soil-microbe System on the Hulunber Steppe, China

Grazing Affects the Ecological Stoichiometry of the Plant-soil-microbe System on the Hulunber Steppe, China

Academic Unit

College of Arts and Sciences

Publication Date

9-2019

Document Type

Article

Abstract

Grazing affects nutrient cycling processes in grasslands, but little is known by researchers about effects on the nutrient stoichiometry of plant-soil-microbe systems. In this study, the influence of grazing intensity (0, 0.23, 0.34, 0.46, 0.69, and 0.92 AU ha-1) on carbon (C), nitrogen (N) and phosphorus (P) and their stoichiometric ratios in plants, soil, and microbes was investigated in a Hulunber meadow steppe, Northeastern China. The C:N and C:P ratios of shoots decreased with grazing increased. Leaf N:P ratios <10 suggested that the plant communities under grazing were N-limited. Heavy grazing intensities increased the C:N and C:P ratios of microbial>biomass, but grazing intensity had no significant effects on the stoichiometry of soil nutrients. The coupling relationship of C:N ratio in plant-soil-microbial systems was tightly significant compared to C:P ratio and N:P ratio according to the correlation results. The finding suggested grazing exacerbated the competition between plants and microorganisms for N and P nutrition by the stoichiometric changes (%) in each grazing level relative to the no grazing treatment. Therefore, for the sustainability of grasslands in Inner Mongolia, N inputs need to be increased and high grazing intensities reduced in meadow steppe ecosystems, and the grazing load should be controlled within G0.46.

Journal Title

Sustainability

Volume

11

Issue

19

DOI

doi:10.3390/su11195226

Grazing Affects the Ecological Stoichiometry of the Plant-soil-microbe System on the Hulunber Steppe, China

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