The bottom-up effects of aridity and the top-down effects of grazing shape biodiversity across trophic levels in the Inner Mongolian grassland
- 1School of Ecology and Environment, Inner Mongolia University, 010021, Hohhot, Inner Mongolia, People's Republic of China
- 2College of Urban and Environmental Sciences, Peking University, 100871, Beijing, People's Republic of China
- 3Ministry of Education Key Laboratory of Ecology and Resource Use of the Mongolian Plateau and Inner Mongolia Key Laboratory of Grassland Ecology, School of Ecology and Environment, Inner Mongolia University, 010021, Hohhot, Inner Mongolia, People's Republic of China
Abstract
Aridity poses a severe threat to global biodiversity, and grazing further exacerbates ecological stress in drylands. Plants and soil organisms regulate nutrient cycling and ecosystem stability through trophic cascade effects. It remains unclear whether aridity and grazing have consistent effects across trophic levels. We selected 65 paired grazing and ungrazing sites along a natural aridity gradient in the Inner Mongolian grassland in which we explored the diversity of plants, soil bacteria, fungi, nematodes and the impacts of aridity and grazing on trophic cascade effects. Increasing aridity significantly decreased the species richness of plants, pathotrophic fungi, saprotrophic fungi, herbivorous and bacterivorous nematodes. Grazing significantly increased bacterial richness and reduced the richness of herbivorous and omnivorous-predatory nematodes. Overall, aridity exerted a stronger impact on biodiversity compared with grazing. Aridity induced bottom-up effects by initially reducing plant richness, with cascading effects on soil fungal richness and higher trophic communities. Grazing reduced omnivorous-predatory nematode richness, which decreased the richness of lower trophic level organisms through top-down effects. Our research highlights different multi-trophic cascades of aridity and grazing in grasslands, emphasizing the necessity for deeper investigation into biodiversity responses across trophic levels under global change and land use.
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BibTeX
@article{gong2026bottomup,
title = {{The bottom-up effects of aridity and the top-down effects of grazing shape biodiversity across trophic levels in the Inner Mongolian grassland}},
author = {Xiaoqian Gong and Nier Su and Jia Wen and Le Ma and Biao Zhu and Qing Zhang},
journal = {Proceedings of the Royal Society B: Biological Sciences},
year = {2026},
month = oct,
doi = {10.1098/rspb.2026.0561},
url = {https://doi.org/10.1098/rspb.2026.0561},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - The bottom-up effects of aridity and the top-down effects of grazing shape biodiversity across trophic levels in the Inner Mongolian grassland
AU - Xiaoqian Gong
AU - Nier Su
AU - Jia Wen
AU - Le Ma
AU - Biao Zhu
AU - Qing Zhang
PY - 2026
DA - 2026/10/21
JO - Proceedings of the Royal Society B: Biological Sciences
DO - 10.1098/rspb.2026.0561
UR - https://doi.org/10.1098/rspb.2026.0561
AB - Aridity poses a severe threat to global biodiversity, and grazing further exacerbates ecological stress in drylands. Plants and soil organisms regulate nutrient cycling and ecosystem stability through trophic cascade effects. It remains unclear whether aridity and grazing have consistent effects across trophic levels. We selected 65 paired grazing and ungrazing sites along a natural aridity gradient in the Inner Mongolian grassland in which we explored the diversity of plants, soil bacteria, fungi, nematodes and the impacts of aridity and grazing on trophic cascade effects. Increasing aridity significantly decreased the species richness of plants, pathotrophic fungi, saprotrophic fungi, herbivorous and bacterivorous nematodes. Grazing significantly increased bacterial richness and reduced the richness of herbivorous and omnivorous-predatory nematodes. Overall, aridity exerted a stronger impact on biodiversity compared with grazing. Aridity induced bottom-up effects by initially reducing plant richness, with cascading effects on soil fungal richness and higher trophic communities. Grazing reduced omnivorous-predatory nematode richness, which decreased the richness of lower trophic level organisms through top-down effects. Our research highlights different multi-trophic cascades of aridity and grazing in grasslands, emphasizing the necessity for deeper investigation into biodiversity responses across trophic levels under global change and land use.
SN - 0962-8452
SN - 1471-2954
ER -