Cyanobacterial and moss biocrusts shape soil nematode community in dryland mountain ecosystems with increasing aridity

Yanfeng Wang; Bo Xiao; Wanfu Wang; Tadeo Saéz-Sandino; Manuel Delgado-Baquerizo

doi:10.1016/j.scitotenv.2024.172750

Cyanobacterial and moss biocrusts shape soil nematode community in dryland mountain ecosystems with increasing aridity

Sci Total Environ. 2024 Apr 26:931:172750. doi: 10.1016/j.scitotenv.2024.172750. Online ahead of print.

Authors

Yanfeng Wang¹, Bo Xiao², Wanfu Wang³, Tadeo Saéz-Sandino⁴, Manuel Delgado-Baquerizo⁵

Affiliations

¹ Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling 712100, China; University of Chinese Academy of Sciences, Beijing 100049, China.
² Key Laboratory of Arable Land Conservation in North China, Ministry of Agriculture and Rural Affairs/College of Land Science and Technology, China Agricultural University, Beijing 100193, China; State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling 712100, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: xiaobo@cau.edu.cn.
³ Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China.
⁴ Departamento de Sistemas Físicos, Químicos y Naturales, Universidad Pablo de Olavide, Sevilla 41013, Spain.
⁵ Laboratorio de Biodiversidad y Funcionamiento Ecosistémico, Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS), CSIC, Seville E-41012, Spain.

PMID: 38677426
DOI: 10.1016/j.scitotenv.2024.172750

Abstract

Soil nematodes are the most abundant animals on Earth and play critical roles in regulating numerous ecosystem processes, from enhancing primary productivity to mineralizing multiple nutrients. In dryland soils, a rich community of microphyte organisms (biocrusts) provide critical habitats for soil nematodes, but their presence is being threatened by increasing aridity induced by global climate change. Despite its importance, how types of biocrusts and aridity index influence soil nematode community in dryland mountain ecosystems remains largely unknown. To fill these knowledge gaps, we conducted a field survey with contrasting aridity indexes (0.2, 0.4, and 0.6) and three types of biocrusts (cyanobacterial, cyanobacterial-moss mixed, and moss crusts) in the topsoil (0-5 cm) from the northern Chinese Loess Plateau. We found that the abundance (number of individuals per gram of soil), richness (number of Operational Taxonomic Units; OTUs), and diversity (number of different species) of soil nematodes were remarkably higher under biocrusts than in bare soils, regardless of aridity index and types of biocrusts. Our results also showed that the same variables had the highest values in moss crusts compared to cyanobacterial and cyanobacterial-moss mixed crusts. Structural equation modelling further revealed that biocrust types and traits (i.e., biocrust thickness, chlorophyll content, shear force, and penetration resistance) are the most important factors associated with both nematode abundance and richness. Together, our findings indicate that biocrusts, especially moss cover, and less stressful aridity conditions favor soil nematodes community in dryland mountain regions. Such knowledge is critical for anticipating the distribution of these animals under climate change scenarios and, ultimately, the numerous ecosystem services supported by soil nematodes.

Keywords: Aridity index; Biological soil crust; Chinese loess plateau; Microbiotic crust; Soil animal community.