In: Sydowia 78, (2026): 165-177; ISSN 0082-0598, DOI 10.12905/0380.sydowia78-2026-0165, Published online on january 12th, 2026

Habitat-specific network stability: fungal community cohesion increases as habitat quality improves in Songnen saline-alkali grasslands

Xiaoyu Lu, Yajie Liu, Zihe Wang, Jinhua Li & Chunxue Yang*

College of Landscape Architecture, Northeast Forestry University, Harbin, 150040, China * e-mail: senxiu99@163.com

Lu X., Liu Y., Wang Z., Li J. & Yang C. (2026) Habitat-specific network stability: fungal community cohesion increases as habitat quality improves in Songnen saline-alkali grasslands. – Sydowia 78: 165–177.

Fungi are ubiquitous components of soil ecosystems, with their community composition profoundly shaped by soil environmental conditions. Despite their ecological significance in saline-alkali grasslands, the assembly mechanisms of soil fungal communities across habitat gradients remain poorly understood. To elucidate the relationships between soil properties and fungal community composition and stability, we investigated habitats of varying quality within the Songnen grassland using ITS rRNA gene sequencing. Our results revealed significant variations in both soil physicochemical properties and fungal community structure across the four habitat levels. Soil conditions showed progressive improvement with increasing of the habitat quality. Alpha diversity differed significantly between the lowest-quality habitat (L1) and the other levels, while distinct compositional differences were evident across all levels. Ascomycota emerged as the dominant fungal phylum at all habitat levels, although its relative abundance varied considerably. At the genus level, electrical conductivity (EC) and pH were identified as the soil factors most strongly correlated with both total fungal and arbuscular mycorrhizal (AM) fungal community composition. Furthermore, cooccurrence network analysis demonstrated that fungal communities in the lowest-quality habitats exhibited the most fragmented and unstable structures. This research examines three key questions: (1) How habitat quality modulates AM fungal compositional shifts; (2) Whether key drivers differ between total fungi and AMF subgroups; (3) Whether network stability reflects functional resilience in degraded grasslands.

Keywords: grassland habitat level, soil fungal communities, arbuscular mycorrhizal fungi, ecological networks, community
assembly.