Abstract Mycorrhizal association networks, which represent community-level bitrophic interactions between plants and fungi, consistently exhibit distinct topological patterns across ecosystems. Clarifying their elevation-related dynamics is crucial for predicting the effects of climate change on plant community assembly and ecosystem resilience. On the basis of a systematic sampling of plant roots across ten elevational belts in an oak-dominated forest, we investigated the effects of elevation on mycorrhizal network specialization as well as the relative contributions of climate, plant, and soil characteristics. Our results revealed that (1) plant diversity decreased and mycorrhizal fungal diversity increased as the elevation increased. (2) Ten mycorrhizal network displayed elevated specialization (H’2) at mid-elevation zones and subalpine treelines and exhibited a hollow-shaped variation in terms of the standard effect size of H’2 (SES(H’2)) and species specialization of plants (SES(d’)), indicating that the high H’2 at subalpine treelines was mainly caused by passive sampling. (3) The SES(H’2) exhibited significantly positive relationships with plant diversity, litter thickness, and soil moisture, whereas soil parameters had negligible effects. (4) Fungal species specialization (SES(d’)) increased along with increases in the plant diversity, litter thickness, plant crown density, and soil moisture, implying that plant and climate filters governed fungal partner selection. Our findings indicate that the plant diversity and climate condition—rather than edaphic factors—serves as determinants of mycorrhizal network specialization in temperate forest ecosystems.
Lin et al. (Wed,) studied this question.