Responses of soil nematode to rising atmospheric CO₂ concentrations

Elevated atmospheric CO₂ (eCO₂) impacts the structure and function of terrestrial ecosystems. Soil nematodes occupy a pivotal position within the soil food web. Soil nematode communities not only regulate key processes such as soil carbon accumulation, organic matter decomposition and nutrient cycling, but also serve as important indicators for assessing the sustainability impacts of climate change on soil ecosystems. Here, we review the past decade research progress on the responses of soil nematode communities to eCO₂, encompassing the response characteristics of nematode abundance, diversity and key functional groups across different ecosystems. We especially emphasize the adaptive interaction mechanisms between specific functional group (plant-parasitic nematodes) and plants under eCO₂ conditions. eCO₂ alters plant photosynthetic carbon allocation and enhances soil carbon inputs, consequently increasing the total abundance and diversity of soil nematode communities. However, these effects exhibit distinct taxonomic specificity and vary significantly across ecosystems. Notably, in farmland ecosystems, plant-parasitic nematodes demonstrate enhanced adaptive capacity under eCO₂ advantages, which is likely to exacerbate crop damage risks. The key future research should highlight on developing high-precision nematode classification and quantification techniques, constructing synergistic plant-nematode economic spectrum models to predict soil ecological functions, and deepening the catastrophic patterns of plant-parasitic nematodes under climate change.