Soil and water bioengineering impacts on biodiversity: multi-taxon monitoring in landslide restoration

Landslides, as complex geomorphological disturbances, deeply reshape landscapes and influence ecosystem dynamics by exposing new substrates, redistributing soil and organic matter, and altering hydrological and nutrient cycles. In this context, Soil and Water Bioengineering (SWBE) techniques represent an effective Nature-Based Solution (NBS) that combines mechanical slope stabilisation with ecological restoration. This study evaluated the ecological effectiveness of SWBE interventions for shallow landslide restoration within mountainous forest environments of Central Italy. An integrated assessment of soil physicochemical properties and biological indicators—herbaceous and tree vegetation, soil microorganisms, and soil fauna—was carried out across three sites: a restored landslide (SWBE), a naturally recovering landslide (natural), and an undisturbed reference site (control). Vegetation emerged as the most responsive indicator of recovery, with the restored site showing significantly higher alpha diversity than both the natural and control sites. Although different pedological conditions characterised the three study sites, microbial communities' metabolic diversity and soil fauna composition showed strong resilience, reaching values comparable to undisturbed conditions. Overall, SWBE restoration effectively paired slope stability with the native ecological processes, promoting the establishment of diverse and functionally relevant plant communities. These findings highlight the dual benefits of SWBE as a sustainable solution for erosion control, slope stabilisation and biodiversity enhancement. Finally, long-term multi-taxon monitoring is suggested to further clarify the trajectories of ecological succession and ecosystem functionality in restored mountain environments.