Vegetation recovery masks decoupled soil responses following land-use transition to ground-mounted photovoltaic parks

Land-use transitions associated with the rapid expansion of ground-mounted photovoltaic (GMPV) parks represent an emerging anthropogenic disturbance with potential consequences for plant–soil feedbacks and ecosystem stability. While vegetation re-establishment is often used as an indicator of ecosystem recovery following such transitions, it remains unclear whether aboveground recovery reliably reflects the recovery of belowground soil processes.

Here, we use multi-year monitoring to examine vegetation dynamics, soil biotic responses, and soil carbon and nutrient trajectories following the conversion of a lowland forest plantation into a GMPV park in subtropical Taiwan. Vegetation cover beneath twelve solar panels was monitored monthly, while soil arthropod communities were sampled using pitfall traps over one year, with adjacent forest plantation plots serving as reference sites. Soil organic carbon (SOC) and total nitrogen concentrations were quantified during the construction phase (2022) and one and two years after operation (2024 and 2025).

Vegetation cover increased steadily beneath solar panels during the operational phase and was accompanied by a pronounced increase in soil arthropod abundance, exceeding that observed in the reference forest. Taxonomic richness approached forest levels; however, community composition remained significantly distinct, indicating the emergence of a novel soil biotic assemblage. In contrast, SOC and total nitrogen concentrations showed no detectable recovery over the same period. The dominance of fern vegetation appeared to provide insufficient organic inputs to support soil carbon accumulation, revealing a clear decoupling between aboveground vegetation recovery and belowground carbon and nutrient dynamics.

Rather than testing specific mechanisms, this observational study identifies a consistent recovery pattern that generates testable hypotheses. We propose that, in typhoon-prone regions, engineering requirements for GMPV installations may impose stronger constraints on soil structure, potentially amplifying soil compaction and hydrological alteration, thereby delaying the recovery of soil carbon and nutrient pools despite rapid vegetation re-establishment. These findings highlight the risk that vegetation-based assessments may mask persistent soil limitations and emphasize the need to incorporate soil biological and biogeochemical indicators when evaluating the long-term sustainability of renewable energy landscapes in climate-risk-prone regions.