Abstract:

Aims: The establishment of national parks is crucial in protecting the integrity of natural ecosystems and biodiversity. As one of the first ten pilots, the Qianjiangyuan National Park system pilot (hereafter referred to as Qianjiangyuan) has developed the easement-inspired adaptive management and achieved remarkable outcomes. However, it remains unclear how this creative management might influence the soil microorganisms and systematic evaluation is in need.

Methods: We took Qianjiangyuan as the study area and collected surface soils from rice paddies in the different districts and under different management types. Four management types were included, namely, reformed land within the park, abandoned land within the park, unreformed land within the park, and unreformed land outside the park. We employed high-throughput sequencing techniques to characterize the community composition and structure of both bacteria and fungi. We then analyzed the driving forces behind the spatial patterns of bacterial and fungal communities.

Results: Compared to the other three types of lands, contents of soil nitrogen and phosphorus and heavy metals were relatively low in the abandoned land, but they were similar in the other three types. The bacterial communities were dominated by Proteobacteria (48.57%) and Acidobacteria (31.62%), while the fungal communities were dominated by Ascomycota (78.31%) and Basidiomycota (16.28%). Bacterial communities varied largely in lands under different management types, with significant difference between abandoned land and other three types, while the other three types were similar. Fungal communities showed slight variation, with significant difference being identified only between abandoned land and outside unreformed land. We found significant correlation between soil environmental factors and spatial variation of bacterial communities. The most important five factors driving bacterial spatial patterns were pH, chromium, total nitrogen, available phosphorus, and organic matter. However, no significant correlation was detected between fungal communities and soil environmental factors. Analysis of neutral community models found that neutral processes played an important role in the spatial distribution of both bacterial and fungal communities.

Conclusion: Based on these findings, we conservatively conclude that no significant impacts have been produced by land reforming policy so far. In contrast, the abandoned land may have begun rewilding. Therefore, long-term monitoring is needed to comprehensively assess whether and how ecological protection easement will impact the recovery of rice soils.

Key words: national park, ecological protection easement, soil microbial communities, bacteria, fungi