The effect of soil and plant material transplants on vegetation and soil biota during forest restoration in a limestone quarry: A case study
Abstract
Transplantation of soil and plant litter has been suggested as a tool to speed up the establishment of target communities during restoration. In this study, we explored the effect of transplanting soil and plant litter on plant and soil biota communities in an already afforested limestone quarry.
Soil or plant litter from a mature deciduous forest was transplanted into post-mining sites overgrown by 14-year-old deciduous trees planted here as part of a past reclamation effort. In this quarry six experimental sites were set up: three sites were fully fenced, while at the other three sites only individual planted trees were protected against deer by a wire mesh tightly surrounding the tree.
One site from fully protecting regime and one site from partly protecting regime was treated with either (1) soil transplant addition, (2) plant litter addition, or was (3) not treated at all. We studied microbial, plant and animal communities, the latter with an emphasis on nematodes for their bioindication potential, and compared the experimental sites with a nearby semi-natural forest (or serie of releves from target habitats in case of plants) used as reference sites.
The vegetation was sampled using standard phytosociological approach, the biomass of major microbial groups was assessed using PLFA, and free-living soil nematodes, soil mesofauna (in our case mainly springtails and mites), and soil macrofauna were sorted into elcological or taxonomical groups. Only nematodes and microbial communities differed among experimental sites, but none of the studied groups showed significant differences between individual transplanted treatments and samples from reference sites.
When we used Canonical correlation analysis (CCA) followed by variation partitioning, we found that transplant treatment, fencing, or their interaction explained a significant portion of data variability in all groups except macrofauna. Only plants and nematodes were significantly affected by the treatments, whereas all groups (except macrofauna) were affected by location and fencing and also by the interaction of all above mentioned factors.
In cases where these interactions were significant, soil transplant treatments showed higher similarity to the reference than the control without any soil or plant litter. This suggests that soil transplantation may speed up recovery of forest soils and understorey above it in a reclaimed quarry, especially in case of plant communities, but the described effect is strongly modified by other environmental factors.