Affiliation:
1. Biology Department Pace University One Pace Plaza New York NY 10038 U.S.A.
2. Department of Environment and Development University for Peace El Rodeo de Mora San José Cd Colón Costa Rica
3. Monteverde Institute Puntarenas Costa Rica
4. Vermont Cooperative Fish and Wildlife Research Unit, Rubenstein School of the Environment and Natural Resources University of Vermont Burlington VT U.S.A.
5. Molecular and Genomics Informatics Core (MaGIC) Rutgers New Jersey Medical School 205 South Orange Avenue Newark NJ 07103 U.S.A.
6. The Genomics Center, Biochemistry and Molecular Genetics Rutgers New Jersey Medical School 185 South Orange Ave, MSB F653 Newark NJ 07103 U.S.A.
Abstract
This study assessed whether a natural regeneration or active tree‐planting reforestation strategy better restored the C and N‐cycle processes and associated microbiota within soils after 18 years in a Premontane Wet Life zone site in Monteverde, Costa Rica, compared to adjacent old secondary forest and pasture soils (both >60 years). Our findings apply to small‐scale restoration sites (<0.5 ha plots) commonly used in Monteverde. Both restoration strategies showed recovering soil C and N‐cycle processes with similar levels of TN, NH4+, NO3−, Biomass‐C, and efficiency of organic C use. Both strategies appeared to positively influence the recovery of the levels and community compositional stability of the Actinobacterial, Acidobacterial, N‐fixing (N‐Fixer) bacterial, ammonium‐oxidizing bacterial, and complex organic C‐degrading fungal communities. The main differences between the two strategies were that the tree‐planted and pasture soils had similar compositions of the Actinobacterial, N‐Fixer, and Fungal complex organic C degrader, while the natural regeneration and pasture soils had similar compositions of these groups and the Acidobacteria. However, the community compositions of all five microbial groups were different between restored forest and the old secondary forest soils. These results suggest that while the soil ecosystems from both reforestation strategies are recovering, after 18 years, there is still more recovery to occur. Lastly, possible indicators of post‐restoration soil ecosystem enhancement included increasing constancy of critical microbial group composition, efficiency of organic C conversion to biomass, Biomass‐C, NH4+, NO3−, and levels of Acidothermus, Acidobacteria subgroups 2, 3, and 5, Archaeorhizomyces, Anaeromyxobacter, Bradyrhizobium, Nitrosomonas, Flavobacterium, and Nitrospira.