Research article - Peer-reviewed, 2020
Tropical Rainforest Restoration Plantations Are Slow to Restore the Soil Biological and Organic Carbon Characteristics of Old Growth Rainforest
Bonner, Mark T. L.; Allen, Diane E.; Brackin, Richard; Smith, Tim E.; Lewis, Tom; Shoo, Luke P.; Schmidt, SusanneAbstract
Widespread and continuing losses of tropical old-growth forests imperil global biodiversity and alter global carbon (C) cycling. Soil organic carbon (SOC) typically declines with land use change from old-growth forest, but the underlying mechanisms are poorly understood. Ecological restoration plantations offer an established means of restoring aboveground biomass, structure and diversity of forests, but their capacity to recover the soil microbial community and SOC is unknown due to limited empirical data and consensus on the mechanisms of SOC formation. Here, we examine soil microbial community response and SOC in tropical rainforest restoration plantings, comparing them with the original old-growth forest and the previous land use (pasture). Two decades post-reforestation, we found a statistically significant but small increase in SOC in the fast-turnover particulate C fraction. Although the delta C-13 signature of the more stable humic organic C (HOC) fraction indicated a significant compositional turnover in reforested soils, from C-4 pasture-derived C to C-3 forest-derived C, this did not translate to HOC gains compared with the pasture baseline. Matched old-growth rainforest soils had significantly higher concentrations of HOC than pasture and reforested soils, and soil microbial enzyme efficiency and the ratio of gram-positive to gram-negative bacteria followed the same pattern. Restoration plantings had unique soil microbial composition and function, distinct from baseline pasture but not converging on target old growth rainforest within the examined timeframe. Our results suggest that tropical reforestation efforts could benefit from management interventions beyond re-establishing tree cover to realize the ambition of early recovery of soil microbial communities and stable SOC.Keywords
Mixed-species plantations; Soil fungi and bacteria; Soil carbon sequestration; Microbial function and composition; Microbial ecology; Land use changePublished in
Microbial Ecology2020, volume: 79, number: 2, pages: 432-442
Publisher: SPRINGER
Authors' information
Bonner, Mark
University of Queensland
Bonner, Mark
Swedish University of Agricultural Sciences, Department of Forest Ecology and Management
Allen, Diane E.
Dept Environm and Sci
Allen, Diane E.
Univ Queensland
Brackin, Richard
Univ Queensland
Smith, Tim E.
Univ Sunshine Coast
Lewis, Tom
Univ Sunshine Coast
Shoo, Luke P.
Univ Queensland
Schmidt, Susanne
Univ Queensland
UKÄ Subject classification
Soil Science
Forest Science
Publication Identifiers
DOI: https://doi.org/10.1007/s00248-019-01414-7
URI (permanent link to this page)
https://res.slu.se/id/publ/104872