Stalled gaps or rapid recovery : the influence of damage on post-logging forest dynamics and carbon balance

• Main Author: Lincoln, Philippa R.
• Published: University of Aberdeen 2008
• Subjects: 634.9; Forest dynamics : Forests and forestry : Logging
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.495923

I assessed forest dynamics, stand structure and composition using repeated measurements of permanent plots over twelve years, in areas logged according to RIL guidelines and areas logged conventionally (CL) in Sabah, Malaysia. I compared successful pathways between treatments and used stand dynamics data to estimate carbon fluxes and pools over twelve years. Matrix models were used to generate projections of carbon emissions, sequestration and storage over a thirty-year logging cycle. Stem density (439 stems ha^-1 (95% CI = 358 – 477), basal area (32 m² ha^-1 (95% CI = 23-44) ) and carbon stored in above ground biomass (AGB, 1160 Mg C ha^-1 (95% CI = 97 – 232)) did not differ from prelogging levels twelve years after RIL. There was no recovery of these years variables after CL (246 stems ha^-1 (95% CI = 200 – 303), basal area 20 m² ha^-1 (95% CI = 13-28), carbon in AGB 101 Mg C ha^-1 (95% CI = 58 – 157)). Mortality, growth and recruitment rates remained elevated throughout the study. Both damaged and undamaged trees experiencing high mortality, especially after CL. Stalled, tree-less gaps and vine-covered building phase forest covered 54% of the CL area and appeared to have increased over time. Closed canopy and tree-dominated building phase forest dominated the RIL areas (81%). Total carbon storage over a thirty year logging cycle after RIL is projected to be 40% higher than after CL and result in reduced emissions of 88 Mg C ha^-1 and increased sequestration of 27 Mg C ha^-1. The total carbon benefit of using RIL instead of CL in lowland dipterocarp forest is projected to be 196 Mg C ha^-1 over a cutting cycle. My comparisons and projections of emissions, sequestration and storage in above-ground biomass show that the carbon benefit of reduced-impact logging exceeds previous projections. RIL areas are likely to provide substantial co-benefits in timber stocking, biodiversity conservation and resilience to climate change compared with CL areas.