Recovery of biomass and merchantable timber volumes twenty years after conventional and reduced-impact logging in Amazonian Brazil

Author(s)

Vidal, Edson ; West, Thales A. P. ; Putz, Francis E.

• Document type: Journal article
• Source: FOREST ECOLOGY AND MANAGEMENT; v. 376, p. 1-8, SEP 15 2016.
• Web of Science Citations: 16

Abstract

Concerns about the sustainability of tropical forestry motivated this study on post-logging timber and carbon dynamics over a 20-year period in Paragominas, Para, Brazil. Previously unlogged forest was subjected to conventional logging (CL), reduced-impact logging (RIL), or was set aside as an unlogged control. All trees >= 25 cm DBH and all trees of commercial species >= 10 cm DBH were monitored in a 24.5 ha plot in each treatment, with a 5.25 ha subplot in each for monitoring all trees >= 10 cm DBH. Above-ground biomass and bole volumes of merchantable species were tracked based on 10 inventories made between 1993 and 2014. Pre-logging biomass and bole volumes of commercial species were estimated as 237, 231, and 211 Mg ha(-1), and 78, 80, and 70 m(3) ha(-1), in the RIL, CL, and unlogged plots, respectively. One year after logging, biomass was reduced 14% by RIL and 24% by CL with corresponding merchantable species volume reductions of 21% and 31%. By 2014, biomass and bole volumes of commercial species had recovered 95% and 98% of their pre-logging stocks in the RIL plot but only 76% and 72% in the CL, plot, respectively; timber volumes from large trees (>= 50 cm DBH) were only recovered to 81% in the RIL plot and to 53% in the CL plot. Over the first twenty years after logging, average volume increments from commercial species were substantially higher in the RIL plot (0.72 m(3) ha(-1) year(-1)) than in the CL plot (0.08 m(3) ha(-1) 1 year). Recovery of both biomass and timber volumes were temporarily reversed between 2009 and 2014 due to a 4-fold increase in annual mortality rates in the RIL plot and a 5.5-fold increase in the CL plot (as well as a 3-fold increase in the control plot), all presumably related to the extreme drought of 2010. Our findings support the claim that use of RIL techniques accelerates rates of biomass and timber stock recovery after selective logging. (C) 2016 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 09/13277-5 - METHODOLOGY FOR CARBON OFFSET PROJECTS INVOLVING THE CONVERSION FROM CONVENTIONAL LOGGING TO FOREST MANAGEMENT WITH REDUCED IMPACT LOGGING.
• Grantee: Thales Augusto Pupo West
• Support type: Scholarships in Brazil - Master
• FAPESP's process: 13/16262-4 - Long-term monitoring of the dynamics of an logging forest conventional and forest management techniques in the Eastern Amazon and its relationship with climate change in forests managed for wood production
• Grantee: Edson José Vidal da Silva
• Support type: Regular Research Grants