Recovery of above-ground tree biomass after moderate selective logging in a central Amazonian forest

dc.contributor.authorOtani, T
dc.contributor.authorLima, A.J.N.
dc.contributor.authorSuwa, R.
dc.contributor.authorAmaral, M.R.
dc.contributor.authorOhashi, S.
dc.contributor.authorPinto, A.C.
dc.contributor.authorSantos, J. dos
dc.contributor.authorKajimoto, T.
dc.contributor.authorHiguchi, N
dc.contributor.authorIshizuka, M.
dc.titleRecovery of above-ground tree biomass after moderate selective logging in a central Amazonian foresten
dcterms.abstractWe examined the recovery and dynamics of living tree above-ground biomass (AGB) after selective logging in an Amazonian terra firme forest managed by a private company. The forest consisted of 24 blocks (including one set aside for conservation) selectively logged in different years on a managed schedule. Trees ?10 cm in diameter at breast height (dbh) were surveyed in 2006 in 192 0.25-ha plots, in 2010 in 119 plots, and in 2012-2013 in 54 plots. A logistic growth model factoring in logging dynamics and mean AGB of a block in these years was established. Referencing the mean AGB of the unlogged forest, the model indicated that the logged forest would take on average 14 years to re- gain its preharvest AGB after selective logging at 1.9 trees ha-1 (dbh > 50 cm). In 2010 and 2012-2013, the AGB increased significantly for small and large trees (10-20 cm and >60 cm dbh, respectively) in the logged forest. In con- trast, it decreased significantly for medium-sized trees (30-50 cm dbh) in the unlogged forest. Comparisons with the previous studies mainly conducted in the other regions of Amazon suggested that the estimated AGB recovery period with moderate logging intensity was almost appropriate and likely acceptable to forest managers.en
dcterms.accessRightsOpen access
dcterms.bibliographicCitationOtani, T., Lima, A.J., Suwa, R., Amaral, M.R., Ohashi, S., Pinto, A.C.M., Dos Santos, J., Kajimoto, T., Higuchi, N. and Ishizuka, M., 2018. Recovery of above-ground tree biomass after moderate selective logging in a central Amazonian forest. iForest-Biogeosciences and Forestry, 11(3), p.352.en
dcterms.licenseCopyrighted; all rights reserveden
dcterms.typeJournal Article
fsc.evidenceCategoryFSC impact-related
fsc.focus.forestTypeNatural Forest
fsc.issue.environmentalReduced Impact Logging
is.availability.fullTextFull text available
is.contributor.funderTypeMixed sources
is.contributor.memberForest Stewardship Council
is.coverage.regionSouth America
is.evaluation.collectionInterviews/surveys with certified entities and their representatives and workers/producers
is.evaluation.collectionField Measurement
is.evaluation.counterfactsNot applicable
is.evaluation.dataSourcePrivate company data
is.evaluation.notesThis study is about biomass recovery after harvest following RIL techniques in Amazonian Brazil. The authors investigate variation in biomass recovery according to the time since logging and in comparison to AGB estimates in unlogged plots.
is.evaluation.notesThe study remains quite descriptive and the authors do not provide much explanations about the mechanisms that could have led to the observed results. So the paper provide some interesting results regarding the time necessary for biomass recovery but elements are lacking to understand why and to generalize the results to other contexts.
is.evaluation.notesThe logging concession has been FSC certified in 1997 but there is no information on whether it was still certified during the data collection in 2006, 2010 and 2012/2013.
is.evaluation.notesOne of the main results is that biomass recover in ca. 14 years after logging to level observed in unlogged forests.
is.evaluation.notesAlso, the authors note that there is a greater loss of AGB because of tree mortality in unlogged forests compared to logged forest. This led to an overall net decrease in AGB in unlogged forest compared to logged forest (AGB gain thanks to growth and recruitment were similar in logged and unlogged forest). But it is difficult to imagine that the AGB would continuously decrease over time in unlogged plots. The growth increase in unlogged plots is significantly lower than in logged plots. A possible explanation is that this is probably due to a more stable state of the unlogged forest. The logged plots are more distubred, thus having a more dynamic growth (as also shown by the decrease in annual AGB increment over time after logging): tree fall gaps allow more growth and probably less natural mortality: large trees are cut down and others possibly benefits from less competition for ressources = more favorable conditions.The authors leave the decrease in AGB unexplained. Is is possibly a matter of timescale (sampling over a longer time period could show a different picture) and/or a too simplistic estimation of AGB that does not take into account higher wood density of shade-bearer species that are likely well represented in unlogged forests (-> less volume but same/more biomass compared to logged plots).
is.evaluation.notes“large trees (40-60cm dbh) had significantly less AGB in the unlogged block than in the later-logged blocks“This result is quite surprising because logging should tend to diminish the density of large trees.
is.evidenceSubTypeMonitoring report - performance
is.evidenceTypeMonitoring report
is.focus.productsOther forestry and logging
is.focus.sdgSDG 13 - Climate Action
is.focus.sustainIssueForests and other ecosystems
is.focus.sustainLensLandscape approaches
is.focus.systemElementMandE outcomes and impacts
is.focus.systemElementMandE performance monitoring
is.identifier.schemeNameForest Stewardship Council
is.identifier.schemeTypeVoluntary Sustainability Standards
is.item.reviewStatusPeer reviewed