Effects of manual brushing on 10-year survival and growth of Douglas-fir in the mixed broadleaf – shrub complex of southern interior British Columbia

Manual brushing is used to minimize the competitive effects of paper birch (Betula papyrifera Marsh) and associated broadleaved trees on young Douglas-fir (Pseudotsuga menziesii var. glauca) in southern interior British Columbia. Effects of brushing broadleaved trees, predominantly birch, on interio...

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Main Authors: George Harper, Kevin Brown
Format: Article
Language:English
Published: Canadian Institute of Forestry 2020-07-01
Series:The Forestry Chronicle
Subjects:
Online Access:https://pubs.cif-ifc.org/doi/10.5558/tfc2020-020
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author George Harper
Kevin Brown
author_facet George Harper
Kevin Brown
author_sort George Harper
collection DOAJ
description Manual brushing is used to minimize the competitive effects of paper birch (Betula papyrifera Marsh) and associated broadleaved trees on young Douglas-fir (Pseudotsuga menziesii var. glauca) in southern interior British Columbia. Effects of brushing broadleaved trees, predominantly birch, on interior Douglas-fir survival and growth were studied on four sites. Treatments were applied when plantations were five to nine years old. Through 10 years post treatment, brushing did not affect Douglas-fir survival, but increase height by 22 % and stem diameter by 31 % and the differences were greater than seen at five years. After 10 years, linear models described a declining Douglas-fir height or diameter with increasing broadleaved tree density. Boundary line analysis was used to describe maximum treatment response to broadleaved density and two distance independent competition indices for birch and broadleaves, combining either cover or density with relative heights (CRH, DRH, respectively). A negative exponential relationship was fit to 10-year Douglas-fir heights and diameters with increasing values CRH or DRH. Competition thresholds for density, CRH and DRH were not apparent. The quantile regression results indicated the 10-year response of young Douglas-fir diameter to brushing occurred primarily with the largest 55 % to 85 % of the population, CRH and DRH respectively.
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spelling doaj-art-e668274241cc40669be7f77a4c2d2d7f2025-08-20T04:00:44ZengCanadian Institute of ForestryThe Forestry Chronicle0015-75461499-93152020-07-01960215216410.5558/tfc2020-020Effects of manual brushing on 10-year survival and growth of Douglas-fir in the mixed broadleaf – shrub complex of southern interior British ColumbiaGeorge Harper0Kevin Brown1Ministry Forests, Lands, Natural Resource Operations and Rural Development, Resource Practices Branch, Victoria, British ColumbiaKR Brown and Associates, Victoria, British ColumbiaManual brushing is used to minimize the competitive effects of paper birch (Betula papyrifera Marsh) and associated broadleaved trees on young Douglas-fir (Pseudotsuga menziesii var. glauca) in southern interior British Columbia. Effects of brushing broadleaved trees, predominantly birch, on interior Douglas-fir survival and growth were studied on four sites. Treatments were applied when plantations were five to nine years old. Through 10 years post treatment, brushing did not affect Douglas-fir survival, but increase height by 22 % and stem diameter by 31 % and the differences were greater than seen at five years. After 10 years, linear models described a declining Douglas-fir height or diameter with increasing broadleaved tree density. Boundary line analysis was used to describe maximum treatment response to broadleaved density and two distance independent competition indices for birch and broadleaves, combining either cover or density with relative heights (CRH, DRH, respectively). A negative exponential relationship was fit to 10-year Douglas-fir heights and diameters with increasing values CRH or DRH. Competition thresholds for density, CRH and DRH were not apparent. The quantile regression results indicated the 10-year response of young Douglas-fir diameter to brushing occurred primarily with the largest 55 % to 85 % of the population, CRH and DRH respectively.https://pubs.cif-ifc.org/doi/10.5558/tfc2020-020Douglas-fir plantationsbroadleaved vegetationmanual brushingsurvivalheight growthdiameter growth
spellingShingle George Harper
Kevin Brown
Effects of manual brushing on 10-year survival and growth of Douglas-fir in the mixed broadleaf – shrub complex of southern interior British Columbia
The Forestry Chronicle
Douglas-fir plantations
broadleaved vegetation
manual brushing
survival
height growth
diameter growth
title Effects of manual brushing on 10-year survival and growth of Douglas-fir in the mixed broadleaf – shrub complex of southern interior British Columbia
title_full Effects of manual brushing on 10-year survival and growth of Douglas-fir in the mixed broadleaf – shrub complex of southern interior British Columbia
title_fullStr Effects of manual brushing on 10-year survival and growth of Douglas-fir in the mixed broadleaf – shrub complex of southern interior British Columbia
title_full_unstemmed Effects of manual brushing on 10-year survival and growth of Douglas-fir in the mixed broadleaf – shrub complex of southern interior British Columbia
title_short Effects of manual brushing on 10-year survival and growth of Douglas-fir in the mixed broadleaf – shrub complex of southern interior British Columbia
title_sort effects of manual brushing on 10 year survival and growth of douglas fir in the mixed broadleaf shrub complex of southern interior british columbia
topic Douglas-fir plantations
broadleaved vegetation
manual brushing
survival
height growth
diameter growth
url https://pubs.cif-ifc.org/doi/10.5558/tfc2020-020
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AT kevinbrown effectsofmanualbrushingon10yearsurvivalandgrowthofdouglasfirinthemixedbroadleafshrubcomplexofsoutherninteriorbritishcolumbia