Open Collections

UBC Faculty Research and Publications

A comparison of Grand fir and Douglas-fir growth performance in the Elk River Tree Farm Klinka, Karel; Bernardy, Paul; Chourmouzis, Christine 1998-04-11

You don't seem to have a PDF reader installed, try download the pdf

Item Metadata


52383-SSES016.pdf [ 101.23kB ]
JSON: 52383-1.0107266.json
JSON-LD: 52383-1.0107266-ld.json
RDF/XML (Pretty): 52383-1.0107266-rdf.xml
RDF/JSON: 52383-1.0107266-rdf.json
Turtle: 52383-1.0107266-turtle.txt
N-Triples: 52383-1.0107266-rdf-ntriples.txt
Original Record: 52383-1.0107266-source.json
Full Text

Full Text

Scientia Silvica Extension Series, Number  16, 1998A Comparison of Grand Fir and Douglas-Fir Growth Performancein the Elk River Tree FarmIntroductionThe superior growth of grand fir (Abies grandis) compared toDouglas-fir (Pseudostuga menziesii) on suitable coastal siteshas previously been recognized  on the  basis of qualitativeobservations with little empirical evidence.  For example, D.E.McMullan (1977, pers. comm.) reported 18% higher volumefor a grand fir tree of the same height and age as a 108-year-old Douglas-fir plus tree  (No. 622)This study  was undertaken by Bernardy (1988)  to examinepossible differences in the growth of grand fir  and Douglas-fir  growing in  a mixed 40-year-old plantation of unknownorigin.  Trends in height, diameter and annual volume incrementbetween the two species over time were examined.  Expectedgrowth performance (i.e.  volume and form)  of each specieswas inferred from trends identified at time of sampling.MethodsThe plantation is  located  in  the  Elk River Tree  Farm on theQuinsam River flats,  Vancouver  Island.  The site had a stronglyfluctuating water table, the soil moisture regime (SMR) wasestimated as winter-wet and summer-fresh, and the soil nutrientregime  was estimated as rich.    Such special SMRs have notbeen considered in characterizing the quality of coastal forestsites until recently.Stem analysis was carried out on ten trees of each species withsample  trees  chosen to  represent dominant and codominanttrees.  Height and diameter at breast height was measured for20 trees of each species and the average calculated.Annual height increment for each of the last 15 years (1973-1987) and length of live crown were also recorded.  The treeswere then sectioned and disks collected at 30, 60, and 130 cmabove germination point with another eight disks sampled atequal spacing between 130 cm and the  top  of the  tree.  Barkthickness  and the  width of all  rings  were measured on eachdisc.  These measurements were then used to calculate annualdiameter and volume increments.ResultsMean growth performance data and standard deviations for eachspecies are given in Table 1. No significant differences wereidentified in total height, diameter at breast height, or lengthof live crown.  Significant differences were also not apparentwhen these variables were examined over the 1973-1987 periodFigure 1. Trends in cumulative annual height increment betweenDouglas-fir and grand fir (1972 - 1987).Figure 2. Trends in cumulative annual diameter increment betweenDouglas-fir and grand fir (1972 - 1987).141618202224262830'72 '73 '74 '75 '76 '77 '78 '79 '80 '81 '82 '83 '84 '85 '86 '87Grand firDouglas- firHeight (m)Date 222426283032343638core '75 '76 '77 '78 '79 '80 '81 '82 '83 '84 '85 '86Grand firDouglas- firDiameter (cm)Date s t)rtt)fen)fslhr)lem3)r .)3)5)3)6)8)r .)2)0)5)6)3)Table 1. Mean (std. dev.) growth performance measures forDouglas-fir and grand fir.using repeated-measures analysis of variance (ANOVA).  Theslightly  greater height and diameter of grand fir  appears torepresent  a continuing trend  (Figures 1 and 2).    The similarlive  crown lengths  in  both species  may imply  that  shadetolerance in this environment is comparable between the twospecies.Scientia Silvicais published by the Forest Sciences Department,The University of British Columbia, ISSN 1209-952XEditor: Karel Klinka ( Paul Bernardy ( and design: Christine Chourmouzis ( support: Natural Science and Engineering Council of CanadaCopies available  orK. Klinka, Forest Sciences Department, UBC,3036-2424 Main Mall, Vancouver, BC, V6T 1Z4Changes in diameter with height were evaluated in each species.Taper was found to be approximately the same.  Regression ofdiameter against height showed  Douglas-fir decreased indiameter by 1.33 cm for  each meter of height and grand firdecreased an average of 1.30 cm for each meter of height.  Whenthe  average diameter of each species  was plotted againstsampling height the two species were indistinguishable.DiscussionEstimates of growth performance prior to  this  stand reachingage 28 would have led to different results.  The early successof Douglas-fir on this  site  appears to  be in  decline whereasgrand fir appears to be performing consistently well.  Grand firnow has a greater total  height and diameter (not  significant)and total volume (p <0.01).  Grand fir growth rate continues toincrease at a greater rate than Douglas-fir growth rate.  Grandfir also had better general form, with smaller and fewer branchesthan  Douglas-fir.    Therefore, the  growth of grand fir  prior to30 years of age does not appear to give a reliable prediction ofits potential productivity.It  must be noted that  this  study  has investigated  growthperformance on only one site,  using a small  sample  size.Caution should be exercised when considering other sites andstand conditions.  However, in the absence of growth data forthe  coastal population of grand fir,  these  results  represent  avaluable initial  contribution to  tree  species  selection  andsuggest further investigation is warranted, particularly on siteswhere grand-fir may be a more productive tree than Douglas-fir.ReferencesBernardy,  P.  1988.  Classification  and  rehabilitationinterpretations of hardwood ecosystems in the Elk River TreeFarm. M.Sc. thesis, University of  British Columbia, Vancouver,BC. 101 pp.Grand fir had a consistently greater annual volume incrementsince 1974.  If this trend continues grand fir will soon have amuch greater volume than Douglas-fir on an individual tree basis(Figure  4).   The greater current annual volume increment  ofgrand fir relative to Douglas-fir was significantly different overtime  based on repeated  measures ANOVA (p  <0.001).   Thecontribution of each year was relatively consistent over the 12year period.Douglas-fir trees  had  significantly  poorer  branchingcharacteristics than  grand fir.    Douglas-fir has a significantlygreater number of branches per whorl (p <0.006) and branchesof larger  diameter (p  <0.003).Mean total volume for grand fir was approximately 12% higherthan that of Douglas-fir at time of sampling.  However, the meantotal  volume in  1974 was 24% greater for  Douglas-fir thangrand fir (Figure 3).Figure 3. Trends in cumulative volume increment between Douglas-fir and grand fir (1972 - 1987).Figure 4. Trends in annual increment between Douglas-fir and grandfir (1972 - 1987). '75 '76 '77 '78 '79 '80 '81 '82 '83 '84 '85 '86Grand firDouglas- firVolume (m3 )Date '75 '76 '77 '78 '79 '80 '81 '82 '83 '84 '85 '86Volume (m3 )Date Grand firDouglas-fir


Citation Scheme:


Citations by CSL (citeproc-js)

Usage Statistics



Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            async >
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:


Related Items