![Page 1: Thinning Impacts on Even-aged Stands of Eucalyptus in Brazil](https://reader035.vdocuments.net/reader035/viewer/2022081513/56816569550346895dd7f7d4/html5/thumbnails/1.jpg)
Thinning Impacts on Even-aged Stands
of Eucalyptus in Brazil
Gilciano S. Nogueira – UFVJM/Brazil Peter L. Marshall – UBC/CanadaValerie Lemay – UBC/CanadaHelio Garcia Leite – UFV/Brazil
João Carlos Chagas Campos – UFV/Brazil
June 21, 2010 Missoula, MT
Western Mensurationists’ Conference
![Page 2: Thinning Impacts on Even-aged Stands of Eucalyptus in Brazil](https://reader035.vdocuments.net/reader035/viewer/2022081513/56816569550346895dd7f7d4/html5/thumbnails/2.jpg)
Introduction
Plantation forest in Brazil: 6.6 million hectares, representing 0.8 % of the land area
From 2004 to 2008 the area in eucalyptus plantation increased by 33.1%, or 1.1 million ha
solid wood products is minimal
![Page 3: Thinning Impacts on Even-aged Stands of Eucalyptus in Brazil](https://reader035.vdocuments.net/reader035/viewer/2022081513/56816569550346895dd7f7d4/html5/thumbnails/3.jpg)
Introduction
Advances in wood technology and design have allowed various uses of eucalyptus wood as a solid product
![Page 4: Thinning Impacts on Even-aged Stands of Eucalyptus in Brazil](https://reader035.vdocuments.net/reader035/viewer/2022081513/56816569550346895dd7f7d4/html5/thumbnails/4.jpg)
Introduction
The demand for wood from large trees has been supported by illegal harvesting in native forests
Consequently, there are also few studies on the impact of thinning in stands of eucalyptus in Brazil
![Page 5: Thinning Impacts on Even-aged Stands of Eucalyptus in Brazil](https://reader035.vdocuments.net/reader035/viewer/2022081513/56816569550346895dd7f7d4/html5/thumbnails/5.jpg)
Introduction
Studies of thinning in eucalyptus are strategic for Brazil, both economically and environmentally
Thinning in eucalyptus forests can help increase Brazilian participation in the global market for solid wood products and may reduce pressure on Brazilian native forests
![Page 6: Thinning Impacts on Even-aged Stands of Eucalyptus in Brazil](https://reader035.vdocuments.net/reader035/viewer/2022081513/56816569550346895dd7f7d4/html5/thumbnails/6.jpg)
Introduction
An experiment was established to obtain a database reliable for analyzing the difference among thinning treatments and for developing growth and yield models for thinned eucalyptus stands
Requirements: - Selection of the sample units was deliberate (selective sampling), so that
representation of the medium and extreme site conditions is guaranteed
- The sample units were sufficiently large to faithfully represent the silvicultural practices applied to the remainder of the stand
![Page 7: Thinning Impacts on Even-aged Stands of Eucalyptus in Brazil](https://reader035.vdocuments.net/reader035/viewer/2022081513/56816569550346895dd7f7d4/html5/thumbnails/7.jpg)
Objective
To analyze the effect of thinning on growth of stand
variables in eucalyptus forests
![Page 8: Thinning Impacts on Even-aged Stands of Eucalyptus in Brazil](https://reader035.vdocuments.net/reader035/viewer/2022081513/56816569550346895dd7f7d4/html5/thumbnails/8.jpg)
Overview of the experiment
- Species: Eucalyptus grandis x Eucalyptus urophylla hybrid
- Location: Northeast region of Bahia State, Brazil
![Page 9: Thinning Impacts on Even-aged Stands of Eucalyptus in Brazil](https://reader035.vdocuments.net/reader035/viewer/2022081513/56816569550346895dd7f7d4/html5/thumbnails/9.jpg)
Overview of the experiment
- Planting date: June/July 1993
- Date of installation of the permanent plots: September 1995
- Company: Bahia Specialty Cellulose (BSC) (http://www.bahiaspeccell.com)
- Initial spacing between trees: 3.0 X 3.0 m
- Thinnings accomplished: two selective thinnings, in 1998 and 2004
- Final harvest: at the end of 2007
![Page 10: Thinning Impacts on Even-aged Stands of Eucalyptus in Brazil](https://reader035.vdocuments.net/reader035/viewer/2022081513/56816569550346895dd7f7d4/html5/thumbnails/10.jpg)
Experimental Design- based on level-of-growing-stock installation standards
- Located in 3 installations, comprising medium and good quality site conditions
![Page 11: Thinning Impacts on Even-aged Stands of Eucalyptus in Brazil](https://reader035.vdocuments.net/reader035/viewer/2022081513/56816569550346895dd7f7d4/html5/thumbnails/11.jpg)
Experimental Design
- Replicated randomized complete block with repeated measures- 6 blocks (two in each installation), each one involving two repetitions;
- 4 treatments, corresponding to different basal area percentages removed in each thinning :
Treatment 1: 20% without pruning;
Treatment 2: 35% without pruning;
Treatment 3: 50% without pruning;
Treatment 4: 35% with pruning up to 6.0 meters;
- Each block contained 8 permanent rectangular plots, with an area of 2,600 m2, totaling 48
plots (6 blocks x 2 repetitions x 4 treatments)
![Page 12: Thinning Impacts on Even-aged Stands of Eucalyptus in Brazil](https://reader035.vdocuments.net/reader035/viewer/2022081513/56816569550346895dd7f7d4/html5/thumbnails/12.jpg)
- Layout
Experimental Design
Block 1
Block 2
3 2
2 1
1 4
4 3I II
99,28
204,0 m
3 2
1 4
4 3
2 1III IV
99,28
204,0 m
Block 1 Block 2
Block 2Block 1A
3 2
2 1
1 4
4 3III IV
119.0 m
176.8 m
B
C
![Page 13: Thinning Impacts on Even-aged Stands of Eucalyptus in Brazil](https://reader035.vdocuments.net/reader035/viewer/2022081513/56816569550346895dd7f7d4/html5/thumbnails/13.jpg)
Experimental Design
- Replicated randomized complete block with repeated measures- 6 blocks (two in each installation), each one involving two repetitions;
- 4 treatments, corresponding to different basal area percentages removed in each thinning :
Treatment 1: 20% without pruning;
Treatment 2: 35% without pruning;
Treatment 3: 50% without pruning;
Treatment 4: 35% with pruning up to 6.0 meters;
- Each block contained 8 permanent rectangular plots, with an area of 2,600 m2, totaling 48
plots (6 blocks x 2 repetitions x 4 treatments)
- Plots were buffered by a few rows of trees on each side
![Page 14: Thinning Impacts on Even-aged Stands of Eucalyptus in Brazil](https://reader035.vdocuments.net/reader035/viewer/2022081513/56816569550346895dd7f7d4/html5/thumbnails/14.jpg)
Marked boundaries of a plot
![Page 15: Thinning Impacts on Even-aged Stands of Eucalyptus in Brazil](https://reader035.vdocuments.net/reader035/viewer/2022081513/56816569550346895dd7f7d4/html5/thumbnails/15.jpg)
Measurement Year ofmeasurement
Age (month)
Age (year) Note
1 1995 27 2.3 before 1st thinning2 1996 40 3.3 before 1st thinning3 1997 50 4.2 before 1st thinning; 1st stem analysis (6 trees per dbh class)4 1998
61 5.1after 1st thinning
5 1999 75 6.3 after 1st thinning6 2000 87 7.3 after 1st thinning7 2001 100 8.3 after 1st thinning8 2002 111 9.3 after 1st thinning9 2003 124 10.3 after 1st thinning
10 2004 136 11.3 after 1st thinning11 2005 147 12.3 after 2nd thinning12 2006 157 13.1 after 2nd thinning13 2007 164 13.7 after 2nd thinning; 2nd stem analysis (6 trees per dbh class)
- Data
Measurements
![Page 16: Thinning Impacts on Even-aged Stands of Eucalyptus in Brazil](https://reader035.vdocuments.net/reader035/viewer/2022081513/56816569550346895dd7f7d4/html5/thumbnails/16.jpg)
After 1st thinning (61 months)
After 1st thinning (87 months)
MeasurementsAfter 1st thinning (101 months)
After 2nd thinning (165 months)
![Page 17: Thinning Impacts on Even-aged Stands of Eucalyptus in Brazil](https://reader035.vdocuments.net/reader035/viewer/2022081513/56816569550346895dd7f7d4/html5/thumbnails/17.jpg)
Volume equation
HtLndbhLnVtLn 23523.1751165.1-10.28859 998.02 R
outside bark:
inside bark:
HtLndbhLnVtLn 22368.174249.1-10.39158 998.02 R
![Page 18: Thinning Impacts on Even-aged Stands of Eucalyptus in Brazil](https://reader035.vdocuments.net/reader035/viewer/2022081513/56816569550346895dd7f7d4/html5/thumbnails/18.jpg)
Volume equation
Distri b u ti o n o f Ra w re si d u a l s
E xp e cte d No rm a l
-0 .3 0 -0 .2 5 -0 .2 0 -0 .1 5 -0 .1 0 -0 .0 5 0 .0 0 0 .0 5 0 .1 0 0 .1 5 0 .2 00
2 0
4 0
6 0
8 0
1 0 0
1 2 0
1 4 0
1 6 0
1 8 0
2 0 0
No of obs
P re d i cte d vs. O b se rve d V a l u e sD e p e n d e n t va ria b le : L n V t ib
-5 .0 -4 .5 -4 .0 -3 .5 -3 .0 -2 .5 -2 .0 -1 .5 -1 .0 -0 .5 0 .0
P re d icte d V a lu e s
-5 .0
-4 .5
-4 .0
-3 .5
-3 .0
-2 .5
-2 .0
-1 .5
-1 .0
-0 .5
0 .0
Observed V
alues
9 5 % co n f id e n ce
P re d i cte d vs. Re si d u a l S co re sDe p en d e n t va ri ab l e : L n V tib
-5 .0 -4 .5 -4 .0 -3 .5 -3 .0 -2 .5 -2 .0 -1 .5 -1 .0 -0 .5 0 .0
P re d i cte d V a lu e s
-0 .2 5
-0 .2 0
-0 .1 5
-0 .1 0
-0 .0 5
0 .0 0
0 .0 5
0 .1 0
0 .1 5
0 .2 0
0 .2 5
Residuals
9 5 % co n f i de n ce
Di stri b u ti o n o f Ra w re sid u a l s E xp e cte d No rm a l
-0 .3 0 -0 .2 5 -0 .2 0 -0 .1 5 -0 .1 0 -0 .0 5 0 .0 0 0 .0 5 0 .1 0 0 .1 5 0 .2 0 0 .2 50
2 0
4 0
6 0
8 0
1 0 0
1 2 0
1 4 0
1 6 0
1 8 0
2 0 0
No of obs
P re d i cte d vs. O b se rve d V a l u e sDe p e n d e n t va ria b l e : L n V to b
-4 .5 -4 .0 -3 .5 -3 .0 -2 .5 -2 .0 -1 .5 -1 .0 -0 .5 0 .0 0 .5
P re d ic te d V a lu e s
-4 .5
-4 .0
-3 .5
-3 .0
-2 .5
-2 .0
-1 .5
-1 .0
-0 .5
0 .0
0 .5
Observed V
alues
9 5 % co n f id e n ce
P re d i c te d vs. Re sid ua l S co re sDe p e n d e n t va ri a b le : L n V to b
-5 -4 -3 -2 -1 0
P re d i cte d V a l ue s
-0 .2 5
-0 .2 0
-0 .1 5
-0 .1 0
-0 .0 5
0 .0 0
0 .0 5
0 .1 0
0 .1 5
0 .2 0
0 .2 5
Residuals
9 5 % co n fid e n ce
outside bark
inside bark
![Page 19: Thinning Impacts on Even-aged Stands of Eucalyptus in Brazil](https://reader035.vdocuments.net/reader035/viewer/2022081513/56816569550346895dd7f7d4/html5/thumbnails/19.jpg)
Height equation
dbhdbhLn
SISILnAgeAgeLnHtLn-0.016830.64171
-0.4935512.928360.00231-0.42280-29.32738
97.02 R
Installation A
dbhdbhLn
SISILnAgeAgeLnHtLn0.01233-0.54414
0.6872217.218170.00238-0.45930-38.23811
dbhdbhLn
SISILnAgeAgeLnHtLn0.03013-0.81710
0.4116412.671100.00774-0.85823-32.40495
Installation B
Installation C
97.02 R
98.02 R
![Page 20: Thinning Impacts on Even-aged Stands of Eucalyptus in Brazil](https://reader035.vdocuments.net/reader035/viewer/2022081513/56816569550346895dd7f7d4/html5/thumbnails/20.jpg)
Height equation
Distri b u ti o n o f Ra w re si d u a l s E xp e cte d No rm a l
-0 .2 0 -0 .1 6 -0 .1 2 -0 .0 8 -0 .0 4 0 .0 0 0 .0 4 0 .0 8 0 .1 2 0 .1 6 0 .2 00
1 0 0
2 0 0
3 0 0
4 0 0
5 0 0
6 0 0
7 0 0
8 0 0
No of obs
P re d i cte d vs. O b se rve d V a lu e s
De p e n d e n t va ri a b l e : L n Ht
2 .0 2 .2 2 .4 2 .6 2 .8 3 .0 3 .2 3 .4 3 .6
P re d i cte d V a l u e s
2 .0
2 .2
2 .4
2 .6
2 .8
3 .0
3 .2
3 .4
3 .6
Observed V
alues
9 5 % co n f i d e n ce
A
Distri b u ti o n o f Ra w re si d u a l s E xp e cte d No rm a l
-0 .2 0 -0 .1 6 -0 .1 2 -0 .0 8 -0 .0 4 0 .0 0 0 .0 4 0 .0 8 0 .1 2 0 .1 6 0 .2 00
1 0 0
2 0 0
3 0 0
4 0 0
5 0 0
6 0 0
7 0 0
8 0 0
No of obs
P re d i cte d vs. O b se rve d V a lu e sDe p e n d e n t va ri a b le : L n Ht
2 .0 2 .2 2 .4 2 .6 2 .8 3 .0 3 .2 3 .4 3 .6
P re d i cte d V a lu e s
2 .0
2 .2
2 .4
2 .6
2 .8
3 .0
3 .2
3 .4
3 .6
Observed V
alues
9 5 % co n fi d e n ce
P re d ic te d vs. Re si d u a l S co re sDe p e n d e n t va ria b le : L n Ht
2 .0 2 .2 2 .4 2 .6 2 .8 3 .0 3 .2 3 .4 3 .6
P re d i cte d V a lu e s
-0 .2 0
-0 .1 5
-0 .1 0
-0 .0 5
0 .0 0
0 .0 5
0 .1 0
0 .1 5
0 .2 0
Residuals
9 5 % co n fi d e n ce
B
P re d i cte d vs. Re sid u a l S co re s
2 .0 2 .2 2 .4 2 .6 2 .8 3 .0 3 .2 3 .4 3 .6
Predic ted Values
-0 .2 0
-0 .1 5
-0 .1 0
-0 .0 5
0 .0 0
0 .0 5
0 .1 0
0 .1 5
0 .2 0
Residuals
9 5 % co n fi d e n c e
![Page 21: Thinning Impacts on Even-aged Stands of Eucalyptus in Brazil](https://reader035.vdocuments.net/reader035/viewer/2022081513/56816569550346895dd7f7d4/html5/thumbnails/21.jpg)
Height equation
Distri b u ti o n o f Ra w re si d u a l s
E xp e cte d No rm a l
-0 .2 0 -0 .1 6 -0 .1 2 -0 .0 8 -0 .0 4 0 .0 0 0 .0 4 0 .0 8 0 .1 2 0 .1 6 0 .2 00
5 0
1 0 0
1 5 0
2 0 0
2 5 0
3 0 0
3 5 0
4 0 0
No of obs
P re d i cte d vs. O b se rve d V a lu e sDe pe n d e n t va ri a b le : L n H t
1 .8 2 .0 2 .2 2 .4 2 .6 2 .8 3 .0 3 .2 3 .4 3 .6
P re d i cte d V a lu e s
1 .8
2 .0
2 .2
2 .4
2 .6
2 .8
3 .0
3 .2
3 .4
3 .6
Observed V
alues
9 5 % co n fi d e n ce
P re d i cte d vs. Re sid u a l S co re s
De p e n d e n t va ri a b le : L n Ht
2 .0 2 .2 2 .4 2 .6 2 .8 3 .0 3 .2 3 .4 3 .6
P re d i c te d V a lu e s
-0 .2 0
-0 .1 5
-0 .1 0
-0 .0 5
0 .0 0
0 .0 5
0 .1 0
0 .1 5
0 .2 0
Residuals
9 5 % co n fid e n ce
C
![Page 22: Thinning Impacts on Even-aged Stands of Eucalyptus in Brazil](https://reader035.vdocuments.net/reader035/viewer/2022081513/56816569550346895dd7f7d4/html5/thumbnails/22.jpg)
Growth trendMean per treatment Individual values
![Page 23: Thinning Impacts on Even-aged Stands of Eucalyptus in Brazil](https://reader035.vdocuments.net/reader035/viewer/2022081513/56816569550346895dd7f7d4/html5/thumbnails/23.jpg)
Growth trendsMean per treatment Individual values
![Page 24: Thinning Impacts on Even-aged Stands of Eucalyptus in Brazil](https://reader035.vdocuments.net/reader035/viewer/2022081513/56816569550346895dd7f7d4/html5/thumbnails/24.jpg)
Growth trendsMean per treatment Individual values
![Page 25: Thinning Impacts on Even-aged Stands of Eucalyptus in Brazil](https://reader035.vdocuments.net/reader035/viewer/2022081513/56816569550346895dd7f7d4/html5/thumbnails/25.jpg)
Growth trendsMean per treatment Individual values
![Page 26: Thinning Impacts on Even-aged Stands of Eucalyptus in Brazil](https://reader035.vdocuments.net/reader035/viewer/2022081513/56816569550346895dd7f7d4/html5/thumbnails/26.jpg)
Analysis
Variables: - periodic monthly increment (absolute): total height, dominant height,
quadratic mean diameter and volume per tree - periodic monthly increment (percentage): basal area per hectare and
volume per hectare
Periods: A and B1
(61 to 87)3
(147 to 165)2
(87 to 137)1
(61 to 87)2
(61 to 87)
C
![Page 27: Thinning Impacts on Even-aged Stands of Eucalyptus in Brazil](https://reader035.vdocuments.net/reader035/viewer/2022081513/56816569550346895dd7f7d4/html5/thumbnails/27.jpg)
Analysis
Anova: Mixed linear model, with thinning as the whole plot factor and period as the split-plot factor
Random effect: block block*thinning Repetition(block*thinning) period period*thinning
Fixed effect: thinning
Pairwise comparisons: Bonferroni test
![Page 28: Thinning Impacts on Even-aged Stands of Eucalyptus in Brazil](https://reader035.vdocuments.net/reader035/viewer/2022081513/56816569550346895dd7f7d4/html5/thumbnails/28.jpg)
Effect on periodic increment of average total height
A B C
A: only thinning 35% and thinning 35% + pruning were equal
B and C : Only thinning 20% was different from the other treatments
There is thinning effect
![Page 29: Thinning Impacts on Even-aged Stands of Eucalyptus in Brazil](https://reader035.vdocuments.net/reader035/viewer/2022081513/56816569550346895dd7f7d4/html5/thumbnails/29.jpg)
Effect on periodic increment of dominant height
No thinning effect
![Page 30: Thinning Impacts on Even-aged Stands of Eucalyptus in Brazil](https://reader035.vdocuments.net/reader035/viewer/2022081513/56816569550346895dd7f7d4/html5/thumbnails/30.jpg)
Effect on periodic increment of quadratic mean diameter
A B C
A, B and C: only thinning 35% and thinning 35% + pruning were equal
There is thinning effect
![Page 31: Thinning Impacts on Even-aged Stands of Eucalyptus in Brazil](https://reader035.vdocuments.net/reader035/viewer/2022081513/56816569550346895dd7f7d4/html5/thumbnails/31.jpg)
Effect on periodic increment of basal area per hectare
A B C
A, B and C: only thinning 35% and thinning 35% + pruning were equal
There is thinning effect
![Page 32: Thinning Impacts on Even-aged Stands of Eucalyptus in Brazil](https://reader035.vdocuments.net/reader035/viewer/2022081513/56816569550346895dd7f7d4/html5/thumbnails/32.jpg)
Effect on periodic increment of volume per hectare
A B C
A, B and C: only thinning 35% and thinning 35% + pruning were equal
There is thinning effect
![Page 33: Thinning Impacts on Even-aged Stands of Eucalyptus in Brazil](https://reader035.vdocuments.net/reader035/viewer/2022081513/56816569550346895dd7f7d4/html5/thumbnails/33.jpg)
Effect on periodic increment of volume per tree
A
A, B and C: only thinning 35% and thinning 35% + pruning were equal
There is thinning effect
B C
![Page 34: Thinning Impacts on Even-aged Stands of Eucalyptus in Brazil](https://reader035.vdocuments.net/reader035/viewer/2022081513/56816569550346895dd7f7d4/html5/thumbnails/34.jpg)
Conclusion
No surprise!
![Page 35: Thinning Impacts on Even-aged Stands of Eucalyptus in Brazil](https://reader035.vdocuments.net/reader035/viewer/2022081513/56816569550346895dd7f7d4/html5/thumbnails/35.jpg)
Conclusion
Thinning affected the growth of total height, diameter, basal area per hectare, total volume per tree and total volume per hectare, but did not affect the growth of dominant height
Thinning prevented regular tree mortality
Prunning did not affect the growth trend of the variables analyzed