van Doorn et al. 2011_Links between biomass and tree demography_SUPPL

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					 1   Supplementary Material
 2


 3   Tree census protocols


 4           For the 13,981 trees in our database, we encountered four types of tree-accounting

 5   problems: moved or missing plot centers, “dead” trees returning to life, lost trees (tags that could

 6   not be found), and missed trees in the original survey (trees measured for the first time in the

 7   resurvey but too large to be considered new recruits).


 8          Out of a total of 371 plots, we experienced three moved stakes (one of which was

 9   obviously chewed up by an animal) and one entirely missing stake. In these cases, we relocated

10   the plot center by projecting the old boundaries from the position of the tagged trees. In only one

11   of the four cases was there any uncertainty about the specific location of the plot center. To

12   prevent this problem in the future, two witness trees were chosen in each plot. The bearing and

13   distance was recorded from the witness trees to the plot center.


14          Eight trees were recorded as dead in the original survey (8/1613 or 0.5%) but upon

15   resurvey were found to be alive (i.e. at least one live leaf). Tree status was changed to alive in

16   1995/6. Given the possibility that recently defoliated trees may re-leaf and survive, this source of

17   error cannot be completely eliminated given our criteria for determining the vitality of trees.

18          To mitigate the problem of lost stems, we ranked all tagged trees in the original survey

19   based on the certainty with which we knew their fate:

20         0: we found the tree with the tag




                                                                                                          1
21         1: probable; we found the tree in the right place and it was approximately the correct size

22          and species

23         2: no trace; we never found a probable tree after 15 person-minutes of dedicated

24          searching (3 people searching for 5 minutes each or 1 person searching for 15 minutes)

25

26          Of the 13,981 trees in the original inventory, 97% still had a tag (find rank = 0) leaving

27   455 “lost” trees. Of these trees, 421 lacked tags but fit the description of a tree in the inventory

28   (find rank = 1). The remaining 34 trees could not be found after searching (find rank = 2) and

29   were assumed to be dead and downed (tree status = 6). Most of these 34 trees were relatively

30   small < 15 cm dbh) and located in dense forests and/or steep terrain.

31          “Missed” trees were live untagged trees that should have been large enough to be counted

32   in the original census but had not been inventoried. We considered the maximum possible

33   growth rate to be a 4 cm absolute diameter increment over 10 years – a maximum based on the

34   long-term growth records in HBEF (2007). However we did not consider every untagged tree in

35   the plot  14 cm dbh a missed tree. We defined a toroidal buffer zone that included the area

36   between the perimeter of the plot (12.62 m radius) and the perimeter of an “inner” plot 12.22 m

37   radius. We used this buffer zone to differentiate between trees that were truly missed in the

38   original survey and trees that may have been intentionally excluded because there were

39   considered outside of the plot. Our edge buffer assumes a 3% linear error in radial measurements

40   (6% error in area determination). Only trees  14 cm found outside the buffer zone (from the

41   center until 12.4 m from the center) were tagged and noted as missing in the original survey. For

42   example, a 15 cm tree at 12.1 m from the center would be tagged but a 15 cm tree 12.5 m from

43   the center would be ignored. By this protocol, 79 live untagged trees, corresponding to 0.06% of

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44   all measured stems, were too large to be counted as recruits, meaning they must have been

45   missed in the original census. We created species-specific growth regressions to back-calculate

46   the dbh of the missed trees in 1995/6. This protocol for handling missed trees avoids a potential

47   accounting bias common to long-term forest plot studies. During the second inventory, we did

48   not check for trees that were included in the original survey but may be outside of the plot

49   boundary. It was simply too time consuming. Thus without an edge buffer zone, we would only

50   include missing trees but have no means to determine if existing tagged trees should be excluded.

51          We followed a strict protocol in measurement of tree diameters. We used a height pole to

52   determine breast height (1.37 m) and always recorded dbh from the uphill side of the tree.

53   Exceptional cases such as clumped, split, or wounded trees were dealt with by the following

54   rules: If more than one stem originated from the same root system, each stem 10-cm was

55   measured separately and given a unique tag. Split trees were counted as two trees if split below

56   breast height, but only as one tree if split above. Trees wounded at breast height were either

57   measured directly above or below the wound, depending on which would give the most

58   representative measure of the tree’s volume. Data recorders had access to the original data and

59   would check for “unusual” changes in diameter growth, i.e. > 3 cm increment or negative

60   growth. The data collector would be asked to check the measurement (without being told the

61   original measurement) and then asked to report any abnormalities (e.g., peeling bark, bulge in

62   trunk). The second measurement was used, regardless if the discrepancy persisted. Any

63   abnormalities in the stem that may influence dbh were recorded. This approach was designed to

64   minimize measurement error without introducing bias.




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65   Biomass estimates

66

67          Stem volume was computed using species-specific allometric equations calculated for

68   trees harvested within Hubbard Brook Valley (Siccama et al. 1994 ; Whittaker et al. 1974). For

69   the three most important species in the Valley, separate equations were derived for trees sampled

70   across the elevation gradient. Bole parabolic volume was chosen as the best indicator of biomass.

71   Less important species that were not specifically sampled, were assigned equations for

72   morphologically similar species.

73          The general form of the equation is:

74


75   [S1]

76

77   where height is in centimeters, dbh is in centimeters, and parabolic volume is in cm3. Tree height

78   was estimated from a set of species- and elevation-specific allometric equations that predict

79   height as a function of species, dbh and elevation. The elevation bands are comprised of low (<

80   630 m), medium (630-710 m), and high (> 710 m). A complete table of coefficients is attached

81   (Table S1). The equation form for balsam fir height is linear:

82

83   [S2]

84

85   where a and b are estimated parameters. The equation form for all other species heights is

86   asymptotic:

87

                                                                                                       4
 88   [S3]

 89

 90   where x0 is the intercept and a and b are estimated parameters.

 91          Once the parabolic volume of each tree was calculated, we applied the biomass equations

 92   (Table S2) taken from Whittaker et al. (1974) and Siccama et al. (1994). The general form is:

 93

 94   [S4]

 95

 96   where PV is the parabolic volume in cm3. A biomass estimate is calculated for each part of a

 97   tree: lightwood, darkwood, wood weight, bark weight, branch, dead branch, current twigs and

 98   leaves, and root system. Darkwood and lightwood are calculated and converted to proportions,

 99   which are then applied to the wood mass estimate and are called stem weight. It is necessary to

100   separate current twig and leaf equations since the twigs stay on the trees and the leaves fall off

101   (Whittaker et al. 1974). Additionally, old needle weight was estimated for conifers (Siccama et

102   al. 1994). The sum of the parts (stem, bark, branch, dead branch, current twigs and leaves, old

103   needle, root system) was then used to calculate total biomass. Standing dead and snags were

104   discounted with rotting factors for different biomass components.

105          We calculated total live biomass of the overall forest to be able to directly compare to

106   other studies, but for the population level analyses, we only report aboveground biomass, since

107   belowground biomass tracks aboveground (based on the equations) and aboveground biomass

108   allometry has been validated (Arthur et al. 2001; Fahey et al. 2005; Siccama et al. 1994). In the

109   validation study, an independent estimate of aboveground biomass in HBEF was compared with

110   allometric estimates. The allometric and measured estimates of aboveground biomass did not

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111   differ significantly (Arthur et al. 2001). In addition, most of the official reported biomass

112   estimates from Hubbard Brook only include aboveground biomass.


113   Uncertainty analysis

114

115          To detect statistically relevant changes in forest biomass and tree demography, we

116   analyzed the uncertainty associated with key metrics. Non-overlap of 95% confidence intervals

117   (or their Bayesian equivalent, credibility intervals) was used as the standard of significant

118   change.

119          Fahey et al. (2005) described the error propagation techniques and accuracy assessment

120   for aboveground tree biomass estimates at Hubbard Brook. Briefly, they applied Monte Carlo

121   simulation (Fahey and Knapp 2007) to quantify the propagation of errors in plot-level estimates

122   of tree biomass. Sources of uncertainty include measurement error, sampling error, and

123   prediction error associated with two allometric equations (dbh-to-height, volume-to-mass). On

124   average the relative root mean square error (i.e., precision) of plot-level estimates was ± 34%. In

125   a stand-level comparison between allometric estimates of biomass (with error propagation) and

126   whole-tree harvest estimates (biomass weighed), the two approaches were within 3% (Fahey et

127   al. 2005). Note that this validation only applies to the aboveground biomass. Thus we only use

128   aboveground biomass for statistical inferences. In all cases, we ran 1000 Monte Carlo

129   simulations where the plot-level estimates varied by 34%. We report the mean value and the 2.5th

130   and 97.5th percentile.

131          We used a hierarchical Bayesian approach to calculate the uncertainty in the mortality

132   estimates. We followed the rationale described in Condit et al. (2006) but modified the


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133   probability distributions to fit our data. At the species level, mortality was distributed as a

134   binomial probability – the tree is either dead or alive. The binomial uncertainty is based on the

135   observed mortality rate and the number of individuals. At the community level, we observed an

136   exponential distribution of annual mortalities for the 19 species in our sample. Only one

137   parameter needs to fit for the exponential distribution – the decay constant. The likelihood for the

138   entire community is the product of the species level binomial probability and the community

139   level exponential probability. Bayes theorem is used to define this joint probability distribution.

140   As described by Condit et al. (2006), the probability of observations for a single species is

141   integrated over every possible decay constant discounting each by the community-wide

142   probability.

143          We used a similar approach to quantify the uncertainty in recruitment and relative

144   diameter growth. For recruitment, we first had to develop a species level probability distribution.

145   For each species, there were 371 observations (i.e. each plot) with values = 0. All species, even

146   the common ones, had distributions with many zeroes. Moreover, the observed value did not

147   account for the chance that a recruit was missed during the interval .Therefore we simulated a

148   normal distribution for each species by randomly sampling the observed distribution with

149   replacement 1000 times. For each run we also estimated the chance that a recruit was missed

150   during the interval by using the observed rate (4.7%) from Siccama et al. (2007). The

151   community-level distribution of recruitment (recruitment rates for the 11 species with recruits)

152   most closely approximated a uniform distribution – all outcomes are equally likely. Thus it

153   provides no constraint on the species-level parameters. But for the sake of consistency with our

154   demographic analyses, we followed through with the hierarchical analysis. For relative growth,




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155   both the within-species and between-species distributions followed a log-normal distribution –

156   the same distributions used in Condit et al. (2006) to calculate uncertainty in relative growth.

157          The Markov Chain Monte Carlo technique with the Gibbs sampler was used to solve

158   numerically the integration and to fit the parameters. The analysis was implemented in the R

159   statistical package using (modified) scripts provided by Condit et al. (2006). We ran the Gibbs

160   sampler for 6,000 steps and stored the last 5,000. The sampler routinely converged in < 100

161   steps. Best estimates of mortality and recruitment were the means of the stored chains.

162   Credibility intervals (Clark 2005) were taken as the 2.5th and 97.5th percentiles of the chains.




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References

Arthur, M.A., Hamburg, S.P., and Siccama, T.G. 2001. Validating allometric estimates of aboveground

living biomass and nutrient contents of a northern hardwood forest. Can. J. For. Res. 31(1): 11-17.


Clark, J.S. 2005. Ideas and Perspectives: Why environmental scientists are becoming Bayesians. Ecol.

Lett. 8(1): 2-14.


Condit, R., Ashton, P., Bunyavejchewin, S., Dattaraja, H., Davies, S., Esufali, S., Ewango, C., Foster, R.,

Gunatilleke, I., and Gunatilleke, C. 2006. The importance of demographic niches to tree diversity.

Science 313(5783): 98.


Fahey, T.J., and Knapp, A.K. 2007. Principles and standards for measuring primary production. Oxford

University Press.


Fahey, T.J., Siccama, T.G., Driscoll, C.T., Likens, G.E., Campbell, J., Johnson, C.E., Battles, J.J., Aber, J.D.,

Cole, J.J., Fisk, M.C., Groffman, P.M., Hamburg, S.P., Holmes, R.T., Schwarz, P.A., and Yanai, R.D. 2005.

The biogeochemistry of carbon at Hubbard Brook. Biogeochemistry 75(1): 109-176.


Siccama, T.G., Fahey, T.J., Johnson, C.E., Sherry, T.W., Denny, E.G., Girdler, E.B., Likens, G.E., and

Schwarz, P.A. 2007. Population and biomass dynamics of trees in a northern hardwood forest at

Hubbard Brook. Can. J. For. Res. 37(4): 737-749.


Siccama, T.G., Hamburg, S.P., Arthur, M.A., Yanai, R.D., Bormann, F.H., and Likens, G.E. 1994.

Corrections to allometric equations and plant tissue chemistry for Hubbard Brook Experimental Forest.

Ecology 75(1): 246-248.




                                                                                                                    9
Whittaker, R.H., Bormann, F.H., Likens, G.E., and Siccama, T.G. 1974. The Hubbard Brook ecosystem

study: Forest biomass and production. Ecol. Monogr. 44(2): 233-254.




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Table S1. Coefficients for height equations by species and elevation in HBEF. The coefficients for
sugar maple also apply to bigtooth aspen, black cherry, grey birch, shadbush and quaking aspen.
Elevation codes refer to: H, high: > 710 m; M, mid: 630-710 m; L, low: < 630 m. The equation form
for balsam fir is: height in meters = a + b∙dbh. For all other species, the equation form is: height
                           -b∙ dbh
in meters = x0 + a ∙ (1 - e        ).
    Species         xo          a         b     Elevation
Sugar maple        1.37     21.5794     0.061       H
                   1.37      23.855    0.0585      M
                   1.37     25.5443    0.0599       L
Beech              1.37     19.1258    0.0627       H
                   1.37      21.676    0.0628      M
                   1.37     25.6262    0.0562       L
Yellow birch       1.37     19.5743    0.0572       H
                   1.37     20.8744    0.0739      M
                   1.37     22.9096    0.0716       L
White ash          1.37      29.534    0.1121       H
                   1.37      29.534    0.1121      M
                   1.37      29.534    0.1121       L
Mountain maple     1.37     29.9598    0.0396       H
                   1.37     29.9598    0.0396      M
                   1.37     29.9598    0.0396       L
Striped maple      1.37     29.9598    0.0396       H
                   1.37     29.9598    0.0396      M
                   1.37     29.9598    0.0396       L
Choke cherry       1.37     19.5743    0.0572       H
                   1.37     19.5743    0.0572      M
                   1.37     19.5743    0.0572       L
Pin cherry         1.37     19.5743    0.0572       H
                   1.37     19.5743    0.0572      M
                   1.37     19.5743    0.0572       L
Balsam fir           0       2.0274    0.5215       H
                     0       2.0274    0.5215      M
                     0       2.0274    0.5215       L
Red spruce         1.37     25.8714    0.0361       H
                   1.37     26.8832    0.0429      M
                   1.37      25.937    0.0533       L
Paper birch        1.37     16.3946    0.0798       H
                   1.37     25.3076    0.0605      M
                   1.37     25.3076    0.0605       L
Mountain ash       1.37     29.9598    0.0396       H
                   1.37     29.9598    0.0396      M
                   1.37     29.9598    0.0396       L
Red maple          1.37     23.6571     0.076       H
                   1.37     23.6571     0.076      M
                   1.37     23.6571     0.076       L
Hemlock            1.37     25.8714    0.0361       H
                   1.37     25.8714    0.0361      M
                   1.37     25.8714    0.0361       L


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Table S2. Coefficients for parabolic volume equations by species and elevation in HBEF. The coefficients (coeff.) for sugar maple also
apply to bigtooth aspen, black cherry, grey birch, shadbush and quaking aspen. Column headings: LIGHT= lightwood, DARK=
darkwood, WW= wood weight, WB= bark weight, BRDW= branch weight, TLDW= dead branch weight, CTLGR= current twig and leaf
weight, RSDW= root system weight, MASS= total mass.
High-elevation (>710 m)
Coeff.       Species         LIGHT      DARK       WW           WB      BRDW        TLDW       CTLGR      RSDW          MASS
  a Sugar maple             0.16964    -3.1448    0.1073     -0.8589    -2.3983    -3.5027      -0.755   -0.25366      0.08781
  b                         0.91478     1.2391    0.9317      0.9501    1.3276     1.3619       0.8341   0.912735     0.993031
  a Beech                    0.7826    -3.6197   0.39268    -0.51047   -0.66119    -1.9559     -0.1251    0.11505      0.57189
  b                         0.77499     1.3576    0.8721      0.8202    0.9922     1.0563       0.7044    0.84058      0.89184
  a Yellow birch           0.086262    -6.4342   -0.2658      -1.124    -1.4132    -4.1681     -0.1649   -0.77214      -0.2195
  b                         0.90697     1.9188    0.9938       0.986    1.1616      1.478       0.7272     1.0103       1.0486
  a White ash                0.7826    -3.6197   0.39268    -0.51047   -0.66119    -1.9559     -0.1251    0.11505      0.57189
  b                         0.77499     1.3576    0.8721      0.8202    0.9922     1.0563       0.7044    0.84058      0.89184
  a Mountain maple          0.14647    -7.9527    0.1465     -0.3176    -1.4382    -1.5962     -0.2574     0.7017      0.64369
  b                         0.88014     1.3293    0.8801      0.7958    1.1896     1.0489       0.6757     0.6767      0.84777
  a Striped maple           0.14647    -7.9527    0.1465     -0.3176    -1.4382    -1.5962     -0.2574     0.7017      0.64369
  b                         0.88014     1.3293    0.8801      0.7958    1.1896     1.0489       0.6757     0.6767      0.84777
  a Pin cherry             0.086262    -6.4342   -0.2658      -1.124    -1.4132    -4.1681     -0.1649   -0.77214      -0.2195
  b                         0.90697     1.9188    0.9938       0.986    1.1616      1.478       0.7272     1.0103       1.0486
  a Choke cherry           0.086262    -6.4342   -0.2658      -1.124    -1.4132    -4.1681     -0.1649   -0.77214      -0.2195
  b                         0.90697     1.9188    0.9938       0.986    1.1616      1.478       0.7272     1.0103       1.0486
  a Balsam fir              0.53664    -3.8215   -0.0847     -0.8024    -0.6338    -0.1339     -0.1375      0.436       0.9711
  b                         0.80794     1.2345    0.9314       0.901    0.9188     0.7636       0.5941     0.7806       0.7926
  a Red spruce              0.53664    -3.8215    0.5048      0.1198    -0.6338    -0.1339     -0.1375      0.436       0.9711
  b                         0.80794     1.2345    0.8138      0.7259    0.9188     0.7636       0.5941     0.7806       0.7926
  a White birch            0.086262    -6.4342   -0.2658      -1.124    -1.4132    -4.1681     -0.1649   -0.77214      -0.2195
  b                         0.90697     1.9188    0.9938       0.986    1.1616      1.478       0.7272     1.0103       1.0486
  a Mountain ash            0.14647    -7.9527    0.1465     -0.3176    -1.4382    -1.5962     -0.2574     0.7017      0.64369
  b                         0.88014     1.3293    0.8801      0.7958    1.1896     1.0489       0.6757     0.6767      0.84777
  a Red maple               0.16964    -3.1448    0.1073     -0.8589    -2.3983    -3.5027      -0.755   -0.25366      0.08781
  b                         0.91478     1.2391    0.9317      0.9501    1.3276     1.3619       0.8341   0.912735     0.993031
  a Hemlock                 0.53664    -3.8215    0.5048      0.1198    -0.6338    -0.1339     -0.1375      0.436       0.9711
  b                         0.80794     1.2345    0.8138      0.7259    0.9188     0.7636       0.5941     0.7806       0.7926


                                                                                                                                         12
Mid-elevation (630-710 m)
Coeff.                        LIGHT     DARK        WW          WB      BRDW       TLDW      CTLGR      RSDW        MASS
  a Sugar maple             0.014922   -2.9012   0.003485   -0.94106    -2.6141   -2.3924   -0.93109    -0.1772   0.062109
  b                          0.94275    1.1023    0.94668    0.94726     1.3203   1.0571     0.84681    0.88769    0.98263
  a Beech                    0.32927   -3.0607    0.18266   -0.54617   -0.35331   -2.6934    0.42891    0.47863    0.61439
  b                           0.8760    1.2381     0.9147    0.83149    0.93443   1.2192     0.58175     0.7797    0.88721
  a Yellow birch            0.093657   -5.1973    -0.0113   -0.69069    -1.4015   -2.3924   -0.41346   -0.86498   -0.07977
  b                          0.90745    1.6498    0.93533    0.88984     1.1498   1.0308     0.73652      1.019     1.0122
  a White ash                0.32927   -3.0607    0.18266   -0.54617   -0.35331   -2.6934    0.42891    0.47863    0.61439
  b                            0.876    1.2381     0.9147    0.83149    0.93443   1.2192     0.58175     0.7797    0.88721
  a Mountain maple           0.14647   -7.9527     0.1465    -0.3176    -1.4382   -1.5962    -0.2574     0.7017    0.64369
  b                          0.88014    1.3293     0.8801     0.7958     1.1896   1.0489      0.6757     0.6767    0.84777
  a Striped maple            0.14647   -7.9527     0.1465    -0.3176    -1.4382   -1.5962    -0.2574     0.7017    0.64369
  b                          0.88014    1.3293     0.8801     0.7958     1.1896   1.0489      0.6757     0.6767    0.84777
  a Pin cherry              0.093657   -5.1973    -0.2658     -1.124    -1.4132   -4.1681    -0.1649   -0.77214    -0.2195
  b                          0.90745    1.6498     0.9938      0.986     1.1616    1.478      0.7272     1.0103     1.0486
  a Choke cherry            0.093657   -5.1973    -0.2658     -1.124    -1.4132   -4.1681    -0.1649   -0.77214    -0.2195
  b                          0.90745    1.6498     0.9938      0.986     1.1616    1.478      0.7272     1.0103     1.0486
  a Balsam fir               0.53664   -3.8215    -0.0847    -0.8024    -0.6338   -0.1339    -0.1375      0.436     0.9711
  b                          0.80794    1.2345     0.9314      0.901     0.9188   0.7636      0.5941     0.7806     0.7926
  a Red spruce               0.53664   -3.8215     0.5048     0.1198    -0.6338   -0.1339    -0.1375      0.436     0.9711
  b                          0.80794    1.2345     0.8138     0.7259     0.9188   0.7636      0.5941     0.7806     0.7926
  a White birch             0.093657   -5.1973    -0.0113   -0.69069    -1.4015   -2.3924   -0.41346   -0.86498   -0.07977
  b                          0.90745    1.6498    0.93533    0.88984     1.1498   1.0308     0.73652      1.019     1.0122
  a Mountain ash             0.14647   -7.9527     0.1465    -0.3176    -1.4382   -1.5962    -0.2574     0.7017    0.64369
  b                          0.88014    1.3293     0.8801     0.7958     1.1896   1.0489      0.6757     0.6767    0.84777
  a Red maple               0.014922   -2.9012   0.003485   -0.94106    -2.6141   -2.3924   -0.93109    -0.1772   0.062109
  b                          0.94275    1.1023    0.94668    0.94726     1.3203   1.0571     0.84681    0.88769    0.98263
  a Hemlock                  0.53664   -3.8215     0.5048     0.1198    -0.6338   -0.1339    -0.1375      0.436     0.9711
  b                          0.80794    1.2345     0.8138     0.7259     0.9188   0.7636      0.5941     0.7806     0.7926




                                                                                                                             13
Low-elevation (<630 m)
Coeff.                    LIGHT     DARK        WW          WB      BRDW       TLDW      CTLGR     RSDW        MASS
  a Sugar maple          0.05954   -3.2323   0.010929   -0.50204    -1.3983   -1.5819    -0.2618  -0.06452   3 0.2574
  b                      0.92549    1.1482    0.93825    0.87625     1.0759   0.7842     0.70421   0.85243   0.93604
  a Beech                0.12799   -3.6915   -0.01576   -0.89476   -0.76433   -2.2116   0.015976 –0.081778   0.23996
  b                       0.9143    1.2857     0.9517    0.89931    1.02813   1.0802     0.66166   0.86955   0.95696
  a Yellow birch         0.26066   -3.6229   0.209363   -0.20868   -1.09461   -2.6546   -0.59274 -0.03825    0.38366
  b                      0.88149    1.3459    0.89722    0.81439     1.0526   1.0996     0.77028   0.85765   0.92187
  a White ash            0.12799   -3.6915   -0.01576   -0.89476   -0.76433   -2.2116   0.015976 –0.081778   0.23996
  b                       0.9143    1.2857     0.9517    0.89931    1.02813   1.0802     0.66166   0.86955   0.95696
  a Mountain maple       0.14647   -7.9527     0.1465    -0.3176    -1.4382   -1.5962    -0.2574    0.7017   0.64369
  b                      0.88014    1.3293     0.8801     0.7958     1.1896   1.0489      0.6757    0.6767   0.84777
  a Striped maple        0.14647   -7.9527     0.1465    -0.3176    -1.4382   -1.5962    -0.2574    0.7017   0.64369
  b                      0.88014    1.3293     0.8801     0.7958     1.1896   1.0489      0.6757    0.6767   0.84777
  a Pin cherry           0.26066   -3.6229    -0.2658     -1.124    -1.4132   -4.1681    -0.1649  -0.77214    -0.2195
  b                      0.88149    1.3459     0.9938      0.986     1.1616    1.478      0.7272    1.0103    1.0486
  a Choke cherry         0.26066   -3.6229    -0.2658     -1.124    -1.4132   -4.1681    -0.1649  -0.77214    -0.2195
  b                      0.88149    1.3459     0.9938      0.986     1.1616    1.478      0.7272    1.0103    1.0486
  a Balsam fir           0.53664   -3.8215    -0.0847    -0.8024    -0.6338   -0.1339    -0.1375     0.436    0.9711
  b                      0.80794    1.2345     0.9314      0.901     0.9188   0.7636      0.5941    0.7806    0.7926
  a Red spruce           0.53664   -3.8215     0.5048     0.1198    -0.6338   -0.1339    -0.1375     0.436    0.9711
  b                      0.80794    1.2345     0.8138     0.7259     0.9188   0.7636      0.5941    0.7806    0.7926
  a White birch          0.26066   -3.6229   0.209363   -0.20868   -1.09461   -2.6546   -0.59274 -0.03825    0.38366
  b                      0.88149    1.3459    0.89722    0.81439     1.0526   1.0996     0.77028   0.85765   0.92187
  a Mountain ash         0.14647   -7.9527     0.1465    -0.3176    -1.4382   -1.5962    -0.2574    0.7017   0.64369
  b                      0.88014    1.3293     0.8801     0.7958     1.1896   1.0489      0.6757    0.6767   0.84777
  a Red maple            0.05954   -3.2323   0.010929   -0.50204    -1.3983   -1.5819    -0.2618  -0.06452   3 0.2574
  b                      0.92549    1.1482    0.93825    0.87625     1.0759   0.7842     0.70421   0.85243   0.93604
  a Hemlock              0.53664   -3.8215     0.5048     0.1198    -0.6338   -0.1339    -0.1375     0.436    0.9711
  b                      0.80794    1.2345     0.8138     0.7259     0.9188   0.7636      0.5941    0.7806    0.7926




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