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Effect of wood ash fertilization on soil chemicalproperties and stand nutrient status and growth ofsome coniferous stands in FinlandAnna Saarsalmi , Eino Mälkönen & Mikko Kukkolaa Vantaa Research Centre , Finnish Forest Research Institute , P.O. Box 18, FI-01301,Vantaa, FinlandE-mail:Published online: 18 Feb 2007.
To cite this article: Anna Saarsalmi , Eino Mälkönen & Mikko Kukkola (2004) Effect of wood ash fertilization on soilchemical properties and stand nutrient status and growth of some coniferous stands in Finland, Scandinavian Journal ofForest Research, 19:3, 217-233, DOI: 10.1080/02827580410024124
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Effect of Wood Ash Fertilization on Soil Chemical Properties andStand Nutrient Status and Growth of Some Coniferous Stands inFinland
ANNA SAARSALMI, EINO MALKONEN and MIKKO KUKKOLA
Vantaa Research Centre, Finnish Forest Research Institute, P.O. Box 18, FI-01301 Vantaa, Finland
Saarsalmi, A., Malkonen, E. and Kukkola, M. (Vantaa Research Centre, Finnish Forest Research
Institute, P.O. Box 18, FI-01301 Vantaa, Finland). Effect of wood ash fertilization on soil chemical
properties and stand nutrient status and growth of some coniferous stands in Finland .
Received July 14, 2003. Accepted Dec. 29, 2003. Scand. J. For. Res. 19: 217�/233, 2004.
The effects of wood ash or wood ash plus nitrogen (N) fertilization on soil chemical properties,
needle nutrient concentrations and tree growth were studied in five coniferous stands, aged
31�/75 yrs, after 5 and 10 yrs. In each experiment 3 t ha�1 of loose wood ash was applied to three
replicated plots (30�/30 m). In three of the experiments 120�/150 kg N ha�1 was applied
together with the same wood ash (WAN). These three experiments also included a stand-specific
fertilization (SSF) treatment, which consisted of 120, 150 or 180 kg N ha�1. Five years after
wood ash or WAN application the pH increase in the humus layer was 1�/1.7 pH-units and in the
0�/5 cm mineral soil layer 0.3�/0.4 pH-units. The increase was approximately the same 10 yrs after
application, and was also associated with an increase in pH in the 5�/10 cm mineral soil layer.
Wood ash or WAN significantly increased both the total and extractable calcium and magnesium
concentrations in the humus layer on all the sites. Wood ash or WAN had an increasing effect on
the boron concentrations, but a decreasing effect on the manganese concentrations in the needles.
Wood ash had no significant effect on the volume growth. The trees on the WAN plots grew as
well as or slightly better than those on the SSF plots. Key words: Acidity, neutralization,
nutrients, Picea abies, Pinus sylvestris.
Correspondence to: A. Saarsalmi, e-mail: anna.saarsalmi@metla.fi
INTRODUCTION
Owing to the slow mineralization of organic matter
considerable amounts of organic nitrogen accumulate
in the soil of boreal coniferous forests. In addition to
natural acidification, forest soils are subjected to
external inputs of acidifying compounds. For this
reason, it has been postulated that the atmospheric
deposition of acidifying compounds will gradually
increase the leaching of base cations (Ca2�, K�,
Mg2�, Na�) and accelerate soil acidification (Berden
et al. 1987). Intensified harvesting, e.g. the utilization
of logging residues, will further increase the depletion
of base cations and the risk of soil acidification
(Nykvist & Rosen 1985, Olsson et al. 1996).
The increased use of forest fuels is generating
large quantities of ash. The recycling of wood ash
could be one means of counteracting natural and
anthropogenic soil acidification and the loss of
nutrients resulting from tree harvesting (Vance 1996,
Eriksson 1998).
Wood ash generally has a good acid-neutralizing
capacity and supplies the soil with a range of mineral
nutrients. A decrease in acidity and an increase in base
saturation following the application of loose (non-
hardened) wood ash havebeen widely reported (Khanna
et al. 1994, Bramryd & Fransman 1995, Fritze et al.
1995, Kahl et al. 1996, Ruhling 1996, Eriksson 1998,
Saarsalmi et al. 2001, Ludwig et al. 2002). Wood ash has
also been found to increase microbial activity in the soil
(Martikainen et al. 1994, Fritze et al. 1994, 1995).
Nitrogen (N) is known to be the main nutrient
limiting the growth of boreal forests (e.g. Kukkola &
Saramaki 1983, Tamm 1991), and N is the only
nutrient that has increased tree growth when added
alone on forested mineral soils in Finland (Kukkola &
Saramaki 1983). Although wood ash does not contain
N, the application of wood ash should promote
mineralization of the considerable reserves of soil
organic N, and thus improve the availability of N for
tree growth.
According to experience gained from wood ash
experiments on mineral soil, the trees usually show no
growth response at all or, in some cases, there is a
slight decrease in growth (Malmstrom 1953, Sikstrom
1992, Prescott & Brown 1998, Moilanen & Issakainen
2000, Jacobson 2003). Owing to its soil ameliorating
effect, wood ash may be useful on forested mineral
soils as long as it is given together with N fertilizer.
Scand. J. For. Res. 19: 217�/233, 2004
# 2004 Taylor & Francis ISSN 0282-7581 DOI: 10.1080/02827580410024124
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The aim of this study was to determine whether
wood ash given either alone or together with N affects
the soil chemical properties and the nutrient status and
growth of trees in coniferous stands on sites of
different fertility.
MATERIALS AND METHODS
Site and stand description
Field experiments were established in 1990�/1993 in
four Scots pine (Pinus sylvestris L.) stands and one
Norway spruce [Picea abies (L.) Karst.] stand repre-
senting a range of site fertilities (Table 1). The tree
stands were middle-aged or older (Table 2). The
experimental stands 402, 407 and 408 were naturally
regenerated, but quite even aged. Stand 415 was
established by sowing and stand 416 by planting. On
three of the stands (402, 415 and 416), the first
commercial thinning took place at the time of estab-
lishment of the experiments, when the basal area was
reduced by 20�/30%. Stands 407 and 408 had been
thinned earlier. In spite of thinning, the diameter
distribution remained still quite large, which is typical
for less fertile pine stands and spruce stands generally.
On the most fertile site (exp. 416) the annual growth
was 7.2 m3 ha�1 (7.2%). In exps 407 and 408 the
volume growth was 2.6 (5.6%) and 2.2 (4.0%) m3 ha�1
yr�1, respectively.
The experiments are located along a climatic and
acidifying deposition gradient running from south to
north (Fig. 1). The annual input of N via deposition
decreases towards the north; from about 10 kg N ha�1
along the southern coast of Finland to about 2 kg N
ha�1 in northern Lapland (Nordlund 2000). The
organic layer in all the experiments was mor and the
soil type haplic podzol.
The N status in both the humus layer and the
mineral soil was the highest in the spruce stand
(Exp. 416) (Tables 3 and 4). In the spruce stand, the
carbon/nitrogen (C/N) ratio of the humus layer was
clearly lower than that in the other experiments.
According to the extractable nutrient concentrations,
the humus layer in experiment 416 was the most
nutrient rich and experiment 408 the most nutrient
poor. The concentrations of extractable nutrients in
both mineral soil layers, and base saturation (BS) in
the 0�/5 cm mineral soil layer, were also the lowest in
exp. 408. In exp. 415, the extractable Ca and Mg
concentrations and BS in both mineral soil layers were
considerably higher than the extractable Ca and Mg
concentrations and BS in the other experiments.
Compared with the diagnostic values for needle
nutrient concentrations, the N concentrations in all
the experiments (Table 5) were below the optimum,
and in exp. 408 below the deficiency level
(Jukka 1988). In exps 407, 408 and 416 the needle B
concentrations were low compared with the average
values for corresponding middle-aged tree stands in
Finland (Malkonen 1991).
Treatments
In all of the experiments, 3 t ha�1 of loose wood ash
(bark ash) was spread at the time of establishment
(Tables 6 and 7). In three of the experiments (exps 407,
415 and 416), 120�/150 kg N ha�1 was applied
together with wood ash (WAN). A stand-specific
fertilization (SSF) treatment, formulated on the basis
of needle and soil analyses, was also included in these
three experiments. In the treatments, N was given as
ammonium nitrate with lime [N 27.5%, calcium (Ca)
4%, magnesium (Mg) 1%], phosphorus (P) as super-
phosphate, boron (B) as fertilizer borate (Na2B4O7 �/5H2O) and copper (Cu) as copper fertilizer (Cu as
different hydroxides). The size of the plots was 30�/30
m, and there were three replications of the treatments
in each experiment.
Table 1. Information about the experimental stands at the time of establishment of the experiments
Exp. Site typea Site indexb (m) Humus layer (cm)
Mineral soil
Parent material/texture Tree species
402 CT 18 2.7 Sorted/fine sand Scots pine
407 MCClT 14 0.9 Sorted/fine sand Scots pine
408 ECT 15 1.0 Sorted/fine sand Scots pine
415 VT 25 3.1 Till/fine sand Scots pine
416 MT 28 3.6 Till/fine sand Norway spruce
a Site types according to the classification of Cajander (1949). CT: Calluna type; MCClT Myrtillus �/Calluna �/Cladonia type;
ECT: Empetrum �/Calluna type; VT: Vaccinium type; MT: Myrtillus type.b Dominant height at an age of 100 yrs.
218 A. Saarsalmi et al. Scand. J. For. Res. 19 (2004)
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Soil sampling
Samples were taken from the humus layer and the
mineral soil at a depth of 0�/5 and 5�/10 cm. The first
round of soil sampling was carried out before wood ash
fertilization: in October�/November 1990 in exps 402
and 407, in August 1991 in exp. 408, in September 1992
in exp. 415, and in May 1993 in exp. 416. Soil samples
were taken systematically at 25 sampling points on the
control, wood ash and WAN-treated plots, and the
samples from the same plot were bulked by layer. The
humus layer samples were taken using a cylinder
(diameter�/58 mm) and the mineral soil samples using
an auger (diameter�/21 mm). The thickness of the
humus layer was measured in conjunction with sam-
pling. Sampling was repeated after 5 yrs, and in exps
402, 407 and 408 also after 10 yrs.
Tree stand measurements
The tree stands were measured at the time the experi-
ments were established, and after 5 and 10 yrs on the
control, wood ash, WAN and SSF plots. The breast
height diameter of all the trees was measured with an
accuracy of 1 mm from two directions. On each plot at
least 30 permanent sample trees representing different
size categories were chosen for tree height measure-
ments using a hypsometer with an accuracy of 1 dm. The
size categories were determined by first dividing all the
trees into five diameter classes, each with the same basal
area. Six trees were then randomly selected as sample
trees from each size category. The sample trees were
used for estimating the height and volume.
The annual radial growth at breast height was
obtained from felled sample trees measured 5 yrs after
the treatments (excluding exp. 402). The trees, five
from each plot (i.e. 15 per treatment), were chosen
randomly to represent five different size categories as
described above.
Needle sampling
Needle samples were collected during the winter before
fertilization. The needle samples were taken from five
sample trees, randomly selected from the dominant
crown layer, on the control, wood ash and WAN plots.
Table 2. Tree stand characteristics at the time of establishment of the experiments
Exp.
Total age
(yrs)
Stems
(no ha�1)
Ddom,a
(cm)
Hdom,b
(m)
Volume
(m3 ha�1)
Volume growthc
(m3 ha�1 yr�1)
402 64 900 19.2 13.9 91.4 5.82
407 75 763 16.6 11.3 46.7 2.60
408 69 704 17.9 12.2 54.1 2.15
415 31 1279 16.3 11.6 89.7 6.66
416 45 1175 22.8 15.0 100.4 7.23
a Dominant diameter; the mean breast height diameter of 100 thickest trees per hectare.b Dominant height; the mean height of 100 thickest trees per hectare.c Growth during the first 5-yr period on the control plots.
Fig. 1. Location of the experiments. Mean long-term
(1961�/1990) effective temperature sum (degree days) is
marked on the map by isotherms.
Scand. J. For. Res. 19 (2004) Effect of wood ash on soil and trees in coniferous stands 219
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The needles were collected from the current needles (C)
growing on the third to fifth branch whorl, counting
from the top, on the southern side of the crown. Needle
sampling was repeated after 5 yrs: in exp. 402 in the same
way as before fertilization, and in the other experiments
on the felled sample trees. The current needles on the
middle branch in the upper quarter of the live crown
were sampled. After 10 yrs, needles were sampled in
exps 402, 407 and 408 in the same way as before
fertilization.
Soil and needle analyses
The soil samples were dried in a ventilated chamber at
a temperature of 30�/408C. The humus samples were
ground in a mill with a 2 mm bottom-sieve, and the
mineral soil samples were passed through a 2 mm sieve
to remove stones and larger roots.
Total element concentrations [P, potassium (K), Ca,
Mg, B, cadmium (Cd),chromium (Cr), Cu, iron (Fe),
manganese (Mn), nickel (Ni), lead (Pb) and zinc (Zn)]
were determined on the humus samples by dry digestion
(5508C for 2 h), extracting the ash with HCl, and
determining the concentrations by inductively coupled
plasma atomic emission spectrometry (ICP/AES)
(ARL 3580). Total N and C were determined on the
humus and mineral soil samples on a CHN analyser.
The organic matter (OM) content of the humus layer
was calculated from the C content of the samples, using
the formula OM�/1.72�/C. Extractable nutrients [P,
K, Ca, Mg and sodium (Na)] were determined on both
the humus and mineral soil samples by extraction with
acid ammonium acetate (pH 4.65) using a ratio of 15 ml
of sample and 150 ml of extractant. The suspensions
were left to stand overnight before being shaken for 1 h
and then filtered. The concentrations of the individual
Table 3. Nutrient status and acidity parameters in the humus layer at the time of establishment of the experiments
Extractable
Exp.
OM
(t ha�1)
Total N
(g kg�1 OM)
C/N ratio P K Ca Mg pH BS (%) CECe EA Exch. Al
(mg kg�1 DM) (mmol kg�1 DM)
402 30.2 13.1 44.4 132 432 1062 110 3.7 39 191 116 53
407 16.1 11.9 49.0 138 357 1123 144 3.6 46 167 90 31
408 12.3 12.5 46.6 75 286 469 76 3.4 33 116 78 38
415 25.3 13.7 42.4 96 414 1091 142 3.8 70 110 33 11
416 34.9 19.9 29.3 158 716 1514 274 3.8 61 194 76 31
OM: organic matter; N: nitrogen; C/N: carbon/nitrogen; P: phosphorus; K: potassium; Ca: calcium; Mg: magnesium;
DM: dry matter; BS: base saturation; CECe: cation exchange capacity; EA: exchangeable acidity; Exch. Al: exchangeable
aluminium.
Table 4. Nutrient status and acidity parameters in the different mineral soil layers (on a dry matter basis) at the
time of establishment of the experiments
Extractable
Exp. Soil depth (cm)
Total N
(g kg�1)
C/N ratio P K Ca Mg pH BS (%) CECe EA Exch. Al
(mg kg�1) (mmol kg�1)
402 0�/5 1.49 29.1 9.10 36.10 55.10 7.52 4.6 12.9 34.9 30.4 26.0
407 0�/5 0.65 19.9 5.72 18.28 16.97 5.12 4.8 11.2 16.8 15.0 12.6
408 0�/5 0.47 20.3 4.68 15.03 13.38 4.03 4.1 9.0 16.6 15.1 11.9
415 0�/5 0.86 27.3 8.67 38.65 199.73 23.80 4.1 41.3 31.2 18.0 12.8
416 0�/5 1.54 22.3 7.45 35.42 46.83 12.05 4.3 12.1 37.6 33.1 29.7
402 5�/10 0.99 27.3 8.78 20.43 13.07 3.70 5.0 9.2 17.6 16.0 15.3
407 5�/10 0.53 20.4 4.50 12.75 6.80 2.55 5.2 11.7 8.5 7.6 7.0
408 5�/10 0.38 20.4 3.55 10.48 5.87 2.50 4.6 10.2 8.6 7.7 7.5
415 5�/10 0.58 21.2 7.33 15.13 119.65 13.98 4.6 33.3 23.2 15.5 14.4
416 5�/10 1.25 20.6 5.48 18.97 30.47 6.37 4.7 11.8 23.2 20.5 20.3
N: nitrogen; C/N: carbon/nitrogen; P: phosphorus; K: potassium; Ca: calcium; Mg: magnesium; BS: base saturation;
CECe: cation exchange capacity; EA: exchangeable acidity; Exch. Al: exchangeable aluminium.
220 A. Saarsalmi et al. Scand. J. For. Res. 19 (2004)
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nutrients were determined by ICP/AES. The analytical
methods are described in Halonen et al. (1983).
pH was determined in a water suspension with a ratio
of 15 ml of sample and 25 ml of distilled water.
Exchangeable acidity (EA) (H��/Al3�) was
determined on a KCl extract with a ratio of 15 ml of
sample and 150 ml 1.0 M KCl by titration with 0.05 M
NaOH to an endpoint of pH 7.0. Exchangeable
aluminium (Al) was determined by back-titration with
0.02 N H2SO4 to pH 7.0 after 10 ml of 4% NaF solution
had been added to the extract (Halonen et al. 1983).
The needle samples were dried (708C, 48 h) and
analysed separately for each tree. Needle unit mass
(mg needle�1) was determined separately for each
tree. The concentrations of P, K, Ca, Mg, Mn, Cu, Zn,
Fe and B were determined on finely ground needles by
dry digestion (5508C for 2 h) and extraction with HCl
(Halonen et al. 1983), and the filtered solutions were
analysed by ICP/AES. The N concentration was
determined on a CHN analyser.
Calculation of the results
The effective cation exchange capacity (CECe)
was calculated as the sum of equivalent values of
extractable Ca, Mg, K and Na and EA. Base satura-
tion (BS) was obtained from the proportion of the sum
Table 5. Average needle nutrient concentrations and
average needle dry mass at the time of establishment of
the experiments
Exp. Nutrient
Mean
(g kg�1) Nutrient
Mean
(mg kg�1)
402 N 12.5 (0.3) B 26.3 (0.7)
407 11.3 (0.1) 5.8 (0.3)
408 10.8 (0.2) 7.9 (0.5)
415 12.7 (0.2) 10.7 (0.7)
416 12.7 (0.3) 9.0 (0.6)
402 P 1.70 (0.04) Cu 4.6 (0.2)
407 1.44 (0.02) 6.3 (0.3)
408 1.27 (0.02) 4.2 (0.2)
415 1.79 (0.04) 3.1 (0.2)
416 1.60 (0.05) 2.2 (0.2)
402 K 4.97 (0.13) Fe 55 (2)
407 4.64 (0.09) 46 (1)
408 4.82 (0.10) 36 (1)
415 4.60 (0.10) 44 (1)
416 4.32 (0.24) 32 (1)
402 Ca 2.23 (0.08) Mn 567 (26)
407 2.04 (0.09) 639 (19)
408 2.15 (0.08) 372 (15)
415 2.21 (0.09) 513 (15)
416 3.26 (0.21) 782 (61)
402 Mg 1.05 (0.03) Zn 73 (3)
407 1.36 (0.03) 64 (4)
408 1.18 (0.03) 50 (1)
415 1.06 (0.02) 43 (1)
416 1.23 (0.04) 17 (1)
Dry mass (mg needle�1)
402 12.7 (0.5)
407 8.6 (0.4)
408 8.9 (0.3)
415 12.9 (0.5)
416 4.0 (0.2)
Data are shown as mean (SEM).
N: nitrogen; B: boron; P: phosphorus; Cu: copper;
K: potassium; Fe: iron; Ca: calcium; Mn: manganese;
Mg: magnesium; Zn: zinc.
Table 6. Fertilizer treatments used in the experiments
(tree stand measurements only were made for the SSF
treatment)
1 Control
2 Wood ash application:
Exp. 402: wood ash 3 t ha�1
Exp. 408: wood ash 3 t ha�1
3 Wood ash and nitrogen application (WAN):
Exp. 407: wood ash 3 t ha�1 and N 120 kg ha�1
Exp. 415: wood ash 3 t ha�1 and N 150 kg ha�1
Exp. 416: wood ash 3 t ha�1 and N 150 kg ha�1
4 Stand specific fertilization (SSF):
Exp. 407: N 120 and B 2 kg ha�1
Exp. 415: N 150, Cu 3 and B 1 kg ha�1
Exp. 416: N 180, P 40, Cu 3 and B 1 kg ha�1
N: nitrogen; B: boron; Cu: copper; P: phosphorus.
Table 7. Element concentrations in the wood ashes used
in the experiments
Element 402 407 & 408 415 416
P (g kg�1) 6.8 14.5 25.4 12.6
K (g kg�1) 18.2 40.4 37.3 36.3
Ca (g kg�1) 232 209 235 278
Mg (g kg�1) 14.4 36.2 33.4 20.3
Al (g kg�1) 50.1 6.2 13.7 9.4
Cu (g kg�1) 0.08 0.08 0.20 0.08
Fe (g kg�1) 9.1 5.9 8.1 4.3
Mn (g kg�1) 8.4 20.3 12.2 16.2
S (g kg�1) 15.2 2.7 4.8 2.9
Zn (g kg�1) 2.2 1.2 0.6 0.6
Cd (mg kg�1) 6.2 2.3 3.7 1.4
Pb (mg kg�1) 27.2 5.1 116.9 19.0
P: phosphorus; K: potassium; Ca: calcium; Mg: magnesium;
Al: aluminium; Cu: copper; Fe: iron; Mn: manganese;
S: sulfur; Zn: zinc; Cd: cadmium; Pb: lead.
Scand. J. For. Res. 19 (2004) Effect of wood ash on soil and trees in coniferous stands 221
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of the equivalent Ca, Mg, K and Na concentrations
out of CECe.
Statistical significance of the difference in soil
nutrient parameters and needle nutrient concentra-
tions was tested using the independent-samples t -test.
The equality of variances was tested with Levene’s test.
Pooled or separate variances were used depending on
the equality of the variances.
The stand characteristics at the start and end of the
first and second 5-yr study periods were calculated using
the KPL calculation programme for sample plots
(Heinonen 1994). A function based on breast height
diameter and height was used for calculating the volume
of the sample trees (Laasasenaho 1982). The height and
volume of trees other than the sample trees were
estimated by means of regression functions. The growth
for each 5-yr period was calculated as the difference
between consecutive measurements (the same trees at
the start and at the end of each period). Statistical
significance of the differences in volume growth be-
tween the treatments was tested using analysis of
variance. Bonferroni’s test was used to test the equality
of the treatment means. The following model was used
for the individual experiments: yij �/m�/tj�/eij , where
yij is the growth for block i (i�/ 1, 2, 3) and treatment j
(j�/1, 2 or j�/1, 2, 3), m is the total mean, t is the fixed
effect of treatment j , and eij is the residual effect for
observation ij .
RESULTS
Soil organic matter
In exp. 402, wood ash decreased the organic matter
content in the humus layer but increased it in the 0�/5
cm mineral soil layer 5 yrs after application (data not
shown). In the other experiments, however, neither
wood ash nor WAN had any significant effect on the
organic matter content in either the humus layer or the
mineral soil layers.
Soil acidity
Wood ash or WAN significantly elevated the pH in the
humus layer and in the 0�/5 cm mineral soil layer on all
the sites (Fig. 2). In the southern experiments
(exps 402, 415 and 416) the difference in humus layer
acidity between the treatments after 5 yrs was 1.4�/1.7
pH-units, and in the northern experiments (exps 407
and 408) 1.0�/1.1 pH-units. In the uppermost mineral
soil layer, the difference in acidity between the treat-
ments was 0.3�/0.4 pH-units 5 yrs after application.
After 10 yrs the difference in the humus layer acidity
between the treatments was 1.8 pH-units in exps 402 and
408, and 1.1 units in exp. 407. On the treated plots, a
decrease in soil acidity was evident after 10 yrs in the
uppermost mineral soil layer in exp. 408, and in both of
the mineral soil layers in exps 402 and 407.
Wood ash or WAN significantly decreased the EA
(80�/90%) in the humus layer in all the experiments
(Table 8). The exchangeable Al concentration in the
humus layer decreased on the treated plots in all the
experiments, being 0�/14% of that on the control plots
after 5 yrs. A decrease in the EA and Al concentration
was also found in the uppermost mineral soil layer on
the wood ash or WAN plots 5 yrs after application
Fig. 2. pH in the humus and mineral soil layers in the
experiments 5 and 10 yrs after the treatments. See explana-
tion in Table 6. Standard error of the mean is marked on the
columns by bars. Statistically significant differences between
the treatments are indicated by asterisks: *p B/0.05,
**p B/0.01, ***p B/0.001. WAN: wood ash and nitrogen.
222 A. Saarsalmi et al. Scand. J. For. Res. 19 (2004)
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(Fig. 3). However, the decrease was not significant in all
cases. As was the case in the humus layer, the decrease in
the EA and exchangeable Al concentration in the
mineral soil was most pronounced in exp. 416. After
10 yrs a significant decrease in EA in both the humus
layer and the uppermost mineral soil layer was found on
the treated plots in exps 402, 407 and 408.
Nutrient and heavy metal concentrations in the humus
layer
Wood ash or WAN had no effect on the total N
concentrations in the humus layer in any of the
experiments (Fig. 4). Neither wood ash nor WAN
had any effect on the C/N ratio in any of the
experiments after 5 yrs (Fig. 4). In exp. 402, however,
there was a significant increase in the C/N ratio on the
wood ash treated plots after 10 yrs.
Wood ash or WAN significantly increased both the
total and extractable Ca and Mg concentrations in the
humus layer on all the sites (Fig. 5). Compared with
the control, the increase in the extractable Ca con-
centrations was 4.6- to 7.5-fold and of Mg 2.6- to 3.4-
fold after 5 yrs, and in exps 402, 407 and 408 5- to 9-
fold and 4-fold, respectively, after 10 yrs. After 5 yrs
WAN resulted in elevated concentrations of both total
and extractable P and K in exp. 415 and of P in exp.
416. After 10 yrs significant increases in both total P
and K were found on the wood ash or WAN plots in
exps 402, 407 and 408. There were also increases in the
extractable concentrations of these nutrients, but the
differences were not significant in all cases.
After 5 yrs wood ash or WAN significantly increased
the total B concentrations in the humus layer in all the
experiments (Appendix). There was a similar trend of
elevated total Mn and Zn concentrations in the humus
layer on the treated plots. The difference between the
treatments was, however, significant only in exps 415
(Zn) and 416 (Mn and Zn), i.e. after the WAN
treatment. A significant increase in the total Cd
concentration was found in the humus layer on the
WAN plots in exp. 415. After 10 yrs significantly
elevated concentrations of total B, Cd, Mn and Zn
were found in the humus layer on the treated plots in
exps 402, 407 and 408.
Nutrient concentrations in the mineral soil
Wood ash fertilization resulted in significantly elevated
N concentrations in both the 0�/5 and 5�/10 cm mineral
soil layers in exp. 402, but only after 5 yrs (Fig. 4). There
were no differences in the total N concentrations
between the treatments in the other experiments.
Although both wood ash and WAN resulted in
elevated Ca and Mg concentrations in the 0�/5 cm
mineral soil layer, the differences between the treat-
Table 8. Effective cation exchange capacity (CECe), base saturation (BS), exchangeable acidity (EA) and
exchangeable aluminium (Al) concentration (range in parentheses) in the humus layer in the experiments 5 and 10
yrs after the treatments
CECe (mmol kg�1 DM) BS (% DM) EA (mmol kg�1 DM) Al (mmol kg�1 DM)
Exp. Sampling ControlWood asha
or WANb ControlWood asha
or WANb ControlWood asha
or WANb ControlWood asha
or WANb
402 After 5 yrs 119 191* 38 94*** 73.3 11.3*** 41.8 6.0***(101�/131) (150�/219) (32�/42) (89�/96) (69.1�/76.9) (8.8�/15.9) (39.6�/44.5) (3.3�/10.4)
After 10 yrs 163 486** 45 98*** 89.1 8.4*** n.d. n.d.(145�/179) (397�/599) (38�/50) (96�/99) (87.7�/90.1) (4.0�/14.1)
407 After 5 yrs 147 272 48 94*** 76.2 15.8*** 25.9 3.2***(137�/162) (220�/361) (47�/49) (92�/96) (69.9�/83.6) (12.7�/18.3) (23.7�/27.6) (1.5�/4.4)
After 10 yrs 130 267*** 46 95*** 70 14.6** n.d. n.d.(120�/135) (243�/282) (40�/51) (94�/95) (59.1�/80.3) (11.8�/17.0)
408 After 5 yrs 127 232 33 93*** 84.6 14.0*** 42.2 4.0***(126�/128) (151�/325) (28�/39) (90�/96) (78.0�/91.8) (13.5�/14.4) (35.6�/49.4) (1.7�/6.0)
After 10 yrs 158 445* 45 98** 87.2 10.5*** n.d. n.d.(155�/160) (346�/576) (37�/49) (96�/98) (80.5�/99.5) (8.2�/13.6)
415 After 5 yrs 200 598** 74 98*** 50.4 9.6** 8.6 0*(183�/228) (465�/697) (72�/78) (96�/100) (50.0�/51.1) (0.0�/18.8) (7.2�/10.4) (0�/0)
416 After 5 yrs 193 666*** 65 99* 67.1 7.2** 27.7 0.4*(192�/194) (614�/725) (60�/73) (98�/99) (51.5�/77.5) (3.9�/9.7) (13.2�/36.8) (0.0�/1.0)
See Table 6 for explanations of treatments.a Experiments 402 and 408.b Experiments 407, 415 and 416.
DM: dry matter; WAN: wood ash and nitrogen; n.d.: not determined.
*p B/0.05, **p B/0.01, ***p B/0.001.
Scand. J. For. Res. 19 (2004) Effect of wood ash on soil and trees in coniferous stands 223
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ments were significant after 5 yrs in only a few cases
(Fig. 6). In exps 402, 408 and 415 there was also a
significant increase in the Mg concentration in the
5�/10 cm mineral soil layer. After 10 yrs significantly
elevated concentrations of Ca and Mg were found in the
uppermost mineral soil layer on the treated plots in exp.
407 and in both mineral soil layers in exps 402 and 408.
Cation exchange capacity and base saturation
Wood ash or WAN increased the CECe in the humus
layer on all the sites (Table 8). The increase was
most pronounced after 5 yrs in exp. 416 where CECe
on the treated plots was more than 3-fold that on the
control plots. After 10 yrs the increase in the CECe
between treatments was 2-fold in exp. 407 and 3-fold in
exps 402 and 407. Apart from two cases there were no
differences in CECe between the treatments in the
mineral soil in any of the experiments (Fig. 3).
Wood ash or WAN significantly increased BS 5 yrs
after application both in the humus layer and in the
uppermost mineral soil layer in all the experiments
(Table 8, Fig. 3). In the humus layer, the increase in BS
after 5 yrs was most pronounced in exps 402 and 408,
which initially had the lowest BS values, and the least
in exp. 415, where the BS had initially been the
highest. After 10 yrs there was an increase in BS in
all the wood ash or WAN-treated soil layers in exps
402, 407 and 408.
Fig. 3. Effective cation exchange capacity (CECe), base saturation (BS), exchangeable acidity (EA), and exchangeable
aluminium (Al) concentration (on dry matter basis) in the different mineral soil layers in the experiments 5 and 10 yrs after the
treatments. See explanations in Table 6 and Fig. 2.
224 A. Saarsalmi et al. Scand. J. For. Res. 19 (2004)
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Needle nutrient concentrations
Wood ash or WAN increased the B concentrations in
the needles in all the experiments, apart from in exp. 415
5 yrs after application (Fig. 7). In contrast, there was a
significant decrease in the Mn concentrations on the
treated plots in all the experiments. An increase in the
concentrations of B and a decrease in the concentra-
tions of Mn were also found in the needles on the treated
plots after 10 yrs in exps 402, 407 and 408. Wood ash or
WAN had no effect on the needle N concentrations in
any of the experiments. Elevated Ca concentrations
were found on the treated plots in the needles in exps 402
and 408 after both 5 and 10 yrs. The response of the
needle Ca concentration to the WAN treatment was
contradictory after 5 yrs. Wood ash alone had no effect
on the P and K concentrations in the needles. In
contrast, WAN had in most cases an increasing effect
on the needle P and K concentrations.
Tree growth
Wood ash given alone had no effect on volume growth
in the southernmost experiment (exp. 402) during the
Fig. 4. Total nitrogen (N) concentration (on an organic matter basis) and carbon/nitrogen (C/N) ratio in the humus layer and
in the different mineral soil layers (on a dry matter basis) 5 and 10 yrs after the treatments. See explanations in Table 6 and Fig.
2. WAN: wood ash and nitrogen.
Scand. J. For. Res. 19 (2004) Effect of wood ash on soil and trees in coniferous stands 225
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first 5-yr period, and a 9% non-significant positive
effect during the second 5-yr period (Fig. 8). In exp.
408, which was also located on a relatively infertile
site, there was a non-significant 7�/8% increase in the
volume growth during the first and second 5-yr
periods on the ash-treated plots.
During the first 5-yr period a significant 42�/71%
increase in the volume growth occurred on the WAN
plots in exps 407, 415 and 416, and of 36�/62% on the
SSF plots with N but no wood ash. The relative response
was most pronounced in exp. 407, which initially had a
much lower growth level than that in exps 415 and 416.
During the second 5-yr period, a non-significant 26%
increase in volume growth occurred on the WAN plots
in exp. 407; in contrast, there was no longer any growth
response to the SSF treatment. The growth response to
the WAN and SSF treatments did not differ in either
exp. 415 or exp. 416 during the second 5-yr period. The
response to these treatments was, however, no longer
significant. In the spruce stand (exp. 416), the response
to WAN and SSF was 29�/30% (p�/0.18) and in the pine
stand (exp. 415) 7�/10% (p�/0.56).
The radial growth results indicate the timing of the
response (Fig. 9). In exp. 408 a slight negative growth
response was seen after wood ash application, which
levelled off after two growing seasons. The growth
reaction given by WAN was the greatest during the
second (exp. 415) or third (exp. 407) year after
Fig. 5. Total and extractable phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg) concentrations (dry matter
basis) in the humus layer in the experiments 5 and 10 yrs after the treatments. See explanations in Table 6 and Fig. 2. WAN:
wood ash and nitrogen.
226 A. Saarsalmi et al. Scand. J. For. Res. 19 (2004)
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application in the pine stands, and during the fourth
year after application in the spruce stand (exp. 416).
DISCUSSION
Similar increases in extractable Ca and Mg concentra-
tions, and in some cases also in K and P, in the humus
layer following wood ash application have been
reported in other studies (Levula 1991, Priha &
Smolander 1994, Bramryd & Fransman 1995, Kahl
et al. 1996, Ruhling 1996, Eriksson 1998, Levula et al.
2000, Ludwig et al. 2002). Wood ash-induced increases
in the Ca and Mg concentrations in the humus layer
can be of long duration (Saarsalmi et al. 2001). In this
study, elevated extractable Ca, Mg and also P con-
centrations were found even after 10 yrs. Many of the
elements present in wood ash can be retained in the
humus layer as a result of the decrease in the
availability of the elements due to the pH increase,
or to complexation with organic compounds (Bram-
ryd & Fransman 1995). The humus layer thus acts as a
trap for many of the elements added in wood ash. This
may partly explain the long-lasting, nutritional effects
of wood ash application.
Wood ash generally has a strong neutralizing and
buffering capacity. The hydroxyl ions formed as a result
of the dissolution of the CaO, MgO, K2O and NaOH in
the ash neutralize the protons in the soil solution and
those bound on cation-exchange sites in the soil. The
released cations (Ca2�, Mg2�, K� and Na�) displace
the protons and Al3� cations occupying cation-ex-
Fig. 6. Extractable phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg) concentrations (dry matter basis) in the
different mineral soil layers in the experiments 5 and 10 yrs after the treatments. See explanations in Table 6 and Fig. 2. WAN:
wood ash and nitrogen.
Scand. J. For. Res. 19 (2004) Effect of wood ash on soil and trees in coniferous stands 227
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change sites. In this study, wood ash or WAN decreased
the exchangeable Al concentration in both the humus
and mineral soil. Similar significantly and inversely
related results between the exchangeable Al concentra-
tion and wood ash application have also been reported
in other studies (Unger & Fernandez 1990, Bramryd &
Fransman 1995, Kahl et al. 1996, Saarsalmi et al. 2001).
A decrease in acidity following the application of
wood ash on forested mineral soils has also been
reported in several other studies (Martikainen 1984,
Levula 1991, Baath & Arnebrandt 1994, Priha &
Smolander 1994, Bramryd & Fransman 1995, Fritze et
al. 1995, Malkonen 1996, Tamminen 1998, Levula et
al. 2000, Ludwig et al. 2002). According to these
studies, the pH increase in the humus layer induced by
wood ash application has been 0.3�/2.4 pH-units
during 1�/12 yrs after the application of 1�/7 t ha�1
of ash. The effect of wood ash on the acidity of the
humus layer can be of long duration. In a study
carried out by Saarsalmi et al. (2001), a wood ash-
induced increase of 0.6�/1.0 pH-units was found in the
humus layer even 16 yrs after wood ash application
with a dose of 3 t ha�1.
In this study, a wood ash-induced pH increase was
found after 5 yrs in the 0�/5 cm mineral soil layer, and
after 10 yrs also in the 5�/10 cm mineral soil layer. The
neutralization effects of wood ash probably become
evident in the mineral soil at a slower rate than in
the humus layer. Consequently, in the study of Saar-
salmi et al. (2001) an increase of 0.2�/0.3 pH units was
found in the 0�/10 cm mineral soil layer 16 yrs after ash
application of 3 t ha�1, but not yet after 7 yrs.
Until recently, only untreated, loose wood ash has
mainly been available for Finnish studies. Since the
sharp increase in soil pH after wood ash application can
have negative effects on the ground vegetation (Kellner
& Weibull 1998, Jacobson & Gustafsson 2001) and
microfauna (Huhta 1984), doses of loose wood ash
exceeding 2.5�/3.0 t ha�1 are not recommended for use
on mineral soils (Malkonen et al. 2001). Pelleted or
granulated ash reduces the reactivity of the ash, and has
been shown to have less drastic effects on the pH of the
soil (Eriksson et al. 1998).
Wood ash has been reported to have no effect on
needle N concentrations on forested mineral soil
(Moilanen & Issakainen 2000, Jacobson 2003, Arvids-
son & Lundkvist 2002). In this study, no response to
either wood ash or WAN application was found in the
needle N concentrations. Normal N fertilization
usually increases the needle N concentration for a
period of a few years. The time between the
N application and first needle sampling was five
growing seasons, and hence it was no longer possible
to detect the effect of N application in the needles.
The increase in the needle B concentration after
wood ash application found in this study is in
agreement with the results obtained by Jacobson
(2003). In contrast, wood ash had no effect on the
P, K and Ca concentrations in the needles. Arvids-
son & Lundkvist (2002), however, found increases in
the P, K and Ca concentrations in the needles of
Fig. 7. Total nutrient concentrations in the needles 5 and 10 yrs after the treatments. See explanations in Table 6 and Fig. 2. N:
nitrogen; P: phosphorus; Mn: manganese; Cu: copper; K: potassium; Ca: calcium; Zn: zinc; Fe: iron; Mg: magnesium;
B: boron; WAN: wood ash and nitrogen.
228 A. Saarsalmi et al. Scand. J. For. Res. 19 (2004)
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young Norway spruce stands 5 yrs after wood ash
application. Jacobson (2003) reported increases in
needle K concentrations in 30�/60-yr-old coniferous
stands during the first few years, but not after 7 yrs
following ash application. According to Jacobson
(2003), however, wood ash had no significant effect
on needle P and Ca concentrations.
No significant volume growth response to wood ash
was found in this study. The results are in agreement
with the experience usually gained in wood ash experi-
ments in Scots pine or Norway spruce stands on mineral
soil (Malmstrom 1953, Sikstrom 1992, Moilanen &
Issakainen 2000, Jacobson 2003). Prescott & Brown
(1998), however, reported that in an N-limited 9-yr-old
plantation of western red cedar (Thuja plicata ) in
British Columbia, wood ash (5 t ha�1) addition resulted
in a significantly reduced height increment during the 5-
yr period following ash application.
In a series of seven field experiments established in
30�/60-yr-old Scots pine and Norway spruce stands in
Sweden, the relative growth response to wood ash of
different origin and composition was positively corre-
lated with site fertility (Jacobson 2003). Consequently,
on the most fertile sites, the effect of wood ash addition
averaged over the sites was a 4�/10% non-significant
increase in volume growth by the end of the 5�/11 yr
study. On the three less fertile pine sites, the effect of
wood ash addition averaged over the sites was a 3�/8%
non-significant reduction in volume growth.
The significant growth increase caused by the WAN
treatment during the first 5-yr period in exps 407, 415
and 416 was apparently caused by the inclusion of
N. This was apparent when the growth response to the
WAN treatment was compared with the similar
response to the SSF treatment with N but no wood
ash. However, the addition of ammonium N to wood
ash-fertilized soil can result in nitrification and the
leaching of nitrate (Martikainen 1984, Hogbom et al.
2001). This is because nitrification in acid forest
soils is mainly controlled by ammonium availability,
base saturation and soil pH. In the spruce stand
(exp. 416) where the SSF treatment included P, the
added P may have had some effect on the volume
growth (Kukkola & Saramaki 1983).
Fig. 8. Volume growth of the tree stands during the first and second 5-yr period after the treatments. See explanation in Table
6. Mean values with the same letter do not differ significantly from each other (p �/0.05). SSF: stand-specific fertilization;
WAN: wood ash and nitrogen.
Scand. J. For. Res. 19 (2004) Effect of wood ash on soil and trees in coniferous stands 229
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According to Laakkonen et al. (1983), the duration of
the effect of N fertilization in mature pine stands in
southern Finland has usually been about 7 yrs for pine
and about 10 yrs for spruce. In the spruce stand
(exp. 416), a slight response to both the WAN and
SSF treatments was still evident during the second 5-yr
period. In the pine stands (exps 407 and 415), there was
no longer any growth increase due to the SSF treatment
during the second 5-yr period, but there was still a slight
growth increase due to the WAN treatment in exp. 407.
According to the results obtained by Levula (1991),
the increase in volume growth during the first 5-yr
period in a Scots pine stand on a Vaccinium vitis-idaea
site was the same irrespective of whether N fertilization
with a dose of 180 kg N ha�1 was added either alone or
together with 2 t ha�1 of bark ash. Similarly, according
to Jacobson (2003), the growth response was the same in
two Scots pine stands on poor sites in northern Sweden
during the first 5-yr period, irrespective of whether
ammonium nitrate with lime (180 kg N ha�1) was
added either alone or together with 3 t ha�1 of wood
ash. However, according to Pettersson (1990), wood ash
reduced the response to N fertilization. Pettersson
(1990) reported that there may be a loss of N via
ammoniavolatilization caused by the increase in soil pH
after loose wood ash application. Similarly, the volume
increment in a Scots pine stand on a poor site in
northern Sweden was significantly higher when the
wood ash was added 9 months after N addition,
compared with the treatment with simultaneous
N plus wood ash addition (Jacobson 2003).
Wood ash contains varying concentrations of toxic
heavy metals such as Cd, mercury (Hg) and Pb. One of
the major concerns regarding the negative effects of
wood ash application is that it might lead to increased
concentrations of Cd in the soil. Tamminen (1998)
reported an increase in the concentration of Cd in the
humus layer in two pine seedling stands in southern
Finland 6 yrs after wood ash application with a dose of 3
t ha�1. Bramryd & Fransman (1995), however, found
no increase in the Cd concentration in the humus layer
in a 35-yr-old pine stand in southern Sweden 10 yrs after
wood ash application with doses of either 2 or 7 t ha�1.
Apart from a significant increase in the Cd concentra-
tion in the humus layer in exp. 415 in this study, neither
wood ash nor WAN had any significant effect on the Cd
concentration 5 yrs after application. Although ele-
vated Cd concentrations were found on the treated plots
after 10 yrs, the concentrations of Cd and other heavy
metals were, in all cases, within the normal variation
range of the concentrations of these heavy metals in
Finnish soils (Tamminen 2000).
The Cd concentrations in wood ash normally vary
from 4 to 20 mg kg�1 (Jonsson & Nilsson 1996). In
Finland, a dose of 2.5�/3 t ha�1 of wood ash is
considered to be suitable on forested mineral soils
(Malkonen et al. 2001). This dose is expected to have a
soil ameliorating effect for some decades. The amount
of heavy metals applied in this dose has not been
found to retard the decomposition of the organic
matter (Fritze et al. 1994, 2000) or to accumulate to a
significant degree in forest berries (Silfverberg
& Issakainen 1991, Levula et al. 2000).
Fig. 9. Mean annual radial growth at breast height of the
felled sample trees (15 trees per treatment) before and after
the treatments. See explanation in Table 6. SSF: stand-
specific fertilization; WAN: wood ash and nitrogen.
230 A. Saarsalmi et al. Scand. J. For. Res. 19 (2004)
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In conclusion, wood ash can be used to counteract the
acidification of forest soil and to compensate for the loss
of nutrients resulting from tree harvesting and leaching.
Since the growth response on forested mineral soils to
wood ash fertilization alone seems, at least on poorer
sites, to be insignificant or even lead to a growth decline,
its direct economic benefits appear to be relatively
negligible. Particular attention should be paid to the
question of whether wood ash, with its soil ameliorating
and fertilization effects, can be utilized on poor sites
together with N fertilizer.
ACKNOWLEDGEMENTS
We thank John Derome for revising the English of this
manuscript and Anne Siika for preparing the figures.
REFERENCES
Arvidson, H. & Lundkvist, H. 2002. Needle chemistry in
young Norway spruce stands after application of crushed
wood ash. Plant Soil 238: 159�/174.
Baath, E. & Arnebrant, K. 1994. Growth rate and response
of bacterial communities to pH in limed and ash treated
soils. Soil Biol. Biochem. 26: 995�/1001.
Berden, M., Nilsson, T., Ingvar, Rosen, K. & Tyler, G. 1987.
Soil acidification�/extent, causes and consequences. An
evaluation of literature information and current research.
Report 3292. National Swedish Environmental Protec-
tion Board.
Bramryd, T. & Fransman, B. 1995. Silvicultural use of wood
ashes�/effects on the nutrient and heavy metal balance in
a pine (Pinus sylvestris, L.) forest soil. Water Air Soil
Pollut. 85: 1039�/1044.
Cajander, A. K. 1949. Forest types and their significance.
Acta For. Fenn. 56 (5): 1�/71.
Eriksson, H. 1998. Short-term effects of granulated wood
ash on forest soil chemistry in SW and NE Sweden.
Scand. J. For. Res. Suppl. 2: 43�/55.
Eriksson, H., Nilsson, T. & Nordin, A. 1998. Early effects of
lime and hardened and non-hardened ashes on pH and
electrical conductivity of the forest floor, and relations to
some ash and lime qualities. Scand. J. For. Res. Suppl. 2:
56�/65.
Fritze, H., Smolander, A., Levula, T., Kitunen, V. &
Malkonen, E. 1994. Wood-ash fertilization and fire
treatments in a Scots pine forest stand: effects on the
organic layer, microbial biomass, and microbial activity.
Biol. Fertil. Soils 17: 57�/63.
Fritze, H., Kapanen, A. & Vanhala, P. 1995. Cadmium
contamination of wood ash and fire-treated coniferous
humus: effect on soil respiration. Bull. Environ. Contam.
Toxicol. 54: 775�/782.
Fritze, H., Perkiomaki, J., Saarela, U., Katainen, R., Tikka,
P., Yrala, K., Karp, M., Haimi, J. & Romantschuk, M.
2000. Effect of Cd-containing wood ash on the microflora
of coniferous forest humus. FEMS Microbiol. Ecol. 32:
43�/51.
Halonen, O., Tulkki, H. & Derome, J. 1983. Nutrient
analysis methods. Metsantutkimuslaitoksen tiedonantoja
121: 28 pp.
Heinonen, J. 1994. KPL�/a computer programme
package for computing stand and single tree character-
istics from sample measurements. Finn. For. Res. Inst.
Res. Pap. 504: 80 pp. (In Finnish with English
summary.)
Hogbom, L., Nohrstedt, H.-O. & Nordlund, S. 2001. Effects
of wood-ash addition on soil-solution chemistry and soil
N dynamics at a Picea abies (L.) Karst. site in southwest
Sweden. SkogForsk Report 4: 20 pp.
Huhta, V. 1984. Response of Cognietta sphagnetorum
(Enchytraeidae) to manipulation of pH and nutrient
status in coniferous forest soil. Pedobiologia 27:
340�/345.
Jacobson, S. 2003. Addition of stabilized wood ashes to
Swedish coniferous stands on mineral soils�/effects on
stem growth and needle nutrient concentrations. Silva
Fenn. 37: 437�/450.
Jacobson, S. & Gustafsson, L. 2001. Effects on ground
vegetation of the application of wood ash
to a Swedish Scots pine stand. Basic Appl. Ecol. 2:
233�/241.
Jonsson, O. & Nilsson, C. 1996. Aska fran biobranslen (Ash
from biofuel). K. skogs- lantbr.akad. tidskr. 135: 25�/36.
(In Swedish.)
Jukka, L. (ed.). 1988. Metsanterveysopas (Forest Health
Guide). Metsatuhot ja niiden torjunta (Forest damaging
agents and their control). Samerka Oy, Helsinki. ISBN
951-9176-34-9. (In Finnish.)
Kahl, J. S., Fernandez, I. J., Rustad, L. E. & Peckenham, J.
1996. Threshold application rates of wood ash to an acid
forest soil. J. Environ. Qual. 25: 220�/227.
Kellner, O. & Weibull, H. 1998. Effects of wood ash on
bryophytes and lichens in a Swedish pine forest. Scand. J.
For. Res. Suppl. 2: 76�/85.
Khanna, P. K., Raison, R. J. & Falkiner, R. A. 1994.
Chemical properties of ash derived from Eucalyptus litter
and its effects on forest soils. For. Ecol. Manage. 66: 107�/
125.
Kukkola, M. & Saramaki, J. 1983. Growth response in
repeatedly fertilized pine and spruce stands on mineral
soils. Commun. Inst. For. Fenn. 114: 55 pp.
Laakkonen, O., Keipi, K. & Lipas, E. 1983. Profitability of
nitrogen fertilization in mature forests on mineral soils.
Folia For. 577: 20 pp. (In Finnish with English
summary.)
Laasasenaho, J. 1982. Taper curve and volume functions for
pine, spruce and birch. Commun. Inst. For. Fenn. 108: 74
pp.
Levula, T. 1991. Tuhkalannoitus kangasmaalla (Ash fertili-
zation on mineral soil). Metsantutkimuslaitoksen tiedo-
nantoja 394: 49�/59. (In Finnish.)
Levula, T., Saarsalmi, A. & Rantavaara, A. 2000. Effects of
ash fertilization and prescribed burning on macronutri-
ent, heavy metal, sulphur and 137Cs concentrations in
Scand. J. For. Res. 19 (2004) Effect of wood ash on soil and trees in coniferous stands 231
Dow
nloa
ded
by [
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Uni
vers
ity o
f M
anch
este
r L
ibra
ry]
at 0
9:02
22
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embe
r 20
14
lingonberries (Vaccinium vitis -idaea). For. Ecol. Manage.
126: 269�/277.
Ludwig, B., Rumpf, S., Mindrup, M., Meiwes, K.-J. &
Khanna, P. K. 2002. Effects of lime and wood ash on soil-
solution chemistry, soil chemistry and nutritional status
of a pine stand in northern Germany. Scand. J. For. Res.
17: 225�/237.
Malkonen, E. 1991. Neulas- ja maa-analyysien kayt-
tokelpoisuus metsanhoitotoimenpiteiden suunnittelussa
(The role of needle and soil analysis in the planning of
silvicultural treatments). In Makkeli, P. P. & Hotanen, J.
(eds). Metsankasvatuksen perusteet turve- ja kiven-
naismailla. Metsantutkimuspaiva Joensuussa 1991. Met-
santutkimuslaitoksen tiedonantoja 383: 52�/61. (In
Finnish)
Malkonen, E. 1996. Tuhka kangasmetsien lannoitteena (Ash
as forest fertilization on mineral soils). In Finer, L.,
Leinonen, A. & Jauhiainen, J. (eds). Puun ravinteet
tuhkana takaisin metsaan? Metsantutkimuslaitoksen tie-
donantoja 599: 21�/26. (In Finnish.)
Malkonen, E., Kukkola, M. & Finer, L. 2001. Energiapuun
korjuu ja metsamaan ravinnetase (Energy tree harvesting
and soil nutrient status). In Nurmi, J. & Kokko, A. (eds).
Biomassan tehostetun talteenoton seurannaisvaikutukset
metsassa (Consequence of utilization of bioenergy in
forests). Metsantutkimuslaitoksen tiedonantoja 816: 31�/
52. (In Finnish.)
Malmstrom, C. 1953. Skogsforskningen har ordet. Skogen
40: 30�/31. (In Swedish.)
Martikainen, P. J. 1984. Nitrification in two coniferous forest
soils after different fertilization treatments. Soil Biol.
Biochem. 16: 577�/582.
Martikainen, P. J., Ohtonen, R., Silvola, J. & Vuorinen, A.
1994. The effects of fertilization on forest soil microbiol-
ogy. Effect of fertilization on forest ecosystem. Biological
Research Reports, Univ. of Jyvaskyla 38: 40�/79. ISBN
951-34-0231-2.
Moilanen, M. & Issakainen, J. 2000. Tuhkalannoituksen
metsavaikutukset (Effects of wood ash on forests).
Metsatehon raportti 93: 18 pp. (In Finnish.)
Nordlund, G. 2000. Air pollutants. Emissions, air
quality and acidifying deposition. In Malkonen, E.
(ed.). Forest Condition in a Changing Environ-
ment�/The Finnish Case, pp. 49�/59. Forestry Sciences,
Vol. 65. Kluwer Academic, Dordrecht. ISBN 0-7923-
6228-4.
Nykvist, N. & Rosen, K. 1985. Effect of clear-felling and
slash removal on the acidity of northern coniferous soils.
For. Ecol. Manage. 11: 157�/169.
Olsson, B. A., Bengtsson, J. & Lundkvist, H. 1996. Effects of
different forest harvest intensities on the pools of
exchangeable cations in coniferous forest soils. For.
Ecol. Manage. 84: 135�/147.
Pettersson, F. 1990. Complementary fertilization after
whole-tree thinning. Institutet for skogsforbattring. In-
formation vaxtnaring-skogsproduktion 2 1990/91. Up-
psala. (In Swedish with English summary.)
Prescott, C. E. & Brown, S. M. 1998. Five-year growth
responses of western red cedar, western hemlock, and
amabilis fir to chemical and organic fertilizers. Can. J.
For. Res. 28: 1328�/1334.
Priha, O. & Smolander, A. 1994. Fumigation�/extraction and
substrate-induced respiration derived microbial biomass
C, and respiration rate in limed soil of Scots pine sapling
stands. Biol. Fert. Soils 17: 301�/308.
Ruhling, A. 1996. Effects of wood-ash on fungi and vascular
plants, and on heavy metal concentrations in berries and
edible fungi. NUTEK. Ramprogram askaterforing. R
1996: 49, Stockholm. (In Swedish with English
summary.)
Saarsalmi, A., Malkonen, E. & Piirainen, S. 2001. Effects of
wood ash fertilization on forest soil chemical properties.
Silva Fenn. 35: 355�/368.
Sikstrom, U. 1992. Stemgrowth of Scots pine and Norway
spruce on mineral soils after treatment with a low lime
dose, nitrogen fertilizer and wood ash. Institutet for
Skogsforbattring, Rapport 27: 22 pp. (In Swedish with
English summary.)
Silfverberg, K. & Issakainen, J. 1991. Effects of ash
fertilization on forest berries. Folia For. 769: 1�/23. (In
Finnish with English summary.)
Tamm, C. O. 1991. Nitrogen in Terrestrial Ecosystems.
Springer, Heidelberg.
Tamminen, P. 1998. Typpi- ja tuhkalannoitus punalatikan
vaivaamassa mannikossa (Nitrogen- and ash fertilization
in a pine stand infested by Aradus cinnamomeus ).
Metsatieteen aikakauskirja. Folia For. 3: 411�/420. (In
Finnish.)
Tamminen, P. 2000. Soil factors. In Malkonen, E. (ed.).
Forest Condition in a Changing Environment �/ The
Finnish Case, pp. 338�/359. Forestry Sciences,
Vol. 65. Kluwer Academic, Dordrecht. ISBN 0-7923-
6228-4.
Unger, Y. L. & Fernandez, I. J. 1990. The short-term effects
of wood-ash amendment on forest soils. Water Air Soil
Pollut. 49: 299�/314.
Vance, E. D. 1996. Land application of wood-fired and
combination boiler ashes: an overview. J. Environ. Qual.
25: 937�/944.
232 A. Saarsalmi et al. Scand. J. For. Res. 19 (2004)
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Appendix A. Average total micronutrient and heavy metal concentrations in the humus layer (dry matter basis) in
the experiments 5 and 10 yrs after the treatments
402 407 408 415 416
Sampling Control
(mg kg�1)
Wood ash
(mg kg�1)
Control
(mg kg�1)
WAN
(mg kg�1)
Control
(mg kg�1)
Wood ash
(mg kg�1)
Control
(mg kg�1)
WAN
(mg kg�1)
Control
(mg kg�1)
WAN
(mg kg�1)
B After 5 yrs 2.8* (0.4) 4.9 (0.5) 1.6* (0.1) 7.3 (1.1) 1.6* (0.1) 7.4 (2.0) 3.0* (0.1) 12.5 (1.7) 3.6** (0.2) 13.2 (1.0)
After 10 yrs 1.2** (0.2) 6.3 (1) 0.3** (0.1) 2.7 (0.4) 0.7* (0.05) 9.9 (2.6)
Cd After 5 yrs 0.24 (0.15) 0.14 (0.04) 0.29 (0.13) 0.10 (0.0) 0.54 (0.45) 0.19 (0.09) 0.10* (0.0) 0.24 (0.02) 0.15 (0.04) 0.47 (0.30)
After 10 yrs 0.25*** (0.01) 0.76 (0.05) 0.22** (0.01) 0.27 (0.01) 0.20* (0.0) 0.40 (0.06)
Cr After 5 yrs 18.3 (1.8) 16.2 (1.1) 9.2 (1.2) 10.3 (0.9) 13.3 (1.8) 16.7 (1.7) 27.8 (3.8) 21.5 (3.5) 23.5 (4.6) 20.4 (1.6)
After 10 yrs 18.1 (5.4) 26.1 (3.4) 23.0 (3.9) 15.1 (3.3) 15.3 (2.8) 24.8 (6.5)
Cu After 5 yrs 4.0 (0.3) 4.8 (0.6) 6.1 (0.6) 7.9 (0.3) 5.1 (0.3) 6.2 (0.9) 6.9** (0.4) 14.3 (1.4) 7.4* (0.4) 9.7 (0.5)
After 10 yrs 6.2*** (0.3) 11.1 (0.4) 4.9 (0.4) 5.8 (0.2) 5.9 (0.5) 9.3 (1.5)
Fe After 5 yrs 5127 (178) 5307 (183) 2110 (286) 2633 (253) 3190 (190) 3190 (653) 3653 (519) 3680 (270) 4560 (340) 3417 (249)
After 10 yrs 3120 (144) 3470 (143) 2500 (488) 3223 (783) 2407 (213) 2243 (262)
Mn After 5 yrs 77 (2) 153 (29) 138 (9) 463 (90) 75 (12) 227 (77) 664 (71) 1870 (564) 872* (152) 1407 (66)
After 10 yrs 83** (5) 774 (38) 100*** (11) 584 (12) 84* (13) 853 (178)
Ni After 5 yrs 11.2 (1.0) 9.7 (0.9) 5.6 (0.4) 6.2 (0.4) 7.3 (1.1) 8.1 (1.3) 15.7 (1.8) 12.6 (2.4) 13.9 (2.3) 12.6 (0.8)
After 10 yrs 17.8 (4.9) 23.2 (3.1) 17.7 (3.0) 11.0 (2.8) 14.3 (2.1) 23.4 (4.5)
Pb After 5 yrs 45.4 (1.6) 39.7 (2.6) 48.9 (6.1) 56.9 (3.5) 37.3 (0.9) 35.7 (0.4) 34.7* (2.1) 44.3 (2.0) 33.8 (2.0) 29.8 (1.0)
After 10 yrs 53.4 (0.8) 50.6 (2) 38.1 (3.0) 36.8 (1.3) 35.4 (2.1) 35.6 (0.7)
Zn After 5 yrs 38.7 (3.2) 60.0 (9.1) 42.5* (3.1) 59.1 (4.2) 37.6 (1.9) 39.6 (4.6) 69.2* (3.1) 117.8 (10.6) 53.0** (8.2) 103.7 (2.9)
After 10 yrs 47.7** (3.9) 210.3 (17.9) 31.1*** (1.1) 57.2 (1.8) 42.3* (2.3) 60.8 (4.1)
Data are shown as mean (SEM).
See Table 6 for explanations of treatments.
WAN: wood ash and nitrogen; B: boron; Cd: cadmium; Cr: chromium; Cu: copper; Fe: iron; Mn: manganese;
Ni: nickel; Pb: lead; Zn: zinc.
*p B/0.05, **p B/0.01, ***p B/0.001.
Scand. J. For. Res. 19 (2004) Effect of wood ash on soil and trees in coniferous stands 233
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