The effects of forest liming on fertilization on fine-root growth

V o l u n ~ p a p e r

THE EFFECTS OF FOREST LIMING ON FERTILIZATION ON FINE-ROOT GROWTH

Hans Persson and Kerstin Ahlstr6m

The Swedish University of Agricultural Sciences

Department of Ecology and Environmental Research

Box 7072

S-750 07 Uppsala, SWEDEN

Abstract. Results are reported from the investigations of fine-root development in Norway spruce and

Scots pine stands in South and Central Sweden, subjected to different ~ and fertilization regimes.

The growth responses of the fine roots to varying mineral nutrient regimes seem to he dependent on the

tree species, the age of the tree population and soil conditions. Nitrogen fertilization in some of

the investigated stands had negative effects on the developa~it of fine roots, resulting in a reduction

in the amou/it of fine roots £o about 50% of that in the eontrol. However, negative effects were not

consistent in all stands, positive growth responses were also obtained. In these stands, the arot~t of

fine roots was increased by 2 to 3 times. Liming in combination with fertilization resulted in a

strong decrease in the amotknt of fine roots to about 80% of that in the control in some of the inves-

tigated stands. Liming in high doses is expected to produce a persistent increase in li~ (H20) and base

saturation in the soil. However, results from the present study suggest that liming may have a

negative effect on the development of tree fine roots, particularly in areas with a high N deposition.

The application of crushed dolomite had less negative effects on fine root development than crushed

oalcitrie lime and different types of residue products, such as wood and peat ashes.

I. Introduction

Widespread soil acidification has been reported on productive forest

sites in S and SW Sweden (of. Tamm and Hallb~cken, 1988; Falkengren-

Grerup, 1987). The acidification processes caused a pH (H20) decrease of

about one unit in many of those forest stands. There is no evidence that

existing differences in forest history, climate, or soil mineralology

could explain this difference. The most likely explanation is the

difference in the acid deposition load. At lower pH, loss of important

cations (Ca, Mg, K and Na) takes place. Thus, Falkengren-Grerup (1987)

reported that the available storage of Ca and Mg was on an average decreased by 50%.

As a consequence of soil acidification, destabilization of root

systems has been observed (of. Persson, 1985; Persson and B6rjesson,

1986; Puhe et al., 1986). In four Norway spruce stands in S and SW

Sweden with varying degrees of needle-loss in the canopy, damage symptoms

(fine-root loss) were observed in the root systems, in particular in the

mineral soil horizons. Root damage is usually observed as a decline in

the amount of living fine-roots, an increase in the amount of dead fine

roots, an increase in the amount of dead vs live fine roots (a lower

live/dead ratio) and an increasing amount of dead medium and coarse

roots. The tree roots are more superficially distributed, which makes

them more sensitive to various kinds of environmental stress e.g. wind

movement, summer drought and shortages of mineral nutrients.

The most important factors (of. e.g. Ulrich, 1989; Kuyper and de

Vries, 1989) which may cause a reduction in fine-root growth and mycorrhizal development are:

Water, Air, and Soil Pollution 54: 365-375, 1990/91. © 1990/91 Kluwer Academic Publishers. Printed in the Netherlands.

366 H. PERSSON AND K. AHLSTROM

(i) ion-imbalances, viz. a reduction in base saturation with subsequent losses of, i.e~ Ca and Mg from the soil by leaching and an increased concentration of AI-, Fe-, H-ions and, in many cases, of heavy metals in the rhizosphere; and

(2) high N deposition leading to a decreased mycorrhizal frequency and a root system more sensitive to disturbances (drought, wind-break, nutrient shortage, etc.).

By adding lime material and compensatory fertilization, in cases where nutrient deficiency is observed, it may be possible to increase the ability of both soil and trees to withstand some of these stress factors.

The chemistry and degree of acidity of the soil are most important in root-rhizosphere relationships. The processes of ion uptake of, e.g. P, Mg and Ca are dependent on the degree of penetration of fine roots and mycorrhizas into the soil (of. Puhe et al., 1986). If the uptake process is hampered, the growth of the whole tree is affected. Root damage in this context may underline a pre-disposing stress, thus reducing water and mineral nutrient uptake.

Measures to counteract soil acidification and nutrient leaching on productive forest sites by liming and fertilization are still at an experimental stage; however, there is strong evidence of negative short- term effects on the development of fine roots and mycorrhizas (of.

Persson, 1988). The data reported in the present paper have been extracted from different projects aimed at shedding light on the mechanisms determining the growth dynamics of fine roots in relation to the mineral nutrient conditions of the forest soil (ef. e.g. Ahlstr6m et al., 1988; Persson, 1988).

2. Materials and Methods

A short description of the investigated stands is to be found in Table I. Most of the trials, such as H~cksvik, Nissafors, Tormoser6d, V~rnamo and Vr~, have been established by the Institute of Forest Improvement (Insti- tutet f6r Skogsf6rbattring) in order to test different fertilizer regimes on forest growth. The other stands (Strgsan, Hassl6v and Oringe) were established as part of the experiments with fertilizers and lime at the Swedish University of Agricultural Sciences (of. Popovic and Andersson, 1984; Andersson and Persson, 1988; Tamm, 1985). All stands except H~cksvik, a mixed coniferous stand, and Vr~, a Scots pine J (Pinus syZves~ris L.) stand, consisted of Norway spruce (Picea abies [L.] Karst).

Different experimental treatments were carried out in the trials (of. Table I) aimed at testing the effects of different fertilizers (V~rnamo) and pH-increasing substances and their application rate (Oringe and HasslOv). Besides N, other growth-limiting elements such as Mg, P, K, and micromineral nutrients were added in some trials. The investigated stands varied between 18 and 99 yr of age. All stands, except Strgsan in the Central part of Sweden, were located in S and SW Sweden. Data on the effects of the experimental treatments in aboveground tree growth are so far only available from H~cksvik and Str~san, where positive responses for all treatments were obtained, and for Tormoser6d and VrA where no effects were observed.

EFFECTS OF FOREST LIMING AND FERTILIZATION ON FINE-ROOT GROWTH 367

Table I

Short description of the investigated stands. Positive effect on aboveground tree growth = (+); negative = (-); no effect on tree growth (0); no revision on aboveground tree growth carried out yet =(n). N* = ammonium nitrate; N** = urea; Micro = micro-mineral nutrients.

Forest Species Avg. Treat- Stand Age ment

1985 Started

Different Treatments/ Effect on Tree Growth

H~cksvik Scots pine 99 1983

Hassl6v Norway spruce 36 1983

Nissafors Norway Spruce 42 1984

0ringe Norway spruce 44 1984

Strgsan Norway spruce 18 1967

Tormoser~d Norway spruce 84 1982

V~rnamo Norway spruce 46 1983

Vrg Scots pine 74 1978

Control; 150 kg N* ha -I (15~) (+); 225 kg N* ha -I (+); Nor-way spruce 150 kg N* + 15 kg Mg + (85~) Micro ha -I (+)

Control; 1.750 kg CaCO 3 ha-l; 1.550 kg Dolomite ha-l; 3.450 kg Dolomite ha-i; 8.750 kg Dolomite ha -I (n)

Control; 150 k~N* ha-l; 150 kg N* + 20 kg Mg ha- 150 kg N* + 20 kg P ha -I + 20 kg Mg + 39 kg K + Micro ha -I (n)

Control; 3.550 kg Dolomite ha-l; 2.000 kg CaCO 3 ha-l; 3.830 kg CaCO 3 ha-l; 2.800 kg Wood ash ha- l; 2.800 kg Peat ash ha -I (n)

Control; 60-120 kg N* + 0-80 kg K + 0-22 kg Mg + Micro ha -I yr -I (+); 60-120 kg N* + 0-40 kg P + 0- 80 kg K + 0-22 kg Mg + Micro ha -I yr -I (+); 60-120 kg N* + 0-40 kg P + 0-80 k S K + 4.000 kg CaCO 3 + Micro ha -~ yr -I (+)

Control; 150 kg N* ha -I (0); 225 kg N* ha -I (0): 150 kg N** + 15 kg Mg + Micro ha -I (0)

Control: 150 kg N* ha -I" 150 kg N** ha-l; (n)

Control; 150 kg N* + 2.000 CaCO 3 ha -I (0); 150 kg N* ha -I (0); 150 kg N**ha -I (0)


The effects of the experimental treatments on fine-root growth was measured using ingrowth cores installed in the forest soil and then successively removed (cf. Persson, 1980). The ingrowth core technique, in this context, is an ideal method of comparing different experimental treatments/gradients. In order to install the ingrowth cores in the stony soil substrate, an iron bar was used to make holes in the ground. Since it was impossible to obtain an opening of known diameter when large rocks sometimes had to be removed, sieved soil was refilled both into the ingrowth cores and into any gaps within the vicinity of the cores. A nylon stocking with an outside diameter somewhat larger than the inner diameter of the hole was inserted into the hole with the help of a plastic tube (diameter = 7 cm). The mesh size of the stockings was 7.5, thus allowing roots to penetrate freely. The hole was refilled with root-free mineral soil from the same stand and replaced with the help of a wooden dowel.

The ingrowth cores were resampled by digging around them using a long spade and removing the surrounding soil. The cores were then stored in a deep-freeze at -20°C until final sorting could be carried out. The living and dead root fragments were sorted into different diameter fractions, the diameter measurements being made in the middle of each fragment with vernier callipers (Persson, 1978; Vogt and Persson, 1989). The diameter classes were living and dead roots: < 1 mm; 1 to 2 mm; and > 2 mm. The living and dead fine roots were sorted into tree roots (coniferous roots) and the roots of other species (dwarf shrubs, herbaceous and graminaceous species). The latter fraction was not included in the data presented in this paper. The total length of the fine roots was estimated using a Comair root length scanner. Subsequent to the length measurements, the root fractions were dried at +55 ° C for 48 hr and weighed to the nearest mg.

3. Results

Results from experiments on the growth responses of the fine roots to different fertilization and liming regimes are to be found in Tables II and III and in Figures 1 and 2. In the 30 yr old Norway spruce stand at Strgsan, no significant changes were obtained in two of the fertilization regimes investigated compared with the controls, in terms of both dry weight and length. However, a considerably lower amount of fine roots was obtained in the trial with both fertilizers and lime, the total dry weight of the fine roots (biomass + necromass) in the ingrowth cores of the latter stand was 35% of that in the control. The fine roots at StrAsan were furthermore thicker (cf. Table III) than on the other sites (e.g. the ratio of fine-root length/weight varied between ii and 13 in the different treatments). The data from Str~san are, however, not directly comparable with the data from other sites, since the ingrowth cores were installed in this stand in June 1985 and in the other stands at the end of October 1985. From the viewpoint of stem wood production, the fertilized and limed trial and the two fertilized trials were more productive than the control (A. Aronsson, unpublished data). The tree stand at StrAsan had developed under rather favorable soil conditions, viz. on a slope with till substrate and percolating soil water.


Table II

Dry weight (g DW 55°C m -2) of living fine roots (diameter < i mm) and the total amount of roots (living + dead root fractions in ingrowth cores installed in some fertilization and liming experiments in June 1985 for the forest stand Strgsan and in the end of October 1985 for the other stands. All ingrowth cores were resampled in the middle of October 1987. The estimates are given as means + 1 S.E. (n = 8). N* = ammonium nitrate; N** = urea; Micro = micro-mineral nutrients; Differences between fertilized and control areas at P < 0.05 (analysis of variance) are indicated by different letters: a capital indicates a numerically higher estimate.

Forest Stand/Treatment Fine Roots Total Roots

H~cksvik Control 52 + 31 a 61 + 37 a Fertilized 150 kg N* ha -I 83 + 37 A 107 + 47 A Fertilized 225 kg N* ha -I 116 + 47 B 154 ~ 75 B Fertilized 150 kg N* + 15 kg Mg + Micro ha -I 66 _+ 20 a 102 + 45 a

Nissafors Control 114 + 67 A 134 + 83 a Fertilized 150 kg N* 113 + 54 a 140 + 76 A Fertilized 150 kg N* + 20 kg Mg ha -I 66 _+ 54 a 80 _+ 79 a Fertilized 150 kg N* 20 kg P + 39 kg K +

20 kg Mg + Micro ha -I 91 ! 40 a 104 ± 44 a

Str~san Control 114 + 90 a 150 +127 a Fertilized 60-120 kg N* + 0-80 kg K + 0-22

kg Mg + Micro ha -I yr -I 141 i 90 A 202 ±119 A Fertilized 60-120 kg N* + 0-40 kg P + 0-22

kg Mg + Micro ha -I yr -I 127 ± 97 a 182 ±146 a Fertilized 60-120 kg N* + 0-40 kg P + 0-80

kg K + 0-22 kg Mg + 4.000 kg CaCO 3 + Micro ha -I yr -I 39 i 25 B 52 ± 39 B

Tormoser~d Control 165 +124 A 299 +167 A Fertilized 150 kg N* ha -I 143 ~ 75 a 206 +I04 a Fertilized 225 kg N* ha -I 140 + 93 a 205 $127 a Fertilized 150 kg N* + 15 kg Mg + Micro ha -I 90 + 86 a 133 $I19 a

V~rnamo Control 68 + 48 A 79 + 50 A Fertilized 150 kg N* ha -I 131 + 61 b 161 ~ 77 b Fertilized 150 kg N** ha -I 152 $ 61 B 174 + 70 B

Vr~ Control 90 + 36 A 103 + 44 A Fertilized 150 kg N* + 2.000 kg CaCO 3 ha -I 29 + 15 c 33 $ 18 c Fertilized 150 kg N* ha -I 46 $ 32 be 48 ~ 34 be Fertilized 150 kg N** ha -I 62 $ 37 b 62 + 41 b


Table III

Root length (m m -2) and root length/weight (m g l) ratios for living fine roots (diameter < 1 mm) obtained in ingrowth cores (cf. Table 2) installed in some fertilization and liming experiments. The estimates are given as means + 1 S.E. (n = 8). N* = ammonium nitrate; N** = urea; Micro = micro-mineral nutrients; Differences between fertilized and control areas at P < 0.05 (analysis of variance) are indicated by different letters: a capital indicates a numerically higher estimate.

Forest Stand/Treatment Fine-Root Length/Weight Length Ratio

H~cksvik Control 1040 + 630 a 20 + 3 Fertilized 150 kg N* ha -I 1620 $ 790 A 19 $ 3 Fertilized 225 kg N* ha -I 2340 $ 920 B 20 ~ 2 Fertilized 150 kg N* + 15 kg Mg + Micro ha -I 1350 $ 490 a 20 $ 4

Nissafors Control 2710 + 1810 A 23 + 4 Fertilized 150 kg N* 2600 + 1250 a 23 + 3 Fertilized 150 kg N* = 20 kg Mg ha -I 1340 $ 1190 a 20 ~ 5 Fertilized 150 kg N* 20 kg P + 39 kg K +

20 kg Mg + Micro ha -I 2230 ! 1330 a 24 ~ 4

StrAsan Control 1330 + 920 a 12 + 2 Fertilized 60-120 kg N* + 0-80 kg K + 0-22

kg Mg + Micro ha -I yr -I 1520 ± 980 A ii ± 2 Fertilized 60-120 kg N* + 0-40 kg P + 0-22

kg Mg + Micro ha -I yr -I 1610 ± 1300 a 13 ± 4 Fertilized 60-120 kg N* + 0-40 kg P + 0-80

kg K + 0-22 kg Mgl+ 4.000 kg CaCO 3 + Micro ha- yr -I 480 ± 300 B 12 ± 4

Tormoser6d Control 2660 + 2150 A 17 + 4 Fertilized 150 kg N* ha -I 2570 + 1450 a 18 + 3 Fertilized 225 kg N* ha -I 2210 ~ 1340 a 16 + 2 Fertilized 150 kg N* + 15 kg Mg + Micro ha -I 1460 _+ 1440 a 16 _$ 3

V ~ a m o Control 1170 + 850 A 17 + 2 Fertilized 150 kg N* ha -I 2770 $ 1310 b 22 $ 3 Fertilized 150 kg N** ha -I 3590 _~ 1600 B 24 _$ 3

Vr& Control 2560 + 990 A 29 + 5 Fertilized 150 kg N* + 2.000 kg CaCO 3 ha -I 820 + _ 420 c 29 _ $ 7 Fertilized 150 kg N* ha -I 1190 ! 950 bc 25 ± 5 Fertilized 150 kg N** ha -I 1790 ± 1160 b 28 ± 3


Negative responses to N fertilization (with ammonium nitrate) and fertilization (with ammonium nitrate) plus lime on fine-root growth were obtained at Vrg (Table II). The total amounts of fine roots in the ingrowth cores in the latter treatments (biomass ± necromass) were 47 and 32%, respectively, of the amounts in the control. No significant difference was obtained with fertilization with urea. In this stand, which consists of Scots pine on a nutrient-poor podzol with a hard iron pan beneath the leached horizon, the experimental treatments generally seem to have hampered root development. The fine roots were generally thinner (Table III) than on the other sites (e.g. the ratio of fine-root length/weight varied between 25 and 29 in the different treatments). No significant effects on stem wood (unpublished data from the Institute of Forest Improvement) are to be found from an inventory made in the latter stand.

Negative trends in the data on root growth were generally found at Nissafors and Tormoser6d (Tables II and III). Although the amounts of fine roots in the fertilized plots were not significantly different from the controls, the consistent negative pattern of the changes at both Nissafors and Tormoser6d in all three trials, make it clear that negative responses should be expected in these stands. The highest average levels of fine roots in the ingrowth cores (Tables II and III) were to be found in the control at Tormoser6d. At this site the soil profile had a greater mixture of organic matter (peat) compared with all other sites. At Tormoser6d, no effects of fertilization on step wood increment were indicated (data from the Institute of Forest Improvement); no such data are available from Nissafors for the time being. This suggests that some other mineral nutrient(s) than N (e.g. P) may limit stem wood growth in this area.

The data on root growth from the investigations at Varnamo and at H~cksvik generally showed a positive growth development of fine roots in the fertilized trials. At Varnamo, the total dry weight of the fine roots (biomass + necromass) was 2.4 times that of the control in the ammonium nitrate and 3.1 times in the urea trial, respectively. At H~cksvik, a positive response was obtained in the plot with the highest amount of N fertilizers (22 kg ammonium nitrate). In the latter trial, the total dry weight of the fine roots was 2.3 times that of the control. At Hgcksvik the impact on stem-wood growth of fertilization was positive in all trials included in the present study (data from the Institute of Forest Improvement).

Available data from the liming experiment at Oringe, up until 3 yrs after the experiment started (cf. Table I; Figure i), indicate negative effects of ashes, particularly peat ash (2.800 kg ha-l). The amount of fine roots in the peat ash trial was significantly lower (PI= 0.05) than in the control in 1986 and 1987. For wood ash (2.800 kg ha- ) and a high dose of crushed lime (3.830 kg ha-l), consistent negative trends were also found. On the other hand liming with dolomite lime (3.550 kg ha -1 ) and crushed lime in low doses (2.000 kg ha -1 ) had no effect or trends to a positive effect on fine root development, as compared with the control.

Data from the liming experiment at Hassl6v, 2 yr. after liming (cf. Table I; Figure 2), indicate a ~ositive effect of liming at a low dose of crushed dolomite (1.550 kg ha-±). The amount of fine roots (Figure 2) was significantly higher (p = 0.005) in the dolomite treatment on both sampling occasions than in all other liming treatments on both sampling occasions. Furthermore, it was significantly higher than on the control.


300

tz~

C )

~ z00

N 100 Z

O

. < 0

1985 I 1986

DOLOMITE (3,550 kg ha -I) . . . . . . .._ . . . . . . . 0 CALEITRIC LIME (2.000 kg ha

. . . . . . ".-.5 ............ .~ EONTROL j - - ~ . . . . . . . . . ........... WOOD ASH (2.800 kg ha 4)

... 1 1 ~ ' - . ......... -.-~. ...... -v CALEITRIE LIME (3.830 kg ha 1.1.--y ~,~.~.~:~:-"-~"~ .... _ ..... -e PEAT ASH (2.800 kg ha -~)

I ...... -.~.f _-41 ....

S 'O 'N 'D IJ ' F ' M ' A ' M ' J ' J ' A ' S ' O ' N ' D I J ' F ' M ' A ' M ' J ' J ' A ' S ' O ' N ' D I J ' F ' t 1987 t 1988

Figure I. The growth development in ingrowth cores (8 in each sampling and treatment) of fine roots (< i mm in diameter) at 0ringe. Sampling was carried out on November 12, 1985, November ii, 1986, and on October 27, 1987. In the diagram only living fine-roots (< i mm in diameter) are included.

_ 300 e.J ' f f

t ~ B 200 0 r.,,."

N u_

~_ 100 O

z

O

< 0

.~- ~ - ~ " ~ . 1 . 1 . ~ , ~ DOLOMITE (1.550 kg ha -I )

. ~ - ~ " EONTROL . ~ - - ' ~ ' ~ _.~3 DOLOMITE (3./+50 kc 3 ha-l)

~ - ~ ' ~ . ...... ---~ DOLOMITE (8.750 kg ha-') ' " . . . . . " ........ EALEITRIE LIME (I,750 kg ha-

J'A'S'O'N'DIJ'F'M~A'M'J'J 'A'S'O'N'DIJ 'F'M~A~M'J'J'A'S'0'N'DI 1985 I 1986 1987 I 1988

Figure 2. The growth development in ingrowth cores (8 in each sampling and treatment) of fine roots at Hassl6v. Sampling was carried out on November 12, 1985 and on October 29, 1987 (cf. Figure i).


With higher doses of dolomite lime (3.450 and 8.570 kg ha -1 , respectively), no effects on fine-root growth were to be found. This is also the case for the low dose of crushed lime (1.750 kg ha-l).

In both liming experiments at Hassl6v and at 0ringe no fertilization was carried out. The root studies in both these stands were carried out during the first years after liming when the vertical movement of the lime, causing an increase in pH and cation exchange capacity (CEC) in the uppermost part of the soil profile, had just started (cf. Andersson and Persson, 1988). No data are available on the long-term effects of liming on root growth for the time being.

4. Discussion

In forests a substantial part of the total mineral nutrient storage is bound up in structural parts of the trees. A large fraction of mineral nutrients are then removed each time the trees are harvested. The on- going process of soil acidification from acid rain furthermore causes accelerated losses of important cations in the percolating soil water, which cannot be completely replaced by weathering. In many forests, therefore, compensatory fertilization is necessary. At present, research on the effects of forest fertilization has mainly been directed towards the effects on tree growth or wood increments. Attempts to correlate the growth dynamics of fine roots in forests with soil chemistry have so far led to inconclusive results (cf. Ahlstr6m et al., 1988; Persson, 1980). Knowledge of how the tree roots and mycorrhiza react to different kinds of fertilizers are, to a great extent, lacking and are urgently needed before fertilization can be applied on a large scale.

Negative effects of a high N supply on the development of the fine roots and mycorrhizas have been noted by many authors (cf. e.g. Ahlstr6m et al., 1988; Buchholz and Neumann, 1964; Farell and Leaf, 1974; Heinsdorf and Schulzke, 1969; Heinrich and Wojewoda, 1976; Menge et al., 1977; Meyer, 1984; Ohenoja, 1978; Paavilainen, 1967; Persson, 1980; Ritter and T611e, 1978). The effects of N fertilization on the mycorrhizal roots are similar to those reported from heavily polluted areas (cf. Arnolds, 1988; Kuyper and de Vries, 1989). However, as were shown by the data of the present study, the negative effects of N fertilization on fine roots were not consistent in all stands (cf. Tables II and III), since positive effects were obtained in some of the trials at HAcksvik and at V~rnamo. The growth responses of fine roots to different fertilization regimes seem to be dependent on the tree species, the age of the tree population and soil conditions. While the negative effects of N fertilization have been very well documented in literature, less is known about the effects of other types of fertilization, e.g. with different kinds of macronutrients and mieronutrients and liming.

According to available information, liming in many cases has negative effects on fine roots and their distribution in the soil and on the development of mycorrhizal root tips (cf. Adams et al., 1978; Blaschke, 1986; Fiedler and Hunger, 1963; Hunger~ 1962; Murach, 1987; Murach and Sch~nemann, 1985; Z6ttl, 1964). Available data from the present study (Tables II and III) indicate a considerable decrease in the amount of fine roots in the limed and N-fertilized trial at Vr~ in the limed and fertilized (N, P, K, Mg + micro-mineral nutrients) (cf. Tamm 1985) trial at Str~san. Thus, fertilization in combination with liming seems to have


a strong negative effect on the development of fine roots. It is, therefore, likely that, in areas with a high N deposition, liming may cause a decrease in the amount of fine roots.

Our knowledge of the effects of liming on forest growth are mainly based on old experiments, in which root growth was not taken into account (Derome et ai., 1986; Hallb~cken and Popovic, 1985; Nihlg~rd and Popovic, 1984; Popovic and Andersson, 1984). Both Scots pine and Norway spruce on poor sites will usually react with a decrease in stem wood production for a period of i0 to 30 yr after which a growth increase may follow (cf. Andersson and Persson, 1988). The latter reduction in tree growth for a period after liming has been related to a decreased net N mineralization in the organic layer. When finally the liming effect reaches the mineral soil, causing an increase in the pH there, the effect on the N mineralization will be the reverse (cf. Andersson and Persson, 1988). Both crushed calcitic and dolomitic lime have limited solubilities and will affect the pH and base-saturation in the mineral soil horizons very slowly. In this context, the negative effects of high lime doses on the fine-root growth/should not be forgotten. It is likely that a reduced root function in the organic layer due to the effect of lime, may be the prime reason for the decrease in tree growth after liming. In particular, in forest stands with a superficial and reduced fine-root system due to soil acidification (cf. Puhe et al., 1986), the trees may react negatively to liming.

Acknowledgment

This work was supported financially by the Swedish Council for Forestry and Agricultural Research and the Swedish National Environmental Protection Board.

References

Adams, S.N., Cooper, J.E., Dickson, E.L. and Seaby, D.A.: 1978, Forestry

51, 57. Andersson, F. and Persson, T.: 1988, SNV Rapport 3518. Ahlstr6m, K., Persson, H. and B6rjesson, I.: 1988, Plant and Soil 106,

179. Arnolds, E.: 1988, Trans. Brit. Mycol. Soc. 90, 391. Blaschke, H.: 1986, Forstw. Obl. 105, 324. Buchholz, F. and Neumann, E.: 1964, Albrecht Thaer Arch. 8, 525. Derome, J., Kukkola, M. and M&ik6nen, E.: 1986, SNV Rapport 3084. Falkengren-Grerup, U.: 1987, Environmental Pollut. 43, 79. Farrel, E.P. and Leaf, A.L.: 1974, Can. J. For. Res 4, 366. Fiedler, H.J. and Hunger, W.: 1963, Arch. Forstwes. 12, 936. Hallb~cken, L. and Popovic, B.: 1985, SNV Rapport PM 1880. Heinsdorf, D. and Sehulzke, D.: 1969, Arch. Forstwes. 18, 731. Heinrich, Z. and Wojewoda, W.: 1976, Ekol. Pol. 24, 319. Hunger, W.: 1962, Tagungsber. Dal. 50, 179. Kuyper, Th. W. and de Vries, B.W.L.: 1989, in press, "Forest Ecosystems

and their Components," p.O0. Muraeh, D.: 1987, "Air Pollution and Ecosystems," COST International

Symposium in Grenoble 1822 May 1987, p. 445.


Murach, D. and Schfinemann, E.: 1985, Allg. Forst. Zeitschrift 43, 1151. Menge, J.A., Grand, L.F. and Haines, L.W.: 1977, For Se~. 23, 37. Meyer, F.H.: 1984, Allg. Forst Zeitschrift 39, 212. NihlgArd, B. and Popovic, B.: 1984, SNV Rapport 1851. Ohenoja, E.: 1978, Ann. Bot. Fenn. 15, 38. Paavilainen, E.: 1967, Folia Forestalia 31, i. Persson, H.: 1978, Oikos 30, 508. Persson, H.: 1980, Acta Phytogeogr. Suec. 68, i01. Persson, H.: 1985, (ed.) "Vad h~nder med skogen - skogsd6d pg v~g," Liber

F6rlag AB, Stockholm. Persson, H.: 1988, "Liming as a measure to improve soil and tree condi-

tions in areas affected by air pollution," SNV Rapport 3518, p. 71. Persson, H. and B6rjesson, I.: 1986, "Indirect Effects of Air Pollution

on Forest Trees" Proc. COST Workshop, J~lich, 5-8 December 1985, p. 61.

Popovic, B. and Andersson, F.: 1984, SNV Rapport 1792. Puhe, J., Persson, H. and B6rjesson, I.: 1986, All E. Forst Zeitschrift

20, 488. Ritter, G. and T611e, H.: 1978, Beitr. Forstw. 4, 162. Tamm, C.O.: 1985, f. Skogs- o. Lantbr. adad. tidskr. Suppl. 17, 9. Tamm, C.O.: and Hallb~cken, L.: 1988, Ambio i, 56. Ulrich, B.: 1989, in press, Adv Environ. Sci. 4, Springer-Verlag,

Berlin. Vogt, K. and Persson, H.: 1989, in press, "Techniques and Approaches in

Forest Tree Ecophysiology," CRS Press, Inc., Florida, p.00. Z6ttl, H.W.: 1964, Mitt. Staatsforstvervaltung Bayerns 34, 333.

The effects of forest liming on fertilization on fine-root growth

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