Infection experiments with Gremmeniella abietina on seedlings of Norway spruce and Scots pine

Conidia of Gremmeniella abietina infected and caused disease symptoms in annual shoots of both Scots pine (Pinus sylvestris) and Norway spruce (Picea abies) seedlings. In Norway spruce shoots the infection remained largely latent, with only a few seedlings showing symptoms. Mycelial growth inside the shoots was faster in Scots pine than in Norway spruce and was favoured by low temperature in both hosts. The shoots of Norway spruce seedlings had higher endophyte populations than those of Scots pine, and the populations were decreased by low temperatures. Reductions in the normal epiphytic or endophytic flora by acid mist treatments seemed to favour the development of G. abietina.     

An integrated spatial assessment of the investment potential of three species in southern Ontario, Canada inclusive of carbon benefits

This study explores the economic feasibility of several long-rotation afforestation scenarios for southern Ontario, Canada. Three species, red pine (Pinus resinosa Ait.), Norway spruce (Picea abies L.) and black walnut (Juglans nigra L.) are examined. We integrate growth and yield models, site suitability maps, and several management scenarios to investigate the investment attractiveness of these species inclusive and exclusive of carbon sequestration values. We report net present values (NPV), internal rates of return (IRR) and two break-even price metrics. For wood value only scenarios the IRRs range from 4.3 to 4.6% for red pine and 3.4–3.6% for Norway spruce (for the most attractive 10,000 ha, in a single rotation scenario). Black walnut had rates of return 3.5–3.7% for the most attractive 10,000 ha area. Adding carbon valued at Cdn $3.4 per metric ton CO_2 − e (roughly 2005 prices in the Chicago Climate Exchange) increases rates of return by about 0.6% for red pine and Norway spruce and 0.4% for black walnut scenarios. Perhaps surprisingly these returns are comparable and better than 20-year rotation hybrid poplar plantations. To achieve a 6% real rate of return break-even carbon prices were $10.7/t CO_2 − e for red pine, $12.6/t CO_2 − e for Norway spruce and $17.2/t CO_2 − e for black walnut (again for the “best” 10,000 ha). Although somewhat unremarkable, the results suggest that these longer-rotation species may be a better investment than perhaps previously expected if landowners have the appropriate site conditions.     

Eine Methode zur Prüfung der Anfälligkeit und Ausbreitungsresistenz der Fichte (Picea abies Karst.) gegenüber dem Wurzelschwamm Fomes annosus (Fr.) Cooke1

A method for examining Norway spruce (Picea abies Karst.) for susceptibility and resistance to the spread of Fomes annosus (Fr.) Cooke . An easily applied method is described for determining the results of infections and the reactions of young Norway spruce to Fomes annosus. By the use of genetically homogeneous material, e. g. clonal plants, the importance of environmental factors such as nutrient supply and also the varying virulence of different fungal strains can be studied.     

Economic evaluation of cyclic regimes in beech (fagus sylvatica L.)

A general model for comparing the profitability of natural regeneration in beech (Fagus sylvatica L.) with planting of Norway spruce (Picea abies L.) is developed. The model is basically a method of comparing a series of net present values. An example of using the model is given: BEECH (90–110) denotes a cyclic regime in which regeneration is initiated at age 90 of a stand, and the canopy trees are cleared at age 110. This regime is compared with the alternative of planting Norway spruce. Economic data used for the comparison are representative of the southeastern regions of Denmark. The conclusion of the comparison is as follows: BEECH (90–110) is superior to planting of Norway spruce for required real rates of return up to 3–4%. For higher required rates of return planting of Norway spruce is preferable.     

Root growth capacity and field performance of Pinus sylvestris and Picea abies seedlings

Correlations between root growth capacity (RGC), at the time of planting, and field performance were studied for Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) seedlings. Before planting a gradient in seedling viability was generated through exposure to low root temperatures and different winter storage regimes. The hypothesis that high RGC values would improve field performance was to some extent verified for pine seedlings while no correlations could be registered for spruce. Reasons for these results are discussed.     

Superoxide dismutase (SOD) activity in Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies L. Karst.) needles in northern Finland

The superoxide dismutase (SOD EC 1.15.1.1) activity in Scots pine (Pinus sylvestris) and Norway spruce (Picea abies L. Karst.) needles in urban and rural trees of northern Finnish populations was studied. Enzyme activity was higher in pine than in spruce needles. Two pine clones from eastern Finland and Lapland revealed great differences in specific SOD enzyme activity.     

Nekrotische Flecken an Nadeln von Picea abies-ein Symptom des Fichtensterbens?

Necrotic spots on needles of Picea abies-a symptom of Norway spruce decline? On needles of Picea abies and other conifers necrotic spots were observed. Preliminary experiments showed that similar symptoms could be caused by photooxidants.     

Prediction of individual tree growth in managed stands of mixed Picea abies (L) Karst,and Betula pendula Roth & Betula pubescens Ehrh.

The individual tree growth in stands of mixed Norway spruce (Picea abies (L.) Karst.) and birch (Betula pendula Roth & Betula pubescens Ehrh.) is estimated using basal area and height growth functions for each species separately. The individual tree growth models are distant dependent and the number, size and proximity of neighbours are expressed as size‐ratio competition indices. The competition indices were calculated using a basal area factor gauge to define competitors. The tree growth functions are based on data from nine mixed stands of Norway spruce and birch. The recursive multivariate regression approach is used. The growth functions have standard deviation about the function/standard deviation about the mean (sf/sm) values between 31 and 61% and the evaluations made with root mean square error (rmse) give estimates which vary between 8 and 45 % of the observed mean value. These values are comparable with the precision reported in other studies. In the present investigation the distant dependent indices are important independent variables. It seems suitable to describe the change in growth conditions from retarded to released growth by means of size ratio competition indices. For birch, a positive effect on growth is obtained the more the total competition consists of Norway spruce. For Norway spruce a negative effect on growth is obtained the more the total competition consists of Norway spruce. The lower competitors have a positive effect on the growth of the spruce trees. The interpretation should be that it is better to have a small competitor than a larger one, not that small competitors as such have a positive effect on growth of Norway spruce.     

Untersuchungen zur biologischen Bekämpfung von Heterobasidion annosum an Fichte (Picea abies) mit antagonistischen Pilzen

Investigations on biological control of Heterobasidion annosum in Norway spruce (Picea abies H. Karst.) with antagonistic fungi. I. Production of inoculum and interaction experiments in vitro. Thirty isolates of 22 fungal species were examined in vitro for sporulation, for germination of the spores, and for antagonism of mycelia against three strains of H. annosum. Viable spores were produced by 17 isolates, antagonism was shown by 28 isolates.     

Polyamines in embryogenic cultures of Norway spruce (Picea abies) and red spruce (Picea rubens)

Embryogenic cultures of red spruce (Picea rubens Sarg.) and Norway spruce (Picea abies (L.) Karst.) were initiated from dissected mature zygotic embryos. The tissues were grown on either proliferation medium or maturation medium. On proliferation medium, the embryogenic tissue continued to produce early stage somatic embryos (organized meristems attached to elongated, suspensor-like cells), whereas on maturation medium fully mature embryos developed from the embryonic tissue. Analysis of polyamines in tissues grown on these two media showed that: (1) both putrescine and spermidine concentrations were always higher in cultures grown on proliferation medium than in cultures grown on maturation medium; (2) in both species, spermidine concentrations declined with time in the tissues grown on maturation medium; and (3) spermine was present in only minute quantities and showed only a small change with time. The presence of difluoromethylornithine in the culture medium had little effect on polyamine concentration, whereas the presence of difluoromethylarginine caused a decrease in putrescine concentrations in both red spruce and Norway spruce tissues grown on proliferation medium or maturation medium.     

The effects of nitrogen fertilization on the ultrastructure of mesophyll cells of conifer needles in northern Finland

Cytological injuries in needles of Scots pine (Pinus sylvestris L.) and Norway spruce [Picea abies (L.) Karst.] were studied at light and electron microscope level in northern Finland. Needle samples were taken from fertilized (mainly with nitrogen) and nonfertilized trees during winter 1980. The results are discussed in relation to the severe climate and growth response of the trees.     

Establishment of the Second Rotation in the Jutland Heath Plantations

The paper describes briefly the silvicultural methods used toregenerate stands of pure Norway spruce (Picea abies Karst.)or Norway spruce mixed with a small proportion of Silver fir(Abies alba Mill.) on the poor heath soils of Jutland. Regenerationafter clear felling, uniform shelterwood, and shelterwood stripfelling is described. The last method has advantages over theother two.     

Freezing temperatures in the root zone—effects on growth of containerized Pinus sylvestris and Picea abies seedlings

Roots of 1‐year‐old containerized seedlings of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) were experimentally frozen in December. The seedlings were then grown for 3 weeks in a growth chamber and evaluated with regard to root growth capacity (RGC) and shoot elongation. The subsequent RGC of Scots pine declined as root zone temperatures were lowered from ‐6°C to ‐11°C and from ‐11°C to ‐16°C. Almost no root growth was observed after exposure to ‐20°C. Shoot growth was also negatively affected by low root temperatures but less than root growth. Low root temperatures did not affect Norway spruce as much as Scots pine, although root and shoot growth of Norway spruce were reduced after exposure to the lowest test temperatures (‐16°C and ‐20°C). The length of exposure, ranging between 1 and 8 hours had no effect on subsequent growth.     

Heterobasidion annosum root rot in Picea abies: Modelling economic outcomes of stump treatment in Scandinavian coniferous forests

Abstract

The economic outcomes of stump treatment against spore infections of the root rot pathogen Heterobasiodion annosum s. l. were analysed based on simulations in four stands typical of Swedish forestry and forest management: (A) Norway spruce [Picea abies (L.) Karst.] stand on former agricultural soil (SI?=?32), (B) Norway spruce stand (SI?=?26) on forest land; (C) Mixed stand of Norway spruce and Scots pine (Pinus sylvestris L.) (SI?=?24) with only H. parviporum present, i.e. no infection of Scots pine and no possibility of interspecies spread of disease between hosts; and (D) same as C, but H. annosum s. str. (Fr.) Bref and H. parviporum Niemelä & Korhonen present, i.e. interspecies spread of disease possible. Models for disease development, growth and yield and cross-cutting were used in the simulations. The simulated decay frequency in Norway spruce trees ranged between 2 and 90%. Stump treatment at the previous final felling and in all thinning operations was profitable at interest rates 1 and 3% in stands A, B and D, but not in stand C. In stand C, no stump treatment at all or treatment in thinnings only gave the highest net future value. Implications for stump treatment in practical forestry are discussed.     

Growth in supplementarily planted Picea abies regenerations

Abstract

An experiment was established in 1978 in two Norway spruce [Picea abies (L.) Karst.] plantations in southern Sweden to study yield after mortality in patches with and without supplementarily planted (SP) seedlings. Gaps of different sizes were created by removing the originally planted seedlings. The gaps were either left unplanted or a supplementary planting was performed with one of four species [Norway spruce, Scots pine (Pinus sylvestris L.), lodgepole pine (Pinus contorta Dougl.) or hybrid larch (Larix deciduas Mill×L. Leptolepis Gord.)] 2 (at Knäred) or 6 years (at Ullasjö) after the original plantation. In 2002, most of the SP Scots pine, lodgepole pine and hybrid larch seedlings were dead or severely damaged by roe deer and moose. Survival was high among SP Norway spruces, but they had slower growth than the originally planted spruces. Growth was lower at Ullasjö than at Knäred. In Ullasjö, growth was lower in small gaps than in large gaps. Trees in original regeneration in areas surrounding unplanted gaps were larger than trees surrounding gaps with SP seedlings, which in turn were larger than originally planted trees in plots without gaps. In conclusion, because the original plantation surrounding unplanted gaps used a large part of the open space and growth of SP seedlings was slow, supplementary planting resulted in an insignificant growth increase. However, supplementary planting may increase the timber quality of trees surrounding the gaps, although this effect remains to be quantified.     

Über die Ursachen und Kriterien der Immissionsresistenz bei Fichte,Picea abies (L.) Karst1

Causes and criteria of resistance to air pollution in Norway spruce, Picea abies (L.) Karst. IV. Recovery of injured needles, connections between forms of resistance and summary of results to date. Water potential measurement of resistant clones of Norway spruce treated with SO₂ showed that they recovered better than control clones or were at least not so permanently affected. From a variety of experiments on fumigation, it was concluded that reflexive and “internal” resistance were associated. The results of the series of papers so far are summarised.     

Variation in growth of Heterobasidion parviporum in a full-sib family of Picea abies

Abstract

Heterobasidion parviporum (Fr.) Niemelä & Korhonen and Heterobasidion annosum (Fr.) Bref. sensu lato are some of the major forest pathogens in the northern hemisphere causing root and butt rot to conifers. The relative susceptibility to H. parviporum was investigated in a full-sib family of Norway spruce [Picea abies (L.) Karst.] by inoculating a set of 252 cloned progenies from a controlled cross. Four ramets of each progeny were used and the 2-year-old rooted cuttings were incubated for 6 weeks under greenhouse conditions. The condition of the cuttings was assessed visually and all the plants were in excellent vigour with no mortality recorded during the experiment. To score the relative susceptibility, lesion length in the inner bark and fungal growth in the sapwood were measured. Among the progenies, significant differences were found for fungal growth in the sapwood (p<0.0005). There was no significant difference for lesion length; however, there was a significant positive correlation between fungal growth and lesion length. The broad-sense heritability was 0.11 for fungal growth. This shows that the genetic component for susceptibility to H. parviporum can be detected even within a full-sib family of Norway spruce and that there is a potential for mapping quantitative trait loci for this trait in Norway spruce.     

Economics of Forest Thinnings and Rotation Periods for Finnish Conifer Cultures

In this study simultaneous optimization of thinnings and clear-cutting was investigated. The density-dependent whole-stand model was specified for all relevant Finnish Norway spruce (Picea abies (L.) Karst.] and Scots pine (Pinus sylvestris L.) site indices and solved by non-linear programming. Sensitivity analysis showed that in some cases and owing to endogenous thinnings the optimal rotation length may increase with the rate of interest and site fertility, and decrease with harvesting cost. The number of thinnings is more sensitive to changes in the rate of interest, logging conditions and site productivity for Scots pine stands than for Norway spruce stands. Economic optimization suggests that for both species the first thinning should be performed later than officially recommended. The last thinning should be heavier than officially recommended, especially at high rates of interest. This increases the optimal rotation length compared with solutions under restricted thinning intensity.     

Biological control of Heterobasidion annosum (Fr.) Bref. (Fomes annosus) in Finland

Fresh stumps of Norway spruce (Picea abies) were inoculated with Peniophora gigantea (Fr.) Massee, Botrytis cinerea Pers. ex Fr., Gliocladium deliquescens Sopp, Trichoderma viride Pers. ex Fr. ex S. F. Gray aggr. and Verticicladiella procera Kendrick in order to study their effect on infection by Heterobasidion annosum (Fr.) Bref. The organisms colonizing spruce stumps under natural conditions were identified by collecting samples in the field. In addition, the effect of season of the year, air temperature, precipitation and relative air temperature on fungal colonization of the stumps was investigated.     

Fluorometrische Beurteilung der relativen SO2-Resistenz von Fichte (Picea abies [L.] Karst.) anhand niedermolekularer Metabolite aus Nadelextrakten

Fluorometric examination of the relative insistence to SO₂ of Norway spruce (Picea abies [L.] karst.) using low molecular metabolites from needle extracts. Relatively resistant and “normal” spruce grafts were shown by a fluorometric method to possess different concentrations of fluorescent needle metabolites. The described method could be useful in verifying resistence qualities of Norway spruce.