Infection of advance regeneration of Norway spruce by Heterobasidion parviporum

2001 ◽  
Vol 31 (6) ◽  
pp. 937-942 ◽  
Author(s):  
Tuula Piri ◽  
Kari Korhonen
Keyword(s):  
Picea Abies ◽  
Norway Spruce ◽  
Root Rot ◽  
Heterobasidion Annosum ◽  
Advance Regeneration ◽  
Mean Size ◽  
The Mean ◽  
Vegetative Spread ◽  
Overstory Trees

The incidence of Heterobasidion root rot in the advance regeneration of Norway spruce (Picea abies (L.) Karst.) was studied in nine stands at four different localities in southern Finland. The mean age of the unthinned advance regeneration on the 17 sample plots ranged from 14 to 44 years. On infested plots, the proportion of Norway spruce infected by Heterobasidion varied from 22.2 to 75.0% (mean 52.5%) in the overstory and from 1.8 to 68.2% (mean 21.1%) in the advance regeneration. The corresponding values on healthy-looking control plots were 0–6.7% (mean 5.9%) and 1.3–3.9% (mean 2.4%), respectively. Of the 138 Heterobasidion genets identified, 98.5% belonged to Heterobasidion parviporum Niemelä & Korhonen and 1.5% to Heterobasidion annosum (Fr.) Bref. s.s. The incidence of Heterobasidion root rot in advance regeneration was positively correlated with the mean size and age of the advance regeneration and the proportion of infected trees in the overstory and negatively correlated with the regeneration density. Vegetative spread through root contacts from overstory trees to the surrounding regeneration accounted for at least 53% of the Heterobasidion infections in the advance regeneration. The origin of the rest of the infections in advance regeneration remained unclear, but at least part of them may have started from spore infection on injured or dead roots. Our results suggest that, on sites infected by H. parviporum, advance growth of Norway spruce should not be used for regeneration even though the spruces look healthy and show no external signs of infection.

The effect of winter thinning on the spread of Heterobasidion parviporum in Norway spruce stands

2008 ◽  
Vol 38 (10) ◽  
pp. 2589-2595 ◽  
Author(s):  
Tuula Piri ◽  
Kari Korhonen
Keyword(s):  
Picea Abies ◽  
Norway Spruce ◽  
Root Rot ◽  
Rapid Expansion ◽  
Areal Unit ◽  
Tree Generation ◽  
Thinning Operation ◽  
Spruce Stands ◽  
The Mean ◽  
Vegetative Spread

Genets of Heterobasidion were identified in eight 43- to 56-year-old Norway spruce ( Picea abies (L.) Karst.) stands in southern Finland. Four of the stands had been thinned in winter ca. 10 years prior to the study, and four had been left unthinned. It was hypothesized that the felling of decayed trees promotes the vegetative spread of the fungus from thinning stumps into the adjacent trees, and hence the Heterobasidion genets should be larger in thinned stands. Although the number of infected stumps per areal unit was lower and the genets were slightly smaller in the previous tree generation of thinned plots, the genets, particularly the old ones, in the present tree generation were larger on thinned plots. The genets originating from the previous rotation included, on average, 12.2 trees on thinned plots and 6.7 trees on unthinned plots. The mean number of trees infected by new genets (not found in previous generation) was also slightly higher (p < 0.05) on thinned than on unthinned plots, 1.8 and 1.2 trees, respectively. The results indicate that the rapid expansion of old Heterobasidion infections after a thinning operation may significantly contribute to the occurrence of root rot in the residual stand.

Early development of root rot in young Norway spruce planted on sites infected by Heterobasidion in southern Finland

2003 ◽  
Vol 33 (4) ◽  
pp. 604-611 ◽  
Author(s):  
Tuula Piri
Keyword(s):  
Picea Abies ◽  
Norway Spruce ◽  
Root Rot ◽  
Heterobasidion Annosum ◽  
Tree Stand ◽  
Clear Cutting ◽  
Plantation Age ◽  
Armillaria Cepistipes ◽  
Experimental Plots ◽  
Armillaria Species

Root rot infections in Norway spruce (Picea abies (L.) Karst.) regeneration, planted after the clear-cutting of spruce on sites infested by Heterobasidion, were investigated on 21 experimental plots in eight 2- to 23-year-old plantations. Heterobasidion root rot became evident about 10 years after planting and the proportion of infected spruces increased steadily with plantation age. The average number of planted spruces infected per old decayed stump was 0.2 trees in 2- to 9-year-old plantations, 0.8 trees in 11- to 15-year-old plantations, and 1.8 trees in 20- to 23-year-old plantations. About 10 and 20 years after planting, 7 and 23% of the planted spruces in the disease centers were infected by Heterobasidion. Heterobasidion parviporum Niemelä & Korhonen, and Heterobasidion annosum (Fr.) Bref. s. str. caused 98 and 2% of the Heterobasidion infections in the previous spruce rotation, and 96 and 4% in the spruce regeneration, respectively. In all, 71% of the infected regeneration trees were attacked by a Heterobasidion genet that was also isolated from the stumps of the previous tree stand. Armillaria species (Armillaria borealis Marxmüller & Korhonen and Armillaria cepistipes Velenovský) were isolated from 7% of the planted spruces.

scholarly journals The Profitability of Cross-Cutting Practices in Butt-Rotten Picea abies Final-Felling Stands

Forests ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 874 ◽  
Author(s):  
Kärhä ◽  
Räsänen ◽  
Palander
Keyword(s):  
Picea Abies ◽  
Norway Spruce ◽  
Processing Time ◽  
Wood Quality ◽  
Study Data ◽  
Heterobasidion Annosum ◽  
Time And Motion ◽  
The Cross ◽  
Motion Studies ◽  
The Impact

Research Highlights: This study offers new information on the cross cutting of decayed stems with the sounding of short (0.5 m) offcuts and the bucking of longer (3.0 m) butt-rotten poles. Background and Objectives: The root and butt-rot fungus Heterobasidion annosum sensu lato (Fr.) Bref. causes wood quality damage to trees in softwood forests. When timber is harvested in butt-rotten forests, it is essential that the decayed part of the tree is recognized and cut away from a stem, while the healthy and good quality log section of a stem is cross cut with precision sawlogs. The objective of the study was to investigate the impact of two off-cutting methods on stem processing time, cutting productivity, sawlog volume, and commercial value at the roadside landing when harvesting timber from the butt-rotten Norway spruce (Picea abies (L.) Karst.) final-felling forests. Materials and Methods: The length of the short offcuts used was 0.5 m. The results of the cross-cutting practices were compared to the decayed pulpwood poles of 3 m from the butt of the rotten stems. Time and motion studies were carried out in stands before the profitability calculations. The study data consisted of 1980 Norway spruce sawlog stems. Results: Sounding of the short offcuts added significantly to the stem processing time of butt-rotten stems, but the sawlog volume and the timber value recovery of the stems were higher than those of the decayed pulpwood poles of 3 m. Conclusions: The study concluded that sounding of butt-rotten Norway spruce stems with one to three offcuts is economically profitable if the diameter of the decayed column at the stem stump’s height is small (≤5 cm). In contrast, when the width of the decay is larger (>5 cm), it is more profitable to first cross cut the decayed pulpwood pole of 3 m and then to observe the height of the decayed part of the stem.

Spread of S and P group isolates of Heterobasidion annosum within and among Picea abies trees in central Lithuania

1998 ◽  
Vol 28 (7) ◽  
pp. 961-966 ◽  
Author(s):  
Rimvydas Vasiliauskas ◽  
Jan Stenlid
Keyword(s):  
Picea Abies ◽  
Norway Spruce ◽  
Field Data ◽  
Heterobasidion Annosum ◽  
Related Difference ◽  
Spruce Wood

Spread of Heterobasidion annosum (Fr.) Bref. was investigated in a 60-year-old Norway spruce (Picea abies (L.) Karst.) stand in central Lithuania. Of the 375 trees sampled, H. annosum was isolated from 85 (22.7%). Forty nine (56.3%) of the isolates belonged to the S group and 38 (43.7%) to the P group. Among the S-group isolates, 35 genets occupied 49 trees (1.4 trees per genet on average). In the P group, 24 genets were detected in 37 trees (1.5 trees per genet on average). The largest S and P genets were 21 and 20 m in diameter, respectively. The S group spread was more extensive within stems than for the P group; mean length of the decay column for S-group isolates was 459 ± 159 cm (mean ± SD), and it was 327 ± 101 cm for P-group isolates (p = 0.0001). Average stump area affected by decay was 56 ± 15%for the S group, and 47 ± 16% for the P group (p = 0.016). This is the first published field data on intersterility group related difference in decay extension in tree stems. The S group is better adapted than the P group to growth in Norway spruce wood.

scholarly journals The effect of root rot and bark-stripping on wind stability of Norway spruce (Picea abies (L.) H. Karst.) = Parastās egles (Picea abies (L.) H. Karst.) vēja noturības izmaiņas sakņu trupes un stumbra mizas bojājumu ietekmē

2020 ◽  
Author(s):  
◽  
Oskars Krisans ◽  
Keyword(s):  
Climate Change ◽  
Picea Abies ◽  
Norway Spruce ◽  
Root Rot ◽  
Mechanical Stability ◽  
Stem Volume ◽  
Natural Disturbances ◽  
Bark Stripping ◽  
Secondary Failure ◽  
Spruce Stands

Climate change causes gradual decline of economic value of Norway spruce forestry except in boreal and hemiboreal forest zones that will remain suitable for this tree species. However, also in this region frequency and scale of damages caused by natural disturbances (abiotic and biotic factors) are expected to increase. Norway spruce will remain its economic significance and role in carbon sequestration in Latvia, if forest management practices will be changed to prevent or minimize the damages caused by natural disturbances. Information on effect of natural disturbances and their interactions on trees is vital for development of recommendations for adaptation of forestry to climate change. The aim of the thesis is to assess the effect of root rot and bark-stripping on possibility of wind induced damages in Norway spruce stands. Tree mechanical stability was primarily determined by its stem volume; however, the presence of damages, caused by biotic agents, such as root rot and bark-stripping, significantly reduced it. Morphometric parameters of Norway spruce stem and root plate differed significantly between stands on drained peat and mineral soils. Root-rot notably and significantly affected mechanical stability of trees regardless of soil type and volume of root-soil plate, resulting in similar reduction of wind load necessary to cause both primary and secondary failure. Consequences of bark-stripping primarily affected root-soil anchorage, more commonly causing uprooting than stem fracture. Most pronounced was reduction of resistance against primary failure. Changing wind climate, high population density of cervids and presence of root-rot will lead to increased risk of damages caused by (repeated) storms and subsequent legacy effects. The survival of forest stands depends on dimensions of trees and exposure time to different damaging agents, and, at current climate and silvicultural practice, was significantly reduced when transitioning into third age class (41-60 years). Targeted forestry, ensuring planting of improved material, lower initial density, timely precommercial thinning and thus ensuring faster reach of the tree dimension required for final harvest will reduce the time when stands are subjected to significant wind damage risk, thus minimizing the possibility of such disturbance and boosting value of Norway spruce stands.

Effects of stand density on outcrossing rate in two Norway spruce (Picea abies) populations

1991 ◽  
Vol 69 (12) ◽  
pp. 2704-2708 ◽  
Author(s):  
M. Morgante ◽  
G. G. Vendramin ◽  
P. Rossi
Keyword(s):  
Picea Abies ◽  
Mating System ◽  
Norway Spruce ◽  
Stand Density ◽  
Major Effect ◽  
Outcrossing Rate ◽  
High Density ◽  
Low Density ◽  
The Mean ◽  
Key Words Mating System

The mating system was investigated in two neighbouring Norway spruce (Picea abies (L.) Karst.) populations with markedly different stand densities. The amount of outcrossing was estimated using open-pollinated array data at four enzyme loci. Multilocus estimates of the proportion of viable progeny owing to outcrossing were 0.956 and 0.955 for the low- and high-density stand, respectively, indicating that the large reduction in stand density had no impact on outcrossing rates. The multilocus estimate was higher than the mean single-locus estimate only for the low-density stand. The lowering of the mean estimate in the low-density stand is probably a consequence of the clustering of related individuals. The regression of pollen allele frequencies on ovule genotype, which is a direct measure of the effective selfing caused by consanguineous matings, had a significant coefficient for the low-density stand and a nonsignificant one for the high-density stand. This obvservation confirms that the major effect of low-stand density in Norway spruce is the occurrence of consanguineous matings. Key words: mating system, outcrossing rate, inbreeding, Norway spruce, stand density.

Interactions between Norway spruce (Picea abies) and Heterobasidion annosum. I. Infection of nonsuberized and young suberized roots

1994 ◽  
Vol 72 (6) ◽  
pp. 872-883 ◽  
Author(s):  
W. K. Heneen ◽  
M. Gustafsson ◽  
G. Karlsson ◽  
K. Brismar
Keyword(s):  
Picea Abies ◽  
Norway Spruce ◽  
Cell Walls ◽  
Heterobasidion Annosum ◽  
Root Infection ◽  
Host Reaction ◽  
Outer Cortex ◽  
Fungal Enzymes ◽  
Transmission Electron ◽  
Inner Cortex

Nonsuberized and young suberized roots of Norway spruce (Picea abies) were inoculated with an S-strain of Heterobasidion annosum for 2–20 days. The roots were sectioned for light microscopy and transmission electron microscopy. They were susceptible to infection at both stages of development. The host reaction to delimit the infection was the formation of a necrotic ring barrier in the outer cortex. In cases where the inner cortex also became infected, fungal hyphae accumulated just before the endodermis, which acted as a new barrier. Only in nonsuberized roots did the hyphae succeed in penetrating the stele, and within 3 days after inoculation the stele was almost completely digested. Other resistance reactions included accumulation of phenolic deposits, secondary thickening of cell walls, and formation of papillae. The hyphae were able to grow within and across cell walls. The presence of translucent areas around penetrating hyphae possibly reflected the digestive action of fungal enzymes. The hyphae showed signs of degeneration when entrapped in encompassing cellular deposits. Key words: Norway spruce, Heterobasidion annosum, root infection, nonsuberized roots, young suberized roots, microscopy.

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