scholarly journals Spore Dispersal by Dothistroma septosporum in Northwest British Columbia

2015 ◽  
Vol 105 (1) ◽  
pp. 69-79 ◽  
Author(s):  
Kennedy Boateng ◽  
Kathy J. Lewis

We studied spore dispersal by Dothistroma septosporum, causal agent of a serious outbreak of red band needle blight in lodgepole pine plantations in northwest British Columbia. Spore abundance was assessed at different distances and heights from inoculum sources and microclimatic factors were recorded during two consecutive years. Conidia were observed on spore traps from June to September during periods of rainfall. It was rare to detect spores more than 2 m away from inoculum sources. The timing and number of conidia dispersed were strongly tied to the climatic variables, particularly rainfall and leaf wetness. Should the trend toward increased spring and summer precipitation in the study area continue, the results suggest that disease spread and intensification will also increase. Increasing the planting distances between lodgepole pine trees through mixed species plantations and overall reduction in use of lodgepole pine for regeneration in wet areas are the best strategies to reduce the spread of the disease and enhance future productivity of plantations in the study area.

Author(s):  
L. A. Golovchenko ◽  
N. G. Dishuk ◽  
S. V. Panteleev ◽  
O. Yu. Baranov

Red band needle blight, or Dothistroma needle blight is one of the most common and harmful diseases of pine. The causative agents of the disease are pathogenic micromycetes Dothistroma septosporum (Dorogin) M. Morelet and Dothistroma pini Hulbary. Dothistroma needle blight was firstly detected in Belarus in 2012 year, but till now information about this disease in the republic is fragmentary. The article presents the results of a survey of different pine trees, carried out in the period 2016–2020 years in botanical and dendrological gardens, forest nurseries and mini-arboretums at forestry enterprises, urban stands, nurseries of decorative plants, garden centers, for the presence of Dothistroma needle blight. The species identification of the causative agent of the disease was carried out by mycological and molecular genetic methods. In this study, Dothistroma needle blight was revealed on individual trees of Pinus mugo, P. nigra and P. ponderosa in the stands of the Central Botanical Garden of the NAS of Belarus, the dendrological garden of the Glubokoe experimental forestry enterprise, in the nurseries of decorative plants in the Grodno and Minsk regions. In the collected samples of needles, the invasive species Dothistroma septosporum was identified. The frequency of occurrence of the pathogen was 4.8–7.2 %, the proportion of observation sites in which this disease was detected at 60 %. The detection of Dothistroma needle blight on pine trees, mainly on planting material imported from abroad, indicates a transboundary route of D. septosporum entering the country. Analysis of literature data indicates the potential danger of Dothistroma needle blight for pine stands in the republic, which in turn requires the organization of regular monitoring of the disease and the development of methods to limit the spread of D. septosporum in the republic.


2003 ◽  
Vol 79 (5) ◽  
pp. 892-897 ◽  
Author(s):  
Alex J Woods

Forest management in the Interior Cedar Hemlock (ICH) zone of the Kispiox TSA in northwest British Columbia has focused on two tree species. Interior spruce (Picea engelmanni Parry ex Engelm. × Picea glauca (Moench) Voss) and lodgepole pine (Pinus contorta var. latifolia Dougl. ex Loud.) have dominated plantations, while historically, western hemlock (Tsuga heterophylla (Raf.) Sarg.), true firs (Abies lasiocarpa (Hook.) Nutt. and (Abies amabilis (Dougl. ex Loud.) Dougl. ex Forbes) and western redcedar (Thuja plicata Donn ex D. Don), have dominated the landscape. Tomentosus root disease (Inonotus tomentosus (Fr.) Teng) and Dothistroma needle blight (Mycosphaerella pini Rostr. in Munk) are the principal diseases affecting interior spruce and lodgepole pine plantations, respectively. Tomentosus root disease was found in 92% of spruce-dominated stands 100 years and older in the study area. The annual recruitment of dead interior spruce and lodgepole pine tree volume due to the disease in those stands is 4.29 m3/ha or 51 990 m3. The incidence of Tomentosus root disease in ten randomly selected spruce leading plantations aged 25–30 years ranged from 0.6% to 10.4% and averaged 5.9% of the host trees. Dothistroma needle blight was the most prevalent pest in a survey of 100 randomly selected lodgepole pine plantations and has caused considerable crop tree mortality. The disease has even caused mortality in 55-year-old lodgepole pine trees. Maintaining species diversity is essential to long-term forest health. Intensive planting of interior spruce and lodge-pole pine in this study area appears to have exacerbated disease problems. Key words: forest health, species diversity, interior spruce, lodgepole pine, Tomentosus root disease, Dothistroma needle blight


2009 ◽  
Vol 39 (12) ◽  
pp. 2505-2519 ◽  
Author(s):  
Cedar Welsh ◽  
Kathy Lewis ◽  
Alex Woods

Native pathogens are normally limited in the damage they cause by host resistance and (or) environmental conditions that limit one or more phases of the disease cycle. Changes to host or environmental conditions can relax these limits and result in disease emergence. Until recently, Dothistroma needle blight (Dothistroma), caused by Dothistroma septosporum (Dorog.) Morelet, has had only minor impacts on native forest trees in western North America. Over the past decade in the forests of northwestern British Columbia, Canada, Dothistroma has caused extensive mortality in managed plantations of lodgepole pine ( Pinus contorta Dougl. ex Loud. var. latifolia Engelm.), and even mature pine trees are succumbing. We used dendrochronological techniques to reconstruct the temporal patterns of past Dothistroma outbreaks in the area using tree-ring series from sites with documented outbreaks. We found that Dothistroma outbreaks in northwest British Columbia have occurred periodically over the last 174 years, with an increase in outbreak incidence and extent since the 1940s. The most distinct change observed in the outbreak history has been the greater severity and synchrony among the sites affected during the current outbreak. A recently observed climate change trend over the study area may represent an environmental trigger that synchronized the current outbreak causing the widespread emergence of the disease.


2003 ◽  
Vol 83 (4) ◽  
pp. 465-474 ◽  
Author(s):  
C. E. Bulmer ◽  
M. Krzic

We determined post-establishment tree growth and soil properties on rehabilitated log landings and forest plantation sites with medium texture in northeastern British Columbia. Six years after rehabilitation treatments were applied, 60% of rehabilitated landing plots had more than 1000 stems ha-1, while 17% had fewer than 600 stems ha-1. The average height of undamaged lodgepole pine trees on rehabilitated landings was consistently lower than for trees of the same age on plantations. Surface (0–7 cm) and subsurface (10–17 cm) soil bulk densities were higher for rehabilitated landings than for adjacent plantations. Rehabilitated landing and plantation soils had similar values of total and aeration porosity. Plantation soils had higher available water storage capacity (AWSC) than rehabilitated soils. Soil mechanical resistance after landing rehabilitation was often higher than for plantation soils at the same depth. Soils on both rehabilitated landings and plantations showed an increase in mechanical resistance from June to September 2001. With the exception of June 2001, soil mechanical resistance after landing rehabilitation was often higher than 2500 kPa. For surface mineral soils, there were no differences in total C, N, or cation exchange capacity (CEC) between rehabilitated landings and plantations. Rehabilitated landing soils had significantly higher total C and N at 10–17 cm depth than plantation soils, which coincided with higher clay content for the landing subsoils. Key words: Forest soil rehabilitation, soil degradation, soil productivity, soil conservation


1985 ◽  
Vol 15 (5) ◽  
pp. 801-808 ◽  
Author(s):  
E. Von Rudloff ◽  
Martin S. Lapp ◽  
R. G. McMinn

The leaf oil terpene composition of lodgepole pine stands from contrasting moisture regimes (400–1200 mm precipitation) within upland and bog sites in the Prince George area of central British Columbia was investigated. In addition to the terpene patterns recorded previously, a new one with relatively high percentages (5–28%) of the terpinene group was found. This pattern was encountered mainly in old trees with very low yields (less than 0.1%) of volatile oil, especially in trees from shaded stands. The absence of resin canals in the leaves of such trees may be the reason for the low yields, but the reason for the link with relatively high terpinene group percentages is obscure. Young trees growing in the vicinity of such stands had mainly the normal patterns. No differences between upland and bog sites or dry and wet sites were found in young trees. Hence, old trees from bogs or wet sites east of Prince George provided progeny with the normal terpene patterns, even though many of the old trees have the new terpene pattern. Samples from two 12- to 13-year-old provenance trials originating from west and east of Prince George had terpene patterns similar to those of the young trees from the natural stands.


2010 ◽  
Vol 86 (4) ◽  
pp. 484-497 ◽  
Author(s):  
W. Jean Mather ◽  
Suzanne W. Simard ◽  
Jean L. Heineman ◽  
Donald L. Sachs

Lodgepole pine is extensively planted across western Canada but little is known about development of these stands beyond the juvenile stage. We quantified stocking status and damage incidence in sixty-six 15- to 30-year-old lodgepole pine plantations that had previously been declared free-growing in the southern interior of British Columbia. The stands were located in six biogeoclimatic zones: Engelmann Spruce-Subalpine Fir (ESSF), Montane Spruce (MS), Interior Cedar-Hemlock (ICH), Interior Douglas-fir (IDF), Sub-Boreal Spruce (SBS), and Sub-Boreal Pine-Spruce (SBPS). Free-growing standards were no longer met on 27% of plantations, with the worst performance (70% no longer free-growing) in the Interior Cedar-Hemlock forests. Natural regeneration was common but it was half the size of lodgepole pine. Biotic damage, especially hard pine stem rusts, was the dominant factor reducing free-growing densities. Stands were at greater risk of reduced stocking where summer precipitation was higher or soil moisture regimes were wetter and where stands had been broadcast-burned prior to planting or received secondary treatments of brushing or pruning. Reforestation policies that encourage widespread planting of lodgepole pine, particularly in areas where lodgepole pine has limited natural occurrence such as in the ICH zone, should be reconsidered given that health problems are extensive and are expected to increase with climate change.Key words: Pinus contorta, lodgepole pine, free-growing, stocking, forest health, damage, disease


2020 ◽  
Author(s):  
Arnaud Capron ◽  
Nicolas Feau ◽  
Renate Heinzelmann ◽  
Irene Barnes ◽  
Andy Benowicz ◽  
...  

Many current tree improvement programs are incorporating assisted gene flow strategies to match reforestation efforts with future climates. This is the case for the lodgepole pine (Pinus contorta var. latifolia), the most extensively planted tree in western Canada. Knowledge of the structure and origin of pathogen populations associated with this tree would help improve the breeding effort. Recent outbreaks of the Dothistroma needle blight (DNB) pathogen Dothistroma septosporum on lodgepole pine in British Columbia and its discovery in Alberta plantations raised questions about the diversity and population structure of this pathogen in western Canada. Using genotyping-by-sequencing (GBS) on 119 D. septosporum isolates from 16 natural pine populations and plantations from this area, we identified four genetic lineages, all distinct from the other DNB lineages from outside of North America. Modeling of the population history indicated that these lineages diverged between 31.4 and 7.2k years ago, coinciding with the last glacial maximum and the post-glacial recolonization of lodgepole pine in western North America. The lineage found in the Kispiox Valley from British Columbia, where an unprecedented DNB epidemic occurred in the 1990s, was close to demographic equilibrium and displayed a high level of haplotypic diversity. Two lineages found in Alberta and Prince George (British Columbia) showed departure from random mating and contemporary gene flow, likely resulting from pine breeding activities and material exchanges in these areas. The increased movement of planting material could have some major consequences by facilitating secondary contact between genetically isolated DNB lineages, possibly resulting in new epidemics.


2020 ◽  
Vol 50 (12) ◽  
pp. 1383-1390
Author(s):  
Jesse McEwen ◽  
Arthur L. Fredeen ◽  
Thomas G. Pypker ◽  
Vanessa N. Foord ◽  
T. Andrew Black ◽  
...  

We studied the recovery of tree- and stand-level carbon (C) storage in a lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) forest in northern British Columbia that experienced substantial (∼83%) mortality in 2006–2007 (total loss by 2013 = 86%) during a severe mountain pine beetle (MPB; Dendroctonus ponderosae Hopkins, 1902) infestation. Earlier work suggested that this forest recovered positive annual C storage 3 years after attack based on eddy covariance measurements. We sought to confirm these results by examining C storage in surviving pine trees using tree core analysis. Average growth release of surviving lodgepole pine trees was 392% (range of –53% to 2326%) compared with mean decadal growth prior to MPB attack. Nearly 97% of trees underwent a growth release, considerably higher than the 15%–75% reported for lodgepole pine in previous studies. Mean annual stem C storage of the surviving trees in this study was highly correlated (r = 0.88) with 10 years of annual net ecosystem productivity estimates made using the eddy covariance technique, indicating that surviving lodgepole pine remain an important part of C recovery after MPB attack. Mean annual stem C storage was also highly correlated (r = 0.92) with the cumulative percentage of downed stems per hectare at the site, suggesting that increased availability of resources is likely assisting the growth release.


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