Species diversity and forest health in northwest British Columbia

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

2010 ◽  
Vol 86 (4) ◽  
pp. 412-422 ◽  
Author(s):  
Alex J. Woods ◽  
Don Heppner ◽  
Harry H. Kope ◽  
Jennifer Burleigh ◽  
Lorraine Maclauchlan

BC’s forests have already faced two simultaneous, globally significant, epidemics linked to climate change; the Dothistroma needle blight epidemic in NW BC and the massive mountain pine beetle epidemic throughout the BC Interior. Building on these experiences, we have compiled our best estimates of how we believe other forest health agents may behave as climate change continues to influence our forests. We have drawn on literature from around the world but have focused on the situation in BC. We have made management recommendations based on what we have seen so far and what we expect to come.Key words: climate change, forest health, forest insects, forest pathogens, forest management, British Columbia


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.


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.


2015 ◽  
Vol 45 (8) ◽  
pp. 1045-1055 ◽  
Author(s):  
Anya M. Reid ◽  
William K. Chapman ◽  
John Marty Kranabetter ◽  
Cindy E. Prescott

Soil disturbance from organic matter loss and soil compaction can impair site productivity, but less is known about whether these disturbances also affect forest health (defined here as the presence and severity of damaging pests and diseases, mortality, and overall vigour). We used six long-term soil productivity (LTSP) sites in the interior of British Columbia, Canada to test the effects of organic-matter removal and soil compaction on forest health, and to explore the relationship between forest health response and potential indicators of site sensitivity: mineral soil pH, base saturation, carbon to nitrogen ratio (C:N), carbon to phosphorus ratio (C:P), and calcium to aluminum ratio (Ca:Al). Visual forest health surveys were conducted on 5400 15 and 20 year old lodgepole pine (Pinus contorta Dougl. ex Loud.) trees. Soil disturbance treatments significantly affected forest health metrics, but this response typically differed among sites. Principle component analyses indicated the response of healthy trees was negatively related to soil base saturation, the response of dead or dying trees related to soil C:P, and the response of tree disease related to soil Ca:Al, pH, base saturation, and C:N. We found forest health response to soil disturbance varied among sites with relationships between response and soil chemical properties, suggesting a greater vulnerability of pine stands to disease with increasing soil acidity.


1966 ◽  
Vol 42 (2) ◽  
pp. 160-161 ◽  
Author(s):  
A. K. Parker ◽  
D. G. Collis

1995 ◽  
Vol 71 (4) ◽  
pp. 489-496 ◽  
Author(s):  
R. J. Nevill ◽  
P. M. Hall ◽  
J. Beale

To determine the needs and priorities for research on specific topics concerning forest health in British Columbia, a questionnaire was developed and distributed to forest management agencies, forest industry and other research agencies. Response was received from all groups contacted (Pacific Forestry Center [Canadian Forest Service]; BC Ministry of Forests; BC Ministry of Environment Lands & Parks; Industry; and Universities) throughout the province. Forty-two insect, disease, and mammal pests were identified for research. Research priorities for insects and diseases were equally distributed and of greater importance than mammals. Diseases most frequently identified included Armillaria root disease and tomentosus root disease, while the mountain pine beetle and the white pine weevil were foremost among insects. Broadly based issues included pest responses to alternative silvicultural systems, quantification of pest caused losses, and standardized survey methodology between agencies. Lower profile research concerns included the pinewood nematode, nursery pests, and hardwood diseases. The potential introduction into the province of exotic pests such as the Gypsy moth was identified as an emerging issue. Key words: forest health, research priorities, forest insects, disease, mammal pests


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.


2014 ◽  
Vol 60 (No. 11) ◽  
pp. 484-486 ◽  
Author(s):  
A.J. Woods

As the climate continues to change, gaps in our understanding of how the altered environment will affect forest hosts and their pathogens widen. In some areas pathogens thought to be present for centuries are changing their behaviour. Dothistroma needle blight caused by the fungus Dothistroma septosporum in northwest British Columbia (BC), Canada, is a good example. In this area both the pathogen and the host, lodgepole pine (Pinus contorta var. latifolia), are considered native species, but here Dothistroma has been responsible for killing mature host trees, which is unprecedented. A plausible link between warmer, wetter summers and directional climate change has been suggested as the primary driver. Those environmental conditions appear to be affecting the host/pathogen relationship for other diseases in the neighbouring central interior of BC including comandra blister rust (Cronartium comandrae). Disrupted host/pathogen relationships tend to favour the short-lived more adaptable pathogens rather than their long-lived hosts. These changes in forest health have not been well accounted for in fields of forest science that have been built on stability and predictability.    


2011 ◽  
Vol 41 (8) ◽  
pp. 1598-1605 ◽  
Author(s):  
William K. Chapman ◽  
Bruce Schellenberg ◽  
Teresa A. Newsome

This trial, conducted near Nakusp, British Columbia, compares pushover logging (combination tree felling and root removal technique using large machines to push trees out of the ground) with handfalling logging (no root removal) for effects on the incidence of armillaria root disease in postharvest regeneration. Pushover logging did not reduce levels of root disease, expressed as percentage tree mortality, over handfalling harvesting on this site. High variability of measured disease levels within some treatments and few replicates lowered the power of the trial. However, in addition to being statistically insignificant, the mean differences between the two main treatments were small and biologically uninteresting, and the response was inconsistent in direction. The trial also included three mature timber retention levels as treatments, and there seemed to be a trend of declining root disease with increased retention of stems. This phenomenon should be further investigated as current literature is not clear on the response of armillaria to partial harvesting. There was a strong suggestion of a difference between susceptibility of natural and planted seedlings to armillaria root disease, with natural regeneration being less susceptible. Thuja plicata Donn ex D. Don was less affected by armillaria root disease than other species in this trial, whether it was planted or naturally regenerated.


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