scholarly journals Spread of Heterobasidion annosum in Christmas Tree Plantations of the United States Pacific Northwest

2007 ◽  
Vol 97 (5) ◽  
pp. 551-556 ◽  
Author(s):  
N. L. Dart ◽  
G. A. Chastagner ◽  
T. L. Peever

The population structure of Heterobasidion annosum in the Pacific Northwest (PNW) Christmas tree plantations was estimated at two spatial scales to assess the relative importance of primary and secondary infection, colonization, and spread of the pathogen. Ninety-three isolates from single trees in 27 discrete mortality pockets and 104 isolates from 12 individual root systems of noble and Fraser fir trees were sampled near Mossyrock, Washington. Isolates were genotyped using somatic compatibility assays and microsatellite markers to determine the spatial scale at which dispersal of single genotypes (genets) was occurring. All isolates sampled from different trees in discrete mortality pockets had distinct genotypes, whereas the root systems of single trees were dominated by one or two genotypes. These results suggest that infection of PNW Christmas trees results from frequent primary infection events of adjacent stumps and localized secondary spread within root systems rather than clonal spread of the pathogen between adjacent trees. We hypothesize that mortality pockets may be due to availability of infection courts and/or variation in inoculum levels during selective harvesting of patches of mature trees.

2001 ◽  
Vol 133 (1) ◽  
pp. 151-154 ◽  
Author(s):  
Richard Berthiaume ◽  
Christian Hébert ◽  
Conrad Cloutier

The balsam twig aphid, Mindarus abietinus Koch, is a major pest of balsam fir, Abies balsamea (L.) Mill. (Pinaceae), grown as Christmas trees in eastern Canada and the United States (Nettleton and Hain 1982; Kleintjes 1997). This aphid has three or four generations from April to July, and overwinters as eggs on fir shoots. Mature fundatrices deposit progeny on new shoots in late May. Infested shoots develop into pseudogalls characterised by stunting and needle distortion, thus reducing the aesthetic value of trees.


2018 ◽  
Vol 150 (5) ◽  
pp. 632-636 ◽  
Author(s):  
Jean-Frdéric Guay ◽  
Amy Bernier-Desmarais ◽  
Jean-François Doherty ◽  
Conrad Cloutier

AbstractThe pine needle scale, Chionaspis pinifoliae (Fitch) (Hemiptera: Diaspididae), has the status of an emerging pest in Christmas tree (Pinaceae) plantations in Québec, Canada. The scale is not known to cause any significant damage yet and is not generally monitored by growers. However, it can be an obstacle for exportation to Christmas tree markets where scale insects are strictly regulated. In this study, we describe its life cycle in Christmas tree plantations in southern Québec. We confirm the presence of both parthenogenetic and sexual forms of the scale on Fraser fir Abies fraseri (Pursh) Poiret (Pinaceae) grown as Christmas trees, and of parasitoid and Coccinellidae (Coleoptera) specialists that could contribute to its control.


2016 ◽  
Vol 149 (2) ◽  
pp. 191-203 ◽  
Author(s):  
S.E. Blatt ◽  
C. Bishop ◽  
J. Sweeney

AbstractChristmas trees from Nova Scotia, Canada are banned from import into the European Union (EU) because they may be infected with the pinewood nematode, Bursaphelenchus xylophilus (Steiner and Buhrer) Nickle (Nematoda: Parasitaphelenchidae). Monochamus Dejean (Coleoptera: Cerambycidae) species known to vector pinewood nematode are present in Nova Scotia but their abundance in Christmas tree plantations and surrounding stands has not been assessed. We conducted trapping surveys and experiments in 2014 and 2015 to determine the species of Monochamus and their relative abundance in Nova Scotia Christmas tree plantations and the surrounding forests. We also compared commercially available traps and lures from Europe (cross-vane traps, Galloprotect lure=monochamol+ipsenol+α-pinene+2-methyl-3-buten-2-ol) and North America (intercept panel traps, North American lure=monochamol+ipsenol+α-pinene+ethanol) for their efficacy at catching Monochamus species in a 2×2 factorial experiment. We captured three Monochamus species (M. scutellatus (Say), M. notatus (Drury), and M. marmorator Kirby) in Nova Scotia Christmas tree plantations. Mean trap catches were greater within the plantations than in the surrounding forests. North American panel traps coated with Fluon® and baited with the European lure caught the most M. notatus and M. scutellatus and would be most suitable for survey and monitoring.


2017 ◽  
Vol 149 (6) ◽  
pp. 801-812 ◽  
Author(s):  
Jean-François Doherty ◽  
Jean-Frédéric Guay ◽  
Conrad Cloutier

AbstractThe balsam twig aphidMindarus abietinusKoch (Hemiptera: Aphididae) is a major pest of economic importance for the Christmas tree industry. Global warming during the 21st century could potentially increase local population densities and reinforce the pest status of this aphid in commercial fir (AbiesMiller; Pinaceae) plantations in Québec, Canada. During this study, we tested the effects of a warmer environment on colony growth rates ofM. abietinusand aphid morph composition during the second generation of its cycle, which is key to colony size growth and potential damage to Christmas trees. We monitoredM. abietinuspopulations on two host fir species and one host fir variety, in order to understand the early season dynamics of this aphid and its host tree. It was possible to distinguish the two overlapping generations of winged aphids leaving colonies, which led to observing a much higher proportion of wingless daughters, produced by the stem mother, than what had previously been reported. Colony growth rates were significantly higher in a warmer environment than in the nearby plantation, suggesting that warmer temperatures in late spring and early summer may provide the suitable conditions required forM. abietinuscolonies of greater density.


2021 ◽  
Vol 13 (3) ◽  
pp. 1259
Author(s):  
Stephen ES Crook ◽  
Arielle Levine ◽  
David Lopez-Carr

The ecosystem services concept has emerged as a guiding principle in natural resource management over the past two decades, and an ecosystem services approach to management is currently mandated as a core element of United States National Forest planning. However, the concept of ecosystem services has been interpreted and operationalized in a variety of ways, leaving a pronounced knowledge gap regarding how it is understood and implemented in different contexts. To better understand the conceptualization and implementation of the concept within United States National Forests, semi-structured interviews with planners and managers of the Pacific Northwest Region were conducted at the region, forest, and ranger district levels, addressing the following topics: (1) how has the ecosystem services concept been perceived by managers and planners?; (2) what are the perceived key ecosystem services offered by National Forest lands?; (3) how has the concept been applied at multiple spatial scales?; and (4) what are perceived challenges or opportunities related to applying the concept in the National Forest context? Results indicate that although participants had a high level of understanding of the ecosystem services concept, there was not a clear, widely adopted approach to considering ecosystem services in management. Through qualitative analysis, three general perspectives arose: one employed the concept to fulfill regulatory requirements at the National Forest scale, a second engaged with ecosystem services to improve participatory planning at the project scale, and a third, business as usual perspective, considered ecosystem services as new language for describing longstanding National Forest priorities. These results draw attention to the challenges of implementing an ecosystem services-based approach in the United States National Forest context and the continued need for the development of management-relevant methods for describing and quantifying ecosystem services.


2019 ◽  
Vol 151 (3) ◽  
pp. 350-364 ◽  
Author(s):  
Suzanne Blatt ◽  
Charlane Bishop ◽  
Karen Burgher-MacLellan

AbstractThe occurrence of Bursaphelenchus xylophilus (Steiner and Buhrer) (Nematoda: Aphelenchida: Parasitaphelenchidae) (pinewood nematode) in Canada prevents export of wood products, including Christmas trees (Pinaceae), to Europe. A nationwide survey in 1992 extracted B. xylophilus from mature, dead, or dying balsam fir (Abies balsamea (Linnaeus) Miller; Pinaceae), but not young, healthy Christmas trees. Three species known to harbour B. xylophilus are found in Nova Scotia, but incidence of B. xylophilus within these species is unknown. Monochamus Dejean (Coleoptera: Cerambycidae) species were collected from nine and 20 sites, in 2014 and 2015, respectively, using panel traps baited with a Monochamus lure and evaluated for the presence of pinewood nematode using molecular methods after DNA isolation. Beetles were processed for DNA isolation individually in 2014 and in batches (same species and sex from same collection site and date) in 2015. Bursaphelenchus xylophilus was recovered from all three Monochamus species (M. marmorator Kirby, M. notatus (Drury), and M. scutellatus (Say)) captured in Nova Scotia Christmas tree plantations. Percentage of beetles harbouring B. xylophilus varied with species and sex. Fourteen beetle samples were selected and sent for polymerase chain reaction sequencing. Sequencing results indicated that Bursaphelenchus xylophilus found in Nova Scotia are most similar to isolates from Canada (New Brunswick and Québec), the United States of America, and China.


Forests ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 554
Author(s):  
Debalina Saha ◽  
Bert M. Cregg ◽  
Manjot Kaur Sidhu

Weeds interfere with Christmas tree growth at any time and at any stage of production. Growers mostly rely on mechanical mowing and applications of herbicides for weed control in their fields. However, herbicides can be phytotoxic to non-target plants, can cause environment-related issues, and their repeated application can even cause herbicide-resistant weeds. The main objective of this manuscript is to provide a review of non-chemical weed control strategies in Christmas tree production and identify areas where current practices could potentially be improved or in which further research is required. Preventing the introduction of weed seeds requires controlling weeds along farm roads, maintaining clean equipment, and eliminating new weeds before they start seeding. Mowing helps to reduce the number of seeds produced by the weeds and can significantly reduce competition with trees. Shropshire sheep are well suited for grazing Christmas tree plantations as they prefer grazing on grasses and weeds rather than on coniferous trees. Weeds can also be controlled around Christmas trees by mulching. Organic mulch can improve soil moisture, maintain soil temperatures, enhance root establishment and transplant survival, and improve plant establishment and overall growth. Incorporating cover crops into Christmas tree plantations may improve tree growth, quality, and soil fertility and can supplement conventional nitrogen fertilizers. However, if cover crops are not properly managed, they can be highly competitive with the trees. Flaming can cause suppression of many annual weed species but is less effective on larger weeds and needs to be applied with caution. Several insects have been used as biological agents to control selective weed species. However, further research is required to focus on several potential biological agents, different types and depths of mulches, on cover crops types and their competition with different species of Christmas trees and their effects on seedling survival and growth.


Plant Disease ◽  
1997 ◽  
Vol 81 (2) ◽  
pp. 230-230 ◽  
Author(s):  
N. G. Wenner ◽  
W. Merrill

Several needle blight fungi affect natural regeneration and Christmas tree plantations of Abies spp. in northeastern North America. Of these, Phyllosticta multicorniculata Bissett & Palm has been reported from A. balsamea (L.) Mill. in Ontario and Prince Edward Island, and from A. concolor (Gordon & Glend.) Lindl. ex Hildebr. in Wisconsin (1). In Quebec, P. multicorniculata was reported as an endophyte on symptomless needles of A. balsamea (2). In 1994, we collected this fungus in Grafton County, NH, defoliating lower branches of A. balsamea Christmas trees. In July and August 1996, we examined infected A. concolor Christmas trees in Lamoille County, VT. In July, approximately 50% of the 1996 needle complement on the lower 1 m of the crowns was infected and by August the incidence of infection on these branches increased to 75 to 100%. Less severe blighting occurred up to 1.5 m. Dead needles of the 1995 complement bore abundant, mostly empty, pycnidia of P. multicorniculata. The dead and dying distal ends of the 1996 needle complement bore abundant pycnidia of P. multicorniculata in various stages of maturation. This is the first report of this pathogen on Abies spp. in the northeastern U.S. The conidia from actively-sporulating pycnidia bore more numerous and longer appendages (1 to 16, average 7, up to 38 µm long) than the dried herbarium specimens of various ages used in the species description (1 to 5, up to 7 µm long) (1), or similarly reported from culture (2). References: (1) J. Bissett and M. E. Palm. Can. J. Bot. 67:3378, 1989. (2) L. Petrini et al. Sydowia 43:148, 1991.


2016 ◽  
Vol 148 (5) ◽  
pp. 616-618 ◽  
Author(s):  
E.R. Echegaray ◽  
R.N. Stougaard ◽  
B. Bohannon

AbstractEuxestonotus error (Fitch) (Hymenoptera: Platygastridae) is considered part of the natural enemy complex of the wheat midge Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae). Although previously reported in the United States of America, there is no record for this species outside the state of New York since 1865. A survey conducted in the summer of 2015 revealed that E. error is present in northwestern Montana and is likely playing a role in the suppression of wheat midge populations.


2004 ◽  
Vol 34 (1) ◽  
pp. 120-130 ◽  
Author(s):  
Vaidotas Lygis ◽  
Rimvydas Vasiliauskas ◽  
Jan Stenlid

Persistence of the root rot pathogen Heterobasidion annosum (Fr.) Bref. s.s. on infested areas and its transfer to a forest regeneration was studied in three forest sites in eastern Lithuania. The sites represented H. annosum disease centres in Pinus sylvestris L. stands, which were clear-felled and replanted with Betula pendula Roth 25 years prior to our study. Fungal isolation from trees and stumps on each site was performed on both replanted B. pendula and surrounding P. sylvestris from the previous generation. Low productivity of B. pendula stands (45.0–76.1 m3·ha–1), high mortality rates, and comparatively low vigor of trees (measured as crown densities) indicated a strong impact of root rot. Based on somatic incompatibility tests, we detected large spreading areas of clones of H. annosum (up to 48 m across) and old (35- to 40-year-old) clonal individuals. Territorial clones covered areas that encompassed both previous stands of P. sylvestris and current stands of B. pendula. Our results showed that H. annosum is able to persist in root systems of diseased trees for decades and readily attack birch replanted on infested sites. In addition, a total of 83 fungal species (out of 398 isolates) was found as a result of sampling 508 B. pendula, 49 P. sylvestris, 21 Juniperus communis L., and 1 Salix cinerea L. trees.


Sign in / Sign up

Export Citation Format

Share Document