Impact of dwarf mistletoe on some aspects of the reproductive biology of jack pine

1996 ◽  
Vol 72 (3) ◽  
pp. 303-306 ◽  
Author(s):  
Albert Sproule
Keyword(s):  
Reproductive Biology ◽  
Jack Pine ◽  
Dwarf Mistletoe ◽  
Infection Level ◽  
North Central ◽  
Clear Cutting ◽  
Pine Regeneration ◽  
Pine Trees ◽  
Four Levels ◽  
Filled Seeds

A study was conducted in north-central Alberta to examine the effects of dwarf mistletoe on the reproductive biology of jack pine trees with severe, moderate, light and no infection. Fifty cones were collected from each of six trees in each infection class and from three non-infected trees. Cone counts were 401, 547, 787 and 1217 respectively for the four levels of infection. Total seeds per cone were 17.4, 16.3, 27.9 and 25.7. Filled seeds per cone were 13.0, 10.4, 19.9 and 18.9. Numbers of expected germinants per tree were, correspondingly 4442, 3871, 11827 and 18753. These results could be important for managers depending on natural regeneration to produce fully stocked stands following clear-cutting of infected trees. Key words: dwarf mistletoe, germinants, infection level, Jack pine, regeneration

Explosive discharge of jack pine dwarf mistletoe (Arceuthobiumamericanum) seed in Manitoba

1991 ◽  
Vol 21 (4) ◽  
pp. 434-438 ◽  
Author(s):  
David Punter ◽  
Jeannie Gilbert
Keyword(s):  
Relative Humidity ◽  
Stepwise Regression ◽  
Buffer Zone ◽  
Jack Pine ◽  
Dwarf Mistletoe ◽  
Pine Regeneration ◽  
Pine Trees ◽  
The Hours ◽  
Spring Temperatures ◽  
Provincial Park

Seeds of the dwarf mistletoe, Arceuthobiumamericanum Nutt. ex Engelm., explosively discharged from plants parasitizing 40- to 60-year-old jack pine trees (Pinusbanksiana Lamb.), were collected on cheesecloth traps at two sites in Grand Beach Provincial Park at 2-h intervals during daylight hours. Microclimatic variables were continuously recorded during the discharge period. Seeds were recovered up to 18 m from the canopy margin. Seasonal fluctuations in numbers of seeds trapped were attributed in part to fungal hyperparasitism of fruits and high spring temperatures. The spatial distribution of seeds was strongly leptokurtic, with most landing within 12 m of the canopy margin. Neither the onset nor the distance of discharge could be ascribed to any single microclimatic parameter. With one apparent exception, no discharge occurred during the hours of darkness. The number of seeds trapped rose rapidly between sunrise and 11:00 central standard time, when temperature was increasing and relative humidity was falling. Stepwise regression analysis confirmed that change in relative humidity was predominantly responsible for the diurnal periodicity of seed discharge. Based on our observations, we recommend a minimum 20-m buffer zone to protect pine regeneration from A. americanum infected residual trees.

scholarly journals Effects of Lodgepole Pine Dwarf Mistletoe, Arceuthobium americanum, on Jack Pine, Pinus banksiana, Growth in Manitoba

2004 ◽  
Vol 118 (4) ◽  
pp. 595 ◽  
Author(s):  
Brock Epp ◽  
Jacques C. Tardif
Keyword(s):  
Pinus Banksiana ◽  
Growth Models ◽  
Lodgepole Pine ◽  
Wood Quality ◽  
Basal Area ◽  
Jack Pine ◽  
Dwarf Mistletoe ◽  
Tree Form ◽  
Arceuthobium Americanum ◽  
Pine Trees

The Lodgepole Pine Dwarf Mistletoe (Arceuthobium americanum Nutt. ex Engelm.) is an important pathogen of Jack Pine (Pinus banksiana Lamb.). Dwarf Mistletoe alters tree form, suppresses growth, and reduces volume and overall wood quality of its host. Stem analysis and a 3-parameter logistic regression model were used to compare the growth of heavily and lightly to non infected Jack Pine trees. At the time of sampling, no significant reduction in diameter at breast height and basal area were observed in heavily infected trees. However, a significant reduction in height and volume and an increase in taper were observed in heavily infected trees. Growth models predicted a 21.1% lower basal area, 23.4% lower height and 42.1% lower volume by age 60 for the high infection group.

Life cycle of Arceuthobium americanum on Pinus banksiana based on inoculations in Edmonton, Alberta

2006 ◽  
Vol 36 (4) ◽  
pp. 1006-1016 ◽  
Author(s):  
J P Brandt
Keyword(s):  
Life Cycle ◽  
Pinus Banksiana ◽  
Lodgepole Pine ◽  
Jack Pine ◽  
Western Canada ◽  
Dwarf Mistletoe ◽  
Arceuthobium Americanum ◽  
Pine Trees

While lodgepole pine dwarf mistletoe, Arceuthobium americanum Nutt. ex Engelm., is one of the most damaging pests of jack pine (Pinus banksiana Lamb.) in western Canada, no studies have examined the life cycle of this parasite in this pathosystem. Twenty-five jack pine trees in a plantation in Edmonton, Alberta, were inoculated with seeds of A. americanum in the fall of 1998 and 1999; these inoculants were monitored until the dwarf mistletoe plants that arose completed their life cycle. Ninety-two percent of inoculated seeds overwintered on their host. Seventy percent of these seeds germinated, mostly in May. Of these germinants, 69% developed holdfasts. Sixty-eight percent of germinants that developed holdfasts infected their host and produced shoots, primarily between July and August in the second season after inoculation. Of the 56 plants that developed from the 175 inoculations, 34 were pistillate plants and 19 were staminate plants, and 3 immature plants died because the host branch died. Pistillate plants flowered significantly earlier than staminate plants (4.1 vs. 4.7 years). Most pistillate plants produced seed in the fifth year, although one plant produced seed in 4 years. Thus, A. americanum probably has a 5-year life cycle on jack pine.

Pathogenicity of Bursaphelenchusxylophilus on three species of pine

1987 ◽  
Vol 17 (1) ◽  
pp. 51-57 ◽  
Author(s):  
P. J. Bedker ◽  
M. J. Wingfield ◽  
R. A. Blanchette
Keyword(s):  
Jack Pine ◽  
Red Pine ◽  
Pine Wood Nematode ◽  
Pine Wood ◽  
Water Extracts ◽  
Pine Trees ◽  
Branch Death

Three species of 11-year-old pine trees were inoculated with Bursaphelenchusxylophilus in the field. Four branches in single whorls on red, Scots, and jack pine trees were wounded and inoculated with 10 000 nematodes each or with water extracts from Botrytiscinerea cultures. Prior to field inoculations, the pathogenicity of the nematode isolate was confirmed on seedlings in the greenhouse. Fourteen weeks after inoculation, 27 of 80 and 13 of 52 branches were dead or dying on Scots and jack pine trees, respectively. No symptoms were observed on red pine trees inoculated with B. xylophilus or on any controls. Branch death was attributed to the formation of girdling cankers resulting from inoculation. An average of 9.14, 10.39, and 0.02 nematodes were extracted per gram of wood from branch samples collected from Scots, jack, and red pine trees at 14 weeks, respectively, and at 58 weeks an average of 13.82, 1.01, and 0.05 nematodes per gram of wood sampled were recovered. Proportions of branch samples with nematodes declined from 14 to 58 weeks after inoculation. Although limited mortality of branches occurred, the pine wood nematode was not found to cause tree death following inoculation.

Changes in small mammal communities after logging in north-central Ontario

1983 ◽  
Vol 61 (5) ◽  
pp. 970-980 ◽  
Author(s):  
Arthur M. Martell
Keyword(s):  
Small Mammals ◽  
Small Mammal ◽  
Vegetative Cover ◽  
North Central ◽  
Clear Cut ◽  
Clear Cutting ◽  
Small Mammal Community ◽  
Small Mammal Communities ◽  
Mammal Community ◽  
Mammal Communities

Changes in small mammal communities following logging were monitored in clear-cut and strip-cut upland black spruce (Picea mariana) stands and in selectively cut mixed wood stands in north-central Ontario. Clear-cutting and subsequent scarification essentially eliminated the vegetative cover. Much of the ground cover recovered within 5 years and shrubs within 12 years, but mosses and lichens took much longer. The small mammal community in both clear-cut and strip-cut stands changed over the first three years after logging from one dominated by southern red-backed voles (Clethrionomys gapperi) to one dominated by deer mice (Peromyscus maniculatus) and then remained relatively stable for up to 13 years after harvest. That shift was not apparent in selectively cut mixed wood stands where the composition of the small mammal community was similar between uncut stands and stands 4–23 years after harvest. There was relatively little change in total numbers of small mammals after logging. In general, the diversity and evenness of small mammals increased or remained stable in the first 1–3 years following harvest, decreased on older (3–16 years) cuts, and then increased to values similar to those in uncut stands on the oldest (19–23 years) cuts.

The relationship of reproductive biology to the rarity of endemic Aster curtus (Asteraceae)

1999 ◽  
Vol 77 (1) ◽  
pp. 140-149 ◽  
Author(s):  
David E Giblin ◽  
Clement W Hamilton
Keyword(s):  
Pacific Northwest ◽  
Reproductive Biology ◽  
Fluorescent Microscopy ◽  
Pollen Grains ◽  
Field Trials ◽  
Rare Plants ◽  
Glacial Outwash ◽  
Compatible Cross ◽  
Species Rarity ◽  
Filled Seeds

The fecundity of rare plants is a commonly used indicator of performance at the population or species level. However, accurately interpreting reproductive output requires an understanding of a particular species's breeding system. The purpose of this study was to determine if reproductive biology contributes to the restricted distribution of Aster curtus Cronq. We hypothesized that (i) A. curtus, like many Asteraceae species, is self-incompatible, and (ii) that pollinations between patches produce significantly more filled seeds than pollinations within patches. Fluorescent microscopy of pistils harvested after greenhouse pollination showed A. curtus to be partially self-compatible. Cross-pollination resulted in significantly more pollen grains per stigma and significantly greater pollen germination than self-pollination. Similarly, field pollination trials showed that between-patch crosses produced significantly more filled seeds than within-patch crosses. Nevertheless, within-patch pollinations produced substantial levels of filled seed. Results from the greenhouse and field trials suggest that the reproductive biology of A. curtus contributes little to its rarity. Understanding why A. curtus is rare has important implications to the conservation of the glacial outwash prairie. Moreover, the data from this research can be used in further developing predictive models for plant species rarity based on reproductive biology.Key words: Aster, endemic, Pacific Northwest, rarity, reproductive biology, self-incompatibility.

scholarly journals STUDIES ON WHITE PINE BLISTER RUST IN NOVA SCOTIA

1953 ◽  
Vol 29 (3) ◽  
pp. 267-272 ◽  
Author(s):  
W. K. McGinn ◽  
A. G. Davidson
Keyword(s):  
Nova Scotia ◽  
Control Measure ◽  
Systematic Search ◽  
White Pine Blister Rust ◽  
White Pine ◽  
Clear Cutting ◽  
Blister Rust ◽  
Pine Regeneration ◽  
Show Evidence ◽  
Cutting Operation

Studies were undertaken in Nova Scotia to determine (i) the effect of different cutting practices on the establishment of a RIBES population and of white pine regeneration, (ii) whether blister rust is a major factor in retarding the establishment of white pine regeneration, and (iii) the feasibility and cost of RIBES eradication as a direct control measure against blister rust. No relationship was found to exist between RIBES establishment and the degree of cutting. Uncut softwood stands, where white pine is the predominant species, show evidence of producing a future pine crop. Forest types supporting white pine appear to offer the best opportunities for pine reproduction where a clear-cutting operation has given the stand maximum opening. Results of the present study to date do not show that blister rust is a major factor in retarding the establishment of white pine regeneration. To eradicate RIBES from the study area by a complete systematic search required 1 man-hour per acre. Because of the small number of RIBES plants found and of the tendency for them to occur consistently in moist, low-lying habitats, a complete systematic search for these plants appears to be unnecessary. It is suggested that one man, trained to recognize RIBES and their probable location, could cover large forest tracts with a minimum of time expended in searching localities unlikely to support these plants.

Release and dispersal of pollen from dwarf mistletoe on jack pine in Manitoba in relation to microclimate

1990 ◽  
Vol 20 (3) ◽  
pp. 267-273 ◽  
Author(s):  
Jeannie Gilbert ◽  
David Punter
Keyword(s):  
Pollen Grains ◽  
Time Lapse ◽  
Jack Pine ◽  
Dwarf Mistletoe ◽  
Spore Trap ◽  
Insect Visitors ◽  
Time Lapse Photography

The release and dispersal of pollen of Arceuthobiumamericanum Nutt. ex Engelm. parasitizing Pinusbanksiana Lamb. were examined in relation to microclimate in southern Manitoba. Time-lapse photography revealed that once open, the long-lived staminate flowers remain open. The anthers, however, open in response to rising temperatures and falling relative humidities and close under the reverse conditions. Small Diptera (Sciaridae) appeared on the photographs on 25 occasions during the wet spring of 1986. Nectar was scarce on pistillate flowers, but accumulated on the central cushions of staminate flowers when relative humidities were high. In the dry spring of 1987, nectar was rarely seen on the staminate flowers and one small dipteran was photographed just once. Large beads of concentrated nectar (50–65% sugar), however, formed on the stigmas in 1987. Large Diptera were rarely seen in 1986, but were numerous in 1987. Visits to staminate flowers were more frequent than to pistillate (2.7:1.0), but individual insects spent more time on pistillate flowers than staminate (9.6:1.0 s). Pollen grains, trapped on a continuously recording volumetric spore trap, increased in number during warm periods and fluctuated when weather alternated between rainy and dry. Pollination is effected by unspecialized insect visitors and wind. Like other diclinous species, A. americanum represents a compromise between entomophily and anemophily.

scholarly journals Jack Pine Regeneration Following Postcut Burning under Seed Trees in Central Saskatchewan

1988 ◽  
Vol 64 (4) ◽  
pp. 315-319 ◽  
Author(s):  
Z. Chrosciewicz
Keyword(s):  
Populus Tremuloides ◽  
Growth Rates ◽  
Pinus Banksiana ◽  
Forest Regeneration ◽  
Black Spruce ◽  
Timber Harvest ◽  
Jack Pine ◽  
Growing Seasons ◽  
Pine Regeneration ◽  
Slash Burning

An experimental burn in conjunction with a seed-tree system was successful in regenerating jack pine (Pinus banksiana Lamb.) on a fresh to somewhat moist upland, loamy till, cutover site in central Saskatchewan. About 20 well-formed, uniformly spaced seed trees per hectare were left standing during timber harvest. The ignition of logging slash was carried out under preselected weather and fuel conditions so that favorable seedbeds and adequate seed dispersal from the seed trees were produced. Four growing seasons after burning, jack pine stocking by 4-m2 quadrats was 90% with 12 195 seedlings/ha. Aspen (Populus tremuloides Michx.), to a lesser degree black spruce (Picea mariana [Mill.] B.S.P.), and other companion tree species also regenerated with the pine. Various seedbed and regeneration characteristics as well as height growth rates are discussed. Key words: Pinus banksiana, slash burning, seed-tree system, forest regeneration, growth rates, central Saskatchewan.

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