The pattern of invasion and establishment of Piceamariana (Mill.) BSP. into the subcanopy layers of Pinusbanksiana Lamb. dominated stands

1982 ◽  
Vol 12 (4) ◽  
pp. 973-984 ◽  
Author(s):  
T. J. Carleton

Stand age-structure analysis is used to determine whether establishment of Piceamariana (Mill.) BSP. in the subcanopy of Pinusbanksiana Lamb. dominated stands takes the form of a gradual influx or a sudden event. Twenty-six P. banksiana dominated stands were investigated of which 15 contained P. mariana trees at moderate to high densities. Postfire ages ranged from 46 years to 132 years for the oldest P. banksiana cohort in each stand. The 26 stands were subjectively assigned to one of seven groups on the criterion of age-structure histogram appearance. A multivariate test of the hypothesis that such age-structure differences could be due to soil differences was not significant. Three patterns of P. mariana influx were indicated, (i) Gradual influx over a long time span in the oldest stands. (ii) Contemporaneous postfire reestablishment of both P. banksiana and P. mariana on a site. (iii) Invasion of P. mariana cohorts following surface fire activity as evidenced by fire scar dates. Results from a P. mariana seedling survival experiment indicated that depth of burn is of critical importance for black spruce seedling establishment in these stands. However, circumstantial evidence suggests that P. mariana seed supply may also be limiting to establishment success. These observations are discussed briefly in relation to models of forest succession.

1992 ◽  
Vol 70 (6) ◽  
pp. 1157-1167 ◽  
Author(s):  
Mireille Desponts ◽  
Serge Payette

The northernmost jack pine (Pinus banksiana Lamb.) populations in northern Quebec are located at the boreal forest–forest tundra boundary, along the Grande rivière de la Baleine, where they colonize the sandy terraces affected by recurrent fires. The recent fire history in the study area, as deduced from fire scar and age structure data, spans a 216-year period from 1773 to 1988. Forest fires occurred on the sites at intervals averaging 40 to 80 years. The analysis of 19 coniferous stands (jack pine and black spruce (Picea mariana (Mill.) Bsp)) indicated that forest communities younger than 67 years old were open jack pine – Cladina mitis or jack pine – black spruce – C. mitis woodlands, while the oldest stands, more than 132 years old, were dominated by jack pine, black spruce, and Cladina stellaris. Stands less than 67-years-old had an age structure almost normally distributed and regeneration often occurred within less than 30 years after fire in both species, while most stands older than 132 years had a multiaged structure. In sites with a prolonged fire-free interval, jack pine was overgrown by black spruce. Spruce woodlands have developed on sites where the organic layer was relatively thick and continuous and they are the end result of the postfire successional process. However, at several sites both conifer species showed an ability to regenerate in prolonged absence of fire disturbance, particularly in open sites with exposed mineral substrates. At the regional scale, fire frequency during the last 200 years has been high enough to prevent pine exclusion at its range limit. The key requirement for the long-term maintenance of jack pine populations is that fires return at intervals shorter than the average life-span of individual trees. It is concluded that the northernmost jack pine populations are able to maintain and regenerate under present fire conditions. Key words: fire, subarctic, jack pine, postfire regeneration, boreal forest.


Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 843
Author(s):  
Ella R. Gray ◽  
Matthew B. Russell ◽  
Marcella A. Windmuller-Campione

Insects, fungi, and diseases play an important role in forest stand development and subsequently, forest management decisions and treatments. As these disturbance agents commonly occur within and across landscapes, modeling has often been used to inform forest planning and management decisions. However, models are rarely benchmarked, leaving questions about their utility. Here, we assessed the predictive performance of a Bayesian hierarchical model through on–the-ground sampling to explore what features of stand structure or composition may be important factors related to eastern spruce dwarf mistletoe (Arceuthobium pusillum Peck) presence in lowland black spruce (Picea mariana (Mill.) B. S. P.). Twenty-five state-owned stands included in the predictive model were sampled during the 2019 and 2020 growing seasons. Within each stand, data related to the presence of eastern spruce dwarf mistletoe, stand structure, and species composition were collected. The model accurately predicted eastern spruce dwarf mistletoe occurrence for 13 of the 25 stands. The amount of living and dead black spruce basal area differed significantly based on model prediction and observed infestation, but trees per hectare, total living basal area, diameter at breast height, stand age, and species richness were not significantly different. Our results highlight the benefits of model benchmarking to improve model interpretation as well as to inform our understanding of forest health problems across diverse stand conditions.


1989 ◽  
Vol 19 (3) ◽  
pp. 295-308 ◽  
Author(s):  
R. D. Whitney

In an 11-year study in northern Ontario, root rot damage was heaviest in balsam fir, intermediate in black spruce, and least in white spruce. As a result of root rot, 16, 11, and 6%, respectively, of dominant or codominant trees of the three species were killed or experienced premature windfall. Butt rot, which resulted from the upward extension of root rot into the boles of living trees, led to a scaled cull of 17, 12, and 10%, respectively, of gross merchantable volume of the remaining living trees in the three species. The total volume of wood lost to rot was, therefore, 33, 23, and 16%, respectively. Of 1108 living dominant and codominant balsam fir, 1243 black spruce, and 501 white spruce in 165 stands, 87, 68, and 63%, respectively, exhibited some degree of advanced root decay. Losses resulting from root rot increased with tree age. Significant amounts of root decay and stain (>30% of root volume) first occurred at 60 years of age in balsam fir and 80 years in black spruce and white spruce. For the three species together, the proportion of trees that were dead and windfallen as a result of root rot increased from an average of 3% at 41–50 years to 13% at 71–80 years and 26% at 101–110 years. The root rot index, based on the number of dead and windfallen trees and estimated loss of merchantable volume, also increased, from an average of 17 at 41–50 years to 40 at 71–80 years and 53 at 101–110 years. Death and windfall of balsam fir and black spruce were more common in northwestern Ontario than in northeastern Ontario. Damage to balsam fir was greater in the Great Lakes–St. Lawrence Forest region than in the Boreal Forest region. In all three tree species, the degree of root rot (decay and stain) was highly correlated with the number of dead and windfallen trees, stand age, and root decay at ground level (as a percentage of basal area) for a 10-tree sample.


2011 ◽  
Vol 87 (05) ◽  
pp. 612-624 ◽  
Author(s):  
Eric Alvarez ◽  
Louis Bélanger ◽  
Louis Archambault ◽  
Frédéric Raulier

Pre-industrial forest cover portrait is a recognized method for establishing the bases of sustainable forest management. However, it is a spatially and temporally dependant concept that should be used with caution in presence of big fires. The objective of the study was to portray the pre-industrial landscape in a mixedwood temperate forest in central Quebec at different spatial scales. The study was based on archival records from a forest company. The pre-industrial forest cover landscape of our study area was mainly composed of mature or old-growth (>100 years) stands and dominated by mixedwood forest stands with intolerant hardwoods. The main tree species were white birch, black spruce and jack pine, three species associated to forest succession after fire in the boreal forest. Considering the great variability caused by the fires and partial knowledge of this variability, for each spatial scale considered, we propose some management targets based on the main pre-industrial characteristics of this forest. To respect the pre-industrial variability, our study suggested that silviculture should be adapted at different landscape scales. Cover types and age class targets should be based on main preindustrial characteristics at each landscape scale analyzed.


1988 ◽  
Vol 5 (3) ◽  
pp. 185-189 ◽  
Author(s):  
D. Craig Sutherland ◽  
Robert J. Day

Abstract This paper is the first general review of the affects of container volume on the survival and growth of containerized white spruce, black spruce, and jack pine seedlings. The review shows that the literature on this topic is fragmentary and inconsistent. Seedling growth in the greenhouse production phase has been more completely quantified than subsequent establishment and growth after out-planting in the field. In the greenhouse production phase, seedling growth increased from 72 to 360% when the container volume was tripled in size. After outplanting in the field, seedling growth trends were more variable. Seedling height growth increased from 34 to 84% when container volume was tripled in size. Seedling survival was more difficult to assess because of limited data. Only white spruce showed a 10% increase in survival with an increase in container volume. The indications from this literature review suggest that nursery managers and practicing foresters should become more aware of the limitations imposed on seedling survival and growth due to container volume. To maintain optional survival and growth for white spruce, black spruce and jack pine, the container volume should range from 90 to 120 cm3. North. J. Appl. For. 5:185-189, Sept. 1988.


1997 ◽  
Vol 21 (1) ◽  
pp. 11-18 ◽  
Author(s):  
William M. Ford ◽  
A. Sydney Johnson ◽  
Philip E. Hale ◽  
James M. Wentworth

Abstract We analyzed correlations of forest type, age structure, and site index data with weights and antler characteristics of yearling white-tailed deer (Odocoileus virginianus) bucks from specific localities in the Chattahoochee, Cherokee, Nantahala, and Pisgah national forests in Georgia, Tennessee, and North Carolina. Areas in the northern part of the study region produced larger deer with larger antlers than those in the southern portion of the region. These northern areas differed from those to the south in having more diverse ownership and land use and in origins of deer stock. Weights and antler characteristics were significantly correlated (P < 0.05) with percent area in the cove hardwood type, but otherwise were poorly correlated with forest stand type and site index. Percent area in young (0-8 yr old) cove hardwood and in mid-successional (9-20 and 21-40) cove hardwood, pine (Pinus spp.), and upland oak (Quercus spp.) were significantly correlated (P < 0.05) with deer variables, particularly in years following a poor mast crop. Much of the quantifiable habitat influences on deer in the Southern Appalachians probably is masked by low deer densities and the small site quality differences among areas examined. Because much of the forest consists of mature mast-producing oaks and abundant forage is produced in both mature and younger aged stands, deer numbers seem to be below any threshold of quantifiable effects due to forest stand age structure. South. J. Appl. For. 21(1):11-18.


1954 ◽  
Vol 30 (4) ◽  
pp. 372-379 ◽  
Author(s):  
Henri LeBlanc

Lack of reproduction of black spruce, Picea mariana, in pure black spruce stands in old cut-over areas, has always been a great subject of discussion and one for intensive work among foresters. Many reasons such as the absence of an adequate seed supply stored on top of humus, or adverse germination conditions are said to be partly responsible.This study on the humus of this unregenerated cut-over area, indicates clear cutting of this stand will influence the normal concentration of definite micro-nutrients such as manganese and magnesium.The augmentation of manganese in the soil has a detrimental effect on the growth of plants when, its concentration is too high. The diminution of magnesium, which is an element necessary to stimulate the growth, must create abnormal nutritive conditions of the habitat. This visible lack of equilibrium might be the cause of the absence of seedlings of Picea mariana on certain parts of this cut-over area.


2013 ◽  
Vol 89 (03) ◽  
pp. 350-359 ◽  
Author(s):  
Nicole J. Fenton ◽  
Louis Imbeau ◽  
Timothy Work ◽  
Jenna Jacobs ◽  
Hervé Bescond ◽  
...  

Multi-cohort management that creates or maintains an uneven structure within forest stands has been widely advocated as a means to attenuate the impact of forest harvesting. An experimental network was put in place in black spruce forests of northwestern Québec to test this assertion. Here we synthesize the biodiversity results in two main lessons: (1) at least 40% to 60% retention of pre-harvest basal area was required to maintain pre-harvest conditions for most species groups; (2) partial harvests showed the potential to be efficient deadwood delivery systems. In addition to these two main general conclusions, we emphasise that future research should examine whether partial harvest may be able to advance forest succession.


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