Selection cutting in over-mature spruce–fir stands in Quebec

1976 ◽  
Vol 6 (1) ◽  
pp. 69-77 ◽  
Author(s):  
G. F. Weetman ◽  
D. Algar

On the North Shore of the St. Lawrence River in the boreal forest (Forest Section B.1b) there are extensive stands of old-growth black spruce (Piceamariana (Mill.) B.S.P.) and balsam fir (Abiesbalsamea (L.) Mill.). They grow on high-quality valley-bottom sites with a diameter class distribution that is close to the theoretical ideal of the straight-line log relationship considered ideal for selection forests.In 1962, two stands containing about 3500 ft3/acre (246 m3/ha) on 36 acres (14.5 ha) were cut to remove between 20% and 50% of the volume in the form of a selection cut. Basal area and volume, growth, ingrowth, mortality, logging damage, and blowdown losses were monitored in two 5-year remeasurements on a network of 72 permanent sample plots. Only 18 of these plots showed a net loss in basal area for the 10-year period after treatment.It is concluded that in sheltered locations it could be possible to maintain stands such as these in a productive and aesthetically pleasing condition by careful selection cutting.

2010 ◽  
Vol 86 (4) ◽  
pp. 498-510 ◽  
Author(s):  
Jérôme Cimon-Morin ◽  
Jean-Claude Ruel ◽  
Marcel Darveau ◽  
Jean-Martin Lussier ◽  
Philippe Meek ◽  
...  

It is increasingly accepted that silviculture must now try to maintain complex stands. In this context, selection cutting has been suggested as an option for irregular boreal stands. However, selection cutting in virgin stands could prove difficult to apply at a reasonable cost. In an attempt to reduce harvesting costs, two selection cutting patterns were implemented, avoiding tree marking. The efficacy of this approach was evaluated by comparing the results of plots harvested without tree marking to those with tree marking. To proceed in the absence of tree marking, silvicultural types were defined as well as a rule for the selection of stems to harvest; the final choice of stems to fell was therefore left to the operator upon harvesting. The effects of the different silvicultural and tree marking treatments were examined in relation to their ability to maintain the main structural and functional attributes of irregular boreal stands. A follow-up was conducted with regards to structure, composition, residual stand basal area, abundance of woody debris and mortality. The absence of marking did not affect the performance of selection cutting treatments in terms of basal area, quadratic mean diameter and Shannon index. Tree vigour was not modified by harvesting, both with and without tree marking. Stand composition was not influenced by the absence of marking. Snag abundance was reduced to similar levels regardless of marking. Tree marking did not influence the abundance of downed woody debris. As a consequence, it seems possible to apply a simplified approach of selection cutting, without compromising the success of the treatment in these stands.Key words: black spruce, Picea mariana, balsam fir, Abies balsamea, irregular stand, selection cutting, ecosystem management, forest attributes


Author(s):  
Snežana Obradović ◽  
Damjan Pantić ◽  
Milan Medarević ◽  
Biljana Šljukić ◽  
Biljana Pešić

The primary goal of this research was to analyze the structural, production and dynamic changes of theforests of beech and fir in permanent sample plots of Mt. Goč, excluded from regular management fora period of 35 years (1977–2011). The established principles of spontaneous development and selfregulatoryprocesses could have implications on the regular management in these forests located in thearea of Mt. Goč and other areas.The results of this research in the permanent sample plots indicate that the mixed forests of beech andfir have suffered a number of changes in terms of structure and production in the investigated period.Structural disruptions have been the result of a decrease in the share of small and medium-diametertrees, as well as an increase in the share of trees of large dimensions in the total number of trees. Thecurves of distribution have been moved to the right and in terms of shape they differ from the lines thatare typical of selection forests. A relatively large number of trees per hectare and the described distributionby diameter classes have resulted in the high values of basal area and stand volume. In addition,a high volume increment has also been recorded. The quality and incremental capacity of the standshave been reduced due to a significant share of old beech and fir trees. The accumulation of volumeslowed down the dynamics of stand development and hindered rejuvenation and recruitment, as thenecessary prerequisites for structural stability and functionality in selection forests.The observed trends of development in these forests in the sample plots clearly indicate that a structurallystable, socio-economically and ecologically valuable selection forest is possible to achieve only withan active and continuous implementation of a set of management procedures, which primarily refersto selection cutting. Self-regulatory processes that are allowed over time, as in the case of the analyzedsample plots, are increasingly distancing us from this goal.


2013 ◽  
Vol 43 (12) ◽  
pp. 1181-1195 ◽  
Author(s):  
David R. Gray

The spruce budworm (Choristoneura fumiferana Clemens) is perhaps the single most important disturbance agent in Canada’s eastern forests. Climate and forest composition are dominant factors in spruce budworm outbreak dynamics through their direct influences on the pest, its natural enemies, and its hosts, and through their influence on the multitrophic interactions that are important in outbreak dynamics. A combination of four climate variables, three forest composition variables, and one location variable explained 60% of the multivariate variability in outbreak characteristics (duration and severity) in eastern Canada. Outbreak duration was most strongly influenced by April–May accumulation of degree-days; outbreak severity was most strongly influenced by the extreme maximum temperatures of April–May. The basal area of balsam fir had a stronger influence than that of black spruce on duration and on severity. Both outbreak characteristics declined in more northerly locations. Under a projected future (2011–2040) climate scenario the largest increases in outbreak duration and severity are predicted to occur on the Gaspé Peninsula and the north shore of the St. Lawrence River (Quebec). The largest decreases in duration and severity are predicted to occur in southern Ontario and along the Bay of Fundy in New Brunswick and Nova Scotia. The predicted average change in outbreak duration is around –1.3 years. The predicted average change in outbreak severity is only slightly different from zero (around –1.5% defoliation).


1993 ◽  
Vol 69 (4) ◽  
pp. 421-430 ◽  
Author(s):  
P. F. Newton ◽  
G. F. Weetman

A stand density management diagram for black spruce (Picea mariana (Mill.) B.S.P.) was developed using data derived from 49 0.081-ha permanent sample plots and 257 open-grown sample trees located throughout central insular Newfoundland. The diagram illustrated the reciprocal equation of the competition-density effect, self-thinning rule, approximate crown closure line, zone of imminent competition-mortality, and isolines for relative density, quadratic mean diameter and merchantability ratio. Mean prediction error for natural stand trajectories over a 30-projection period were 2.5 dm3 for mean volume, 306 stems/ha for density, 16.1 m3/ha for merchantable volume, 14.3 m3/ha for total volume, and 1.9 m2/ha for basal area. Implementation procedures using a combination of monoareal and polyareal sampling methods were described and the potential application of the diagram for evaluating thinning alternatives was demonstrated. Limitations of the diagram and future research directions were identified. Key words: stand density management diagram, black spruce, natural stands, central Newfoundland


1998 ◽  
Vol 15 (2) ◽  
pp. 98-105 ◽  
Author(s):  
Graham R. Hillman ◽  
Sam K. Takyi

Abstract A split-plot design experiment replicated in four blocks was established to determine the effects of thinning (main plots) and fertilization (subplots) on growth of a 50- to 60-yr-old stagnant stand of black spruce on a shallow peatland (swamp) in Alberta drained in the previous year in a large-scale experimental project to convert it to a future merchantable stand. The thinning treatments were selective hand-spacing to 1600 trees ha-1 and no thinning. The hand-broadcast fertilizer treatments were: no fertilizer, nitrogen (N), phosphorus (P), potassium (K), NP, PK, NK, and NPK. Nitrogen as NH4NO3 was applied at 200 kg ha-1, P as triplesuperphosphate at 100 kg ha-1, and K as potassium chloride at 100 kg ha-1. After six growing seasons, diameter at breast height, basal area, and volume growth were significantly greater in the thinned treatment than for the same number of large (dominant and codominant) trees in the unthinned treatment. Thinning had no significant effect on height growth. Nitrogen significantly increased dbh, height, basal area, and volume growth, and NP increased the basal area and volume growth. P, K, and PK treatments showed little effects on growth, and P applied alone tended to reduce growth. The results indicated it will be beneficial to supplement drainage with thinning or fertilization with N and N-containing fertilizers or with both shortly after drainage, particularly when other researchers have indicated black spruce may take several years to respond to drainage. North. J. Appl. For. 15(2):98-105.


2015 ◽  
Vol 45 (12) ◽  
pp. 1739-1747 ◽  
Author(s):  
Kenneth Agbesi Anyomi ◽  
Jean-Claude Ruel

Boreal ecosystem functioning is largely controlled by disturbance dynamics. There have been efforts at adapting forest management approaches to emulate natural disturbance effects, as this is expected to maintain ecosystem resilience. In many instances, this involves resorting to partial cutting strategies that are likely to increase windthrow losses. The objective of this study was to determine the effects of alternative silvicultural practices on windthrow damage and how these effects vary with the scale of treatment. The study was conducted in the Quebec North Shore region (Canada), an area dominated by balsam fir (Abies balsamea (L.) Mill.) and accompanied by black spruce (Picea mariana (Mill) B.S.P.). Four different silvicultural treatments (overstory removal, heavy partial cutting, and two patterns of selection cutting) and control areas were implemented in 2004 and 2005. The experiment used a nested approach where treatment at the plot level was independent and yet nested within the block-level treatment. At the block level, treatments were applied over 10–20 ha units, leaving a small portion of the block for a smaller application of each treatment (plot scale, 2500 m2). Inventory was carried out before harvesting and monitoring was done yearly after harvesting, with the aim to better understand the plot- and block-level factors that drive windthrow damage levels and the effects of alternative silvicultural treatments. Results after 6–7 years show that basal area proportion windthrown differs substantially between treatments, as well as between treated sites and control sites. Windthrow levels were higher under heavy cuts relative to selection cuts and also increased with balsam fir proportion. Windthrow proportions were better correlated to block-level treatment than plot-level treatment, showing that the environment surrounding the treated plot can have an important effect on windthrow losses. Overall, the selection cutting system, particularly SC2, retains the most green-tree basal area and thus best meets the management objective of retaining old-growth attributes. A simple empirical model was calibrated that could aid in hazard rating.


2011 ◽  
Vol 101 (5) ◽  
pp. 583-593 ◽  
Author(s):  
M. O. Kimberley ◽  
I. A. Hood ◽  
R. L. Knowles

Phaeocryptopus gaeumannii, the cause of Swiss needle-cast, is widely distributed in plantations of Douglas-fir in many parts of the world. Nevertheless, information remains limited on its precise effect on stand growth, particularly in relation to regional climate, and on its consequent economic cost. In New Zealand, the spread of P. gaeumannii over a period of ≈30 years following its discovery in 1959 was closely monitored, and the timing of its arrival in different forests is known. This information was coupled with data from permanent sample plots in order to quantify the associated historical growth increment loss. Analyses revealed a steady decline in growth rate over the period from the first appearance of P. gaeumannii to a point when it stabilized at a lower increment level 14 to 20 years later. The cumulative mean reduction was 25% for mean top height, 27% for basal area, and 32% for stem volume. Volume growth rate decline was greater in the North Island (35%) than the South Island (23%) of New Zealand. These reductions in volume growth are estimated to equate to a loss in net present value of $NZ2,620 ha–1 and $NZ1,470 ha–1 for the North and South Islands, respectively, using a discount rate of 6%. Mortality did not increase as a result of infection by P. gaeumannii. The disease had less effect on cooler sites, especially those with low spring minimum temperatures (P < 0.001). Negligible growth decline occurred on sites with daily minimum October temperatures averaging <3.2°C.


1979 ◽  
Vol 55 (5) ◽  
pp. 189-193 ◽  
Author(s):  
R. S. van Nostrand

Results are given for two NPK fertilizer trials established in 1967 and 1968 in 60-year-old black spruce stands in central Newfoundland. After nine years, replicated Trial 1 showed significant basal area and volume growth response over control for N, NP, NK and NPK treatments. N and NPK produced the greatest response where gains of 20 m3/ha and 23 m3/ha respectively were achieved after nine years. Similar results were obtained from non-replicated Trial 2 after eight years, where all treatments containing N produced approximately equal response. Maximum response in radial increment, measured from increment cores of sample trees, occurred four to six years after initial treatment. Generally, response was greater for dominant and co-dominant trees than for trees in the intermediate crown class.


1989 ◽  
Vol 24 (4) ◽  
pp. 589-608 ◽  
Author(s):  
I.K. Tsanis ◽  
J. Biberhofer ◽  
C.R. Murthy ◽  
A. Sylvestre

Abstract Determination of the mass output through the St. Lawrence River outflow system is an important component in computing mass balance of chemical loadings to Lake Ontario. The total flow rate in the St. Lawrence River System at the Wolfe Island area was calculated from detailed time series current meter measurements from a network of current meters and Lagrangian drifter experiments. This flow is roughly distributed in the ratio of 55% to 45% in the South and North channel, respectively. Loading estimates of selected chemicals have been made by combining the above transport calculations with the ongoing chemical monitoring data at the St. Lawrence outflow. A vertical gradient in the concentration of some organic and inorganic chemicals was observed. The measured concentration for some of the chemicals was higher during the summer months and also is higher in the South Channel than in the North Channel of the St. Lawrence River. These loading estimates are useful not only for modelling the mass balance of chemicals in Lake Ontario but also for serving as input loadings to the St. Lawrence River system from Lake Ontario.


2021 ◽  
Vol 10 (1) ◽  
pp. 27
Author(s):  
Bilal Ahmad Munir ◽  
Sajid Rashid Ahmad ◽  
Raja Rehan

In this study, a relation-based dam suitability analysis (RDSA) technique is developed to identify the most suitable sites for dams. The methodology focused on a group of the most important parameters/indicators (stream order, terrain roughness index, slope, multiresolution valley bottom flatness index, closed depression, valley depth, and downslope gradient difference) and their relation to the dam wall and reservoir suitability. Quantitative assessment results in an elevation-area-capacity (EAC) curve substantiating the capacity determination of selected sites. The methodology also incorporates the estimation of soil erosion (SE) using the Revised Universal Soil Loss Equation (RUSLE) model and sediment yield at the selected dam sites. The RDSA technique identifies two suitable dam sites (A and B) with a maximum collective capacity of approximately 1202 million m3. The RDSA technique was validated with the existing dam, Gomal-Zam, in the north of Sanghar catchment, where RDSA classified the Gomal-Zam Dam in a very high suitability class. The SE estimates show an average of 75 t-ha−1y−1 of soil loss occurs in the study area. The result shows approximately 298,073 and 318,000 tons of annual average sediment yield (SY) will feed the dam A and B respectively. The SE-based sediment yield substantiates the approximate life of Dam-A and Dam-B to be 87 and 90 years, respectively. The approach is dynamic and can be applied for any other location globally for dam site selection and SE estimation.


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