Forest reproduction methods for coastal British Columbia: Principles, criteria, and a stand selection guide

1994 ◽  
Vol 70 (5) ◽  
pp. 569-577 ◽  
Author(s):  
K. Klinka ◽  
G. J. Kayahara ◽  
R. E. Carter

Once a decision to regenerate a particular stand is made at the forest level, a forester has to make critical decisions at the stand level as to the choice of cutting method for existing stands to regenerate the desired species and develop a stand of the desired structure. Two related critical decisions in stand-level forest management are (1) selecting the best tree species to regenerate on a given site, and (2) selecting the appropriate method of cutting existing stands for both the regeneration of the desired species within a certain time and for maintaining or developing the desired stand structure. This paper discusses the management factors and principles and criteria for choosing a cutting method to meet decision (2) (i.e., the reproduction method). The four criteria used to guide the appropriate reproduction method are (1) maximum sustainable forest productivity, (2) stand reliability, (3) silvicultural feasibility, and (4) harvesting feasibility. With these criteria in mind, a stand-level guide devised for coastal British Columbia is proposed. This guide is in the form of a dichotomous key and is based on 13 selected ecological, stand, and management factors. Combining this approach with principles, criteria and guidelines for tree species selection already practiced, regeneration and management objectives can be achieved both on a species-and site-specific basis. Key words: forest reproduction methods, decision support systems, silvicultural prescriptions, harvesting methods, stand regeneration, stand structure

Forests ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1329
Author(s):  
Timo Saksa ◽  
Jori Uusitalo ◽  
Harri Lindeman ◽  
Esko Häyrynen ◽  
Sampo Kulju ◽  
...  

Precision forestry—i.e., the division of a stand to smaller units and managing of the stand at a micro-stand level—provides new possibilities to increase forest growth, arrange forest stand structure and enhance forest health. In the regeneration phase by adjusting the tree species selection, soil preparation, intensity of regeneration measures (method, planting density, and material), and young stand management procedures according to precise information on soil properties (e.g., site fertility, wetness, and soil type) and microtopography will inevitably lead to an increase in growth of the whole stand. A new approach to utilizing harvester data to delineate micro-stands inside a large forest stand and to deciding the tree species to plant for each micro-stand was piloted in central Finland. The case stands were situated on Finsilva Oyj forest property. The calculation of the local growth (m3/ha/year) for each 16 × 16-m grid cell was based on the height of the dominant trees and the stand age of the previous tree generation. Tree heights and geoinformation were collected during cutting operation as the harvester data, and the dominant height was calculated as the mean of the three largest stems in each grid cell. The stand age was obtained from the forest management plan. The estimated local growth (average of nine neighboring grid cells) varied from 3 to 14 m3/ha/year in the case stands. When creating micro-stands, neighboring grid cells with approximately the same local growth were merged. The minimum size for an acceptable micro-stand was set to 0.23 ha. In this case study, tree species selection (Scots pine or Norway spruce) was based on the mean growth of each micro-stand. Different threshold values, varying from 6 to 8 m3/ha/year, were tested for tree species change, and they led to different solutions in the delineation of micro-stands. Further stand development was simulated with the Motti software and the net present values (NPVs (3%)) for the next rotation were estimated for different micro-stand solutions. The mixed Norway spruce–Scots pine stand structure never produced a clearly economically inferior solution compared to the single species stand, and in one case out of six, it provided a distinctly better solution in terms of NPV (3%) than the single species option did. Our case study showed that this kind of method could be used as a decision support tool at the regeneration phase.


2006 ◽  
Vol 36 (11) ◽  
pp. 2826-2838 ◽  
Author(s):  
Roberta Parish ◽  
Joseph A Antos

Elucidating the factors that structure very old forests is crucial to understanding their dynamics. We reconstructed the history of an ancient (1000-year-old) stand in the mountains of coastal British Columbia that contained four tree species (Abies amabilis (Dougl.) Forbes, Chamaecyparis nootkatensis (D. Don) Spach., Tsuga mertensiana (Bong.) Carr., and Tsuga heterophylla (Raf.) Sarg.) in the canopy and the seedling bank. Using dendrochronological procedures, we examined the growth patterns of all trees (>4.0 cm diameter at breast height) in four 0.25 ha mapped plots. We also sampled the seedling bank in the four plots. Age structures indicated variable but rather continuous recruitment for all species. Periods of increased amounts of release or rapid early growth occurred but were not pronounced. Overall, we found little evidence for stand-level disturbance or the formation of large gaps. All four tree species appear able to persist in the stand in the absence of major stand-level disturbance, but the mechanisms contributing to coexistence differ. One species, C. nootkatensis, depends primarily on vegetative reproduction for persistence. Single-tree gap dynamics have predominated in the stand for centuries, placing this stand at the far end of the gradient from forests controlled by large, severe disturbances to those where very small-scale processes predominate.


1984 ◽  
Vol 60 (2) ◽  
pp. 77-85 ◽  
Author(s):  
K. Klinka ◽  
M. C. Feller

Selecting the best tree species for reforesting a forest site is a critical decision in forest management. Ideally, this decision requires that the ecological characteristics of forest trees, sites and ecosystems are known, and that the intent, goal, strategy and objective of forest management are defined. This knowledge can then be used to develop criteria for selecting the most suitable tree species or combination of tree species for a given site. The criteria used in the tree species selection guidelines for southwestern British Columbia are: maximum sustainable productivity, crop reliability and silvicultural feasibility.


2008 ◽  
Vol 159 (4) ◽  
pp. 80-90 ◽  
Author(s):  
Bogdan Brzeziecki ◽  
Feliks Eugeniusz Bernadzki

The results of a long-term study on the natural forest dynamics of two forest communities on one sample plot within the Białowieża National Park in Poland are presented. The two investigated forest communities consist of the Pino-Quercetum and the Tilio-Carpinetum type with the major tree species Pinus sylvestris, Picea abies, Betula sp., Quercus robur, Tilia cordata and Carpinus betulus. The results reveal strong temporal dynamics of both forest communities since 1936 in terms of tree species composition and of general stand structure. The four major tree species Scots pine, birch, English oak and Norway spruce, which were dominant until 1936, have gradually been replaced by lime and hornbeam. At the same time, the analysis of structural parameters indicates a strong trend towards a homogenization of the vertical stand structure. Possible causes for these dynamics may be changes in sylviculture, climate change and atmospheric deposition. Based on the altered tree species composition it can be concluded that a simple ≪copying≫ (mimicking) of the processes taking place in natural forests may not guarantee the conservation of the multifunctional character of the respective forests.


Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 458
Author(s):  
Haiyan Deng ◽  
Linlin Shen ◽  
Jiaqi Yang ◽  
Xiaoyong Mo

Background and Objectives: The stable stand structure of mixed plantations is the basis of giving full play to forest ecological function and benefit. However, the monocultural Eucalyptus plantations with large-scale and successive planting that caused ecological problems such as reduced species diversity and loss of soil nutrients have presented to be unstable and vulnerable, especially in typhoon-prone areas. The objective of this study was to evaluate the nonspatial structure difference and the stand stability of pure and mixed-Eucalyptus forests, to find out the best mixed pattern of Eucalyptus forests with the most stability in typhoon-prone areas. Materials and Methods: In this study, we randomly investigated eight plots of 30 m × 30 m in pure and mixed-Eucalyptus (Eucalyptus urophylla S. T. Blake × E. grandis W. Hill) plantations of different tree species (Neolamarckia cadamba (Roxb.) Bosser, Acacia mangium Willd., and Pinus elliottii var. Elliottii Engelm. × P. caribaea Morelet) on growth status, characterized and compared the distribution of nonspatial structure of the monoculture and mixtures, and evaluated the stand quality and stability from eight indexes of the nonspatial structure, including preservation rate, stand density, height, diameter, stem form, degree of stem inclination, tree-species composition, and age structure. Results: Eucalyptus surviving in the mixed plantation of Eucalyptus and A. mangium (EA) and in the mixed plantation of Eucalyptus and P. elliottii × P. caribaea (EP) were 5.0% and 7.6% greater than those in pure Eucalyptus plantation (EE), respectively, while only the stand preservation rate of EA was greater (+2.9%) than that of the pure Eucalyptus plantation. The proportions of all mixtures in the height class greater than 7 m were fewer than that of EE. The proportions of EA and mixed plantation of Eucalyptus and N. cadamba (EN) in the diameter class greater than 7 m were 10.6% and 7.8%, respectively, more than that of EE. EN had the highest ratio of branching visibly (41.0%), EA had the highest ratio of inclined stems (8.1%), and EP had the most straight and complete stem form (68.7%). The stand stability of the mixed plantation of Eucalyptus and A. mangium presented to be optimal, as its subordinate function value (0.76) and state value (ω = 0.61) of real stand were the largest. Conclusions: A. mangium is a superior tree species to mix with Eucalyptus for a more stable stand structure in the early growth stage to approach an evident and immense stability and resistance, which is of great significance for the forest restoration of Eucalyptus in response to extreme climate and forest management.


1996 ◽  
Vol 76 (2) ◽  
pp. 153-164 ◽  
Author(s):  
B. J. Zebarth ◽  
J. W. Paul ◽  
O. Schmidt ◽  
R. McDougall

Manure-N availability must be known in order to design application practices that maximize the nutrient value of the manure while minimizing adverse environmental impacts. This study determined the effect of time and rate of liquid manure application on silage corn yield and N utilization, and residual soil nitrate at harvest, in south coastal British Columbia. Liquid dairy or liquid hog manure was applied at target rates of 0, 175, 350 or 525 kg N ha−1, with or without addition of 100 kg N ha−1 as inorganic fertilizer, at two sites in each of 2 yr. Time of liquid-dairy-manure application was also tested at two sites in each of 2 yr with N-application treatments of: 600 kg N ha−1 as manure applied in spring; 600 kg N ha−1 as manure applied in fall; 300 kg N ha−1 as manure applied in each of spring and fall; 200 kg N ha−1 applied as inorganic fertilizer in spring; 300 kg N ha−1 as manure plus 100 kg N ha−1 as inorganic fertilizer applied in spring; and a control that received no applied N. Fall-applied manure did not increase corn yield or N uptake in the following growing season. At all sites, maximum yield was attained using manure only. Selection of proper spring application rates for manure and inorganic fertilizer were found to be equally important in minimizing residual soil nitrate at harvest. Apparent recovery of applied N in the crop ranged from 0 to 33% for manure and from 18 to 93% for inorganic fertilizer. Key words: N recovery, manure management


1965 ◽  
Vol 2 (5) ◽  
pp. 442-484 ◽  
Author(s):  
Donald Carlisle ◽  
Takeo Susuki

The highly deformed section at Open Bay is one of the few good exposures of a thick sedimentary unit within the prebatholithic rocks along coastal British Columbia. It provides new structural information relating to emplacement of a part of the Coast Range batholith and it contains an important Upper Triassic fauna unusually well represented. Structural and paleontological analyses are mutually supporting and are purposely combined in one paper.Thirteen ammonite genera from 14 localities clearly substantiate McLearn's tentative assignment to the Tropites subbullatus zone (Upper Karnian) and suggest a restriction to the T. dilleri subzone as defined in northern California.Contrary to an earlier view, the beds are lithologically similar across the whole bay except for variations in the intensity of deformation and thermal alteration. Their contact with slightly older relatively undeformed flows is apparently a zone of dislocation. Stratigraphic thicknesses cannot be measured with confidence, and subdivision into "Marble Bay Formation" and "Open Bay Group" cannot be accepted. Open Bay Formation is redefined to include all the folded marble and interbedded pillow lava at Open Bay. Lithologic and biostratigraphic correlation is suggested with the lower middle part of the Quatsino Formation on Iron River, 24 miles to the southwest. Basalt flows and pillowed volcanics west of Open Bay are correlated with the Texada Formation within the Karmutsen Group.The predominant folding is shown to precede, accompany, and follow intrusion of numerous andesitic pods and to precede emplacement of quartz diorite of the batholith. Structural asymmetry is shown to have originated through gentle cross-folding and emplacement of minor intrusives during deformation.


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