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81-495: Stocksundet is supposed to have received its name from the logs (Swedish: "stock") which used to be laid out in the water to stop invading ships in the Early Middle Ages . This name then led to the place name of Stocksund , on the north side of the sound, and to the heraldry shield of the then Stocksund Municipality between 1955 and 1966. By the 1400s, the road between Roslagen and Stockholm crossed Stocksundet, and by

162-435: A 6-week post-harvest ripening period in the cones to obtain maximum germinability, however, based on cumulative degree-days, seed from the same trees and stand showed 2-week cone storage was sufficient. See Plant nursery Plantations may be considered successful when outplant performance satisfies certain criteria. The term "free growing" is applied in some jurisdictions. Ontario's "Free-to-Grow" (FTG) equivalent relates to

243-609: A bridge for the Roslagsbanan narrow gauge commuter railway. Over time there have been seven bridges across the Stocksundet: 59°23′00″N 18°02′26″E  /  59.38333°N 18.04056°E  / 59.38333; 18.04056 Logging Logging is the process of cutting, processing, and moving trees to a location for transport . It may include skidding , on-site processing, and loading of trees or logs onto trucks or skeleton cars . In forestry ,

324-576: A few big ones. The self-thinning line shows the largest number of trees of a given size/ha that can be carried at any given time. However, Willcocks and Bell (1995) caution against using such diagrams unless specific knowledge of the stand trajectory is known. In the Lake States, plantations have been made with the spacing between trees varying from 3 by 3 to 10 by 10 feet (0.9 m by 0.9 m to 3.0 m by 3.0 m). Kittredge recommended that no fewer than 600 established trees per acre (1483/ha) be present during

405-406: A few modifications for administrative convenience. Seed quality varies with source. Seed orchards produce seed of the highest quality, then, in order of decreasing seed quality produced, seed production areas and seed collection areas follow, with controlled general collections and uncontrolled general collections producing the least characterized seed. When seed is first separated from cones it

486-562: A forest stand that meets a minimum stocking standard and height requirement, and is essentially free of competition from surrounding vegetation that might impede growth. The FTG concept was introduced with the advent of the Forest Management Agreement program in Ontario in 1980 and became applicable to all management units in 1986. Policy, procedures, and methodologies readily applicable by forest unit managers to assess

567-629: A general collection, when only the seed zone of origin is known, or a stand collection from a specific latitude and longitude. The movement of general-collection seed and stock across seed zone boundaries is prohibited, but the use of stand-collection seed and stock in another seed zone is acceptable when the Ontario Climate Model shows that the planting site and place of seed origin are climatically similar. The 12 seed zones for white spruce in Quebec are based mainly on ecological regions, with

648-475: A germination test are commonly expressed as germinative capacity or a germination percentage , which is the percentage of seeds that germinate during a period of time, ending when germination is practically complete. During extraction and processing, white spruce seeds gradually lost moisture, and total germination increased. Mittal et al. (1987) reported that white spruce seed from Algonquin Park, Ontario, obtained

729-614: A measure of the competition level and a measure of crop response. Various competition indices have been developed, e.g., by Bella (1971) and Hegyi (1974) based on stem diameter, by Arney (1972), Ek and Monserud (1974), and Howard and Newton (1984) based on canopy development, and Daniels (1976), Wagner (1982), and Weiner (1984) with proximity-based models. Studies generally considered tree response to competition in terms of absolute height or basal area, but Zedaker (1982) and Brand (1986) sought to quantify crop tree size and environmental influences by using relative growth measures. Tending

810-466: A particular forester, and have been described in the scientific literature), and broad generalizations can be made, these are merely rules of thumb rather than strict blueprints on how techniques might be applied. This misunderstanding has meant that many older English textbooks did not capture the true complexity of silviculture as practiced where it originated in Mitteleuropa . This silviculture

891-403: A plantation. For example, a vigorous white spruce with a strong, multi-budded leading shoot and its crown fully exposed to light on 3 sides would not qualify as free-growing in the current British Columbia Code but would hardly warrant description as unestablished. Competition arises when individual organisms are sufficiently close together to incur growth constraint through mutual modification of

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972-527: A power consumption of 280 VA and power impact of 1.35 amperes. However, no seeds germinated after 6 minutes of exposure to ultrasound. Seed dormancy is a complex phenomenon and is not always consistent within species. Cold stratification of white spruce seed to break dormancy has been specified as a requirement, but Heit (1961) and Hellum (1968) regarded stratification as unnecessary. Cone handling and storage conditions affect dormancy in that cold, humid storage (5 °C, 75% to 95% relative humidity) of

1053-585: A safety principle. In British Columbia, Canada, the BC Forest Safety Council was created in September 2004 as a not-for-profit society dedicated to promoting safety in the forest sector. It works with employers, workers, contractors, and government agencies to implement fundamental changes necessary to make it safer to earn a living in forestry. The risks experienced in logging operations can be somewhat reduced, where conditions permit, by

1134-452: A set of wheels over ten feet tall, initially pulled by oxen. As the logging industry expanded, the 1880s saw the introduction of mechanized equipment like railroads and steam-powered machinery, marking the beginning of the railroad logging era. Logs were moved more efficiently by railroads built into remote forest areas, often supported by additional methods like high-wheel loaders , tractors and log flumes . The largest high-wheel loader,

1215-549: A silvicultural systems, but may also be called rejuvenating or regenerating method depending on the purpose. The high forest system is further subdivided in German: These names give the impression is that these are neatly defined systems, but in practice there are variations within these harvesting methods in accordance with to local ecology and site conditions. While location of an archetypal form of harvesting technique can be identified (they all originated somewhere with

1296-580: A single operation, pre-scarifying the leave strips, post-scarifying the cut strips. Broadcast burning is not recommended as a method of preparing sites for natural regeneration, as it rarely exposes enough mineral soil to be sufficiently receptive, and the charred organic surfaces are a poor seedbed for spruce . A charred surface may get too hot for good germination and may delay germination until fall, with subsequent overwinter mortality of unhardened seedlings. Piling and burning of logging slash, however, can leave suitable exposures of mineral soil. With

1377-444: A stand of red spruce plus scattered white spruce that had been isolated by clearcutting on all sides, so furnishing an opportunity for observing regeneration on different exposures in this old-field stand at Dummer, New Hampshire . The regeneration included a surprisingly large number of balsam fir seedlings from the 5% stand component of that species. The maximum density of spruce regeneration, determined 4 rods (20 m) inside from

1458-764: A view to reducing the time needed to produce planting stock, experiments were carried out with white spruce and three other coniferous species from Wisconsin seed in the longer, frost-free growing season in Florida , 125 vs. 265 days in central Wisconsin and northern Florida, respectively. As the species studied are adapted to long photoperiods , extended daylengths of 20 hours were applied in Florida. Other seedlings were grown under extended daylength in Wisconsin and with natural daylength in both areas. After two growing seasons, white spruce under long days in Florida were about

1539-507: Is called underwater logging , a form of timber recovery. Clearcutting, or clearfelling, is a method of harvesting that removes essentially all the standing trees in a selected area. Depending on management objectives, a clearcut may or may not have reserve trees left to attain goals other than regeneration, including wildlife habitat management, mitigation of potential erosion or water quality concerns. Silviculture objectives for clearcutting, (for example, healthy regeneration of new trees on

1620-443: Is conceivable that any of these three phases ( harvesting , regeneration , and tending) may happen at the same time within a stand, depending on the goal for that particular stand. Regeneration is basic to the continuation of forested, as well as to the afforestation of treeless land. Regeneration can take place through self-sown seed ("natural regeneration"), by artificially sown seed, or by planted seedlings . In whichever case,

1701-429: Is less than in closely spaced stands. Beyond the establishment stage, the relationship of average tree size and stand density is very important. Various density-management diagrams conceptualizing the density-driven stand dynamics have been developed. Smith and Brand's (1988) diagram has mean tree volume on the vertical axis and the number of trees/ha on the horizontal axis: a stand can either have many little trees or

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1782-562: Is mixed with foreign matter, often 2 to 5 times the volume of the seed. The more or less firmly attached membranous wings on the seed must be detached before it is cleaned of foreign matter. The testa must not incur damage during the dewinging process. Two methods have been used, dry and wet. Dry seed may be rubbed gently through a sieve that has a mesh through which only seed without wings can pass. Large quantities of seed can be processed in dewinging machines, which use cylinders of heavy wire mesh and rapidly revolving stiff brushes within to remove

1863-406: Is more dependable than natural regeneration. Planting can involve using seedlings (from a nursery), (un)rooted cuttings, or seeds. Whichever method is chosen it can be assisted by tending techniques also known as intermediate stand treatments. The fundamental genetic consideration in artificial regeneration is that seed and planting stock must be adapted to the planting environment. Most commonly,

1944-595: Is not necessarily considered a type of logging but a harvesting or silviculture method. Cutting trees with the highest value and leaving those with lower value, often diseased or malformed trees, is referred to as high grading . It is sometimes called selective logging, and confused with selection cutting , the practice of managing stands by harvesting a proportion of trees. Logging usually refers to above-ground forestry logging. Submerged forests exist on land that has been flooded by damming to create reservoirs . Harvesting trees from forests submerged by flooding or dam creation

2025-504: Is often far from professional emergency treatment. Traditionally, the cry of "Timber!" developed as a warning alerting fellow workers in an area that a tree is being felled, so they should be alert to avoid being struck. The term " widowmaker " for timber, typically a limb or branch that is no longer attached to a tree, but is still in the canopy either wedged in a crotch, tangled in other limbs, or miraculously balanced on another limb demonstrates another emphasis on situational awareness as

2106-454: Is subject to frost heaving and shrinkage during drought . The forces generated in soil by frost or drought are quite enough to break roots. The range of microsites occurring on the forest floor can be broadened, and their frequency and distribution influenced by site preparation. Each microsite has its own microclimate . Microclimates near the ground are better characterized by vapour pressure deficit and net incident radiation, rather than

2187-718: Is that silviculture is applied at the stand-level , while forestry is a broader concept. Adaptive management is common in silviculture, while forestry can include natural/conserved land without stand-level management and treatments being applied. The origin of forestry in German-speaking Europe has defined silvicultural systems broadly as high forest ( Hochwald ), coppice with standards ( Mittelwald ) and compound coppice, short rotation coppice , and coppice ( Niederwald ). There are other systems as well. These varied silvicultural systems include several harvesting methods, which are often wrongly said to be

2268-493: Is the term applied to pre-harvest silvicultural treatment of forest crop trees at any stage after initial planting or seeding. The treatment can be of the crop itself (e.g., spacing, pruning, thinning, and improvement cutting) or of competing vegetation (e.g., weeding, cleaning). How many trees per unit area (spacing) that should be planted is not an easily answered question. Establishment density targets or regeneration standards have commonly been based on traditional practice, with

2349-402: Is then transported to the landing, where it is bucked and loaded on a truck. This leaves the slash (and the nutrients it contains) in the cut area, where it must be further treated if wild land fires are of concern. Trees and plants are felled and transported to the roadside with top and limbs intact. There have been advancements to the process which now allows a logger or harvester to cut

2430-633: Is used. A common method of cold stratification, is to soak seed in tap water for up to 24 h, superficially dry it, then store moist for some weeks or even months at temperatures just above freezing. Although Hellum (1968) found that cold stratification of an Alberta seed source led to irregular germination, with decreasing germination with increasing length of the stratification period, Hocking's (1972) paired test with stratified and nonstratified Alberta seed from several sources revealed no trends in response to stratification. Hocking suggested that seed maturity, handling, and storage needed to be controlled before

2511-917: Is well established that the regeneration and growth potential of understorey conifers in mixedwood stands is correlated to the density of competing hardwoods. To help apply "free-to-grow" regulations in British Columbia and Alberta, management guidelines based on distance-dependent relations within a limited radius of crop trees were developed, but Lieffers et al. (2002) found that free-growing stocking standards did not adequately characterize light competition between broadleaf and conifer components in boreal mixedwood stands, and further noted that adequate sampling using current approaches would be operationally prohibitive. Many promising plantations have failed through lack of tending. Young crop trees are often ill-equipped to fight it out with competition resurgent following initial site preparation and planting. Perhaps

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2592-406: The broadleaves , however, are able to regenerate by the means of emergence of shoots from stumps (coppice) and broken stems. Any seed, self-sown or artificially applied, requires a seedbed suitable for securing germination . In order to germinate , a seed requires suitable conditions of temperature, moisture , and aeration . For seeds of many species, light is also necessary, and facilitates

2673-938: The "Bunyan Buggie," was built in 1960 for service in California, featuring wheels 24 feet (7.3 m) high. After World War II, mechanized logging equipment, including chainsaws, diesel trucks, and Caterpillar tractors , transformed the logging industry, making railroad-based logging obsolete. With the advent of these tools, transporting logs became more efficient as new roads were constructed to access remote forests. However, in protected areas like United States National Forests and designated wilderness zones, road building has been restricted to minimize environmental impacts such as erosion in riparian zones . Today, heavy machinery such as yarders and skyline systems are used to gather logs from steep terrain, while helicopters are used for heli-logging to minimize environmental impact. Less common forms of logging, like horse logging and

2754-460: The "mixedwoods", largely preclude the utility of generalizations and call for the development of management practices incorporating the greater inherent complexity of broadleaf-conifer mixtures, relative to single-species or mixed-species conifer forest. After harvesting or other disturbance, mixedwood stands commonly enter a prolonged period in which hardwoods overtop the coniferous component, subjecting them to intense competition in an understorey. It

2835-579: The 17th century, a ferry was provided. In 1716 the first bridge across the Stocksundet was built, principally to facilitate the movement of troops to the west in the event of an attack by Russia . Since then, there have been a total of seven bridges built across the strait. From west to east, the strait is spanned by a bridge for the Stockholm metro , a road bridge for the European route E18 , and

2916-635: The adoption of various forms of reproduction cuttings that provided partial shade or protection to seedlings from hot sun and wind. The main objective of echeloned strips or border-cuttings with northeast exposure was to protect regeneration from overheating, and was originated in Germany and deployed successfully by A. Alarik in 1925 and others in Sweden. On south and west exposures, direct insolation and heat reflected from tree trunks often result in temperatures lethal to young seedlings, as well as desiccation of

2997-569: The best predictors for white spruce in B.C., and Quebec can forecast seed maturity some weeks in advance by monitoring seed development in relation to heat-sums and the phenological progression of the inflorescence of fireweed ( Epilobium angustifolium L.), an associated plant species. Cone collection earlier than one week before seed maturity would reduce seed germination and viability during storage. Four stages of maturation were determined by monitoring carbohydrates, polyols, organic acids, respiration, and metabolic activity. White spruce seeds require

3078-592: The cones prior to extraction seemingly eliminated dormancy by overcoming the need to stratify. Periods of cold, damp weather during the period of cone storage might provide natural cold (stratification) treatment. Once dormancy was removed in cone storage, subsequent kiln-drying and seed storage did not reactivate dormancy. Haddon and Winston (1982) found a reduction in viability of stratified seeds after 2 years of storage and suggested that stress might have been caused by stratification, e.g., by changes in seed biochemistry, reduced embryo vigor, seed aging or actual damage to

3159-448: The early life of a plantation. To insure this, at least 800 trees per acre (1077/ha) should be planted where 85% survival may be expected, and at least 1200/ac (2970/ha) if only half of them can be expected to live. This translates into recommended spacings of 5 by 5 to 8 by 8 feet (1.5 m by 1.5 m to 2.4 m by 2.4 m) for plantings of conifers, including white spruce in the Lake States. A strategy for enhancing natural forests' economic value

3240-544: The edge of the stand on a north 20°E exposure, was 600,000/ha, with almost 100,000 balsam fir seedlings. A prepared seedbed remains receptive for a relatively short period, seldom as long as 5 years, sometimes as short as 3 years. Seedbed receptivity on moist, fertile sites decreases with particular rapidity, and especially on such sites, seedbed preparation should be scheduled to take advantage of good seed years . In poor seed years, site preparation can be carried out on mesic and drier sites with more chance of success, because of

3321-421: The effectiveness of a herbicide treatment include: weather, especially temperature, prior to and during application; weather, especially wind, during application; weather, especially precipitation, in the 12 to 24 hours after application; vegetation characteristics, including species, size, shape, phenological stage, vigour, and distribution of weeds; crop characteristics, including species, phenology, and condition;

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3402-751: The effectiveness of regeneration programs were still under development during the Class Environmental Assessment hearings. In British Columbia, the Forest Practices Code (1995) governs performance criteria. To minimize the subjectivity of assessing deciduous competition as to whether or not a plantation is established, minimum specifications of number, health, height, and competition have been specified in British Columbia. However, minimum specifications are still subjectively set and may need to be fine-tuned in order to avoid unwarranted delay in according established status to

3483-403: The effects of other treatments, such as preliminary shearblading, burning or other prescribed or accidental site preparation; and the herbicide used, including dosage, formulation, carrier, spreader, and mode of application. There is a lot that can go wrong, but a herbicide treatment can be as good or better than any other method of site preparation. The study of competition dynamics requires both

3564-450: The embryo. They further questioned the quality of the 2-year-old seed even though high germination occurred in the samples that were not stratified. Cold stratification is the term applied to the storing of seeds in (and, strictly, in layers with) a moist medium, often peat or sand, with a view to maintaining viability and overcoming dormancy. Cold stratification is the term applied to storage at near-freezing temperatures, even if no medium

3645-482: The entire tree including branches and tops. This technique removes both nutrients and soil cover from the site and so can be harmful to the long-term health of the area if no further action is taken, however, depending on the species, many of the limbs are often broken off in handling so the result may not be as different from tree-length logging as it might seem. Cut-to-length logging is the process of felling, delimbing, bucking, and sorting ( pulpwood , sawlog, etc.) at

3726-583: The generally longer receptivity of seedbeds there than those on moister sites. Although an indifferent seed year can suffice if seed distribution is good and environmental conditions favourable to seedling germination and survival, small amounts of seed are particularly vulnerable to depredation by small mammals. Considerable flexibility is possible in timing site preparation to coincide with cone crops. Treatment can be applied either before any logging takes place, between partial cuts, or after logging. In cut and leave strips, seedbed preparation can be carried out as

3807-502: The germination of seeds in other species, but spruces are not exacting in their light requirements, and will germinate without light. White spruce seed germinated at 35 °F (1.7 °C) and 40 °F (4.4 °C) after continuous stratification for one year or longer and developed radicles less than 6 cm (2.4 in) long in the cold room. When exposed to light, those germinants developed chlorophyll and were normally phototropic with continued elongation. For survival in

3888-703: The highest fatality rate of 23.2 per 100,000 full-time equivalent (FTE) workers and a non-fatal incident rate of 8.5 per 100 FTE workers. The most common type of injuries or illnesses at work include musculoskeletal disorders (MSDs), which include an extensive list of "inflammatory and degenerative conditions affecting the muscles , tendons , ligaments , joints , peripheral nerves , and supporting blood vessels ." Loggers work with heavy, moving weights, and use tools such as chainsaws and heavy equipment on uneven and sometimes steep or unstable terrain . Loggers also deal with severe environmental conditions, such as inclement weather and severe heat or cold. An injured logger

3969-584: The implicit aim of getting the stand quickly to the free-to-grow stage. Money is wasted if more trees are planted than are needed to achieve desired stocking rates, and the chance to establish other plantations is proportionately diminished. Ingress (natural regeneration) on a site is difficult to predict and often becomes surprisingly evident only some years after planting has been carried out. Early stand development after harvesting or other disturbance undoubtedly varies greatly among sites, each of which has its own peculiar characteristics. For all practical purposes,

4050-499: The local environment. Plants may compete for light, moisture and nutrients, but seldom for space per se . Vegetation management directs more of the site's resources into usable forest products, rather than just eliminating all competing plants. Ideally, site preparation ameliorates competition to levels that relieve the outplant of constraints severe enough to cause prolonged check. The diversity of boreal and sub-boreal broadleaf-conifer mixed tree species stands, commonly referred to as

4131-483: The logging industry employed 86,000 workers and accounted for 93 deaths. This resulted in a fatality rate of 108.1 deaths per 100,000 workers that year. This rate is over 30 times higher than the overall fatality rate. Forestry/logging-related injuries (fatal and non-fatal) are often difficult to track through formal reporting mechanisms. Thus, some programs have begun to monitor injuries through publicly available reports such as news media. The logging industry experiences

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4212-455: The longer term, there must be an adequate supply of essential nutrients and an absence of smothering. In undisturbed forest, decayed windfallen stemwood provides the most favorable seedbed for germination and survival. Seedlings growing on such sites are less likely to be buried by accumulated snowpack and leaf litter, and less likely to be subject to flooding . Advantages conferred by those microsites include: more light, higher temperatures in

4293-519: The manual logging era before the 1880s, the railroad logging era from the 1880s to World War II , and the modern mechanized era that began after the war. In the early days, felled logs were transported using simple methods such as rivers to float tree trunks downstream to sawmills or paper mills. This practice, known as log driving or timber rafting , was the cheapest and most common. Some logs, due to high resin content, would sink and were known as deadheads. Logs were also moved with high-wheel loaders,

4374-502: The maximum rate (94% in 6 days) and 99% total germination in 21 days after 14-week pre-chilling. The pre-treatment of 1% sodium hypochlorite increased germinability. Encouraged by Russian success in using ultrasonic waves to improve the germinative energy and percentage germination of seeds of agricultural crops, Timonin (1966) demonstrated benefits to white spruce germination after exposure of seeds to 1, 2, or 4 minutes of ultrasound generated by an M.S.E. ultrasonic disintegrator with

4455-493: The method of managing seed and stock deployment is through a system of defined seed zones, within which seed and stock can be moved without risk of climatic maladaptation. Ontario adopted a seed zone system in the 1970s based on G.A. Hills' 1952 site regions and provincial resource district boundaries, but Ontario's seed zones are now based on homogeneous climatic regions developed with the Ontario Climate Model. The regulations stipulate that source-identified seedlots may be either

4536-478: The minimum standards for 2+1 and 2+2 outplanting stock of Lake States species. Their survival when lifted in February and outplanted in Wisconsin equalled that of 2+2 Wisconsin-grown transplants. Artificial extension of the photoperiod in the northern Lake States greatly increased height increment of white and black spruces in the second growing season. Optimum conditions for seedling growth have been determined for

4617-430: The most direct evaluation of the effect of competition on plantation establishment is provided by an effective herbicide treatment, given it is performed correctly and without contamination of waters of the state. The fact that herbicide treatment does not always produce positive results should not obscure the demonstrated potential of herbicides for significantly promoting plantation establishment. Factors that can vitiate

4698-459: The need for stratification could be determined. Later, Winston and Haddon (1981) found that the storage of white spruce cones for 4 weeks at 5 °C prior to extraction obviated the need for stratification. Seed maturity cannot be predicted accurately from cone flotation, cone moisture content, cone specific gravity; but the province of B.C. found embryo occupying 90% + of the corrosion cavity and megagametophyte being firm and whitish in colour are

4779-501: The performance of regeneration depends on its growth potential and the degree to which its environment allows the potential to be expressed. Seed, of course, is needed for all regeneration modes, both for natural or artificial sowing and for raising planting stock in a nursery . The process of natural regeneration involves the renewal of forests by means of self-sown seeds, root suckers, or coppicing. In natural forests, conifers rely almost entirely on regeneration through seed. Most of

4860-610: The production of containerized planting stock. Alternating day/night temperatures have been found more suitable than a constant temperature; at 400 lumens/m light regime, a 28 °C/20 °C day/night temperatures have been recommended for white spruce. However, temperature optima are not necessarily the same at different ages and sizes. In 1984, R. Tinus investigated the effects of combinations of day and night temperature on height, caliper, and dry weight of 4 seed sources of Engelmann spruce. The 4 seed sources appeared to have very similar temperature requirements, with night optima about

4941-424: The restocking of any clearcut opening would be questionable. At least seven variable factors may influence seed germination: seed characteristics, light, oxygen, soil reaction ( pH ), temperature, moisture, and seed enemies. Moisture and temperature are the most influential, and both are affected by exposure. The difficulty of securing natural regeneration of Norway spruce and Scots pine in northern Europe led to

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5022-442: The risk of wildfires , and restore ecosystem functions, though their efficiency for these purposes has been challenged. Logging frequently has negative impacts. The harvesting procedure itself may be illegal , including the use of corrupt means to gain access to forests; extraction without permission or from a protected area; the cutting of protected species; or the extraction of timber in excess of agreed limits. It may involve

5103-503: The rooting zone, and better mycorrhizal development. According to a 1940 survey in the Porcupine Hills of Manitoba , approximately 90% of spruce seedlings were germinating from this substrate. Mineral soil seedbeds are more receptive than the undisturbed forest floor, and are generally moister and more readily rewetted than the organic forest floor. However, exposed mineral soil, much more so than organic-surfaced soil,

5184-425: The same as those in Wisconsin, but twice as tall as plants under natural Wisconsin photoperiods. Under natural days in Florida, with the short local photoperiod, white spruce was severely dwarfed and had a low rate of survival. Black spruce responded similarly. After two growing seasons, long day plants of all 4 species in Florida were well balanced, with good development of both roots and shoots, equaling or exceeding

5265-449: The same of slightly lower than daylight optima. Tree provenance is important in artificial regeneration. Good provenance takes into account suitable tree genetics and a good environmental fit for planted / seeded trees in a forest stand. The wrong genotype can lead to failed regeneration, or poor trees that are prone to pathogens and undesired outcomes. Artificial regeneration has been a more common method involving planting because it

5346-448: The seed slightly before it is run through a fanning mill for the last time. Any moistened seed must be dried before fermentation or moulding sets in. A fluorescein diacetate (FDA) biochemical viability test for several species of conifer seed , including white spruce, estimates the proportion of live seed (viability) in a seedlot, and hence the percentage germination of a seedlot. The accuracy of predicting percentage germination

5427-401: The short and medium terms, a germinant needs: a continuing supply of moisture; freedom from lethal temperature; enough light to generate sufficient photosynthate to support respiration and growth, but not enough to generate lethal stress in the seedling; freedom from browsers , tramplers, and pathogens ; and a stable root system. Shade is very important to the survival of young seedlings. In

5508-416: The site) and a focus on forestry distinguish it from deforestation . Other methods include shelterwood cutting , group selective , single selective , seed-tree cutting , patch cut , and retention cutting . The above operations can be carried out by different methods, of which the following three are considered industrial methods: Trees are felled and then delimbed and topped at the stump. The log

5589-449: The so-called " timber mafia ". Excess logging can lead to irreparable harm to ecosystems, such as deforestation and biodiversity loss . Infrastructure for logging can also lead to other environmental degradation . These negative environmental impacts can lead to environmental conflict . Additionally, there is significant occupational injury risk involved in logging. Logging can take many formats. Clearcutting (or "block cutting")

5670-991: The standard measurements of air temperature , precipitation , and wind pattern. Aspect is an important component of microclimate, especially in relation to temperature and moisture regimes. Germination and seedling establishment of Engelmann spruce were much better on north than on south aspect seedbeds in the Fraser Experimental Forest , Colorado; the ratios of seeds to 5-year-old seedlings were determined as 32:1, 76:1, and 72:1 on north aspect bladed-shaded, bladed-unshaded, and undisturbed-shaded seedbeds, respectively. Clearcut openings of 1.2 to 2.0 hectares (3.0 to 4.9 acres) adjacent to an adequate seed source, and not more than 6 tree-heights wide, could be expected to secure acceptable regeneration (4,900, 5-year-old trees per hectare), whereas on undisturbed-unshaded north aspects, and on all seedbed treatments tested on south aspects, seed to seedling ratios were so high that

5751-458: The stump area, leaving limbs and tops in the forest. Mechanical harvesters fell the tree, delimb, and buck it, and place the resulting logs in bunks to be brought to the landing by a skidder or forwarder . This method is routinely available for trees up to 900 mm (35 in) in diameter. Logging methods have changed over time, driven by advancements in transporting timber from remote areas to markets. These shifts fall into three main eras:

5832-479: The surface soil, which inhibits germination. The sun is less injurious on eastern exposures because of the lower temperature in the early morning, related to higher humidity and presence of dew . In 1993, Henry Baldwin, after noting that summer temperatures in North America are often higher than those in places where border-cuttings have been found useful, reported the results of a survey of regeneration in

5913-515: The term logging is sometimes used narrowly to describe the logistics of moving wood from the stump to somewhere outside the forest , usually a sawmill or a lumber yard . In common usage, however, the term may cover a range of forestry or silviculture activities. Logging is the beginning of a supply chain that provides raw material for many products societies worldwide use for housing , construction , energy , and consumer paper products. Logging systems are also used to manage forests , reduce

5994-435: The total volume produced by a stand on a given site is constant and optimum for a wide range of density or stocking. It can be decreased, but not increased, by altering the amount of growing stock to levels outside this range. Initial density affects stand development in that close spacing leads to full site utilization more quickly than wider spacing. Economic operability can be advanced by wide spacing even if total production

6075-495: The treatment(s) of forest stands are used to conserve and improve their productivity. Generally, silviculture is the science and art of growing and cultivating forest [crops], based on a knowledge of silvics .The study of the life-history and general characteristics of forest trees and stands, with particular reference to local/regional factors. The focus of silviculture is the control, establishment and management of forest stands. The distinction between forestry and silviculture

6156-443: The tree down, top, and delimb a tree in the same process. This ability is due to the advancement in the style felling head that can be used. The trees are then delimbed, topped, and bucked at the landing. This method requires that slash be treated at the landing. In areas with access to cogeneration facilities, the slash can be chipped and used for the production of electricity or heat. Full-tree harvesting also refers to utilization of

6237-501: The use of mechanical tree harvesters, skidders, and forwarders. Silviculture Silviculture is the practice of controlling the growth, composition/structure, as well as quality of forests to meet values and needs, specifically timber production. The name comes from the Latin silvi- ('forest') and culture ('growing'). The study of forests and woods is termed silvology . Silviculture also focuses on making sure that

6318-686: The use of oxen, still exist but are mostly superseded. Logging is a dangerous occupation. In the United States, it has consistently been one of the most hazardous industries and was recognized by the National Institute for Occupational Safety and Health (NIOSH) as a priority industry sector in the National Occupational Research Agenda (NORA) to identify and provide intervention strategies regarding occupational health and safety issues. In 2008,

6399-471: The wings. In the wet process, seed with wings attached are spread out 10 cm to 15 cm deep on a tight floor and slightly moistened throughout; light leather flails are used to free seed from the wings. B. Wang described a unique wet dewinging procedure in 1973 using a cement mixer , used at the Petawawa tree seed processing facility. Wings of white and Norway spruce seed can be removed by dampening

6480-617: Was culturally predicated on wood production in temperate and boreal climates and did not deal with tropical forestry . The misapplication of this philosophy to those tropical forests has been problematic . There is also an alternative silvicultural tradition which developed in Japan and thus created a different biocultural landscape called satoyama . After harvesting comes regeneration, which may be split into natural and artificial (see below), and tending, which includes release treatments, pruning , thinning and intermediate treatments. It

6561-405: Was within +/- 5 for most seedlots. White spruce seed can be tested for viability by an indirect method, such as the fluorescein diacetate (FDA) test or ‘Ultra-sound'; or by the direct growth method of ‘germination'. Samples of white spruce seed inspected in 1928 varied in viability from 50% to 100%, but averaged 93%. A 1915 inspection reported 97% viability for white spruce seed. The results of

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