Mechanical felling, using specialized equipment like excavators and feller bunchers, offers a significant leap forward in forestry operations compared to traditional manual methods. The advantages are numerous and impact everything from safety and efficiency to environmental protection and overall cost-effectiveness.
One of the most compelling arguments for mechanical felling is the improved safety it provides. Keeping workers at a distance from falling trees drastically reduces the risk of accidents, a major concern in traditional logging. The controlled environment offered by machines allows for precise felling, minimizing unpredictable movements and potential hazards.
Efficiency gets a substantial boost with mechanical felling. Machines work tirelessly, unaffected by fatigue or weather conditions (to a certain extent), leading to higher production rates. They can handle larger volumes of timber in a shorter time, crucial in meeting demanding deadlines and maximizing output. This increased efficiency has a domino effect, streamlining subsequent operations like delimbing, processing, and transport.
From an environmental perspective, mechanical felling can contribute to sustainable forestry practices. The precision felling minimizes ground disturbance, reducing soil erosion and damage to remaining trees. Selective harvesting becomes easier, allowing for better forest management and the preservation of biodiversity. Furthermore, some machines are equipped to process logging residues, reducing slash and mitigating fire hazards.
Cost-effectiveness is another key advantage. While the initial investment in machinery can be substantial, the long-term benefits often outweigh the costs. Increased production, reduced labor expenses, and minimized environmental remediation contribute to a higher return on investment. Furthermore, the ability to operate in challenging terrain and weather conditions reduces downtime and keeps operations running smoothly.
However, it's important to acknowledge that mechanical felling isn't a one-size-fits-all solution. The suitability of this method depends on factors like terrain, tree size and density, and environmental considerations. Proper planning and skilled operators are crucial for maximizing the benefits and minimizing any potential negative impacts. In conclusion, while careful consideration is necessary, the advantages of mechanical felling in terms of safety, efficiency, environmental protection, and cost-effectiveness make it a compelling approach to modern forestry.
Mechanical felling, using powerful machines like excavators and feller bunchers, definitely speeds up timber harvesting. However, it's not a perfect solution and comes with its own set of drawbacks. One major disadvantage is the potential for increased soil compaction. The heavy machinery, especially when operating on wet or soft ground, can compress the soil, reducing its porosity and hindering root growth for future regeneration. This compaction can also lead to increased runoff and erosion, impacting water quality in nearby streams and rivers.
Another issue is the potential for greater site disturbance. While skilled operators can minimize damage, the sheer size and power of these machines can lead to more soil displacement and damage to remaining trees compared to traditional manual felling. This can disrupt delicate ecosystems and reduce biodiversity. The larger machinery also requires wider access routes, meaning more logging roads, which further fragment the forest landscape and create pathways for invasive species.
Cost is another factor to consider. The initial investment in mechanical felling equipment is substantial, and ongoing maintenance can be expensive. Specialized training is also needed for operators, adding to the overall cost. While efficient in large-scale operations, the expense might not be justified for smaller harvests or selective logging.
Finally, there are safety concerns associated with mechanical felling. Operating heavy machinery in a forest environment can be dangerous, requiring highly skilled operators and strict adherence to safety protocols. The potential for accidents is higher compared to manual felling, posing a risk to both operators and other workers in the area.
In conclusion, while mechanical felling offers benefits in terms of speed and efficiency, it also presents several disadvantages. The potential for soil compaction, increased site disturbance, higher costs, and safety risks need to be carefully considered before choosing this method. A balanced approach, perhaps incorporating elements of both mechanical and manual felling, may be the most sustainable and responsible way forward.
Choosing the right machine for mechanical felling often boils down to a head-to-head between excavators and purpose-built feller bunchers. Both offer advantages, and understanding their strengths and weaknesses is key to making an informed decision. While feller bunchers are designed specifically for the task, excavators offer versatility that can be attractive.
Feller bunchers reign supreme in terms of sheer productivity in clear-cutting and thinning operations. Their specialized design, featuring a dedicated felling head and accumulating arms, allows them to quickly fell, bunch, and delimb trees with remarkable efficiency. This translates to lower operating costs per tree and faster turnaround times, especially in large-scale operations. Their maneuverability in dense stands also gives them an edge.
However, this specialization comes at a price. Feller bunchers represent a significant capital investment and their dedicated nature means they aren't easily repurposed for other tasks. This can be a drawback for smaller operations or those with diverse needs. Transporting them between sites can also be more complex and expensive.
Excavators, on the other hand, offer a compelling alternative thanks to their versatility. Already a staple in many forestry operations for tasks like road building and loading, equipping an excavator with a felling head allows it to take on felling duties as well. This eliminates the need for a dedicated felling machine, saving on capital expenditure and maximizing equipment utilization.
The trade-off is performance. While capable of felling, excavators generally lack the specialized features and optimized design of a feller buncher. This results in lower felling rates and potentially higher processing costs per tree. Their stability can also be a concern, particularly on uneven terrain or when handling larger trees. Furthermore, the frequent switching between attachments can add time and complexity to operations.
Ultimately, the best choice between an excavator and a feller buncher depends on the specific needs of the operation. High-volume, dedicated felling operations will likely benefit from the productivity of a feller buncher. Smaller operations or those requiring equipment versatility might find a suitably equipped excavator a more cost-effective and practical solution. Carefully evaluating factors like stand density, terrain, tree size, and overall operational goals is crucial for making the right decision.
Mechanical tree felling, using powerful machines like excavators and feller bunchers, offers significant advantages in terms of speed and efficiency. However, this efficiency comes with a heightened need for safety awareness. Operating these heavy machines near standing timber presents unique hazards that demand careful planning and execution.
One primary safety concern is the potential for the tree to fall in an unexpected direction. Factors like wind, lean, decay, and root structure can all influence the fall path. A thorough assessment of each tree before felling is crucial. Operators must establish a safe escape route and a clear felling zone, ensuring no personnel are within range of the falling tree or any potential debris. This includes considering the possibility of "barber chairing," where the tree splits vertically during the fall, creating dangerous projectiles.
The machinery itself presents its own set of hazards. Operators need to be fully trained and certified on the specific equipment they are using. Regular maintenance and inspections are vital to ensure the machine is in safe working order. Tracks and stabilizers should be properly positioned to provide a stable platform, especially on uneven terrain. Swinging booms and rotating attachments require constant vigilance to avoid striking nearby objects or personnel.
Personal protective equipment (PPE) is non-negotiable. Operators must wear appropriate clothing, including hard hats, safety glasses, hearing protection, and high-visibility vests. Steel-toed boots are essential to protect against falling debris. Regular breaks are also important to avoid fatigue, which can lead to complacency and errors in judgment.
Environmental considerations also play a role in safe mechanical felling. Operators should be mindful of minimizing damage to surrounding trees and vegetation. Erosion control measures might be necessary in certain areas. Protecting watercourses from debris and fuel spills is also crucial.
Ultimately, safe mechanical tree felling relies on a combination of well-maintained equipment, comprehensive training, and a constant awareness of the potential hazards. By prioritizing safety and adhering to best practices, operators can effectively mitigate risks and create a productive and safe working environment.
Pruning is a horticultural, arboricultural, and silvicultural practice involving the selective removal of certain parts of a plant, such as branches, buds, or roots.
The practice entails the targeted removal of diseased, damaged, dead, non-productive, structurally unsound, or otherwise unwanted plant material from crop and landscape plants. In general, the smaller the branch that is cut, the easier it is for a woody plant to compartmentalize the wound and thus limit the potential for pathogen intrusion and decay. It is therefore preferable to make any necessary formative structural pruning cuts to young plants, rather than removing large, poorly placed branches from mature plants.
Woody plants may undergo a process referred to as "self-pruning", where they will drop twigs or branches which are no longer producing more energy than they require. It is theorized that this process can also occur in response to lack of water, in order to reduce the surface area where water can be lost.[1] This natural shedding of branches is called cladoptosis.
Specialized pruning practices may be applied to certain plants, such as roses, fruit trees, and grapevines. Different pruning techniques may be used on herbaceous plants than those used on perennial woody plants.
Reasons to prune plants include deadwood removal, shaping (by controlling or redirecting growth), improving or sustaining health, reducing risk from falling branches, preparing nursery specimens for transplanting, and both harvesting and increasing the yield or quality of flowers and fruits.
Branch wood is an individual stem that grows off of another stem.
Trunk wood is the main stem of a tree which individual stems grow out of.
This refers to the area below the union of where branch wood attaches with the trunk/stem wood. This can often appear raised.
This refers to the junction between branch wood and trunk/stem wood. It usually looks raised. [2]
Pruning in an urban setting is crucial due to the tree being in drastically different conditions than where it naturally grows.[3]
Arborists, orchardists, and gardeners use various garden tools and tree cutting tools designed for the purpose, such as secateurs, loppers, handsaws, or chainsaws.[4] Additionally in forestry, pole pruners (averruncators in British English) and pole saws are commonly used, and these are often attached to poles that reach up to 5–6 m (16–20 ft). This is a more efficient and safer way of pruning than with ladders. These bush saws on polls have also been motorized as chainsaws which is even more efficient. Older technology used Billhooks, Kaiser blades, and pruning knives. Although still used in some coppicing, they are not used so much in commercial forestry due to the difficulty of cutting flush with the stem. Flush cuts happen when a pruner cuts into the cambium layer of the main trunk, which can happen when a pruner is not precise with pruning cuts, and removes a portion of the branch collar, which can put the tree at risk of entry cords from forest pathogens.
Although there are several different types of pruning, they can be simplified into two categories. One of which is cutting the branch back to a specific and intermediate point, called a "reduction cut", and the other of which is completely removing a branch back to the union where the branch connects which the main trunk, called "removal cut".[5]
A "reduction cut" is when one removes a portion of a growing stem down to a set of desirable buds or side-branching stems. This is commonly performed in well trained plants for a variety of reasons, for example to stimulate growth of flowers, fruit or branches, as a preventive measure to wind and snow damage on long stems and branches, and finally to encourage growth of the stems in a desirable direction.
In orchards, fruit trees are often lopped to encourage regrowth and to maintain a smaller tree for ease of picking fruit. The pruning regime in orchards is more planned, and the productivity of each tree is an important factor.
Branches die off for a number of reasons including sunlight deficiency, pest and disease damage, and root structure damage. A dead branch will at some point decay back to the parent stem and fall off. This is normally a slow process but can be hastened by high winds or extreme temperatures. The main reason deadwooding is performed is safety. Situations that usually demand removal of deadwood include trees that overhang public roads, houses, public areas, power lines, telephone cables and gardens. Trees located in wooded areas are usually assessed as lower risk but assessments consider the number of visitors. Trees adjacent to footpaths and access roads are often considered for deadwood removal.[8]
Another reason for deadwooding is amenity value, i.e. a tree with a large amount of deadwood throughout the crown will look more aesthetically pleasing with the deadwood removed. The physical practice of deadwooding can be carried out most of the year though should be avoided when the tree is coming into leaf. The deadwooding process speeds up the tree's natural abscission process. It also reduces unwanted weight and wind resistance and can help overall balance.
Preventative and structural pruning can be done to mitigate several issues young trees may have in the future. The structural pruning can reduce tree stress, increase the lifespan of trees, and promotes resistance to damage due to natural weather events. Attributes of trees with good structure include excurrent growth by having a single dominant leader, branch unions without included bark, and a balanced canopy. Structural pruning does this by developing or maintaining a dominant leader, identify the lowest branches in the canopy, prevent branches below the permanent canopy from growing too large, keeping all branches less than one half the trunk diameter, space main branches along one dominant trunk, and suppress growth on branches with included bark. [9]
Subordination pruning is done on limbs that will exceed 50% percent of the stem diameter. A reduction cut may be performed while still allowing about 50% of the branch. This is done to help maintain form and deter the formation of co-dominant leaders. Temporary branches may be too large for a removal cut so subordination pruning should be done to slowly reduce a limb by 50% each year to allow the tree to properly heal from the cut. As a tree becomes larger the slower it grows. Reducing the larger limbs for eventual removal will allow for the tree to promote new growth rather than using energy in encouraging unwanted limbs to continue to grow. Removing a large branch increases the likelihood of the cut to not heal properly which also may attract insects, diseases and fungus. [9][10]
Crown thinning is the removal of live healthy branches which increases light penetration, air circulation and reduces wind resistance which reduces risks from damage and the possibility of pest infestation. [11]
Crown raising involves the removal of the lower branches to a given height. The height is achieved by the removal of whole branches or removing the parts of branches which extend below the desired height. The branches are normally not lifted to more than one third of the tree's total height.
Crown lifting is done for access; these being pedestrian, vehicle or space for buildings and street furniture. Lifting the crown will allow traffic and pedestrians to pass underneath safely. This pruning technique is usually used in the urban environment as it is for public safety and aesthetics rather than tree form and timber value.
Crown lifting introduces light to the lower part of the trunk; this, in some species can encourage epicormic growth from dormant buds. To reduce this sometimes smaller branches are left on the lower part of the trunk. Excessive removal of the lower branches can displace the canopy weight, this will make the tree top heavy, therefore adding stress to the tree. When a branch is removed from the trunk, it creates a large wound. This wound is susceptible to disease and decay, and could lead to reduced trunk stability. Therefore, much time and consideration must be taken when choosing the height the crown is to be lifted to.
This would be an inappropriate operation if the tree species’ form was of a shrubby nature. This would therefore remove most of the foliage and would also largely unbalance the tree. This procedure should not be carried out if the tree is in decline, poor health or dead, dying or dangerous (DDD) as the operation will remove some of the photosynthetic area the tree uses. This will increase the decline rate of the tree and could lead to death.
If the tree is of great importance to an area or town, (i.e. veteran or ancient) then an alternative solution to crown lifting would be to move the target or object so it is not in range. For example, diverting a footpath around a tree's drip line so the crown lift is not needed. Another solution would be to prop up or cable-brace the low hanging branch. This is a non-invasive solution which in some situations may be more economical and environmentally friendly. [12]
Selectively pruning a window of view in a tree.
Reducing the height and or spread of a tree by selectively cutting back to smaller branches and in fruit trees for increasing of light interception and enhancing fruit quality.
A regular form of pruning where certain deciduous species are pruned back to pollard heads every year in the dormant period. This practice is usually commenced on juvenile trees so they can adapt to the harshness of the practice. This practice can be used for tree shaping but is also used in specific species which young branches can be sold for floral arrangements.
Deadheading is the act of removing spent flowers or flowerheads for aesthetics, to prolong bloom for up to several weeks or promote rebloom, or to prevent seeding.
In general, pruning deadwood and small branches can be done at any time of year. Depending on the species, many temperate plants can be pruned either during dormancy in winter, or, for species where winter frost can harm a recently pruned plant, after flowering is completed. In the temperate areas of the northern hemisphere autumn pruning should be avoided, as the spores of disease and decay fungi are abundant at this time of year.
Some woody plants tend to bleed profusely from cuts, such as mesquite and maple. Some callus over slowly, such as magnolia. In this case, they are better pruned during active growth when they can more readily heal. Woody plants that flower early in the season, on spurs that form on wood that has matured the year before, such as apples, should be pruned right after flowering as later pruning will sacrifice flowers the following season. Forsythia, azaleas and lilacs all fall into this category.
Tree care is the application of arboricultural methods like pruning, trimming, and felling/thinning[1] in built environments. Road verge, greenways, backyard and park woody vegetation are at the center of attention for the tree care industry. Landscape architecture and urban forestry[2][3] also set high demands on professional tree care. High safety standards against the dangers of tree care have helped the industry evolve. Especially felling in space-limited environments poses significant risks: the vicinity of power or telephone lines, insufficient protective gear (against falling dead wood, chainsaw wounds, etc.) and narrow felling zones with endangered nearby buildings, parking cars, etc.. The required equipment and experience usually transcends private means and is often considered too costly as a permanent part of the public infrastructure. In singular cases, traditional tools like handsaws may suffice, but large-scale tree care usually calls for heavy machinery like cranes, bucket trucks, harvesters, and woodchippers.
Road side trees are especially prone to abiotic stress by exhaust fumes, toxic road debris, soil compaction, and drought which makes them susceptible to fungal infections and various plant pests[4] like the spotted lantern fly.[5] When tree removal is not an option, because of road ecology considerations, the main challenge is to achieve road safety (visibility of road signs, blockage-free lanes, etc.) while maintaining tree health.
While the perceived risk of death by falling trees (a part of the "tree risk" complex) is influenced by media and often hyped (the objective risk has been reported to be close to 1 : 10.000.000, almost as low as death by lightning),[6] singular events have encouraged a "proactive" stance so that even lightly damaged trees are likely to be removed in urban and public traffic surroundings.[3] As a tree ages and nears the end of its safe useful life expectancy (SULE),[7] its perceived amenity value is decreased greatly. A risk assessment normally carried out by local council's arborist to determine the best course of action.[8][9] As with all public green spaces, trees in green urban spaces and their careful conservation is sometimes in conflict with aggressive urban development even though it is often understood how urban trees contribute to liveability of suburbs and cities both objectively (reduction of urban heat island effect, etc.) and subjectively.[10][11][12][13] Tree planting programs implemented by a growing number of cities, local councils and organizations is mitigating the losses and in most cases increasing the number of trees in suburbia.[14] Programs include the planting of 2 trees for every 1 tree removed, while some councils are paying land owners to keep trees instead of removing them for farming or construction.[15]
The voluntary industry consensus standards developed by TCIA, resulted in the ANSI A300 standard, the generally accepted industry standard for tree care practices including trees, shrubs, and other woody plants.[16] It includes the following parts:
Urban Forestry maintains 4.1 million trees on public property, which includes an estimated 3.5 million trees within Toronto's parks and ravines, and approximately 600,000 trees on City streets. ... The focus of our maintenance service is shifting progressively from reactive maintenance to proactive maintenance.
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Ho Chi Minh City has announced a plan to move and cut down 300 trees on Ton Duc Thang Street in District 1 to make space for a bridge connecting to District 2 and a metro station.
Arboriculture (/ˈɑËÂÂÂÂrbÉ™rɪˌkÊŒltʃər, É‘ËÂÂÂÂrˈbÉâ€ÂÂÂËÂÂÂÂr-/)[1] is the cultivation, management, and study of individual trees, shrubs, vines, and other perennial woody plants. The science of arboriculture studies how these plants grow and respond to cultural practices and to their environment. The practice of arboriculture includes cultural techniques such as selection, planting, training, fertilization, pest and pathogen control, pruning, shaping, and removal.
A person who practices or studies arboriculture can be termed an arborist or an arboriculturist. A tree surgeon is more typically someone who is trained in the physical maintenance and manipulation of trees and therefore more a part of the arboriculture process rather than an arborist. Risk management, legal issues, and aesthetic considerations have come to play prominent roles in the practice of arboriculture. Businesses often need to hire arboriculturists to complete "tree hazard surveys" and generally manage the trees on-site to fulfill occupational safety and health obligations.[citation needed]
Arboriculture is primarily focused on individual woody plants and trees maintained for permanent landscape and amenity purposes, usually in gardens, parks or other populated settings, by arborists, for the enjoyment, protection, and benefit of people.[citation needed]
Arboricultural matters are also considered to be within the practice of urban forestry yet the clear and separate divisions are not distinct or discreet.[citation needed]
Tree benefits are the economic, ecological, social and aesthetic use, function purpose, or services of a tree (or group of trees), in its situational context in the landscape.
A tree defect is any feature, condition, or deformity of a tree that indicates weak structure or instability that could contribute to tree failure.
Common types of tree defects:
Codominant stems: two or more stems that grow upward from a single point of origin and compete with one another.
Included bark: bark is incorporated in the joint between two limbs, creating a weak attachment
Dead, diseased, or broken branches:
Cracks
Cavity and hollows: sunken or open areas wherein a tree has suffered injury followed by decay. Further indications include: fungal fruiting structures, insect or animal nests.
Lean: a lean of more than 40% from vertical presents a risk of tree failure
Taper: change in diameter over the length of trunks branches and roots
Epicormic branches (water sprouts in canopy or suckers from root system): often grow in response to major damage or excessive pruning
Roots:
Proper tree installation ensures the long-term viability of the tree and reduces the risk of tree failure.
Quality nursery stock must be used. There must be no visible damage or sign of disease. Ideally the tree should have good crown structure. A healthy root ball should not have circling roots and new fibrous roots should be present at the soil perimeter. Girdling or circling roots should be pruned out. Excess soil above the root flare should be removed immediately, since it presents a risk of disease ingress into the trunk.
Appropriate time of year to plant: generally fall or early spring in temperate regions of the northern hemisphere.
Planting hole: the planting hole should be 3 times the width of the root ball. The hole should be dug deep enough that when the root ball is placed on the substrate, the root flare is 3–5cm above the surrounding soil grade. If soil is left against the trunk, it may lead to bark, cambium and wood decay. Angular sides to the planting hole will encourage roots to grow radially from the trunk, rather than circling the planting hole. In urban settings, soil preparation may include the use of:
Tree wells: a zone of mulch can be installed around the tree trunk to: limit root zone competition (from turf or weeds), reduce soil compaction, improve soil structure, conserve moisture, and keep lawn equipment at a distance. No more than 5–10cm of mulch should be used to avoid suffocating the roots. Mulch must be kept approximately 20cm from the trunk to avoid burying the root flare. With city trees additional tree well preparation includes:
Tree grates/grill and frames: limit compaction on root zone and mechanical damage to roots and trunk
Root barriers: forces roots to grow down under surface asphalt/concrete/pavers to limit infrastructure damage from roots
Staking: newly planted, immature trees should be staked for one growing season to allow for the root system to establish. Staking for longer than one season should only be considered in situations where the root system has failed to establish sufficient structural support. Guy wires can be used for larger, newly planted trees. Care must be used to avoid stem girdling from the support system ties.
Irrigation: irrigation infrastructure may be installed to ensure a regular water supply throughout the lifetime of the tree. Wicking beds are an underground reservoir from which water is wicked into soil. Watering bags may be temporarily installed around tree stakes to provide water until the root system becomes established. Permeable paving allows for water infiltration in paved urban settings, such as parks and walkways.
Within the United Kingdom trees are considered as a material consideration within the town planning system and may be conserved as amenity landscape[2] features.
The role of the Arborist or Local Government Arboricultural Officer is likely to have a great effect on such matters. Identification of trees of high quality which may have extensive longevity is a key element in the preservation of trees.
Urban and rural trees may benefit from statutory protection under the Town and Country Planning[3] system. Such protection can result in the conservation and improvement of the urban forest as well as rural settlements.
Historically the profession divides into the operational and professional areas. These might be further subdivided into the private and public sectors. The profession is broadly considered as having one trade body known as the Arboricultural Association, although the Institute of Chartered Foresters offers a route for professional recognition and chartered arboriculturist status.
The qualifications associated with the industry range from vocational to Doctorate. Arboriculture is a comparatively young industry.