Deforestation and habitat loss

Deforestation and habitat loss

The Impact of Clear-Cutting on Biodiversity.

The whirring of chainsaws echoes through the forest, a grim symphony of destruction. Clear-cutting, the practice of completely removing all trees from a designated area, leaves behind a desolate landscape, a stark contrast to the vibrant ecosystem that once thrived. Its impact on biodiversity is devastating, a ripple effect that extends far beyond the immediate loss of trees.


Forests are intricate webs of life. From the towering canopy to the forest floor, a multitude of species depend on the complex interplay of plants, animals, fungi, and microorganisms. Clear-cutting severs these connections, effectively dismantling the entire system. The immediate consequence is habitat loss. Birds lose their nesting sites, mammals their dens, and insects their host plants. Species specialized to old-growth forests, with their unique microclimates and structural complexity, are particularly vulnerable and often face local extinction.


The removal of trees also leads to drastic changes in the environment. The protective canopy, once a buffer against the elements, is gone. Sunlight, previously filtered through leaves, now beats down on the exposed ground, causing dramatic fluctuations in temperature and humidity. Soil erosion accelerates, stripping away vital nutrients and degrading water quality in nearby streams and rivers. These changes make it difficult for many species to survive, further diminishing biodiversity.


While proponents of clear-cutting often cite economic benefits and the potential for reforestation, the reality is that replanted monoculture forests lack the biodiversity and ecological complexity of natural forests. They are more susceptible to pests and diseases, and they fail to provide the same ecosystem services, such as carbon sequestration and water regulation. The recovery of a clear-cut area to its original state can take centuries, if it ever happens at all.


In conclusion, clear-cutting represents a significant threat to biodiversity. Its destructive impact resonates throughout the ecosystem, leading to habitat loss, environmental degradation, and the potential extinction of vulnerable species. While responsible forest management practices are essential for human needs, the devastating consequences of clear-cutting underscore the urgent need for more sustainable approaches to logging that prioritize the preservation of biodiversity and the long-term health of our forests.

Forest fragmentation, the slicing and dicing of continuous forest into smaller, isolated patches, is like shattering a mirror. The individual pieces might still reflect light, but the complete picture is lost, and the overall reflective power is diminished. This shattering, driven primarily by deforestation and habitat loss, has devastating consequences for the intricate web of life that forests support.


Imagine a once vast, unbroken forest teeming with life. Animals roam freely, seeds disperse widely, and ecological processes flow seamlessly. Now, picture roads, farms, and developments carving into that landscape, leaving behind a fragmented mosaic of shrinking woodland islands. Suddenly, the edges of these fragments become exposed to harsh environmental conditions like increased sunlight, wind, and invasive species. These "edge effects" penetrate deep into the remaining forest, altering microclimates, drying out the understory, and making the habitat unsuitable for many species.


The smaller the fragment, the more pronounced these edge effects become, and the less viable the habitat becomes for many forest-dwelling creatures. Large, wide-ranging animals like jaguars or elephants, which require extensive territories, are particularly vulnerable. Their populations become isolated and genetically impoverished, increasing their risk of extinction. Even smaller, less mobile species suffer as their access to resources like food and mates diminishes.


Fragmentation also disrupts crucial ecological processes. Pollination and seed dispersal become less effective as the distances between forest patches increase, hindering plant reproduction and forest regeneration. Nutrient cycling is altered, and the forest's ability to regulate water flow and prevent soil erosion is compromised. This, in turn, impacts the livelihoods of communities who depend on these ecosystem services.


The consequences of forest fragmentation extend far beyond the borders of the fragmented patches themselves. It contributes to biodiversity loss, climate change, and the disruption of vital ecosystem services. Addressing this issue requires a multifaceted approach that includes protecting existing forests, restoring degraded areas, and creating corridors to connect isolated fragments. Just as piecing together a broken mirror can never fully restore its original form, the ecological damage caused by fragmentation is often irreversible. However, by taking swift and decisive action, we can mitigate further fragmentation and safeguard the remaining fragments of these vital ecosystems for future generations.

Citations and other links

Case Studies of Habitat Loss Due to Tree Cutting.

Deforestation, the clearing of forests for other land uses, is a major driver of habitat loss around the globe. Examining specific case studies reveals the devastating impact of tree cutting on various species and ecosystems. These real-world examples paint a stark picture and underscore the urgent need for conservation efforts.


One heartbreaking example is the plight of orangutans in Borneo and Sumatra. Extensive logging for palm oil plantations has decimated their rainforest habitat. As trees are felled, orangutans lose their homes, their food sources, and the intricate network of branches they rely on for movement. Forced into smaller and smaller fragments of forest, they face increased competition for resources, higher risks of disease, and greater vulnerability to human conflict. The story of the orangutan is a tragic case study of how deforestation directly translates to habitat loss and pushes a species towards extinction.


The Amazon rainforest, often called the "lungs of the planet," offers another sobering case study. Massive deforestation, driven by agriculture, mining, and logging, is fragmenting this vital ecosystem. The loss of trees disrupts the delicate balance of the rainforest, impacting rainfall patterns, increasing soil erosion, and releasing vast amounts of stored carbon into the atmosphere. Countless species, many still undiscovered, are losing their homes as their habitat shrinks. The Amazon's deforestation demonstrates the far-reaching consequences of tree cutting, affecting not only local biodiversity but also the global climate.


A further example can be found in the dry forests of Madagascar. Logging for timber and clearing land for agriculture have dramatically reduced these unique forests, home to an incredible array of endemic species, including lemurs. As the trees disappear, lemurs lose their food sources and shelter, making them vulnerable to predators and the elements. The loss of these forests also contributes to soil erosion and desertification, further degrading the remaining habitat. Madagascar's case highlights how deforestation can lead to a cascade of negative environmental effects, impacting both biodiversity and the overall health of the ecosystem.


These case studies, though just a few examples, demonstrate the devastating consequences of deforestation and habitat loss due to tree cutting. They serve as a stark reminder of the interconnectedness of life on Earth and the urgent need to protect our remaining forests. By understanding the specific impacts of tree cutting on different ecosystems and species, we can develop more effective strategies for conservation and work towards a more sustainable future.

Case Studies of Habitat Loss Due to Tree Cutting.
Mitigation and Reforestation Efforts.

Mitigation and Reforestation Efforts.

Deforestation and habitat loss are twin scourges of the modern era, leaving a trail of devastating consequences for both wildlife and the delicate balance of our planet's ecosystems. But amidst the destruction, there's a growing movement focused on mitigation and reforestation efforts, offering a glimmer of hope for the future. These initiatives aren't just about planting trees; they're about rebuilding ecosystems, protecting biodiversity, and acknowledging our responsibility to the natural world.


Mitigation efforts aim to reduce the impact of deforestation before it even happens. This can involve implementing sustainable logging practices, promoting alternative sources of income for communities that rely on forests, and strengthening land-use regulations to prevent illegal logging and agricultural expansion. It's about finding ways to meet human needs without decimating forests in the process. Think of it as preventative medicine for the environment.


Reforestation, on the other hand, focuses on restoring what has already been lost. This involves planting native tree species in deforested areas, nurturing their growth, and carefully monitoring the progress of these new forests. It's not just about planting any tree, though. Successful reforestation requires a deep understanding of the local ecosystem, ensuring that the right species are planted in the right places to maximize biodiversity and ecological function. It's a painstaking process, often requiring years of dedication and care, but the rewards are invaluable.


The combined power of mitigation and reforestation is critical for tackling the complex problem of deforestation. They are two sides of the same coin, working together to protect and restore our planet's vital forests. While the challenges are immense, the growing awareness of the importance of these efforts, combined with increasing community involvement and scientific advancements, provides a reason for cautious optimism. The future of our forests, and indeed the planet, may well depend on the success of these combined efforts.

 
Tree trimmer on tracked treads
(Click for video)

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.

Tree removal

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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]

Standards

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United States

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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:

  1. Pruning
  2. Soil management
  3. Supplemental support systems
  4. Lightning protection systems
  5. Management
  6. Planting and transplanting
  7. Integrated vegetation management
  8. Root management standard
  9. Tree risk assessment
  10. Integrated pest management

Professional associations

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See also

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References

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  1. ^ Council, Cornwall. "Practical Guidelines for Young Tree Care - Cornwall Council". www.cornwall.gov.uk. Retrieved 2018-04-06.
  2. ^ "Urban Forestry Management in Denver Colorado - Denver Tree Service - Tree Removal - Snow Removal". environmentaltreecarellc.com. Retrieved 2018-06-11.
  3. ^ a b "Urban Forestry Operations". City of Toronto. 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.
  4. ^ Frankfurt, Umweltamt. "Tree protection in Frankfurt : Stadt Frankfurt am Main | Dezernat Umwelt und Gesundheit | Umweltamt". frankfurt-greencity.de (in German). Retrieved 2018-04-06.
  5. ^ "spotted lantern fly".
  6. ^ "EPA – Home" (PDF).
  7. ^ "NOTES ON SAFE USEFUL LIFE EXPECTANCY (SULE RATING) AS USED IN TREE DESCRIPTION" (PDF). strathfield.nsw.gov.au.
  8. ^ Northrop, Andrew K. Koeser, Gitta Hasing, Drew McLean, and Rob (2016-12-20). "Tree Risk Assessment Methods: A Comparison of Three Common Evaluation Forms". edis.ifas.ufl.edu. Retrieved 2018-04-06.cite web: CS1 maint: multiple names: authors list (link)
  9. ^ "Tree Removal Australia – Stay Smart, Save Money". GoTreeQuotes. Retrieved 2018-04-06.
  10. ^ "Greening Our Streets Street Tree Management Plan" (PDF). City of Whittlesea, Australia. 2016.
  11. ^ Peter Mitham (2015). "Redevelopment, urban tree removal raise city residents' concerns". Business Vancouver.
  12. ^ eugenie stockmann (2016). "Are developers to blame for loss of tree cover in urban areas?". The Green Swing.
  13. ^ Dinh Muoi, Thanh Nien News (2016). "Ho Chi Minh City announces massive tree removal plan for metro station". Archived from the original on April 14, 2016. 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.
  14. ^ "Buy Trees and Learn About Trees - Visit our Online Nursery". www.arborday.org. Retrieved 2018-04-06.
  15. ^ "NVIM Quick Reference Guide. Obligations under the Biodiversity Conservation Strategy" (PDF). environment.vic.gov.au.
  16. ^ Advanced Solutions International Inc. "TCIA | A300 Standards". www.tcia.org. Retrieved 2018-04-06.
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Two workers pruning street trees in London during World War I

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.

Pruning terms

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Branch wood, trunk wood, branch collar, branch bark ridge clearly identified on a tree.
 

Branch wood

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Branch wood is an individual stem that grows off of another stem.

Trunk wood

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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.

Branch bark ridge

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This refers to the junction between branch wood and trunk/stem wood. It usually looks raised. [2]

Types of Pruning

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An arborist pruning a tree near the Statue of Liberty

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]

Dense growth results after shearing

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.

  • Thinning: A more drastic form of pruning, a thinning out cut, is the removal of an entire shoot, limb, or branch at its point of origin.[5] This is usually employed to revitalize a plant by removing over-mature, weak, problematic, and excessive growths. When performed correctly, thinning encourages the formation of new growth that will more readily bear fruit and flowers. This is a common technique in pruning roses and for amplifying and "opening-up" the branching of neglected trees, or for renewing shrubs with multiple branches.
  • Topping: Topping is a very severe form of pruning which involves removing all branches and growths down to a few large branches or to the trunk of the tree. When performed correctly it is used on very young trees, and can be used to begin training younger trees for pollarding or for trellising to form an espalier.
  • Raising removes the lower branches from a tree in order to provide clearance for buildings, vehicles, pedestrians, and vistas. [6]
  • Reduction reduces the size of a tree, often for clearance for utility lines. Reducing the height or spread of a tree is best accomplished by pruning back the leaders and branch terminals to lateral branches that are large enough to assume the terminal roles (at least one-third the diameter of the cut stem). Compared to topping, reduction helps maintain the form and structural integrity of the tree.[7]

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.

Deadwooding

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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.

Preventive structural pruning

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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

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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

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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

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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]

Vista pruning

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Selectively pruning a window of view in a tree.

Crown reduction

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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.

Pollarding

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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

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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.

Time period

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Pruning of trees in Chandigarh

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.

See also

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References

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  1. ^ BCMA, Jeremiah_Sandler (2021-02-01). "On Removing Deadwood, Part 1". Tree Care Industry Magazine. Retrieved 2024-05-30.
  2. ^ McKenzie, Rita; Holt, Harvey. "Trees Need a Proper Start – Prune Them Right" (PDF). Urban Forestry Specialists, Forestry and Natural Resources. Purdue University.
  3. ^ Fraedrich, Bruce. “Structural Pruning of Young Trees.” Bartlett Tree Research Laboratories Technical Report.
  4. ^ Encyclopedia of gardening (3rd U.S., rev. and updated ed.). London: DK Pub. 2012. pp. 554–556. ISBN 9780756698287.
  5. ^ a b "Tree Fruit Production Guide". tfpg.cas.psu.edu. Retrieved 20 December 2017.
  6. ^ "Raising - Pruning - Landscape plants - Edward F. Gilman - UF/IFAS". hort.ifas.ufl.edu. Retrieved 2024-05-28.
  7. ^ "Reducing - Pruning - Landscape plants - Edward F. Gilman - UF/IFAS". hort.ifas.ufl.edu. Retrieved 2024-05-28.
  8. ^ "Removal of dead wood - Nelson's Tree Services". Archived from the original on 15 December 2017. Retrieved 20 December 2017.
  9. ^ a b Gilman, Edward F.; Bisson, Amanda (2008-01-24). "Chapter 12 — Developing a Preventative Pruning Program: Young Trees". EDIS. 2008 (1). doi:10.32473/edis-ep315-2007. ISSN 2576-0009.
  10. ^ Gilman, Edward F. (2012). An illustrated guide to pruning (3rd ed.). Clifton Park, NY: Delmar. ISBN 978-1-111-30730-1.
  11. ^ "Crown Reduction - Nelson's Tree Services". Retrieved 20 December 2017.
  12. ^ Smiley, E, and Bruce Fraedrich. “Pruning Standard to Maintain Landscape Trees.” Bartlett Tree Research Laboratories Technical Report.

Bibliography

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  • Sunset Editors, (1995) Western Garden Book, Sunset Books Inc, ISBN 978-0-376-03851-7
  • James, N. D. G, The arboriculturalist's companion, second edition 1990, Blackwell Publishers Ltd, Great Britain.
  • Shigo, A, 1991, Modern arboriculture, third printing, Durham, New Hampshire, USA, Shirwin Dodge Printers.
  • Shigo, A, 1989, A New Tree Biology. Shigo & trees Associates.
  • J.M. Dunn, C.J. Atkinson, N.A. Hipps, 2002, Effects of two different canopy manipulations on leaf water use and photosynthesis as determined by gas exchange and stable isotope discrimination, East Malling, University of Cambridge.
  • Shigo. A. L, 1998, Modern Arboriculture, third printing (2003), USA, Sherwin Dodge Printers
  • British standards 3998:1989, Recommendations for Tree Work.
  • Lonsdale. D, 1999, Principles of tree hazard assessment and management, 6th impression 2008, forestry commission, Great Britain.
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An arborist practicing tree care: using a chainsaw to fell a eucalyptus tree in a park at Kallista, Victoria.

Arboriculture (/ˈɑːrbərɪˌkʌltʃər, ɑːrˈbɔːr-/)[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.

Overview

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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

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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.

Environmental Benefits

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  • Erosion control and soil retention
  • Improved water infiltration and percolation
  • Protection from exposure: windbreak, shade, impact from hail/rainfall
  • Air humidification
  • Modulates environmental conditions in a given microclimate: shields wind, humidifies, provides shade
  • Carbon sequestration and oxygen production

Ecological Benefits

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  • Attracting pollinators
  • Increased biodiversity
  • Food for decomposers, consumers, and pollinators
  • Soil health: organic matter accumulation from leaf litter and root exudates (symbiotic microbes)
  • Ecological habitat

Socioeconomic Benefits

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  • Increases employment: forestry, education, tourism
  • Run-off and flood control (e.g. bioswales, plantings on slopes)
  • Aesthetic beauty: parks, gatherings, social events, tourism, senses (fragrance, visual), focal point
  • Adds character and prestige to the landscape, creating a "natural" feel
  • Climate control (e.g shade): can reduce energy consumption of buildings
  • Privacy and protection: from noise, wind
  • Cultural benefits: eg. memorials for a loved one
  • Medical benefits: eg. Taxus chemotherapy
  • Materials: wood for building, paper pulp
  • Fodder for livestock
  • Property value: trees can increase by 10–20%[citation needed]
  • Increases the amount of time customers will spend in a mall, strip mall, shopping district[citation needed]

Tree Defects

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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.

  • common with decurrent growth habits
  • occurs in excurrent trees only after the leader is killed and multiple leaders compete for dominance

Included bark: bark is incorporated in the joint between two limbs, creating a weak attachment

  • occurs in branch unions with a high attachment angle (i.e. v-shaped unions)
  • common in many columnar/fastigiate growing deciduous trees

Dead, diseased, or broken branches:

  • woundwood cannot grow over stubs or dead branches to seal off decay
  • symptoms/signs of disease: e.g. oozing through the bark, sunken areas in the bark, and bark with abnormal patterns or colours, stunted new growth, discolouration of the foliage

Cracks

  • longitudinal cracks result from interior decay, bark rips/tears, or torsion from wind load
  • transverse cracks result from buckled wood, often caused by unnatural loading on branches, such as lion's tailing.
  • Seams: bark edges meet at a crack or wound
  • Ribs: bulges, indicating interior 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:

  • girdling roots compress the trunk, leading to poor trunk taper, and restrict vascular flow
  • kinked roots provide poor structural support; the kink is a site of potential root failure
  • circling roots occurs when roots encounter obstructions/limitations such as a small tree well or being grown too long in a nursery pot; these cannot provide adequate structural support and are limited in accessing nutrients and water
  • healthy soil texture and depth, drainage, water availability, makes for healthy roots

Tree Installation

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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:

  • Silva cells: suspended pavement over modular cells containing soil for root development
  • Structural soils: growing medium composed of 80% crushed rock and 20% loam, which supports surface load without it leading to soil compaction

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.

UK

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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.

See also

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References

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  1. ^ "arboriculture". Dictionary.com Unabridged (Online). n.d.
  2. ^ "Amenity landscapes • Environment Guide". www.environmentguide.org.nz. Retrieved 2020-04-28.
  3. ^ "Town and Country Planning Association". Town and Country Planning Association. Retrieved 2020-04-28.
  • Harris, Richard W. (1983). Arboriculture: Care of Trees, Shrubs, and Vines in the Landscape. Englewood Cliffs, New Jersey: Prentice-Hall, Inc. pp. 2–3. ISBN 0-13-043935-5.
  • "arboriculture". Merriam-Webster's Collegiate Dictionary, Eleventh Edition. Merriam-Webster.
  • "arboriculture". Encyclopædia Britannica Online. 2007.
  • "arboriculture". The American Heritage Dictionary of the English Language, Fourth Edition Online. Houghton Mifflin Company. 2000.
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Frequently Asked Questions

The main causes are agricultural expansion (clearing land for crops and livestock), logging (for timber and paper products), and urbanization (building cities and infrastructure).
Removing trees eliminates the physical environment that many species depend on for survival, including nesting sites, food sources, and shelter. It also fragments habitats, isolating populations and making them more vulnerable.
Loss of biodiversity (extinction of plant and animal species), disruption of ecosystems, increased greenhouse gas emissions (trees absorb CO2), soil erosion, and altered water cycles.
Selective logging (harvesting only mature trees), reforestation (planting new trees), afforestation (establishing forests in new areas), and using certified sustainable wood products.
Reduce consumption of wood and paper products, support sustainable forestry practices, advocate for stronger forest protection policies, and participate in reforestation efforts.