Tree Biology and Management - PDF

OK, here is the conversion of the attached document into a structured markdown format. I'll focus on transcribing the essential information, structuring it with headings, lists, and tables, and converting mathematical formulas to LaTeX format. ### Photinia (Photinia x fraseri) **Leaves:** * Alte...

OK, here is the conversion of the attached document into a structured markdown format. I'll focus on transcribing the essential information, structuring it with headings, lists, and tables, and converting mathematical formulas to LaTeX format. ### Photinia (Photinia x fraseri) **Leaves:** * Alternate, simple, and evergreen * Lanceolate to oblong * 10 to 20 cm long, 4 to 9 cm wide * Firm and leathery * Acute, Cuneate, finely serrated from base to apex, midrib prominent * Lustrous dark green above, flat medium green below and glabrous * Petioles are about 4 cm long, clothed with whitish hairs * Can be fully clothed with brilliant red foliage, fading to green after two to four weeks. **Buds:** * Inbricate, 2 to 2.5 cm long, greenish-red in color, conical, with a slightly crooked apex * Seven to nine scaled, glabrous, and laterals are small and obscure. **Stem:** * Stout, terete, glabrous, greenish brown in color and prominently dotted with brownish vertical lenticels * Plant's pith is solid and greenish white. **Size:** * Plant grows 3 to 4.5 m (6+) high and about half that in spread. **Habit:** * Photinia outline is upright in youth and old age * Young plants are relatively open, but fill in with time. **Culture:** * Plants are pH adaptable and grow in full sun or partial shade * Does not tolerate extremely wet soils; responds well to fertilizer. * Nitrogen stresses show vividly, with yellow foliage appearing. ### Lily-of-the-valley shrub (Pieris japonica) **Leaves:** * Alternate, simple, evergreen * Obovate-oblong to oblanceolate * 3 to 9 cm long and 1 to 3 cm wide * Crenate-serrate, lustrous dark green above, lighter green beneath and glabrous * New growth is bronze-purple in color. **Flowers:** * Buds form in summer prior to the year of flowering and assist in identification * Perfect, weakly fragrant, white and urn-shaped, about 50 mm long * For two to three weeks from March to April, borne in 8 to 15 cm long, slightly pendulous panicles. **Fruit:** * Dehiscent and comes in five-valved, one fifth inch capsule. **Size:** * Hight ranges from 3 to 3.5 m and is 2 to 2.5 m in spread **Habit:** * Upright evergreen shrub of neat habit, with stiff branches that spread and rosette-like foliage that is dense **Culture:** * This plant grows best in moist, acid, well-drained soil with peat moss or organic matter * Thrives in full sun or partial shade * Not as fastidious for acid soil as other ericaceous plants. ### Rhododendron (Rhododendron macrophyllum) **Leaves:** * Alternate, evergreen, leathery and thick leaves * Oblong-elliptic, 8 to 15 cm in length and 2.5 to 8 cm wide. **Flowers:** * Light to rose pink flowers are borne in racemes of 20 or more. **Fruit:** * Dry, rusty-brown fruit has pubescent capsule that divides into five parts by splitting lengthwise to release the many small seeds * These seeds, including the wing, are less than 25 mm long. **Size:** * These shrubs are usually 2 to 4 m tall at maturity. **Habit:** * Plants growing in the shade have elongated branches and may resemble small trees. * Plants growing in the open form compact, dense bushes. **Description of image:** The image shows an illustration of a rhododendron. The illustration depicts a branch with leaves and flowers. The leaves are elliptic, and the flowers are bell-shaped and clustered together **Culture:** * Pacific rhododendron has shallow roots * Good aeration is important for rhododendron roots, which often will grow deep into loamy soils. * Pacific rhododendron seeds germinate without stratification and are viable for up to two years * The seeds require light for germination. ### English holly* (Ilex aquifolium) **Leaves:** * Simple, alternate, evergreen, leathery, and lustrous * Elliptic and ovate, with undulating margins, measuring 5 to12 cm long and 2 to 6 cm wide. **Flowers:** * Non-showy white flowers, that bloom March to April * Flowers may appear to have both stamens and pistils, but individual plants are functionally uni-sexual. **Fruit:** * Red, drupe, showing in September to October * Showy, persistent, berry-like; 4 to 6 seeds each with own hard endocarp, slightly toxic to people. **Size:** * These trees are usually 10 to 15 m tall and 7 to 10 m wide. **Habit:** * Trees grow as an upright, narrowly pyramidal. **Culture:** * English holly grows in acidic, well-drained soil, and prefers full sun and part sun/shade * It reproduces by seeds dispersed by birds, and by suckering and layering. ### Dichotomous Key * Please refer to learning resource D1 - Identify Common Trees in British Columbia, for information on dichotomous key. ## LINE D: TREE WORK AND MANAGEMENT ### Competency D3: Describe Basic Tree Biology and its Importance to Good Arboriculture Practices An arborist applies their knowledge of basic tree biology to make informed decisions with respect to sound arboriculture practices. | Importance 1 (minimally) to 5 (extremely) | Frequency of use 1 (rarely) to 5 (daily) | | :----------------------------------------- | :-------------------------------------- | | 3 | 2 | **Learning Objectives:** Given the necessary materials the apprentice will be able to describe basic biology and how it relates to sound arboriculture practices, according to Industry standards. **Learning Tasks:** 1. Describe the relation between structures and functions in a tree by discussing the interaction of each within a plant or tree * Primary and secondary meristem growth, stem anatomy, auxins and hormones 2. Explain photosynthesis, transpiration and cell growth in tree parts * Photosynthesis, transpiration, respiration, cell division and growth 3. Describe Dermal/bark tissues * Phloem * Xylem * Parenchyma * Sclerenchyma * Cambium 4. Roots and their function * Root structure and function 5. Discuss correct cuts based on tree biology * Compartmentalization of decay in trees * Branch collars * Wound wood formations * Species resistance to decay ### Tree Biology A better understanding of how trees grow and basic knowledge of tree biology will allow the arborist to better care for them throughout their lives. Trees are living organisms that interact with their environment and survive by forming relationships within it. Understanding the trees' needs, sensitivities and weaknesses enables the arborist to make proper decisions regarding planting and treating trees in different areas. Even properly pruning a tree requires a basic understanding of tree biology and tree structure. ### Hormones Plant hormones are chemicals that regulate the growth of the tree. Plant hormones are produced within the tree, occur in small quantities, and regulate cellular processes in targeted cells within the tree. Hormones also aid in the formation of flowers, stems and leaves, the shedding of leaves, the development and ripening of fruit, and even plant death. Each cell of a plant is capable of producing hormones, unlike animals, which produce and secrete hormones through specialized glands. Hormones are vital to tree growth and without them, they would just be a mass of undifferentiated cells. Plants have five classes of hormones: * Auxins promote stem elongation and inhibit the growth of lateral buds. They are produced in the stem, buds, and root tips. Auxin moves to the darker side of the plant, causing the cells there to grow larger than corresponding cells on the lighter side of the plant. This produces a curving of the plant stem tip toward the light, a plant movement known as *phototropism*. Auxin also plays a role in maintaining *apical dominance*. Most plants have axillary buds located at the nodes (where the leaves attach to the stem). Buds are meristems maintained in a dormant state. Auxin maintains this dormancy. As long as sufficient auxin is produced by the apical meristem, the lateral buds remain dormant. If the apex of the shoot is removed, for example, in the process of pruning, the auxin is no longer produced. This will cause the lateral buds to break their dormancy and begin to grow. The plant becomes bushier. When an arborist trims or prunes a tree or shrub, they are applying apical dominance. * Gibberellins promote stem elongation. Gibberellins production occurs mainly in the plastids (specialized subunits of cells) of roots and young leaves. * Cytokinins promote cell division. They are produced in growing areas, such as meristems at the tip of the shoot. * Abscisic Acid promotes seed dormancy by inhibiting cell growth. This hormone is also involved in the opening and closing of stomata as the leaves wilt. * Ethylene is a gas produced by ripe fruits. Ethylene is used to ripen crops at the same time. ### Tree Stuctures Trees do not just grow from the bottom up, continuing to push up from the bottom of their stems. Instead, they grow in length from their shoot tips and expand their circumference by generating new cells every year. At the end of every shoot there is a site of tissue termed a *meristem* which will develop new growth each year. This new growth is called *extension growth*. New layers of cells are developed at the end of an existing shoot. Meristems are the site of repeated cell division of unspecialized cells. These cells differentiate, and become specialized according to the function they will perform. After cells become specialized, they then form part of the permanent tissue which will then perform a particular role within the plant. There are two types of meristems - apical and axillary * Apical meristems are the sites of the primary growth in a tree, and are found both at the root and shoot tips. The apical meristem gives rise to 3 primary meristems: protoderm, which creates the outer covering of plant; procambium, which creates vascular tissue; and ground meristem, which creates other plant tissue. The ground tissue makes up most of the plant's body, the dermal tissue covers the outside of the plant, and the vascular tissue conducts the water and minerals (nutrients) for the tree. * Axillary meristems grow out of the side of the tree. These meristems are responsible for the secondary thickening, which provides the structural support for the growing tree to get larger. This thickening occurs at the stem and root sections of the plant, and the secondary growth responsible for this thickening occurs in the vascular-cambium and cork cambium of the tree. * Cambium is a layer of actively dividing cells inside a plant or tree which generate growth for the plant. The cambium is filled with undifferentiated cells which have the ability to differentiate into many different types of cells, depending on where in the plant they are growing The vascular cambium is found inside the tissues of the plant, between the xylem and the phloem It is responsible for the width and outward growth seen as plants mature and grow larger New layers also form vascular bundles consisting of phloem and xylem, which aids the transport of water and minerals(nutrients)throughout the plant vascular cambium develops in distinct seasonal rings as the amount of nutrients available rise and falls the cambium of a plant can be vulnerable to damage if serious injury such as a cut, occurs to the vascular cambium the plant may die coric cambium is merismatic tissue which gives rise to the periderm forming part of the bark * Cork cambium is less vulnerable than the vasicular cambium, forming a rough outer layer which protects the plant from damage. **In the section that follows there is are descriptions of four different processes related to biological matter** * Spring provides more daylight hours, allowing more photosynthesis to occur * Spring provides more intense, direct light for photosynthesis *Biological matter in the spring is at its best and the soil and its mineral content are better suited for feeding the plant. * Biological reactions occur more efficiently in temperature conditions Due to these better conditions cambium is more active and therefore the trees grow faster Cells are visibly more developed and more elongated The opposite situation occurs in summer when conditions are less favourable and cell growth is smaller. **Description of Growth Rings** The image dispicts a vascular cambium * In the cambium one can locate, vascular cambium, fusiform intials and ray initials * In the Pith one can locate primary xylem, vascular cambium, primary pholem * In the cortex one canlocate Phellogen, and can see the direction of growth * one can also see Pholem ray, xylem ray and can see the direction of growth * Also depicts Primary Xylem, secondary xylem, vascular cambium , secondary pholem, primary phelloem, cord cambium * Also depicts summer wood and spring wood * finally depictions secondary xylem, vascular cambium, secondary pholem, cord cambium, cord bark and perifirm * These condensed areas of growth look like rings to the human eye * This is why a tree's age can be deduced by the number of summers that the cambium has grown The extent of growth in any year is also the result of the tree's available energy therefore it can give an indication of the the trees health unhealthy trees may have restricted growth even under good conditions Photosynthesis, Transpiration and Cell Growth *Leaves in the shade are often larger than leaves in sun to increase surface area to allow absorption of maximum available light. *Plants with more leaves have a greater total surface area for stomata and so a greater surface area for evaporation water loss. large leaves transpire faster and leaves with smaller surfaces area transpire slower, leaves with a greater number of stomata the surface have a greater number of pores for transpiration. **Leaf Structure** image showing a Leaf Cross Section *It shows the cuticle, upper epidermis, palisade layer, mesophyll cells, lower epidermis, stomata and guard cells *It shows some layers of the leaf *A Leaf is made of many layers that are sandwiched between two layers of tough skin cells called epidermidis * The epidermidis also secretes a waxy substance called the cuticle *These layers protect the leaf from insects bacteria and other pests * Among the epidermidis cells are pairs of sausage shape guard cells * Each pair of guard cells forms a pore called stoma the plural is stomata * Gases enter and exit the leaf through stomata *Most food production takes place in elongated cells called palisade mesophyll -gas exchange occurs in the air spaces between the oddly shaped cells of the spongy mesophyll *Veins support the leaf and filled with vessels that transport food, water, and minerals to the plant This structure allows the processes of photosynthesis, respiration, and transpiration occur **Photosynthesis and Respiration** The image is a photosynthesis illustration The sun shines down as energy, Chlorophyll is in the leaf, the plant uses carbohydrates to all parts of the tree using water from the soil and is released intot he air. Carbon dioxide from the air is also shown *The first step is a better is better understanding of the major differences between plants * Photosynthesis is the ability of plants to internally manufacture tier own food * To produce food , a plant requires energy from sunlight, carbon dioxide ($CO_2$)from the air, and water ($H_2O$) from the soil. any of these indgredients are lacking the process wiill stop * If any factor is removed a long period of time, the plant will die * Any green part is capable of Photosynthesis ${Chloroplasts}$ in those cellls contain pigment called ${Chlorophyll}$ which is used to trap the light energy ${Photosynthesis}$ is dependent upon the availability of light As sunlight increases, the intensity of ${photosynthesis }$ increases. This results in greater food production *Leaves are generally the site of most food production as they are designed for this purpose. The internal leaf tissue contains cells with many ${chloroplasts}$ arranged in such a manner as to allow easy movement of water and air The protective upper and lower skin layers of the leaf include many openings in the leaf formed by two specialized guard cells on either side. These guard cells regulate movement of the gases (${CO_2}$ into, and $O_2$, $H_20$ out of the leaf) involved in ${photosynthesis}$. The lower epidermis of the leaf normally contains the largest percentage of these openings – called *stomata*. Plants convert the energy from light into simple sugars, such as glucose. These sugars may be converted back to water and carbon dioxide, which will release the stored energy through a process called ${respiration}$. This energy is quired for growth in nearly all organisms. Glucose by the process of ${photosynthesis}$ may be used in three ways: 1 It can be converted into chemical required for to growth of plant cells such as cellulose 2 It can converted into starch a storage molecule , that can converted back to glucose when the plant requires it 3 It can be broken down durning the process of respiration, releasinfg enegfy stored in the glucose molecules ${simple Suagrs}$ also are converted to other suagrs and straches(Carbocyhydrates) which may transported to the steams and roots for user of storage or use as buidling block for more cemplex structural such as cell walls *Water also supports ${photosynthesis}$ in serval ways firstly it maintains formness *Water pressure is needed in tissue Water pressure is needed in tree cells to maintain shape and ensure cell growth. *serconly the water it into hydro and oxtygen by the enegry of the sun that has beem transpiration Plunts need large quantitys of water growth transpiration Plants need large quantities of water for growth The most important factor driving wate movement ins plants or water is the process if ${TRANSFORMATION}$ The loss of water forms plant ( $95%$ the water that plant obsorb comes from the soile which is utlilized form transformation however sum portions of plants such as water only $ 5%$ for during photosnthesis for producing carbohydrates essential for plant growth the rate transpiration depdends water within the plants (and soil and sufficient energy (sol radiation) to vaporize water Most if energy surpotinf transformation come dierectly from sun, Hot Sun incfresing , hot weather increases rate transpiration and thus risk for **Transpiration is the process by which a plant loses water, mostly through leaf stomata** Water is pulled through the plants by evaporation water through leaves. ${Transpiration}$ if necessary. for mineral transport to the plants or colling plant (1for ell growth and also for matenance the water of within it The amount water lost depemds on several invromental and cause from somata in to leaf increase for transpiration. (every tree has layers of back inner the inner bark hard inner and the out the the hardness and or helps Damage tot the bark can prove to the trees of vascular. and code can be the if and and cannot to dealth the die many kind or trees an be distinivte bark and bark and is or and they the tree ***The barks a young tree, or quite thin*** cork cambium a layer of tissue the cambial cells are bix shape and is growing sessaon conutally in size The code cambium id the scurce de The function vasicur to produce thus, asiculum musr from dcecondagrowith and on the inside Bot xylem xylar are tissus The xylem is a tubluar , so, Pholem Part if the inner bark conducts the product of and more ### Xylem Xylem is the water transporting tissue in plants that is effectively dead when it reaches functional maturity. Water is pulled up the xylem by the force of transpiration (water loss from leaves). Water lost from the leaves causes diffusion of additional water molecules out of the leaf vein xylem, creating a tug on water molecules along the water columns within the xylem. This change in pressure causes water molecules to rise up from the roots to eventually the leaves. The loss of water from the root xylem allows additional water to pass through the endodermis into the root xylem. Xylem exists as non-living tissue at maturity but pholem is alive. ### Pith and Pith Rays At the center of the tree trunk or branch is an area of loose, thin walled tissues called the pith. This also serves as a store of reserve food during the winter season ### Parenchyma Tissue is the most common versatile of tissue parenchyma cells are living at maturity The cell is the parenchyma tissue by wind so repair ### Sclerenchyma Tissue to cells can often what is cells ### The Root system roots a support The image is a croos section of a root cell root. 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