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Tree Physiology, Forestry, and Fire Ecology • Angiosperms – commonly known as hardwoods: – Produce flowers – Protect their seeds inside a fruit – Are pollinated by insects and other animals • Gymnosperms – commonly known as softwoods: – Protect their seeds on cone scales – Are pollinated by wind Monocots and Dicots: Read Only Monocots • 1 cotyledon • parallel veins • scattered vascular bundles • flowers with 3 petals or multiples • fibrous root Dicots: • 2 cotyledons • branched veins • vascular bundles in rings • flowers with 4 or 5 petals (or multiples) • tap root Tree Physiology • Deciduous trees lose their leaves in the fall. Without leaves, the tree is less likely to suffer ice and wind damage during the winter, but it is unable to produce food. Parts of a Tree • Outer Bark - protects trees from the elements (dead phloem cells). • Phloem – inner bark – pipeline that delivers food (made in the leaves) to other parts of the tree. • Cambium – living cell layer of the tree which adds cells to the outside (which become phloem) and to the inside (which become xylem). • Xylem is composed of sapwood and heartwood • Xylem – pipeline where water is moved from the roots to the leaves. – Sapwood is the new wood which transports water. As new layers of sapwood are laid down, inner layers lose their vitality and turn to heartwood. – Heartwood – is the central, supporting pillar of the tree. It is composed of dead xylem cells. A. B. C. D. E. Bark Phloem Cambium Sapwood Heartwood becomes darker b/c the xylem gets clogged up Photosynthesis ___CO2 + ___ H2O ↔ C6H12O6 + ___ O2 Cellular Respiration Paper Plate • Draw rings to correspond to your age. • List ten events that impacted your life: – You will number them on the rings – Then list them on the back of the plate. Forestry Definitions • Forest – area where predominant cover is trees. • Forestry – practice of planting, tending, and managing forests for timber production. • Sustainable forestry – managing forests to meet the needs of the present without compromising the needs of future generations. • Renewable resource – a resource that has the ability to replenish itself through natural processes (within our lifetime). • Sustainable yield – the maximum rate at which people can use a renewable resource without reducing its ability to renew itself. • Stand – a group of trees that are similar in age and in species composition. SC Forests • 12.3 million acres of South Carolina’s land area are forested. That is 64% of it’s 19 million acres. • Timber is the #1 cash crop in SC. • Wood products industry employs 50, 000 people in SC. Who Owns SC Forests? National forest 5% Nonindustrial private 74% Forest industry 16% Other public 5% South Carolina Forest Type Distribution 12.3 Million Acres* Bottomland Hardwood 20.3% Upland Hardwood 19.4% Oak-Pine 11.7% Pine Plantations 24.8% Natural Pine 23.8% BMPs • Best Management Practices – set of voluntary guidelines designed to limit negative impacts on the land during forestry operations in accordance with Section 404 of the Clean Water Act. • SMZs – stream management zones – specific BMPs that are a set of guidelines to protect riparian areas (strips of vegetation along watersheds) from sedimentation during forestry operations. Harvesting Methods • Clear Cut – the practice of removing an entire stand of trees in one harvest. • Seed Tree – is very similar to clear cutting except that a few seed-producing trees are left. These trees are removed after the stand is regenerated. This method is reserved for tree species whose seeds are dispersed by wind. – 10-15 mature trees are left per acre Clear Cut Seed Tree • Shelterwood – process of regenerating a stand through a series of two or three cuts. The first cut removes 50% of the stand. The second cut removes half of the remaining stand. The third cut removes the rest of the mature trees. • Shelterwood cuts provide wildlife with both food and cover while regeneration occurs. It is also more aesthetically pleasing than a clear cut. Shelterwood • Group selection cuts involve removing clusters of trees in an area less than 2 acres. Openings should be at least two times as wide as the height of surrounding trees to allow sunlight to penetrate the forest floor and stimulate regeneration and growth of shade-intolerant trees and herbaceous growth. • Single tree selection – involves removing individual trees. This method is labor intensive but forest communities remain relatively unchanged. Site Prep • Mechanical Site Preparation – involves the physical disturbance of a site by machinery to reduce undesirable plant competition. Mechanical Site Prep • Raking – done to control debris • Plowing – done to till soil so that seedling roots are free to grow. Plow Blades • Bedding – increases seedling survival. • Shearing vegetation and piling debris is called windrowing. When windrows are not burned, they create cover for deer, rabbits, birds, snakes and other wildlife as well as produce food. Dozer with Sear Blade Site Prep • Chemical Site Preparation – involves the use of herbicides to reduce the unwanted vegetation that competes with newly planted trees. • In many cases, after herbicides are used, the site is also burned to further reduce competition and improve soil nutrients. This is called brown and burn Regeneration • Artificial Regeneration – planting seedlings or distributing seeds directly on a recently cleared forest site – typically after a clear cut. • The most common problem with direct seeding (spreading seeds) is regulating the density and spacing between seedlings. • Planting seedlings is more common for southern pine regeneration Regeneration • Natural Regeneration – re-establishment of pine stands from standing trees left on the site. – Seed tree: 10 - 15 mature seed-producing trees are left per acre. – Shelterwood: 20 – 40 mature seed-producing trees are left per acre. Natural vs. Artificial Regeneration Natural Adv: Lower costs Adv: Less labor intensive Adv: Less soil disturbance Adv: More aesthetically pleasing Dis: Less spacing control Dis: Greater seed loss Dis: Don’t use genetically improved seedling Dis: Irregular stands led to difficult harvest Artificial Adv: Control of seed spacing Adv: Use genetically improved seedlings Dis: Higher costs Dis: Higher erosion from site prep Dis: Less aesthetically pleasing Forest Measurements • Site Index: the height a tree will attain on a given site at a given age – usually 50 years. • DBH – Diameter at Breast Height – diameter of the tree taken at 4.5 feet from the base. • Chain – unit of measure used by foresters that equals 66 feet. 10 square chains = 1 acre (An acre is 209 feet by 209 feet) (A circular acre has a radius of 117.75 feet) Forest Measurements • Board foot - unit of wood 1 foot by 1 foot by 1 inch often used to describe the volume of wood produced from a log. • Log – 16.3 foot section of newly harvested tree. • Cord – a measure of wood volume described as a stack 4 feet high, 4 feet wide, and 8 feet long. Dendrochronology Dendrochronology is the dating of past events (climatic changes) through study of tree ring growth The shallow roots of the longleaf pine absorb surface water, which is affected by precipitation. Hurricanes produce large amounts of precipitation with a distinctly lower oxygen isotope composition than that in dew or smaller storms. Tracing tree-rings that contain these lower isotope compositions unveils a record of hurricanes that both supports and surpases the present historical record. The current study looks at a 220year-old record and suggests data up to 400 years can be accessed in future studies. Annual rings: spring wood (light) and summer wood (dark) Douglas fir in New Mexico Ponderosa pine with multiple fire scars Long leaf pine with fire scar Fire scars on a Giant Sequoia White spruce struck by a snow avalanche Ponderosa pine growing alongside a river with an impact scar from a flood Assume all trees were cut in 2010 Age 1. 2. 3. 4. 5. 6. Yr it started growing