This is a basic primer on U.S. Forest Service (FS) timber management on the federal National Forests and Grasslands in Texas (NFGT), the Sabine, Angelina, Davy Crockett and Sam Houston National Forests.
Definitions Used
“Forestry” is the profession which uses science, art, and practice to create, manage, use, and conserve forests and associated resources for human benefit in a sustainable manner to meet desired goals, needs, and values.
“Forest management” is the practical application of biological, physical, quantitative, managerial, economic, management, utilization, and conservation of forests to meet specified goals and objectives while productivity is maintained. Forest management includes aesthetics, fish, recreation, urban values, water, wilderness, wildlife, wood products, and other forest resources.
“Silvics” is the study of the life history and general characteristics of forest trees and “stands” (groups of trees with similar characteristics), with particular reference to environmental factors, as a basis for silviculture.
“Silviculture” is the art and science of establishment, growth, composition, health, and quality of forests and woodlands to meet diverse needs and values of landowners and society on a sustainable basis. Silviculture is the basis for “timber management”.
East Texas Forest Ecology
Conditions in East Texas allow for the growth of many different forests. Forests are the result of geology and the diverse array of soils that have been formed by geology. Although topography (elevation) in East Texas is not great, there are many different “micro-topographies” and “microclimates” that make East Texas Forests diverse.
East Texas Forests are a “transition zone” (“ecotone”), of eastern, southern, and northern forests of the U.S. that interact with such as the coastal prairie, black-land prairie, and oak savannah ecosystems (large areas with their living and non-living elements). An “ecotone” is where ecosystems inter-grade and create a more diverse landscape. Some East Texas Forest Ecosystems are:
1) Oak – Pine Ecosystem
2) Oak – Hickory Ecosystem
3) Pine – Hardwood Ecosystem
4) Oak – Gum – Cypress Ecosystem
These ecosystems are broken down into smaller forest ecosystems which are named for the most prominent or dominant tree species on the landscape. Some forest ecosystems are: American Beech – Southern Magnolia – Loblolly Pine Slope Association, Bald Cypress – Water Tupelo Bottomland Association, and Longleaf Pine – Bluejack Oak Upland Association.
We classify trees by the topographic position where they are usually found. In East Texas, due to the long growing season, high rainfall, and low elevation, a few feet or inches can affect where different trees grow. Topographic elevation varies from zero to 500 feet (from the coast to the Oklahoma border) in East Texas. “Uplands”, “slopes”, and “bottomlands” are where forests exist on the landscape.
Soil moisture is a characteristic that determines where trees live. A “hydric” soil (floodplain) is wet; a “xeric” soil is dry (sandy bank); and a “mesic” soil is intermediate between wet and dry (terrace, levee, or slope above a floodplain). Southern Magnolia is a mesic (intermediate soil moisture) tree, Bald Cypress is a hydric (wet) tree, and Shortleaf Pine is a xeric (dry) tree.
Timber Management
Different “silviculture practices” are used in the NFGT. The U.S. Forest Service uses “even-aged management” to grow and log trees. Even-aged management is a system which prepares a site for planting, plants seedling pine trees, manages these trees as they grow, and then clear, seedtree, or shelterwood cuts the adult trees at the same time and age. Some steps in even-aged management include:
1) Site preparation; 2) Planting or natural regeneration of pine seedlings; 3) Precommercial or mechanical thinning; 4) Prescribed burning; 5) Commercial thinning (logging); 7) Preparation of a silviculture prescription (plan for cutting, planting, and growing trees); 8) Timber cruises (estimate of timber in an area); 9) Timber marking (trees marked for logging); 10) Bids on trees to be logged; 11) Logging (harvesting or removal) of trees; 12) Transport of trees to a mill; 13) Turn trees into wood products (paper, lumber, etc.) at sawmills and pulp mills.
Cutting
Cutting is the most controversial part of forest management, can cause the most significant environmental impacts, and sets the stage for what happens after logging. There are different words for cutting, including “logging, cutting, harvesting, felling, removal, etc.”
Cutting is done with large machines like “feller-bunchers”. A feller-buncher holds, cuts, and stacks trees. The trees are delimbed where they are cut or at a “log landing” (a cleared area for temporary tree storage). A “skidder” (large-tired, hinged, tractor) drags several trees at one time to the “log landing”. A “portable loader” (on a truck) picks trees up and puts them on a “log truck” for transport to a pulp or saw mill.
“Chainsaws” are used to delimb trees, cut trees that are in awkward positions, or for smaller jobs. “Mulchers” or “masticaters” reduce small to moderate sized trees to pieces. “Hand-tools” are used to remove brush, thickets, shrubs, or dense low-growing vegetation.
Even-aged management in the NFGT includes: 1) “Clearcutting” – removes all trees in an area; 2) “Seedtree Cutting” – cuts all trees, except for a small number (10 to 20) that are widely dispersed and retained for seed production (produces a new tree “age class”; 3) “Shelterwood Cutting” – most trees are cut, leaving those needed to produce sufficient shade for a new tree age class. For seedtree and shelterwood cutting, trees can be retained (reserved) or removed later in another cut.
Other cutting done in the NFGT includes: 1) “Thinning” – reduces density of trees in a stand (one tree every 20 to 25 feet) to improve growth (lessen competition for nutrients, water, and organic matter), enhance forest health, or recover potential mortality; 2) “Salvage Cutting” – removal of dead, damaged, or dying trees due to injurious agents (like insects or disease), other than competition, to recover economic value; 3) “Stand Improvement Cutting” – improves the composition, structure, condition, health, and growth of even or uneven-aged stands; and 4) “Sanitation Cutting” – removal of trees to improve stand health by stopping or reducing the actual or anticipated spread of insects or diseases.
“Rotation age” drives forest management. Rotation age is the age when trees are cut. It is used when talking about even-age management. “Uneven-aged management” (growing trees of all ages) manages and cuts trees of all ages.
For the NFGT, rotation ages for the general forest are: 80 years for Shortleaf Pine; 70 years for Loblolly Pine; and 100 years for Longleaf Pine. For forests managed for the federally endangered Red-cockaded Woodpecker (RCW), rotation ages are: 100 years for Loblolly Pine; 120 years for Shortleaf Pine; and 120 years for Longleaf Pine.
Site Preparation and Regeneration
“Site Preparation” is conducted to prepare the ground for planting tree seedlings. Site preparation is done by hand or machine. Its’ purpose is to increase the success of regeneration. Site preparation consists of methods that shear, chop, and or burn. The soil, litter, or vegetation is modified to change its’ microclimate so that the site is more conducive for seedling establishment and growth.
“Regeneration” is done by hand or machine planting of tree seedlings or seeds. Usually genetically improved pine tree seedlings are used. Reseeding of an area can occur naturally from nearby pine trees.
Prescribed Burning
Except for the first few years of forest growth, “prescribed burning” (fire used to shape a forest) is used throughout the tree “stand” (group of trees with similar characteristics) rotation. This is done to reduce the growth of hardwood trees, shrubs, vines, and other woody plants. Prescribed burning can create a forest that is more flammable if woody plants are replaced by grasses and herbaceous vegetation. Some wildlife like more open forests that prescribed burning creates. Prescribed burning helps reduce wildfire potential because much of the highly flammable vegetation is burned to ash or reduced in size or amount.
Prescribed burning is conducted with drip torches or a helicopter. The helicopter releases small ping-pong balls that contain chemicals. The chemicals mix in these ping-pong balls and burst into flame when they hit the ground. The FS burns thousands of acres in a relatively short time. The FS uses “drip torches, fire lanes (lines), fire trucks, backpack sprayers, and other mop-up and smoke management equipment” to contain and put out the prescribed fire.
Red-cockaded Woodpecker (RCW) Management
The FS manages for the federally endangered RCW. The FS grows pine trees on longer rotations so there are more large, mature, old, pine trees. These old pine trees have a greater incidence of red-heart disease (fungal disease) which makes it easier for the RCW to peck a cavity in these trees.
The FS conducts “mid-story removal” (cutting) where most small pine and hardwood trees are removed from around RCW “clusters” (nesting and roosting cavity trees) and “foraging areas” (feeding areas). Mulching and mastication is used to grind-up small pine and hardwood trees in RCW areas.
The FS installs “cavity inserts” (premade cavities) into pine trees which allow RCW’s to breed faster. “Restrictor plates” (protective metal plates) are placed over cavity holes to keep Pileated Woodpeckers from enlarging cavities. If a cavity is enlarged the RCW will not use it. The FS prescribe burns every 2 to 5 years to reduce woody plant growth and create the more open and sparse forest that the RCW prefers.
References
1) “The Dictionary of Forestry”, John A. Helms, editor, The Society of American Foresters, 1998.
2) “Revised Land and Resource Management Plan, Standards and Guidelines, National Forests and Grasslands in Texas”, United States Department of Agriculture, U.S. Forest Service, Southern Region, 1996.
3) Feedback from Larry Shelton, Texas Conservation Alliance, June 2018.
Brandt Mannchen
July 31, 2018