Release Treatments

How intermediate treatments fit into a silvicultural system

Release Treatments: Weeding, Cleaning, Liberation Release operations are those conducted early on in the development of a stand; by definition, while the stand is in the sapling size class or earlier A release treatment designed to free young trees from undesirable, usually overtopping, competing vegetation.

Release Treatments: Weeding, Cleaning, Liberation Objectives for a release operation include: –Reduce dense overstocking – –Improving species and quality composition –

Release Treatments: Weeding, Cleaning, Liberation Release is typically divided into three classes of treatment: –Weeding –Cleaning –Liberation

Release Treatments: Weeding Weeding Conducted during the seedling stage deals primarily with herbaceous weeds and shrubs –Done early in stand establishment to get seedlings out of herbaceous competition –Objectives Secondary objective to reduce mortality that may threaten in some cases, especially when establishing trees in old fields—afforestation.

Release Treatments: Weeding Methods: –Spot or broadcast herbicide –Mechanical Relative growth rates:

Release Treatments: Cleaning Cleaning Treatment made in a stand not past the sapling stage in order to free favored trees from less desirable individuals of the same age but different species (or inferior quality) which overtop them or are likely to do so –Major objective is usually to control species composition by reducing mortality of favored species, but also gains many of the same benefits as thinning –A tree needs release if an inverted cone of 90 degrees intersects branches of undesirable trees –Should follow a survey to determine the need for release

Release Treatments: Cleaning Typically seek a minimum of: – Timing: the earlier, the better –Usually easier, gives more growth benefits Methods for cleaning:

Release Treatments: Liberation Liberation A treatment made in a stand not past the sapling stage in order to free the favored trees from competition of older, overtopping vegetation –Primarily to reduce losses from shading (growth loss or mortality) –Commonly removes “wolf” trees

Release Treatments: Liberation Methods for liberation –Cutting May treat stump with herbicide to prevent sprouting May provide some financial return –Girdling Often ineffective without herbicides – Herbicides Usually applied by cut surface treatment

Release Treatments: Liberation Liberation is often used to correct past mismanagement in a stand – Need to manage the damage caused by removal of these culls –

Other Intermediate Operations Improvement Cutting A cutting made in a stand past the sapling stage in order to improve composition, growth, and quality by removing less desirable trees of any species from the main canopy –Where trees are not merchantable, this is often called TSI (timber stand improvement) and is accomplished by injecting herbicides –Often needed in formerly mismanaged stands –Commonly applied in conjunction with thinning –May provide a commercial return, particularly where there is a good pulpwood market –Note: most good den trees and mast trees would be removed if improvement is applied without restriction

Other Intermediate Operations Salvage Cutting The removal of dead trees or trees being damaged or killed by injurious agents other than competition (e.g., insects, disease, fire, wind), in order to obtain monetary value that would otherwise be lost –Objective is to reduce the loss of wood and money –Often combined with other types of harvest such as thinning and sanitation –Timing is critical—must be completed before the wood becomes unusable

Other Intermediate Operations Sanitation Cutting The removal of vegetation to prevent actual or anticipated spread of insects or disease; often combined with other types of harvest.

Other Intermediate Operations Prescribed Burning as an intermediate stand treatment –Applicable primarily in stands of thick-barked conifers –Requires experience and expertise –Requires investment

Other Intermediate Operations Objectives of prescribed fire –Reduce fuel – –Reduce insects and disease – –Can improve stand access for harvest or inventory – –For some species, improves wildlife habitat

Other Intermediate Operations Potential adverse effects of prescribed fire – –May increase erosion on erodible sites due to soil exposure – –May adversely affect some wildlife—direct mortality or habitat degradation

Other Intermediate Operations Forest Fertilization –An investment, so desirable only where nutrient deficiency is limiting growth significantly – –N and P are the most commonly applied nutrients – –N application usually not a good idea at time of planting –

Other Intermediate Operations Tree Pruning Loss or removal of tree branches, by natural or artificial means –Natural pruning (i.e., self-pruning) is usually initiated by shading Shade intolerants tend to self-prune faster than shade tolerant species – –Artificial pruning is an investment, so only use it where it pays

Pruning Where to Prune?

Pruning How to Prune?

What not to do!

When to Prune? Dead branches: can be removed any time of the year Conifers: may be pruned any time of year, but pruning during the dormant season may minimize sap and resin flow from cut branches

When to Prune? Prune hardwood trees and shrubs in the dormant season to: – –Maximize wound closure in the growing season after pruning – –Discourage excessive sap flow from wounds

Pruning Tools

A Pruning Application: Black Walnut

Black walnut trees do not prune themselves readily –Even small branches tend to leave stubs when they die, and large branches may hang on the tree for many years after they die Lateral branches can be pruned to produce high-value, knot- free wood

A Pruning Application: Black Walnut Pruning can begin once the trees are 10 to 12 feet tall, but should be confined to the lower half of the tree stem How much to prune? Prune live branches during the latter part of the dormant season, but before the trees start to grow in the spring

A Pruning Application: Black Walnut Prune branches when they are small, generally less than 2 inches in diameter –Small wounds are more likely to heal over without becoming infected – –If the tree is growing well, even fairly large wounds (4 to 5 in) can heal successful

A Pruning Application: Black Walnut Continue to prune periodically until at least the first 9 feet of the tree is clear – For nut production, stop pruning at 9 feet For wood production, continue pruning until at least 17 feet –Two veneer logs or one 16 ft sawlog can be produced

Tree Removal Methods Manual, Mechanized, and Chemical

Manual Felling Tools: chainsaw, brushsaw, bucksaw, loppers Not always practical if large numbers of trees must be removed Can damage residual trees Brushsaw for small stems, brush

Manual Felling

Tree Girdling Double girdle 1 in. deep spaced ~ 6 in. apart Later winter, early spring during sap rise Diffuse porous species are poor candidates unless herbicide is used

Mechanized Felling Mechanized removal –Tracked feller buncher Rotating cab with hinged arm Steep, uneven terrain –Hydrostatic feller buncher Easily maneuverable Plantations –3-wheeled feller buncher Lightweight Flat terrain

Mechanized Removal Brush Hog –Small trees and brush

Herbicides Why herbicide? –Effective kill of whole plant with no resprout potential Uses –Precommerical thinning –Release treatments –Improvement cutting –Site preparation –Control of invasive species –Right-of-way maintenance

Herbicide Application Methods Cut surface treatments –Frill girdle (Hack and squirt) –Stem injection –Cut stump Bark, foliage, and soil treatments –Foliar spray –Basal bark application –Basal soil spray

Herbicide Types Amine formulations (water-based) –Water used as “carrier” –Foliar spray, cut surface Herbicide label will specify mixture for given application and target species –Common chemicals: Glyphosate: Roundup, Accord Triclopyr: Garlon 3A Picloram: Tordon K, Pathway Imazapyr: Aresenal 2,4-D

Herbicide Types Ester formulations (oil-based) –Basal oil, diesel, or kerosene used as “carrier” –Cut surface, basal bark Herbicide label will specify mixture for given application and target species –Common chemicals: Triclopyr: Garlon 4

Cut surface treatments

Bark, foliage, and soil treatments

Silvicultural Objectives and Chemical Control Methods