Presentation on theme: "Timber Management Elements of Forestry Kenneth Williams"— Presentation transcript:
1 Timber Management Elements of Forestry Kenneth Williams Fisheries Extension SpecialistLangston University Aquaculture Extension Program
2 Forest ManagementUsed to mean biological manipulation of the forest for timber production.Broader meaning now.
3 Forest Management Internal variables to forest management Temperature RainfallSoil typeTree speciesThese variables control production possibilities
4 Forest Management External influences Federal and state legislation TaxationMarket forces
5 Forest ManagementBalancing the relative productivity of a forest site with the relative net value of the product determines which forest management alternative is selected.Analytical techniques are used to choose management alternatives.
6 Forest ManagementTimber management decisions must consider impacts on other products desired from theforest.
7 Regulated ForestA forest that produces a continuous flow of products of about the same size, quality and quantity over time is called a regulated forest.What are the advantages of this type of forest?
8 Sustained YieldFlow of timber products over multiple – year periods must be more or less continuous.Difficult to maintain sustained yield while transitioning to regulated forest.Why? – trees may all be same age. Can not harvest all of them. Must cut fewer trees during transition period.
9 Sustained YieldThe larger the land area the easier a sustained yield can be managed.Large areas offer greater variability in age classes and more flexibility in timing harvests.Small land owners must use uneven aged management to achieve sustained yield.
10 Sustained YieldTree crops that make up sustained yield may come from the forests of 1 individual or it may be made up of the combined forests of many individuals in a multi- county or state wide area.
11 Sustained YieldPractical industrial mill operations require a continuous daily yield over a wide geographic area for economic operation.
12 Even-aged ManagementExample: 25 acre forest where trees take 25 yrs. to mature. Then the even-aged regulated forest would have 25 stands of equal productivity, each 1 acre in size and each 1 yr older than the next.The 25 yr old stand is harvested each yr and immediately regenerated.Yield is the same each year.
13 Even-aged ManagementConversion to even – age management from the example where all trees in the 25 acre tract were the same age would take 25 years.
14 Even-aged Management Problems – Must decide the desired age structure of the forestHow to manipulate existing forest to obtain it.Existing tree species may not be those that are desired.
15 Uneven-aged StandsTrees differ greatly in age, at least years difference.
16 Uneven-aged Stands Harvest Example Suppose a stand has sufficient age classes that some trees were mature every 4 yrs.Then the stand could be harvested every 4 yrs.Only 4 different stands would be needed to obtain regulation.1 stand cut ea. yr. ea. stand cut every 4 yrs.Thus producing regulated forest and sustained yield.
17 Rotation AgeLength of time from final harvest cut to final harvest cut in even-aged management.There is no final harvest cut in uneven-aged management. The stand always exists and is partially harvested.Length of time between cuts in uneven-aged management is called cutting cycle.
18 The Normal Forest Developed in Germany and Austria mid-1800’s. Based on cutting small, uniform blocks of even-aged timber.3 requirements:Normal increment growthNormal age class distributionNormal growing stock levels
19 The Normal ForestIncrement growth considered normal if it was the maximum attainable for a particular species.(Increment growth – increase in all dimensions of tree growth or value.)
20 The Normal ForestNormal age class distribution consisted of a series of equally productive stands that varied in age with oldest age class equal to rotation age.
21 The Normal ForestNormal growing stock is automatically obtained when increment and age class distribution are normal.
22 The Normal Forest The normal forest does not exist! But the conceptual model has influenced and provides the basis for modern forest management.Ex. Equal annual yields of timber, uniform age rotation and maximum increment growth.
23 Allowable CutAmount of timber available for cutting during a specified time period, usually 1 year.
24 Allowable Cut Allowable cut is often not obtained. Fluctuations in timber demandWeather that prevents accessAvailability of laborGoal is to achieve allowable cut over a multi-year period.Undercutting one year is balanced by over-cutting in other years.
25 Even-aged Forest Mgmt. Most Common Commercially desirable species grow best in even-aged stands because they are shade intolerant.Less harvest expense when clearcuttingLess expense to artificially regenerate a clearcut standWildlife habitats are encouraged by creating forest openings.
26 Reasons For Uneven-Aged Management Small land owners may want as much of a sustained yield as possible to generate cash more frequently.Other forest products may require continuous forest cover. Ex – recreation or aesthetic value.Tree species diversity can enhance wildlife habitat. Both food and shelter.
27 Choice of even-aged or uneven-aged management ? Depends on land owner objectives.
28 Even-Aged ManagementFirst – determine rotation age. Trees grow quickly when young then decrease growth and finally growth rate levels off.At some point volume lost to mortality may exceed growth.Rotation age depends on landowner objectives.Rotation age is chosen that provides maximum value
29 Rotation Age Most common objectives: Maximize wood cut or wood flow Maximize net cash flow
30 Rotation AgeMax. wood flow is obtained by maximizing annual yield. Called Mean Annual Increment (MAI)Total vol. available for harvest in a year divided by the age of the stand.
31 Rotation AgeMaximum net cash flow is determined by economic calculations that take into account costs, land prices and interest rates. The results are called land expectation values (LEV)Rotation age is determined by optimizing the LEV
32 A forest may never be fully regulated because: Changes in ownershipAdditions or subtractions of acreageChanges in ownership objectivesChanges in technology and utilization
33 Harvest SchedulingArea control – cutting is controlled by specifying the number of acres to cut.Basically, total acres in forest divided by rotation age determines how many acres to cut.Oldest stand usually cut first
34 Harvest SchedulingVolume control – cutting controlled by specifying the volume of timber to cut.Based on net annual growth of the stand.Usually used with uneven-aged management.
35 Management Plans Management objectives and policy Forest description Economic expectationsLegal restrictions and public policiesSilviculture practices, cuttingProtection from fire, insects and disease
36 Uneven-Aged Management Determine desirable level of growing stock for stand.Allow it to grow 5-10 yearsCut volume of timber equal to growthForest is regulated by manipulating stands so that an equal volume of timber is cut each year.
37 Uneven-Aged Management Reserve growing stock – that part of the growing stock left uncut to produce growth for future cuts.
38 Uneven-Aged Management Like living on interest without touching principal.
39 Uneven-Aged Management Difficult and complex decisions required for optimal use of the management strategy.Optimal, sustainable diameter distribution for a stand. (number of trees in each dia. class.Optimal species mix for the standOptimal conversion strategy and conversion period for ea. stand.Optimal treatment scheduling
40 Harvest SchedulingComputer models now used for both management systems. Especially for large, complex forests
41 External Influences On Timber Management Market for forest productsFederal and state legislationtaxation
42 External Influences On Timber Management Markets – decisions based on future predictions of timber market prices.Some silviculture practices based on current price of materials and laborConsumer demand for product drives pricing of timber and non-timber products of the forest.
43 External Influences On Timber Management 4 types of legislation affect forest management decisionsEnvironmental legislationHealth and safety legislation (OSHA)Federal forest management legislationState forestry legislation