Forest Mensuration II Lecture 13 Growth and Yield

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Forest Mensuration II Lecture 13 Growth and Yield Models Avery and Burkhart, Chapter 16

Forest Mensuration II Lecture 13 Growth and Yield Models Avery and Burkhart, Chapter 16

A few thoughts § Forest management decisions-making relies on accurate information about both current

A few thoughts § Forest management decisions-making relies on accurate information about both current and future forest resource conditions § Stand-table projections for future growth based on the past may be most accurate for a limited period of time, but – Not reliable for long periods – Not necessarily useful for evaluate treatment alternatives because … § Therefore, many models forecasting stand dynamics are developed, ranging from tables, equations, to computer simulation models

Definition of yield § The total amount available at a given point of time

Definition of yield § The total amount available at a given point of time – gross volume – merchantable volume – biomass

Definition of yield (cont. ) – Merchantability Growth A Total biological growth Top D

Definition of yield (cont. ) – Merchantability Growth A Total biological growth Top D 10 cm: Pj, Sb, Sw, Bf, Ce 16 cm: Pw, Pr, He, Po, Bw 20 cm: other hardwoods B Potential usable growth under present technology and policy C Growth actually removed and utilized Merchantable 30 cm OMNR (1995) Scaling Manual

Definition of yield (cont. ) Plonski 1974 Gross Merchantability

Definition of yield (cont. ) Plonski 1974 Gross Merchantability

Definition of growth § The increase (increment) over a given period of time –

Definition of growth § The increase (increment) over a given period of time – Mean annual increment (MAI) – Periodic annual increment (PAI)

Definition of growth (cont. ) MAI Lecture 13 FORE 3218

Definition of growth (cont. ) MAI Lecture 13 FORE 3218

Definition of growth (cont. ) PAI Lecture 13 FORE 3218

Definition of growth (cont. ) PAI Lecture 13 FORE 3218

Relationships between yield and growth Lecture 13 FORE 3218

Relationships between yield and growth Lecture 13 FORE 3218

Types of Models Nature Whole stand models Application Development Even-aged Simple Empirical Diameter class

Types of Models Nature Whole stand models Application Development Even-aged Simple Empirical Diameter class models Individual tree models Lecture 13 FORE 3218 Process Uneven-aged Sophisticated

Whole stand models Model type § Density-free models – Normal yield tables – Empirical

Whole stand models Model type § Density-free models – Normal yield tables – Empirical yield tables for average stands § Variable density models – Predict yield – Predict growth (g 12) and yield (V 1) Lecture 13 FORE 3218 Equations

Diameter class models Model type § Empirical stand table projections Lecture 13 FORE 3218

Diameter class models Model type § Empirical stand table projections Lecture 13 FORE 3218 Equations

Individual tree models Model type §Distance-dependent §Distance-independent Lecture 13 FORE 3218 Equations

Individual tree models Model type §Distance-dependent §Distance-independent Lecture 13 FORE 3218 Equations

Which type of models is best suited for the following situations? Why? § Depends

Which type of models is best suited for the following situations? Why? § Depends on purposes of modeling…, but if … – Even-aged, single species stands? – Uneven-aged single species stands? – Even- and uneven-aged, mixed-species stands? Lecture 13 FORE 3218

FVS Ontario Visualization The power of arts Lecture 13 FORE 3218 version 1. 0

FVS Ontario Visualization The power of arts Lecture 13 FORE 3218 version 1. 0