average standard wood method

Grading standard wood method: standard wood of equal diameters, standard wood of equal cross-section diameters, standard wood of equal diameters

One-yuan volume table method: the relationship between volume and diameter at breast height, adapted to local areas under the same site conditions, is called local volume table

Binary volume table method: relationship between volume, diameter at breast height, and tree height

High-level tree volume: between one-yuan and two-yuan, grading tree height, essentially a one-yuan wood volume table

Three-dimensional volume table: volume and diameter at breast height, tree height, shape ratio (need to know an upper diameter)

Shape height table method: M=GHF. It is necessary to establish a relationship between the shape height value and the average height of the forest stand to look up the table to determine the shape height value.

Standard table method: M=G/G standard*M standard,

Average experimental shape method: M=G1.3*(H 3) F1.3

Use of angle compass: select points, measure around, calculate G=Fg*Z Fg=2500*(l/L)^2

Basic principles: multiple concentric circles, expanded circle principle

Measure the basal area per unit area of ​​the forest stand with an angle gauge: select the basal area coefficient and the number of angle gauge points, measure around, determine the radius of the sample circle R = 50*d/Fg, and use the distance between the trees and the angle gauge points to determine the count.

Angle gauge measures the number of plants and volume per unit area of ​​a forest stand

Timber species yield rate = timber species volume/total bark volume, timber species yield rate changes with diameter at breast height

The bowl mouth of economical wood is facing down, the bowl mouth of waste wood and fuelwood is facing upward, and the waste wood is on top of economical wood.

felled wood for building lumber

Sample wood making method

Shaving equation: a method of theoretical wood building, a good trunk shape indicator, the relationship between the diameter of each part of the trunk and the height of the part from the tree base, the height of the whole tree, and the diameter at breast height, it can predict the diameter of any part of the trunk, Length from the tree base, volume of any segment, volume of the whole trunk

Seed volume and yield rate of individual trees and stands

Compilation of forest stand species yield table: selection of optimal cutting degree equation, estimation of barked and peeled diameters, tree height curve equation, selection of root barked and peeled volume equations

Volume ratio equation: also called volume ratio, volume of wood species/trunk with bark (barked), used to compile wood species yield table

Consistent cutting/volume ratio equation system: volume can be calculated through calculus

Preparation of a one-yuan wood species yield table: selection of cutting degree equation, harvesting, percentage of peeled volume of wood species, tree height curve, timber species yield rate

Binary wood species yield table: The same diameter may have different tree heights, so the wood yields of the compiled species are compiled according to the changes in tree height and breast diameter.

Use the wood species table to calculate the amount of wood produced by forest species

Basic concept: the amount of change in various survey factors within a certain interval

Types of tree growth: total growth, regular growth, total (regular) average growth, and annual growth

Tree growth equation: a mathematical model in which the total growth of each investigated factor changes regularly with age

Empirical and theoretical equations for tree growth: The theoretical equation takes into account biological characteristics and is more adaptable

Single molecular formula: when t=0, y=0, there is an asymptote, Ymax=A, monotonically increasing, there is no inflection point, suitable for the growth process of broadleaf trees and coniferous trees that grow quickly at the beginning and have no inflection point.

Logistic equation: S-shaped curve, there are two asymptotes Ymax=A, Ymin=Y0, and an inflection point at A/2, which is suitable for the growth process of some slow-growing tree species.

Annual growth function

average growth function

The relationship between the two: in the young stage, both the annual growth amount and the average growth amount increase with age, the annual growth rate increase value is greater than the average growth amount, the annual growth amount reaches the peak earlier than the average growth amount, when the average growth When the amount reaches the highest value, the growth amount of the two is equal, and the growth amount in subsequent years has been lower than the average growth amount.

Tree growth rate: annual growth/total growth of a certain survey factor

The relationship between the growth rates of each investigated factor: section growth rate = DBH growth rate * 2; tree height growth rate = DBH growth rate * k, where k is an index indicating tree height growth ability; volume growth rate = DBH growth rate * ( k 2)

Pressler's growth rate formula: the regular average growth over a certain period of time replaces the annual growth, and the average at the beginning and end of the period replaces the original total.

Schneider volume growth rate formula: Pv=K/n*d, d is the current skinned diameter at breast height, n is the number of growth rings 1cm outside the breast height, K is the growth coefficient, which can be found out by looking up the table

Determination of growth of felled wood

Determination of standing tree growth: Use Schneider's formula to calculate. First look up the table to get the K value, get the peeled diameter at breast height, and then trace the growth of the tree with growth rings 1cm outside the breast height to calculate the growth rate. Then calculate the growth rate.

Stand growth usually refers to the algebraic sum of stock volume, volume growth and dieback.

Types of stand growth: hairy growth, pure growth, net increase, loss, harvesting, advanced

Determination of forest stand growth: volume difference, the volume difference of one diameter step larger and one smaller than the diameter step and the ratio of 2 times the diameter step; step-up method; one-dimensional volume index method, using the sum of the volume growth rate and the diameter at breast height growth rate The relationship between

Stand growth: the amount of change over a period of time; harvest: the total accumulation obtained at a certain time

Factors affecting stand growth and harvest: age distribution, site quality (the same site follows certain rules for final harvest), stand density, management measures

Classification of forest stand growth and harvest prediction models: full forest stand model, single tree growth model (whether to consider the competition index of relative spatial position), diameter order distribution model

Collection and arrangement of modeling data

Fixed-density full-stand model

Variable-density full-stand model

Diameter distribution model

Indirect prediction of realistic forest stand harvest

Indirect prediction of future stand harvest

stand loss equation

Single wood competition index

Classification of single tree growth models

Modeling method of single tree growth model

Single tree loss (survival) model

Single tree growth model example

The accumulation of dry matter in forest plant communities during their life processes

Forest biomass composition and distribution

Tree biomass determination

Determination of tree carbon content

direct harvest method

model estimation method

Biomass estimation parameter method

indirect estimation method

direct estimation method

Site and site quality: Site refers to specific environmental conditions, which remain unchanged for a certain period of time: Site quality is the growth potential of forests or vegetation on the site.

Site quality assessment methods: direct and indirect assessment

Direct evaluation method of site quality: forest stand volume; average height of dominant trees in the forest stand

Indirect evaluation methods of site quality: indirect assessment of growth relationship between different tree species; multivariate status index (using multivariate status index and site factors, including quantitative and qualitative, to establish multiple regression equations; indicator method of special vegetation

Basic concept: an indicator of crowding among trees

Stand density index: tree density; basal area per hectare; tree and diameter per unit area, tree height, and volume structure

Frequencies (D and H), frequencies, histograms and probability distribution curves (normal distribution)

Number of main characteristics of random variables: mean or expectation, variance, skewness, kurtosis

Univariate distribution structure: when only considering diameter at breast height or tree height as a single factor, univariate normal distribution, univariate Weibull distribution

Binary distribution structure: joint structure considering tree height and diameter, bivariate normal distribution, bivariate Weibull distribution

Stand diameter structure and tree height structure

Diameter and tree height structure fitting

The relationship between forest tree diameter and tree height: H=a*D^b

Two-dimensional structure fitting of forest stand diameter and tree height

Non-probability distribution function method of unary distribution: cumulative distribution curve, relative diameter (in a forest stand of the same density, the relative diameter of a tree reflects its relative competitiveness and can be regarded as a competition indicator) cumulative distribution, showing S type distribution

Censored distribution: The starting diameter step is generally 5cm. It can be understood that there is missing data in the front or back of the normal distribution.

Introduction to other non-spatial structures: age structure, tree species distribution structure in mixed forest, relative diameter competition structure, sectional area, volume, shape and number structure, etc.

Relationships between different factor structures

Spatial distribution pattern of forest trees: regular distribution, random distribution, clustered distribution, calculated using angular scale, one target book, 4 adjacent trees, acute angle

Tree mixing degree index: Mixing degree (zero, weak, moderate, strong, extremely strong) is calculated for four adjacent tree species.

Spatial competition index: size ratio, usually diameter, tree height, crown width and other factors can also be used

Factors that objectively reflect forest stand characteristics

Forest stand survey factors and their calculation methods

Standard land definitions and types

Standard investigative work

Survey of forest stand environmental factors: biodiversity, soil, topography, forest naturalness, forest health, ecological function evaluation

Cross-sectional shape of tree trunk: g=D^2*pi/4

Longitudinal section shape of tree trunk: Kunz trunk curve y^2=P*x^r

General quadrature formula: piecewise integral of Kuntzian curve

Approximate quadrature formula for felled wood (parabola)

Calculation formula for distinguishing felled trees (whole trunk)

The impact of measurement errors of diameter and length on volume calculation accuracy: &V^2=4*&D^2 &L^2

Characteristics of single standing tree measurement: V=gfh

Shape number: trunk volume/comparison cylinder volume

Shape height:f*h

Height method: V=2/3*g1.3* (Hr 1.3/2) Hr=Height, the diameter at Hr=1/2 breast diameter

Tree diameter and sectional area

Tree height: Ultrasonic height meter, height under the crown, factors that consider individual vitality and spatial competitiveness

Crown structure: crown width (average of east-west, north-south), crown length (tree height-height under branches), crown length ratio (crown length/tree height), crown completeness (crown width/crown length), projection ratio ( Crown width/diameter at breast height)

tree age

tree volume