"Hubei Larch Pine Fast-growing and High-yielding Forest Cultivation Techniques" 21

Section II Survey Design

Survey design is an important task that must be carried out before harvesting operations. It is the basis for forest harvesting. Good investigation and design work is conducive to strengthening production and operation management, avoiding the blindness of work, and reducing and eradicating waste. The survey design must be conducted by a qualified professional survey and design unit. The design procedures for harvesting mainly include the following:

I. Field investigation

(I) Checking the stand

In order to improve the survey design level, the forest stand must be inspected before the investigation, or the staff of the production line should be aware of the situation of the investigation of the small class forest, including the orientation of the small class, the distribution of forest trees, past operations, tree height, diameter at breast height, density, and dryness of forest trees. Situation and so on. This is conducive to providing investigators with reference data for surveys, and it is also convenient for internal design to test whether various design indicators are reasonable. At the same time, it is required that each wooden surveying scale and area measuring group should keep in constant contact during the field investigation so as to avoid disjoint work and seriously affect the survey design accuracy.

(B) Standard layout

According to the stand condition, square or round plots can be set up in the forest stand with small area, uniform distribution, and orderly forests. The forest plots with larger area, more landform, and more complex forests are often used as strip samples. A starting point is selected on the edge of the forest stand, (this point is used for handheld GPS positioning) as the starting point for the mechanical layout. This point must ensure that the transposed strip in a certain direction can penetrate the entire small class.

The sample bandwidth is 6m, the length is 50m, the area of ​​each belt is 0.45mu, the sampling rate of the sampling belt is 5% or more, the general forest area is less than 100mu, and a "V" or "inverted V" shaped belt is used to fold lines, the forest area 100-200 acres can be set between the "M" shape with a polyline, the forest area of ​​more than 300 acres and then increase the fold line to ensure that the sample runs through the entire small class, Accumulation Accuracy of more than 90%.

Transect settlement should be considered on the basis of the upper, middle, and lower stands of the forest. Because of the human factors in the forest below the forest slope, the stand density is often too small, and the prevailing phenomenon in the upper stand of forest stands is that the upper part does not measure well in past activities. , Forest density, small diameter, sharpness, non-special materials, pay a large proportion of products. In this way, it can balance with the lower part of the stand, and can avoid large errors in the amount of material and structure of the wood and improve the design accuracy. If the accuracy of the small class volume exceeds 90%, it is qualified. Otherwise, according to the stand condition, increase the sample zone (simultaneously measure the material) to achieve the final precision.

(c) Sample survey

1. For the blank holder tree, it is required to use the 50m measuring rope to pull the sample tape, with 3m wide on each side, and measure accurately with a 3m ruler. A 1.3m scale is clearly marked on the rod to determine the position of the DBH and to accurately measure the DBH.

The starting diameter is 6cm, and the measuring diameter is 5M. For forest trees with DBH below 5M, only the number of trees was recorded separately, but the stand factor was not included, and accumulation and production materials were not designed.

Every wooden ruler should be full-footed. For forests that have not been used for many years and the bark has been broken down, inspections should be carried out or appropriate deducted to ensure the accuracy of the survey.

2. Visual inspection The material design is mainly based on visual inspection. According to the factors such as trunk height, dry shape quality (sharpness, degree of bending, side branch thickness and distribution) and other factors, according to the "market demand-oriented, production of marketable products, priority long products, preferred best selling materials". The principle of sculpting materials is usually 2m or longer. For clear-cutting operations, for dense forest stands, small rods can be designed normally. Otherwise, the design of products for large diesel, small poles, and mines can be controlled, especially in remote, inaccessible lands. For designing tending operations, we must strictly control the design of Dichai's products.

For some woods with a dry bending of more than 3%, long products may be given priority and the proportion of short materials (possibly equal internal materials) may be reduced as much as possible. When designing, separate statistics will be made on the outside of logs, columns, columns, etc.

When the material is measured visually, after measuring the DBH, close to the trunk stands under the tree to see the dryness (that is, the degree of curvature) of the forest, decide whether to design the commodity material or the non-commercial material, and then leave the trunk at 3 to 4 meters to see what kind of material is being produced. , the length of the wood species, the diameter of the seed head of the species, and the final length of the material (the length of the material is generally 50 to 75% of the height of the forest). When building materials, we must master the direct opening of the trunk and complete the commercial materials. Otherwise, we must accurately estimate the diameter of the small diameter of the outer material or the by-products, and ensure the product design accuracy.

3, cutting down the wood material According to the operating forest area and operating methods, each small class must cut down 3 to 7 trees as the investigation of stand growth rate and growth and auxiliary material design sample. Clearcut operations: 3 plants below 100 mu; 5 plants from 100 to 200 mu; 7 plants above 200 mu. Nursing homework: 3 plants below 200 mu; 5 plants above 200 mu. After each wooden scale inspection, according to the average diameter of the stand, the average tree height of the stands, and the average dryness of the trees, a standard wood that can represent the average level of the entire stand was selected as the growth rate, growth amount, and material for the growth. The rest of the felled trees were selected according to the degree of discrepancies of the diameter of the diameter of the breast, and the diameter of the breast was selected in addition to the average diameter at breast height. The mean diameter at breast diameter was symmetrical and the number of plants on both sides was equal. Generally, if the stand diameter of the stand is small, after the standard wood is selected, the rest can be selected on the adjacent diameter, for example, the average DBH is 14.2cm. If 3 plants are selected, the other 2 plants can be selected on the 12th and 16th steps, respectively. For 5 strains, the other 4 strains can be selected on the 10th, 12th, 16th, and 18th order. If there are 7 strains, the other 6 strains can be selected on the 8th, 10th, 12th, 16th, 18th, and 20th order steps. Biased to low-order steps.

Falling wood selection must be in the upper part of the stand, the middle part (average standard wood) and the lower part, and must be more than 8m away from the forest edge.

(four) area measurement, job design drawing

1. Area Measurement Measure the actual boundary and area of ​​the forest for the design work. The closing difference is not more than 1%, otherwise the measurement will be repeated. When measuring the area, there must be the director of the forestry area or the forest patroller. Information such as forest maps, topographic maps, forest right certificates or forest rights agreements, and classification management divisions should be carried out in forests where the ownership of trees is state-owned or cooperative. Be familiar with the boundaries of small classes, especially with the collective forest.

It is forbidden to measure two or more small classes together and must be designed separately. The starting point of the measurement is marked with a handheld GPS locator.

2. The job design drawings are based on the forest phase maps, topographic maps and field survey materials to draw job design diagrams. At the time of measurement, clear descriptions of natural objects, natural boundaries, and boundaries of the forest to be harvested that are close to the survey boundary are clearly recorded, sketches are made on-the-spot, and if necessary, handheld GPS positioning is used. In the design of the interior industry, the computer is used to map and calculate the area, and the above conditions are all marked on the area map. When the scheme is approved, the design scheme, forest cutting license, design drawings and the boundary marked on the site are used as the construction of the forest farm. in accordance with.

The woodwork surrounding the design work must be painted and marked. If it is an isolated small class, it is on the outside of the forest, otherwise it will be marked on the inside of the wood outside the boundary of the design forest. After the construction is completed, the forest farm is marked on the woodcut root of the operating forest.

Second, the industry design

According to the Hebei Forest Management Technical Specifications (Trial) and the above requirements, and based on the results of field investigations, the internal design was conducted.

(1) Schedule 1: The operating area must be recorded with actual measured forest area, and all vacant land within forests and forest margins must be deducted. At the same time, the area of ​​small class accounts should be registered in parallel. The type of stand is mainly based on on-site surveys. The slope position, slope direction, soil thickness, and undergrowth of herbaceous plants must be investigated clearly, supplemented by a small class account, must be accurate to facilitate the redesign of the design.

The age of the forest was checked with a ledger or a standard wood age.

The species composition is dominated by dominant trees. When the stock volume of a tree species is from 2% to 5%, it is represented by a "+" sign, and if it is less than 2%, it is represented by a "-" sign.

The number of acres before cutting was determined by dividing the total number of plots by the total area of ​​plots. The average DBH was obtained by using the statistical summary data of each wooden ruler, and the weighted average diameter of the chest height was obtained by using the number of strains as the weight, and it was accurate to 0.1 cm. The volume of mu shall be calculated by dividing the total volume before cutting in the plot by the total area of ​​the plot.

Growth volume, fill in the actual results of analytical wood.

Closed degree survey, using the Rope statistics method, every 5m one sample point, using the test line to lay N sample points in the standard ground, determine whether the point is within the canopy projected area, and the statistics fall on the projected area in each sample point. The sample number U, according to the following formula PC = U / N (see Table 1 of this chapter).

(2) Exhibit 2: The log book, log book, etc. designed by the foreign trader are registered in the bar product column in the other product column in Table 2 respectively, and are in parallel with the waste wood product. The calculation range of the export rate of the commodity material (see Table 2 of this Chapter).

(3) Schedule 3: Based on the stipulated requirements for various product revenue quotas and various cost expenditure quotas, it shall be determined according to the degree of difficulty of the operation site (see Table 3 of this Chapter).

(4) Schedule 4: The update method is manual update. The updated area is the area of ​​the design work forest (not less than the original sub-class cutting area). In Schedule 1, the forest type (or site type) survey must be accurate (including aspect, slope position, elevation, soil thickness, and understory). The updated tree species and their allocation depend on the type of site conditions actually investigated. Generally, half shady slopes, shady slopes, flat slopes, and deep fertile soil plots are still dominated by larch and spruce, mixed with broad-leaved trees; In order to give full play to the advantages of mixed forests, the mixed forests of Pinus sylvestris var. Mongolica, Pinus tabulaeformis, and broad-leaved trees should be used (see Table 4 of this Chapter).

Third, the design accuracy index

Closed within 1% of the small class area, the area error within ± 5%;

Accumulation accuracy is over 90%;

Within 5% of the error of commercial materials, within ± 20% of the by-products;

The number of acres is within 5% error;

Diameter of breast diameter is within ±0.2cm.

Through field investigations, internal business calculations, and preparation of job design programs. Prior to reporting, according to the requirements of the forestry logging permitting department, the forestry farms will be used as a unit to publicize the work week by week. The formulation plan with no objections will be submitted to the higher forestry authorities for approval before the work can be carried out.

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