CN104792319B - A technology for selecting target trees for precise selective felling of forest stands - Google Patents

Abstract

The present invention is the selection technique that a kind of standing forest precisely cuts goal tree selectively.Centered on goal tree, nearest 6 of selection target tree set as object wood, with Weir noy Thiessen polygon as patterned basic, measure horizontal angular dimensions, calculate competition ratio, setting selective cutting rule, goal tree in scientific and reasonable selective cutting standing forest, can simply, quick, rationally quantitatively determine selective cutting goal tree, simple to operation, effectively improve goal tree in selection method and determine efficiency.

Description

A technology for selecting target trees for precise selective felling of forest stands

1. Technical field

The invention relates to a technology for selecting target trees for precise selective felling of forest stands, in particular to a technology for precise selective cutting of forest stands using 7 trees.

2. Technical background

Forest tree production is one of the main economic benefits and has been valued for many years. Under normal circumstances, clear cutting is adopted, but the impact on the surrounding environment after clear cutting is huge, causing a series of environmental problems, which is especially unsuitable today when forest protection is strongly advocated, so selective cutting is often used. The forest can be regenerated through selective cutting. Practice has proved that selective cutting is one of the most important measures that are conducive to the sustainable use of forestry resources. protection, but also contribute to the conservation of biological diversity.

Traditional forest selective logging operations adopt two methods: diameter class selective logging and management selective logging. Logging is decided in strict accordance with the principle of "removing the big ones and keeping the small ones, and removing the bad ones and keeping the good ones". The principle and method are simple, and it is impossible to choose logging quantitatively and scientifically. The purpose of this patent is to propose a selection technology for precise selective cutting of target trees in a forest stand, so as to carry out scientific and reasonable selective cutting operations.

In the traditional selective logging operation, the measurement is limited by the equipment, site conditions, and technical methods used. The workload is heavy and the cycle is long, so it is difficult to quickly obtain satisfactory results. As an important technical method and means of forest survey, the angle gauge has been favored by forestry workers all over the world since it was invented. There are reports. The invention improves the speed of accurate selection of selected felling trees in the selective felling operation through the selection technology of the optimal felling with the angle gauge as a tool, and provides scientific basis and method for the selective felling operation.

3. Contents of the invention

In order to improve the roughness of selective logging selection in traditional selective logging operations, the object of the present invention is to provide a selection technology for precise selective logging of target trees in forest stands.

The purpose of the present invention is achieved like this:

1) In the forest stand away from the forest edge, select the target tree, select the nearest 6 trees around the target tree as the target trees, and measure the horizontal angle between two adjacent target trees;

2) Calculate the horizontal angle parameter of each object tree;

3) Taking the target tree as the center, make a vertical line through each object tree and its connection side length to form a hexagonal ABCDE;

4) Determine the competition ratio of the target tree (number o) by the ratio of the area of the competition space hexagon ABCDEF to the area of the object wood hexagon 123456,

5) Set harvesting principles.

This invention has the following advantages:

1. The first application of 3D angle gauge in selective forest felling operations, expanding the application range of 3D angle gauge;

2. The present invention's precise selection technology for logging is simple and easy to operate, and creates a new method for choosing logging.

4. Description of drawings

Below in conjunction with accompanying drawing and example the present invention is further described.

Fig. 1 to Fig. 4 are the measurement schematic diagrams of the present invention.

5. Specific implementation methods:

A technology for selecting a target tree for precise selective felling of a forest stand and a traditional method, the difference lies in:

1) In the forest stand far away from the edge of the forest, select the target tree, which is recorded as tree o, and select the nearest 6 trees around the target tree as the target tree, which are respectively recorded as i (i=1, 2, ..., 6 ), measure the horizontal angle between two adjacent target trees

2) According to the mathematical model Calculate the horizontal angle parameter α _i of each object tree;

3) With the target tree (number _o ) as the center, each object tree is connected with it to form a side length oi, and its perpendicular line is made through the side length oi. The ratio of the diameters at breast height d _i is determined. Form the hexagon ABCDE, and the vertical intersection points with side length oi are respectively A _i (i=1, 2, ..., 6), A _i is given by the formula Determine its location: where, Be the distance from the target tree (No. O) to the A _i point; is the distance from the object tree (number i) to point A _i ; g _o is the sectional area of the target tree (number o); g _i is the sectional area of the object tree (number i); d _o is the diameter of the target tree (number o); d _i is the diameter of the object tree (number i);

4) The competition ratio of the target tree (number o) is determined by the ratio of the area of the competition space hexagon ABCDEF to the area of the object wood hexagon 123456, and the calculation formula is: Wherein K _o is the competition ratio of target tree (No. 0); A _ABCDEF is the area of competition space hexagon ABCDEF; A ₁₂₃₄₅₆ is the area of object wood hexagon 123456;

5) Harvest according to the following principles:

(1) When β>40°, consider selective felling of the target tree, and when β≤40°, do not selectively fell the target tree;

(2) Calculate the competition ratio K _j of each sample tree j in the forest stand, and then sort, and combine the trunk shape characteristics of the target tree, select the target tree with K _j > k to determine that the harvesting amount n of the large-diameter order tree is _large ;

(3) In the remaining stands, reselect the target tree, calculate the competition ratio of each target tree, and then sort, select the target tree with Kj> _k to determine the cutting amount n _of the middle-diameter tree;

(4) In the remaining stands, re-select the target trees, calculate the competition ratio of each target tree, and then sort them, and select the target trees with K _j >k to ensure that the harvesting amount of small-diameter trees is _small .

Claims (1)

1. A method for selecting a target tree for accurate selective cutting of forest stand is characterized by comprising the following steps: selecting 6 trees closest to the target tree as object trees, setting horizontal angle parameters, calculating competition ratio, setting selective cutting rules, and scientifically and reasonably selecting the target trees in the forest, wherein the specific steps are as follows:

1) in a forest section far away from the forest edge, selecting a target tree, recording the target tree as an o-tree, selecting 6 trees nearest to the periphery of the target tree as object trees, recording the object trees as i (i is 1, 2, 6), and measuring a horizontal included angle between two adjacent object trees

2) According to mathematical modelsCalculating the horizontal angle parameter α of each object tree_i；

3) Using target tree (O tree) as center, connecting all object trees with it to form side length oi, making the over side length oi as vertical line, and setting the foot position according to the chest diameter d of O tree at two ends of side length₀And number i breast diameter d_iThe ratio of the two is determined to form a hexagon ABCDE, and the vertical intersection points of the hexagon ABCDE and the side lengths oi are respectively A_i(i＝1，2，...，6)，A_iBy the formulaDetermining its position: wherein,for the target tree (o tree) to A_iThe distance of the points;for object trees (tree number i) to A_iThe distance of the points; g_oIs the target tree (o tree) cross section area; g_iIs the section area of the object tree (tree number i); d_oTarget tree (o tree) diameter; d_iIs the subject tree (tree i) diameter;

4) the competition ratio of the target tree (o tree) is determined by the ratio of the area of the competition space hexagon ABCDEF to the area of the object tree hexagon 123456, and the calculation formula is as follows:wherein K_oThe competition ratio of the target tree (o tree); a. the_ABCDEFArea of the competition space hexagon ABCDEF; a. the₁₂₃₄₅₆Is the area of object tree hexagon 123456;

5) felling was carried out according to the following principles:

(1) when beta is larger than 40 degrees, the target tree is considered to be selectively cut, and when beta is smaller than or equal to 40 degrees, the target tree is not selectively cut;

(2) calculating the competition ratio K of each sample wood j in the forest_jThen sorting is carried out, and K is selected according to the trunk shape characteristics of the target tree_jDetermining that the harvesting amount n of the large-diameter step trees is large by the target trees more than k;

(3) in the rest forest stands, the target trees are reselected, the competition ratio of each target tree is calculated, then the sequencing is carried out, and K is selected_jDetermining the harvest quantity n of the intermediate-diameter trees by the target trees with the diameter larger than k_In；

(4) In the rest forest stands, the target trees are reselected, the competition ratio of each target tree is calculated, then the sequencing is carried out, and K is selected_jDetermining the cutting amount n of small-diameter step trees by using target trees with the diameter larger than k_Small。