Logging terms and definitions, types and methods of harvesting

1 Terms and Definitions

The following terms and definitions apply to this document.

1.1　林木采伐 tree cutting

A management activity carried out by forests and trees. There are five types of main felling, tending felling, regeneration felling, low-yield (efficient) forest transformation and other felling.

1.2　伐区 cutting area

Geographically connected forest lots that use the same type of felling in the same year are the basic units for the design, construction, management and supervision of forest harvesting operations.

1.3　商业性采伐 commercial cutting

Harvesting for the main purpose of timber production mainly includes the main felling of timber forests and the regeneration of public welfare forests. Logging of public welfare forests that is truly necessary to carry out renewal due to physiological decline, forest death, dying and other phenomena leading to reduced stability, serious degradation or even loss of ecological protection functions is not commercial logging.

1.4　采伐类型harvest type

According to the purpose of forest harvesting, it is divided into six types. There are six types of main felling, tending felling, low-yield forest transformation felling, low-efficiency forest transformation felling, regeneration felling, and other felling.

1.4.1　主伐 final cutting

The type of harvesting of mature and over-mature stands in timber forests for timber harvesting.

1.4.2　抚育采伐 tending cutting

From the canopy closure of young forests to the age level before the harvesting of mature forests, the felling of part of the forest trees in order to improve the stand conditions and promote the growth of retained trees is also called tending thinning or thinning.

1.4.3　更新采伐 regeneration cutting

Harvesting is carried out in order to restore, enhance or improve the ecological functions of shelterbelts and special forests, thereby creating favorable conditions for the regeneration of forest stands.

1.4.4　低产林改造采伐 low yield forest cutting

For the forest stand with poor growth and low economic efficiency, the economic benefits of the stand should be improved by felling low-yield (efficient) trees and introducing high-yield tree species, so as to make it a high-yield forest type.

1.4.5　低效林改造采伐 low efficiency forest cutting

For the forest stand with poor growth and low ecological efficiency, the ecological benefit of the stand should be improved by felling low-yield (efficient) trees and introducing excellent target tree species, so as to make it a high-efficiency forest stand felling type.

1.4.6　其他采伐 other cutting

Felling other than main felling, tending felling, regeneration felling, and transformation of low-yield (efficient) forests includes economic forests, energy forests, mother forests, sparse forests, side trees, scattered trees, seed orchard management, scientific research and disaster wood clearing, forest land acquisition, construction of firebreaks, construction of forest pests and diseases isolation zone, tree harvesting and transplantation, emergency rescue and other special circumstances of felling.

1.5　采伐方式cutting methods

The procedures and methods of felling trees, i.e., the method of harvesting trees. Including clear-cutting, gradual cutting, selective cutting, translucent cutting, thinning, growth cutting and sanitary cutting.

1.5.1　皆伐 clear cutting

Clear-cutting is the main cutting method in which all the trees on the felling area are harvested at one time or basically completed. It can be subdivided into strip clear-cutting and block-like clear-cutting.

1.5.2　渐伐 shelterwood cutting

The main forest cutting method of cutting down all the mature and over-mature trees on the felling area several times in a long period of time (generally not more than one age class). It is also known as the shade wood method or umbrella felling method.

1.5.3　择伐 selection cutting

In a certain area, at certain intervals, the main cutting method of mature and over-ripe trees that have reached a certain diameter class or have certain characteristics are harvested in a single tree or in groups.

1.5.4　透光伐 release cutting

In the young forest stage after canopy closure of the stand, tending and felling was carried out when the target tree species was suppressed by the upper or lateral overlord tree and non-target tree species, and the high growth was significantly affected. Transparent cutting is mainly to cut down inferior trees, overlord trees, sprout strips, large shrubs, vines, etc. in the upper layer or side shade, and keep the dense and even, remove the inferior and retain the superior, adjust the composition and spatial structure of the stand tree species, improve the growth conditions of the retained trees, and promote the high growth of forest trees.

1.5.5　疏伐 thinning cutting

In the young or middle-aged forest stage after the canopy closure of the stand, tending and felling was carried out after the relationship between trees changed from mutual assistance and mutually beneficial growth to mutual inhibition and mutual harm competition. Thinning is mainly carried out on forests of the same age. Cut down the trees with excessive density and poor growth, keep them evenly interdensed, remove the inferior and leave the superior, further adjust the tree species and spatial structure of the stand, and leave a suitable nutrient space for the target trees or retained trees.

1.5.6　生长伐 accretion cutting

In the middle-aged forest stage, tending felling was carried out when the growth of DBH of the stand decreased significantly year after year, and the growth of target trees or retained trees was significantly affected. The overdense near-mature forest due to the lack of management measures in the young and middle-aged stage is also suitable for growth cutting control measures.

1.5.7　卫生伐 sanitation cutting

Tending harvesting in forests affected by natural disasters with the goal of improving the health of forest stands. Sanitary felling mainly removes trees that have been harmed, have lost their cultivation prospects, are difficult to recover or endanger the growth of target trees or retained trees.

1.6　林木分级 forest(trees) classification

The Kraft tree growth grading method was used for tree grading. It is divided into 5 levels.

Grade I: dominant trees, with the largest height and DBH, a large crown and above the main forest layer, and the best light conditions.

Grade II.: Sub-dominant wood, slightly inferior to Grade I Wood in height and DBH, the crown is developed in all directions and is more uniform and symmetrical, the crown is slightly smaller than that of Grade I Wood, and it is in the main forest layer.

Grade III: Medium-sized trees, the height and DBH are worse than those of class I and class II. standing trees, which are medium, with a narrow crown and can reach the main forest layer, but the sides are compressed, and the completeness of the trunk is greater than that of class I and II trees.

Grade IV: Pressed wood, the growth of tree height and DBH is very backward, the canopy is narrow, compressed, usually below the main canopy or only a few can reach the main canopy, mostly trail trees.

Grade V: Dying or dead wood, completely under the main canopy, without direct light, sparse or yellowish canopy, extremely backward in forest growth, on the verge of dying or dead.

1.7　轮伐期 rotation

The time required to rotate all the stands in a forest management unit where clear-cutting is carried out. For the same forest land, the interval between the maturity of the trees and the maturity of the trees through regeneration and cultivation and the re-harvesting is carried out.

1.8　回归年 circle of selective cutting

Also known as the selective cutting cycle. The number of years required to take turns is the business cycle of forest selective felling operations. The return year is the number of years it takes for trees smaller than the harvesting diameter class to continue to grow to meet the harvesting diameter class after the trees in a certain diameter class range have been harvested.

1.9　林分 forest stand

A community with the same internal characteristics such as tree origin, forest facies, tree species composition, age, status level, sparse density, forest type, etc., and a forest that is different from adjacent communities.

1.10 林带forest belt

On the whole, it is a forest lot with long strips or rows as the main shape.

1.11 龄级 age class

Classification of the average age of a tree or stand. That is, according to the requirements of forest management and the biological characteristics of tree species, it is divided into several levels according to a certain number of years as an interval. The number of years included in each age class is called the age class period, and the commonly used ones are 20 years, 10 years, 5 years, and 2 years.

1.12 龄组 age group

The age group of the stand or small class according to the age and age of the main felling. It is usually divided into five age groups: young forest, middle-aged forest, near-mature forest, mature forest, and over-mature forest.

1.13 公益林 non-commercial forest (NCF)

In order to maintain and create a good ecological environment, maintain ecological balance, protect biodiversity, and meet the ecological needs and sustainable development of human society as the main functions, it is mainly to provide forests, woods, and woodlands for public welfare and social products or services.

1.14 商品林 commercial forest (CF)

Forests, woods, and woodlands with the main function of producing wood (bamboo) and providing other forest products to obtain maximum economic output to meet the economic needs of human society are mainly to provide economic products that can enter the market circulation.

1.15 低产林 low yield forest

The growth of the main target tree species, the yield of forest products or the biomass of commercial forests were significantly lower than the average level of the same stand under the same site conditions.

1.16 低效林 low efficiency forest

The imbalance of stand structure and stability and the degradation of system function lead to the fact that the stand productivity and ecological function are significantly lower than the average level of the same stand under the same site conditions.

1.17 森林更新 forestry regeneration

The process of re-forming a new generation of forests after harvesting, either by natural or artificial means. Forest regeneration is usually divided into three ways: artificial regeneration, natural regeneration and artificial promotion of natural forest regeneration.

1.17.1 人工更新 artificial regeneration

Artificial seedlings, seeding or sowing are used for afforestation, and forest regeneration tasks are completed to form artificial forests. or forest regeneration by root cutting after harvesting. Including artificial seedling renewal, artificial sowing renewal, artificial differentiation renewal, etc.

1.17.2 天然更新 natural regeneration

A new generation of forests is formed by using the natural planting of forest trees, root cutting, and root germination. Including natural fly seed renewal, natural sprout renewal, etc.

1.17.3 人工促进天然更新 artificially promoted natural regeneration

It is the process of promoting the growth and development of seedlings and young trees of target tree species and forming a new generation of forests through measures such as loosening soil and weeding, leveling stubble or root breaking, replanting and replanting, removing tillers and seedlings, and removing weeds and shrubs.

2 Types and methods of harvesting

There are six types of forest harvesting, including main felling, tending felling, low-yield forest transformation, low-efficiency forest transformation, regeneration felling, and other felling.

2.1 Harvesting of commercial forests

The harvesting of commercial forests is divided into main felling, tending felling, low-yield forest transformation, and other felling.

2.2 Harvesting of public welfare forests

Felling of public welfare forests is divided into regeneration logging, tending felling, inefficient forest transformation, and other felling.

2.3 The relationship between the type of harvesting and the method of harvesting

Table 1: Correspondence between harvesting types and harvesting methods

Forest category	Clamping method Type of harvesting	Clear-cutting	渐伐	Logging	Translucent felling	Growing felling	Thinning	Sanitary felling
Commodity Forest	principal felling	√	√	√
Tending logging	√	√	√	√
Transformation of low-yield forests	√	√	√	√
Other logging	√	√	√
Public welfare forest	Renewal logging	*	√	√	√
Tending logging	√	√	√	√
Transformation of inefficient forests	√	√	√
Other logging	√	√	√

Note: * It is suitable for seed orchards, mother forests, scientific experimental forests, and forests that are severely degraded and stagnant.