Collection of common terms and meanings in forestry investigation based on lidar

A collection of commonly used terms and meanings in forestry investigation based on lidar

Serial number	Noun	paraphrase	remarks
1	The forest	Arbor is the main body , Including shrubs 、 Herbs and other living things , Occupy a considerable space , Dense growth , And can significantly affect the surrounding community .	Including arbor forest and bamboo forest
2	Trees	The general name of all trees in the forest . It is the main body of the forest . It determines the appearance and internal basic characteristics of the forest , And the economic significance of the forest and its role in affecting the environment , It is the main working object in forest management . According to the economic value and management significance, it is divided into main trees , It is composed of main tree species , And minor trees , It is composed of minor tree species .	It generally refers to trees growing in the forest as opposed to solitary trees .
3	Woodland	Including woodland 、 Open woodland 、 Shrub land 、 Uncultivated forest land 、 Nursery land 、 No standing forest land 、 Barren mountain and wasteland suitable for forestry and forest land for auxiliary production .	Generally referred to as the
4	Stand	The internal characteristics are generally consistent , And a piece of woodland which is obviously different from the adjacent area . A forest in a forest area , It can be composed according to tree species 、 The origin of the forest 、 appearance of a forest 、 Forest age 、 Density 、 Differences in status level and other factors , Divide into different stands .
5	a reception class	It means that the forest is divided into different ownership in the planning and design of forest investigation 、 Land type 、 origin 、 Forest category 、 Forest species 、 Dominant tree species group 、 Age group 、 Canopy closure grade 、 Site type 、 Economic forest production period ( Level of business intensity ) It is divided into different communities with forestry engineering categories , Each community is called a small class . Small class is the smallest unit of forest zoning .
6	Dominant tree species	In a stand , The largest number of （ Generally, it means that the storage volume accounts for the largest proportion ） Tree species .
7	Continuous inventory of forest resources	National Forest Resources Survey . In the State Forestry Administration \ Implemented under the organization of the State Forestry and grassland administration , The interval between reexamination is 5 year . Its purpose is to find out the national or provincial 、 The number of forest resources in the autonomous region 、 Quality and its fluctuation , To formulate the national forestry policy 、 policy , Formulate various forestry plans for the whole country, all provinces and regions, and Dalin district 、 Provide scientific basis for planning and forecasting the development trend of resources . This kind of investigation is based on the province 、 City 、 District or Dalin district as a unit .	A kind of inventory
8	Inventory of class II forest resources	Also known as forest manager survey . Such investigation is based on the State Forestry Administration \ Unified deployment of the State Forestry and grassland administration , The provincial competent forestry department or its entrusted prefectural and municipal competent forestry department shall be responsible for organizing , In forestry production units . The review interval is 10 year . Its purpose is to grasp the current situation and dynamics of forest resources for forestry grass-roots units , Analyze and check the effect of business activities , To provide basis for preparing or revising forest management plan and relevant planning . The quantity and quality of forest resources in this kind of investigation should be implemented to ” a reception class ”, Its accuracy is better than that of a kind of survey .	Class II inventory
9	Three types of surveys	I.e. job design survey . It is a basic forestry production unit designed to meet the cutting area 、 Investigation for afforestation design and tending cutting design .	Three types of surveys
10	Mixed forests	A stand consisting of two or more tree species , The percentage of each kind of trees in the forest shall not be less than 10% .
11	Pure forest	Also called Shan Chunlin . Consisting of a single tree species , Or mixed with other tree species, but the volume accounts for less than 10% respectively , Such as fir forest 、 Pinus tabulaeformis forest 、 Robinia pseudoacacia forest, etc .
12	Standing tree	It has two meanings ：① The sum of the trees that form the main part of the forest ;② The living trees of the woodland that have not been felled .
13	Canopy closure	The extent to which the crowns of trees in a forest touch each other and obscure the ground . In tenths , To the extent that the ground is completely covered 1, Divided into ten levels , In turn 1.0 0.9 0.8……0.1.
14	Tree height	It is generally believed , Height difference between the highest point of single wood and the ground , Is the height of the tree	Including canopy height
15	DBH	（Diameter at breast heigh, DBH） It is short for chest height and diameter . That is, the diameter of the trunk above the ground, which is equivalent to the chest height of ordinary adults , China and most countries stipulate that the chest height is above the ground 1.3 The location of rice .	This position is most convenient for measuring the reading with a wheel ruler
16	Crown width	In a general way , Crown width refers to the average width of trees in the North-South or east-west direction ; Separate each tree from the point cloud , Project the point cloud of a single tree onto a plane , Calculate the convex hull or concave hull of the projection area , Projected area of tree crown , And then the crown width
17	The height under the branch	（height to the crown /height to live crown base） namely , The height from the lowest part of the canopy to the base of the trunk	The value estimated based on point cloud is generally low
18	Canopy	The total number of all tree crowns in the stand
19	Storage capacity	It refers to a certain area of forest （ Including young forests 、 Middle aged forest 、 Near mature forest 、 Mature forest 、 Over mature forest and dead standing forest ） in , The total volume of growing trees （ Expressed in cubic meters ）. It mainly refers to the volume of the trunk .	Airborne lidar can not solve the problem of dead trees
20	Crown volume	The three-dimensional convex hull of the area above the height under the branch , Then the three-dimensional convex hull points are faceted , Calculate the volume of the space enclosed by the convex hull , Is the crown volume .
21	Leaf area index	（leaf area index） It refers to the total photosynthesis area of plants per unit land area , That is, half of the surface area of all blades . At present, the mainstream solution is to calculate inversely through the model in combination with the porosity index （ Porosity =1.00- Canopy closure ）.	This indicator is one of the key indicators for carbon sink calculation
22	Carbon sink \ transaction	Carbon sequestration refers to afforestation 、 Vegetation restoration and other measures , Absorb carbon dioxide from the atmosphere , The process of reducing the concentration of greenhouse gases in the atmosphere , Characterizes the ability to absorb and fix carbon dioxide . Carbon sequestration transaction is the international quantitative transaction of carbon emission rights .	Hot concepts in the forest and grass industry
23	Carbon neutralization	Carbon neutrality refers to national 、 Enterprises 、 Groups or individuals calculate the total amount of greenhouse gas emissions directly or indirectly within a certain period of time , Through afforestation 、 Energy conservation and emission reduction , To offset its own carbon dioxide emissions , To achieve carbon dioxide " Zero emissions ".	The later stage of forest resources investigation must be linked with carbon sink
24	Point cloud filtering	In order to obtain the three-dimensional spatial information of ground objects , Or extract DEM, Need to separate ground data from non ground data , This process is called point cloud filtering , Also known as extracting ground points
25	Point cloud classification	In addition to point cloud filtering , Non ground points also need to be carefully classified , For example, non ground points are further classified into vegetation 、 building 、 Roads, etc
26	normalization	In the process of point cloud filtering and classification , In order to eliminate the influence of topographic relief on classification results , Reduce the height of vegetation points to ground points to a unified datum . It can be simply understood as pulling the ground into a flat plate .	The former is more extensive and mature , The latter is more difficult
27	Single wood partition	It refers to accurately identifying each tree from the point cloud data , It is an important prerequisite for extracting single tree scale forest parameters , As tall as a tree 、 DBH 、 Crown width, etc . There are two main ways ： be based on CHM（Canopy Height Model） And point cloud based .