Forest litter thickness measuring device and method
By designing a forest litter thickness measurement device and a specific pressure-biomass relationship model, the problems of large errors and inaccuracies in forest litter thickness measurement were solved, achieving higher measurement accuracy and stability, and supporting applications such as forest health assessment.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-09
- Publication Date
- 2026-04-03
AI Technical Summary
Existing methods for measuring forest litter thickness suffer from large errors, lack of precision, and high costs, making them difficult to apply to different forest types.
A forest litter thickness measurement device was designed, including a contact base, a connecting vertical rod, a small-weight pressure plate, a large-weight pressure plate, a fixing nut, and a handle that can be lifted and turned. The device measures the litter thickness by setting a specific pressure and calculates the thickness by combining the relationship model between the specific pressure and biomass.
It reduces human error, improves the accuracy and stability of measurements, and provides scientific evidence for fields such as forest fire risk assessment, carbon pool accounting, and pollution diagnosis.
Smart Images
Figure FT_1 
Figure FT_2 
Figure FT_3
Abstract
Description
Technical Field
[0001] This invention belongs to the field of forest litter thickness measurement technology, specifically relating to a forest litter thickness measurement device and method, and also to extended research designs in forest litter research. Background Technology
[0002] Litter, as a unique cover layer on terrestrial soil, is a crucial link connecting vegetation and soil. In nature, the accumulation and decomposition of litter is a central link in the biogeochemical cycling of elements in ecosystems, and plays a vital regulatory role in ecosystem processes such as habitat provision, ecohydrology, and plant dynamics. Scientific surveys of litter are of irreplaceable importance for forest carbon assessment, nutrient cycling, fire prevention, forest pollution diagnosis, and the maintenance of forest ecosystem health, providing crucial data support and theoretical basis for the scientific management and ecological protection of forest resources.
[0003] Litter thickness is a crucial indicator in forest litter surveys. Common survey methods typically involve selecting multiple quadrats within the survey plot, choosing representative litter thickness measurement points within each quadrat, and using a ruler or caliper to vertically insert into the litter layer to read the distance from the surface (top of the undecomposed layer) to the surface of the mineral soil—this is the total litter thickness. Alternatively, the thickness of each layer can be measured and recorded sequentially, from the undecomposed layer to the semi-decomposed layer and then the decomposed layer. However, litter is a naturally accumulated, loose mass of fallen leaves and branches, and its thickness varies significantly due to factors such as rainfall, animal disturbance, and human activity. Furthermore, human error in litter thickness measurement is substantial. Currently, some attempts have been made to measure litter thickness using spectrometers, but due to the relatively complex composition of litter, this method suffers from high cost and limited accuracy when applied to different forest types. Therefore, establishing a convenient, feasible, and accurate technical method for measuring forest litter thickness is a critical bottleneck issue that urgently needs to be addressed in this field. Summary of the Invention
[0004] To address the aforementioned technical problems, this invention provides an economical and accurate forest litter thickness measurement device and method to overcome the shortcomings of existing technologies.
[0005] To achieve accurate measurement of forest litter thickness, this invention provides a forest litter thickness measuring device, comprising a contact base, a connecting vertical rod, a small-weight pressure plate, a large-weight pressure plate, a fixing nut, and a handle for lifting and turning. The contact base is square, and the connecting vertical rod is fixed in the center of the contact base. The connecting vertical rod is threaded. The small-weight pressure plate, the large-weight pressure plate, and the handle for lifting and turning are installed sequentially from bottom to top on the connecting vertical rod. The small-weight pressure plate and the large-weight pressure plate are both annular structures with internal threads that match the connecting vertical rod. The handle for lifting and turning is also threaded to match the connecting vertical rod.
[0006] Preferably, a fixing nut is provided above both the small weight pressure plate and the large weight pressure plate.
[0007] Optionally, the number of small-weight pressure plates is 1-5; the number of large-weight pressure plates is 1-5.
[0008] Optionally, the connecting vertical rod may be made fully threaded or partially threaded at the connection points.
[0009] Furthermore, the small-weight pressure plate and the large-weight pressure plate are made of different materials and have different sizes to achieve the specific pressure generated by the device.
[0010] This invention also provides a method for measuring the thickness of forest litter, comprising the following steps: Step S1: Select representative forest community plots according to the research objectives, and arrange litter survey quadrats within the plots in accordance with the principles of randomness and representativeness; Step S2: Select a forest litter thickness measuring device based on the area of the litter survey plot. The minimum contact area of the forest litter thickness measuring device is 10 cm × 10 cm. Also prepare a cutter or scissors and a ruler. Step S3: Assembly and measurement of the forest litter thickness measurement device: Place the contact base at the selected litter survey plot location. Set a specific pressure by adjusting the position and number of small and large weight pressure plates. Secure the large weight pressure plate with a fixing nut, and then assemble and fix the liftable and screw-on handle. Based on the natural thickness of the litter and the principle of setting a specific pressure, place the device on the litter thickness point to be measured and stabilize it for more than 6 seconds. Use a cutter or scissors to cut the litter layer along the edge of the device contact base and measure the specific pressure thickness of different layers of litter. Collect litter biomass from each plot according to the degree of litter decomposition, bring it back to the laboratory, weigh the fresh weight, and then dry the litter to constant weight in an oven before measuring the dry weight of the litter. Step S4: Based on the forest litter biomass estimation model using litter thickness parameters, perform the calculation as follows: Rate of change in litter thickness under specific pressure: R i = ( H 0 - H i ) / H 0 × 100% Model of the relationship between litter biomass and natural litter thickness: L m = a × H 0 + b × X e + c Model relating litter biomass to litter thickness at a specific pressure: L m = a × H i + b × X e + c in, R i This represents the rate of change in litter thickness under a specific pressure, ranging from 0 to 100, expressed in % (%). H 0 The natural thickness of the debris is expressed in cm. H i For a specific pressure i The thickness of the debris at that time, in cm; L m Litter biomass, expressed in g / cm³ 2 ; X e These are environmental covariates that can directly affect forest litter thickness, such as stand, topography, or climate. a The coefficients in the model relating litter thickness to biomass; b The coefficients of environmental factors in the model relating litter thickness to biomass; c is a constant in the model relating litter thickness to biomass.
[0011] Preferably, in step S1: due to the influence of comprehensive factors such as forest stand composition, geographical climate, topographic factors, and forest age, the degree of variation in litter thickness in forest plots in the survey area may vary significantly. Therefore, the number of litter survey plots in each plot should be at least ≥5 replicates; the minimum survey area of a litter plot is 50 cm × 50 cm.
[0012] The inventors pointed out that the criteria for determining whether a specific pressure setting is suitable for measurement should meet the following three points: 1) It should not cause irreversible structural deformation of the litter; 2) The set pressure should be suitable for measuring the litter thickness of typical forest types in a specific study area and meet the comparability requirements; 3) The litter thickness parameters obtained by applying this method can achieve a confidence level within the range of litter biomass assessment and have stability.
[0013] Furthermore, the forest litter thickness measurement method of the present invention can be applied to the fields of forest fire risk assessment, forest carbon pool accounting, forest pollution diagnosis, and forest health assessment.
[0014] Beneficial effects of this invention: 1. This invention addresses the shortcomings of existing methods for measuring litter thickness, which are not precise enough and introduce significant human error. Direct measurement of the natural thickness of litter is prone to human error due to the loose, fluffy state of the litter, and is also susceptible to variations in thickness caused by uncontrollable factors (such as animal activity, trampling, or weather changes). The forest litter thickness measurement device and method of this invention effectively reduce human error in existing methods, offering high operability, significant results, and long-term usability.
[0015] 2. The purpose of this invention is clear: to develop a scientific and standardized method for measuring litter thickness under specific pressure, thereby solving the problems of inaccuracy and lack of standardization in existing litter thickness measurement methods; at the same time, by determining the good fit between litter thickness under specific pressure and biomass, previous research results can be corrected; thus laying a key parameter guarantee for the research on the widespread application of litter thickness parameters.
[0016] 3. The system design of this invention is portable and durable, with accurate and reliable results and significant effects. It provides a precise measurement device and method for forest litter thickness parameters, improving the stability and reliability of forest litter thickness measurement values. At the same time, the relationship model established by using specific pressure litter thickness and biomass has higher estimation accuracy, and can also provide scientific basis for fields such as forest fire risk assessment, forest carbon pool accounting, forest pollution diagnosis, and forest health assessment. Attached Figure Description
[0017] Figure 1 A device for measuring the thickness of forest litter; Figure 2 Flowchart for forest litter thickness survey research; Figure 3 The fitting relationship between natural litter thickness and biomass; Figure 4 The fitting relationship between litter thickness under specific pressure and biomass; Figure 5 This is the main application direction for forest litter thickness parameters.
[0018] In the diagram: 1-Contact base; 2-Connecting vertical rod; 3-Small weight pressure plate; 4-Large weight pressure plate; 5-Fixing nut; 6-Liftable and screw-on handle. Detailed Implementation
[0019] To make the objectives, technical solutions, features, and effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments.
[0020] A schematic diagram of the forest litter thickness measuring device in this invention is shown below. Figure 1 As shown, it consists of a contact base 1, a connecting vertical rod 2, a small weight pressure plate 3, a large weight pressure plate 4, a fixing nut 5, a handle that can be lifted and turned 6, and tools such as a cutter or scissors and a ruler. The device assembly and measurement should be performed in the following order: Figure 2 : Different litter thickness measurement areas (contact base) can be selected based on the litter thickness in the survey area. First, connect the connecting rod to the contact base; according to the litter thickness and specific pressure setting principles, select a specific pressure to assemble the measuring device, and then determine the selected pressure based on the natural thickness of the litter, and install the number of adjustable pressure plates; fix it with fixing nuts; Using a cutter along the edge of the contact base, litter in the non-measurement area was separated from litter thickness survey area under specific pressure. The thickness of different decomposition levels of litter was recorded with a ruler. Biomass of litter at different decomposition levels was collected. After weighing the fresh weight in the laboratory, the litter was dried to constant weight in an oven at 70 ℃, and the dry weight of the litter was determined.
[0021] A series of field measurement experiments were conducted on different litter thicknesses and pressures for different forest types to determine the optimal combination relationship between litter thickness range and pressure (Table 1). The effects of natural litter thickness measurement and litter thickness at specific pressures on evaluating the fitting relationship of litter biomass were compared and analyzed. Figure 3 The results showed that a specific pressure thickness of litter achieved a higher fitting effect.
[0022] Table 1 shows the optimal combination relationship between forest litter thickness and pressure.
[0023] Beneficial effects of this invention: 1. This invention addresses the shortcomings of existing methods for measuring forest litter thickness, which are not precise enough and introduce significant human error. Direct measurement of the natural thickness of litter is prone to human error due to the loose, fluffy state of the litter, and is also susceptible to variations in thickness caused by uncontrollable factors (such as animal activity, trampling, or weather changes). This invention provides a device and method for measuring forest litter thickness, which effectively reduces human error in existing methods, is highly operable, yields significant results, and has a long service life.
[0024] 2. The purpose of this invention is clear: to develop a scientific and standardized method for measuring litter thickness under specific pressure, thereby solving the problems of inaccuracy and lack of standardization in existing litter thickness measurement methods; at the same time, by determining the good fit between litter thickness under specific pressure and biomass, previous research results can be corrected; thus laying a key parameter guarantee for the research on the widespread application of litter thickness parameters.
[0025] 3. The system design of this invention is portable and durable, with accurate and reliable results and significant effects. It provides a precise measurement device and method for forest litter thickness parameters, improving the stability and reliability of forest litter thickness measurement values. At the same time, the relationship model established by using specific pressure litter thickness and biomass has higher estimation accuracy, and can also provide scientific basis for fields such as forest fire risk assessment, forest carbon pool accounting, forest pollution diagnosis, and forest health assessment.
[0026] Although embodiments of the invention have been shown and described, demonstrating advantages such as ease of operation and stable measurement results, it will be understood by those skilled in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the invention (such as changing the pressure range or measuring the thickness of litter under a certain pressure), the scope of which is defined by the appended claims and their equivalents.
Claims
1. A device for measuring the thickness of forest litter, characterized in that, Includes a contact base (1), a connecting vertical rod (2), a small weight pressure plate (3), a large weight pressure plate (4), a fixing nut (5), and a handle that can be lifted and turned (6). The contact base (1) is square, and a connecting vertical rod (2) is fixed in the center of the contact base (1). The connecting vertical rod (2) is threaded. A small weight pressure plate (3), a large weight pressure plate (4) and a liftable and screw-on handle (6) are installed on the connecting vertical rod (2) from bottom to top. The small weight pressure plate (3) and the large weight pressure plate (4) are both ring structures with threads inside that match the connecting vertical rod (2). The liftable and screw-on handle (6) is provided with threads that match the connecting vertical rod (2).
2. The forest litter thickness measuring device according to claim 1, characterized in that, A fixing nut is provided above the small weight pressure plate (3) and the large weight pressure plate (4).
3. The forest litter thickness measuring device according to claim 1, characterized in that, The number of small-weight pressure plates (3) is 1-5; the number of large-weight pressure plates (4) is 1-5.
4. The forest litter thickness measuring device according to claim 1, characterized in that, The connecting vertical rod (2) is made to be fully threaded or partially threaded at the connection points.
5. The forest litter thickness measuring device according to claim 1, characterized in that, The small-weight pressure plate (3) and the large-weight pressure plate (4) are made of different materials and have different sizes to achieve the specific pressure generated by the device.
6. A method for measuring the thickness of forest litter, characterized in that, Includes the following steps: Step S1: Select representative forest community plots according to the research objectives, and arrange litter survey quadrats within the plots in accordance with the principles of randomness and representativeness; Step S2: Select a forest litter thickness measuring device according to the area of the litter survey plot. The minimum area of the contact base (1) of the forest litter thickness measuring device is 10 cm × 10 cm. The area of the contact base (1) of different sizes can be changed according to the characteristics of forest litter and micro-topography. Also prepare a cutter or scissors and a ruler. Step S3: Assembly and measurement of the forest litter thickness measurement device: Place the contact base (1) at the selected litter survey plot, set the specific pressure by adjusting the position and number of the small weight pressure plate (3) and the large weight pressure plate (4), fix the large weight pressure plate (4) with the fixing nut (5), and then assemble and fix the liftable screw handle (6); according to the natural thickness of the litter and the principle of setting the specific pressure, place the device on the litter thickness point to be measured, and stabilize it for more than 6 seconds. Use a cutter or scissors to cut the litter layer along the edge of the contact base of the device and measure the specific pressure thickness of different layers of litter; according to the degree of litter decomposition, collect the litter biomass in the plot, bring it back to the laboratory, weigh the fresh weight, dry the litter to constant weight in an oven, and then measure the dry weight of the litter. Step S4: Based on the forest litter biomass estimation model using litter thickness parameters, perform the calculation as follows: Rate of change in litter thickness under specific pressure: R i = ( H 0 - H i ) / H 0 × 100% Model of the relationship between litter biomass and natural litter thickness: L m = a × H 0 + b × X e + c Model relating litter biomass to litter thickness at a specific pressure: L m = a × H i + b × X e + c in, R i This represents the rate of change in litter thickness under a specific pressure, ranging from 0 to 100, expressed in % (%). H 0 The natural thickness of the debris is expressed in cm. H i For a specific pressure i The thickness of the debris at that time, in cm; L m Litter biomass, in g / cm³ 2 ; X e These are environmental covariates that can directly affect forest litter thickness, such as stand, topography, or climate. a The coefficients in the model relating litter thickness to biomass; b The coefficients of environmental factors in the model relating litter thickness to biomass; c is a constant in the model relating litter thickness to biomass.
7. The method for measuring forest litter thickness according to claim 6, characterized in that, In step S1: Due to the combined influence of forest stand composition, geographical climate, topographic factors, forest age and other factors, the degree of variation in litter thickness in forest plots in the survey area may vary significantly. Therefore, the number of litter survey quadrats in each plot should be at least ≥5 replicates.
8. The forest litter thickness measurement method described in claim 6 is applied to the fields of forest fire risk assessment, forest carbon pool accounting, forest pollution diagnosis, and forest health assessment.