A device for testing the water holding capacity of tropical plantation litter

Abstract

The utility model discloses a kind of tropical plantation litter water-holding capacity test device, including square containing frame, square containing net bag, first lifting device, frame support base, stem flow simulation round pipe, stem flow simulation top pipe, stem flow simulation bottom pipe, stem flow simulation annular drip flow device, penetration rain simulation drip flow device.The utility model can simulate the state of natural stacking of undecomposed layer, semi-decomposed layer, decomposed layer litter, and have layered weighing function, can directly obtain the weight of each layer litter, facilitate calculating water-holding rate, water absorption rate and other research litter water-holding capacity Key data;The utility model device can simulate rainfall condition in plantation, be conducive to understanding litter layer water absorption condition.The utility model provides a new train of thought for traditional litter water-holding capacity research, is helpful to understand the water-holding capacity of each layer litter under natural state in plantation.

Description

Technical Field

[0001] This utility model belongs to the field of tropical plantation litter research technology, specifically relating to a test device for the water-holding capacity of tropical plantation litter. Background Technology

[0002] As an important component of forest ecosystems, litter plays a crucial role in water conservation, soil and water retention, and regulation of the hydrological cycle. Especially in tropical plantations with high rainfall, where plant species are relatively limited, the water-holding capacity of litter directly impacts the hydrological and ecological functions of the plantations. Therefore, accurately assessing the water-holding capacity of litter is of great significance for the management and ecological research of tropical plantations.

[0003] Currently, most studies on the water-holding capacity of forest litter, both domestically and internationally, employ the immersion method. For example, Chen Gengyan et al. collected litter samples from the undecomposed and semi-decomposed layers, immersed them in clean water in the laboratory, and weighed them periodically to determine the water-holding capacity and absorption rate. Similarly, Cheng Siyuan et al. also used the immersion method, submerging litter samples in water and measuring the water-holding capacity and water-holding rate at different time points. These studies, by fitting the relationship between water absorption rate and time using a power function, provide theoretical data on the water-holding characteristics of litter, laying the foundation for regional forest hydrological research.

[0004] However, the aforementioned existing technologies have significant limitations. Immersion methods typically treat litter samples as isolated or homogeneous individuals, neglecting the layered stacking characteristics of the litter layer under natural conditions. In real tropical plantations, the litter layer is usually formed by the natural stacking of undecomposed, semi-decomposed, and decomposed layers from top to bottom. These layers influence each other due to weight compression and water infiltration, resulting in a dynamic and hierarchical water-holding process. Existing immersion methods fail to reflect this natural stacking state and cannot accurately reflect the water-holding capacity of the litter layer in a real environment, leading to discrepancies between measurement data and actual conditions. Furthermore, immersion methods do not consider the interaction between the litter layer and forest rainfall (such as throughfall and trunk flow), further limiting their accuracy in practical applications.

[0005] Existing technologies also include devices for studying the water-holding capacity of forest litter. For example, Chinese utility model patent 2025101335138 discloses a device for testing the water-holding capacity of forest litter and bryophytes, whose main principle still uses the immersion method. Chinese utility model patent 2019113455741 discloses a vegetation and litter water interception test device, which crudely assesses the overall water interception capacity of litter by the amount of water entering and leaving the forest, and cannot study the water-holding capacity of different litter layers. Its test process differs from the actual conditions of plantations.

[0006] Therefore, there is an urgent need for an experimental device that can simulate the layered stacking state of fallen debris and monitor its water-holding capacity in real time. Utility Model Content

[0007] To address the aforementioned technical problems, the purpose of this utility model is to provide a test device for the water-holding capacity of tropical plantation litter, so as to accurately evaluate the water-holding capacity of tropical plantation litter under natural conditions.

[0008] The purpose of this utility model is achieved as follows: it includes a square holding frame, a square holding net, a first lifting device, a frame support base, a tree trunk flow simulation pipe, a tree trunk flow simulation top pipe, a tree trunk flow simulation bottom pipe, a tree trunk flow simulation annular dripper, and a penetrating rain simulation dripper. The sides of the square holding frame are arranged with railings at intervals, and the gaps between the railings are provided with pins that can slide up and down along the gaps. The top and bottom of the square holding frame are open. There are at least two square holding frames, and multiple square holding frames are stacked one on top of the other. Each square holding frame contains... Each container is provided with a square holding net bag. The top side of the square holding net bag is fixedly connected to the end of the pin shaft. The other end of the pin shaft is T-shaped. The bottom of the square holding net bag has at least one circular hole. The square holding net bag at the edge of the circular hole extends upward to the top of the square holding net bag to form a circular tube mesh structure. The side of the tree trunk flow simulation circular tube is fixedly provided with a guide. The guide is provided with a sliding member that can slide up and down along the guide. The outer side of the sliding member is fixedly connected to the top of the circular tube mesh structure. Multiple square holding frames are stacked up and down corresponding to the tree trunk flow simulation circular tubes. Among the multiple square holding frames, the bottom of the lowest square holding frame is provided with a frame support base, the top surface of the frame support base has a grid-like permeable structure, and the top of the highest square holding frame is provided with a penetrating rain simulated drip device, the bottom of the penetrating rain simulated drip device is provided with a drip head. Among the multiple tree trunk flow simulation pipes, the bottom of the lowest tree trunk flow simulation pipe is provided with a tree trunk flow simulation bottom pipe, the top of the highest tree trunk flow simulation pipe is provided with a tree trunk flow simulation top pipe, and a tree trunk flow simulation annular dripper is fitted on the outer side of the upper part of the tree trunk flow simulation top pipe, and a ring of drip heads is provided at the bottom of the tree trunk flow simulation annular dripper. Each square holding frame is equipped with a first support on the outside, the first support is connected to a first lifting device, and a weight sensor is provided between the first support and the first lifting device.

[0009] The square holding frame is typically square, with internal dimensions such as 1m×1m×0.1m or 2m×2m×0.1m, and a height of 0.1m. If the litter layer is thick, the height can be 0.15m to 0.2m. Stainless steel can be used for the square holding frame. The square holding net can be made of a lightweight material with a certain degree of rigidity, such as nylon net. The sides and bottom of the net should be flat mesh structures, while the top should be open. Alternatively, the net can be made of metal or other lightweight rigid frame materials, with a nylon net covering the frame. The mesh size is determined by the size of the litter. For example, undecomposed litter is usually larger, so a large-aperture net can be chosen to ensure high permeability. Semi-decomposed litter is finer, so a smaller-aperture net can be chosen. Multiple pins can be installed on the sides of the square holding frame to guide the square holding net to move up and down.

[0010] Among them, the guide can be a side-placed U-shaped part, and multiple guides are evenly distributed on the side of the simulated circular tube of the trunk flow; the sliding part that slides with the U-shaped part is a sliding sleeve, which is fitted on the U-shaped part, and the outer side of the sliding part is fixedly connected to the top of the circular tube mesh structure.

[0011] The first lifting device can be a cylinder, with a weight sensor installed at the top of the cylinder piston rod. The bottom of the first bracket is located on the weight sensor. After the first lifting device raises the corresponding square holding frame and square holding net, the weight data detected by the weight sensor is the weight of the square holding frame, square holding net, and fallen debris. The weight of the fallen debris can be obtained by tareing the weight of the square holding frame and square holding net. The second lifting device can also be a cylinder, used to raise and separate the tree trunk flow simulation jacking pipe.

[0012] Among them, the trunk flow simulation ring dripper is a common ring container in this field, with drip heads installed at the bottom. An adjustable flow water supply pipe is connected to the outside of the ring container. The water dripping from the drip heads drips along the outer wall of the trunk flow simulation jacking pipe to simulate trunk flow. The specific flow rate can be based on the trunk flow of the artificial forest measured in the field. The through-rain simulation dripper can be multiple parallel water pipes with multiple drip heads installed at the bottom of the water pipes, covering a square holding frame area. The flow rate is adjusted to control the water output of the drip heads, thereby simulating the through-rain amount. The specific flow rate can be based on the through-rain amount of the artificial forest measured in the field. Among them, the through-rain simulation dripper water pipe above the top of the trunk flow simulation jacking pipe does not need to be equipped with drip heads to avoid the trunk flow simulation jacking pipe.

[0013] It should be noted that the number of circular holes 11 and the number of trunk flow simulation trunks (i.e., the structure composed of trunk flow simulation circular pipes, trunk flow simulation top pipes, and trunk flow simulation bottom pipes) can be flexibly set according to the forest density of the artificial forest plot to simulate trunk flow in the artificial forest plot.

[0014] Preferably, the square holding frame has a first protrusion at the top of its side and a first groove at the bottom of its side. The first protrusion and the first groove correspond one-to-one. In two adjacent square holding frames, the first protrusion of the lower square holding frame is engaged in the first groove of the upper square holding frame. The protrusion can be frustoconical, and the groove and the protrusion are fitted together. This structure of the protrusion and the groove facilitates accurate positioning during the assembly of the square holding frames.

[0015] Preferably, the top side of the simulated tree flow pipe and the top side of the simulated tree flow bottom pipe are each provided with a second protrusion, and the bottom side of the simulated tree flow pipe and the bottom side of the simulated tree flow top pipe are each provided with a second groove. The second protrusion and the second groove of the simulated tree flow pipe correspond one-to-one, the second groove of the simulated tree flow top pipe corresponds one-to-one, and the second protrusion and the second groove of the simulated tree flow bottom pipe correspond one-to-one. In two adjacent simulated tree flow pipes, the second protrusion of the lower simulated tree flow pipe is engaged in the second groove of the upper simulated tree flow pipe, the second protrusion of the uppermost simulated tree flow pipe is engaged in the second groove of the simulated tree flow top pipe, and the second protrusion of the simulated tree flow bottom pipe is engaged in the second groove of the lowermost simulated tree flow pipe. The protrusion can be frustoconical, and the groove and the protrusion are embedded and matched. This structure of protrusion and groove facilitates accurate positioning during the assembly of each section of the simulated tree flow pipe.

[0016] Preferably, the penetrating rain simulation dripper directly above the tree trunk flow simulation jacking pipe has no drip head, and a second support is provided directly above the tree trunk flow simulation jacking pipe. The second support is equipped with a second lifting device, which is connected to the center of the top of the tree trunk flow simulation jacking pipe. Activating the second lifting device drives the tree trunk flow simulation jacking pipe to rise and fall.

[0017] Preferably, the top of the tree trunk flow simulation jacking pipe is closed, and the bottom of the tree trunk flow simulation jacking pipe is closed.

[0018] Preferably, the frame support base is a bottom-suspended base, and a water collection tank is provided below the frame support base; the water collection tank is used to collect and drain the dripping water.

[0019] Preferably, the number of square holding frames is 2 or 3, with 2 square holding frames corresponding to the undecomposed layer and the semi-decomposed layer, respectively, and 3 square holding frames corresponding to the undecomposed layer, the semi-decomposed layer, and the decomposed layer, respectively.

[0020] Compared with the prior art, the present invention has the following technical effects: 1. This utility model device adopts a layered frame-type net structure to simulate different layers of litter formed by varying degrees of decomposition in a natural plantation. The square holding net can move up and down, and after being filled with litter, it can be freely pressed onto the litter layer of the next square holding net, simulating the natural stacking of undecomposed, semi-decomposed, and decomposed litter layers. This utility model device has a layered weighing function, which can directly obtain the weight of each layer of litter, facilitating the calculation of key data such as water holding capacity and water absorption rate for studying the water holding capacity of litter. This utility model device is equipped with a simulated tree trunk of a plantation, which can simulate trunk flow. Combined with the through-rain simulation function, it can simulate rainfall in a plantation, which is beneficial for understanding the water absorption of the litter layer. 2. This utility model device can simulate the state of litter in each layer under natural conditions in tropical plantations and has the function of real-time measurement of key data on the water-holding capacity of litter. It solves the problem of lag in traditional manual sampling and measurement. This experimental device provides a new approach to the study of the water-holding capacity of traditional litter and helps researchers understand the changes in the water-holding capacity of litter in each layer under natural conditions in plantations. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the main structure of the device of this utility model; Figure 2 for Figure 1 A schematic diagram of the uppermost square holding frame and the square holding net in its usage state after being raised. Figure 3 A top view of the top square holding frame; Figure 4 A side cross-sectional view of a simulated circular pipe and circular pipe network structure for trunk flow; In the diagram: 1-Square holding frame, 2-Square holding net bag, 3-First lifting device, 4-Frame support base, 5-Tree trunk flow simulation circular pipe, 6-Tree trunk flow simulation top pipe, 7-Tree trunk flow simulation bottom pipe, 8-Tree trunk flow simulation annular dripper, 9-Penetrating rain simulation dripper, 10-Pin shaft, 11-Circular hole, 12-Circular tube mesh structure, 13-Guide component, 14-Sliding component, 15-First bracket, 16-First boss, 17-Second boss, 18-Second bracket, 19-Second lifting device. Detailed Implementation

[0022] The present invention will be further described below with reference to the embodiments and accompanying drawings, but this does not limit the present invention in any way. Any changes or substitutions made based on the teachings of the present invention shall fall within the protection scope of the present invention.

[0023] Example 1 As attached Figures 1-4The embodiment of the tropical plantation litter water-holding capacity test device shown includes a square holding frame 1, a square holding net 2, a first lifting device 3, a frame support base 4, a trunk flow simulation pipe 5, a trunk flow simulation top pipe 6, a trunk flow simulation bottom pipe 7, a trunk flow simulation annular dripper 8, and a penetrating rain simulation dripper 9. The square holding frame 1 has railings arranged at intervals on its sides, and the gaps between the railings are provided with pins 10 that can slide up and down along the gaps. The top and bottom of the square holding frame 1 are open. There are 3 square holding frames 1, which are stacked one on top of the other. Each square holding frame 1 is equipped with a... A square holding net bag 2 is fixed to the top of the side of the square holding net bag 2 and the end of the pin shaft 10. The other end of the pin shaft 10 is T-shaped. At least one circular hole 11 is opened at the bottom of the square holding net bag 2. The square holding net bag 2 at the edge of the circular hole 11 extends upward to the top of the square holding net bag 2 to form a circular tube mesh structure 12. A guide 13 is fixed to the side of the tree trunk flow simulation circular tube 5. The guide 13 is provided with a sliding member 14 that can slide up and down along the guide 13. The outer side of the sliding member 14 is fixed to the top of the circular tube mesh structure 12. The three square holding frames 1 are stacked up and down corresponding to the tree trunk flow simulation circular tubes 5 respectively. The top of the tree trunk flow simulation jacking pipe 6 is closed, and the bottom of the tree trunk flow simulation bottom pipe 7 is closed. Among the three square holding frames 1, the bottom of the lowest square holding frame 1 is provided with a frame support base 4, the top surface of the frame support base 4 is grid-shaped, and the top of the uppermost square holding frame 1 is provided with a rain-penetrating simulated drip device 9, the bottom of the rain-penetrating simulated drip device 9 is provided with a drip head; the frame support base 4 is a bottom-suspended base, and a water collection tank is provided below the frame support base 4. Among the three tree trunk flow simulation pipes 5, the bottom of the lowest tree trunk flow simulation pipe 5 is provided with a tree trunk flow simulation bottom pipe 7, the top of the uppermost tree trunk flow simulation pipe 5 is provided with a tree trunk flow simulation top pipe 6, and a tree trunk flow simulation annular dripper 8 is sleeved on the outer side of the upper part of the tree trunk flow simulation top pipe 6, and a ring of drip heads is provided at the bottom of the tree trunk flow simulation annular dripper 8. Each square holding frame 1 is provided with a first support 15 on the outside. The first support 15 is connected to the first lifting device 3, and a weight sensor is provided between the first support 15 and the first lifting device 3.

[0024] Example 2 This embodiment of the tropical plantation litter water-holding capacity test device is based on Embodiment 1. The square holding frame 1 has a first protrusion 16 on the top side and a first groove on the bottom side, with the first protrusion 16 and the first groove corresponding one-to-one. In two adjacent square holding frames 1, the first protrusion 16 of the lower square holding frame 1 engages with the first groove of the upper square holding frame 1. The top side of the trunk flow simulation pipe 5 and the top side of the trunk flow simulation bottom pipe 7 both have second protrusions 17, and the bottom side of the trunk flow simulation pipe 5 and the bottom side of the trunk flow simulation top pipe 6 both have second grooves. The second protrusion 17 of the simulated circular tube 5 corresponds one-to-one with the second groove. The second groove of the simulated tree trunk flow top tube 6 corresponds one-to-one with the second protrusion 17 of the simulated tree trunk flow circular tube 5. The second protrusion 17 of the simulated tree trunk flow bottom tube 7 corresponds one-to-one with the second groove of the simulated tree trunk flow circular tube 5. Among the two adjacent simulated tree trunk flow circular tubes 5, the second protrusion 17 of the lower simulated tree trunk flow circular tube 5 is inserted into the second groove of the upper simulated tree trunk flow circular tube 5. The second protrusion 17 of the uppermost simulated tree trunk flow circular tube 5 is inserted into the second groove of the simulated tree trunk flow top tube 6. The second protrusion 17 of the simulated tree trunk flow bottom tube 7 is inserted into the second groove of the lowermost simulated tree trunk flow circular tube 5.

[0025] Example 3 The tropical plantation litter water-holding capacity test device in this embodiment is based on embodiment 2. In this embodiment, the penetrating rain simulated dripper 9 corresponding to the top of the tree trunk flow simulated jacking pipe 6 has no drip head. A second support 18 is provided above the tree trunk flow simulated jacking pipe 6. The second support 18 is provided with a second lifting device 19, which is connected to the center of the top of the tree trunk flow simulated jacking pipe 6. There are two square holding frames 1 and two tree trunk flow simulated circular pipes 5.

[0026] The working principle and working process of this utility model device: Before the experiment, the tree trunk flow simulation jacking pipe 6 was separated from its corresponding tree trunk flow simulation circular pipe 5. Using the corresponding first lifting device 3, all square holding frames 1 except the lowest square holding frame 1 were raised. At this time, the square holding net bag 2 corresponding to each square holding frame 1 naturally drooped below the square holding frame 1. The raising position was such that there was a certain distance between the naturally drooping square holding net bag 2 and the square holding frame 1 below it to facilitate material loading. Then, in a bottom-up order, litter was loaded into the square holding net bags 2, that is, the lowest square holding net bag 2 was filled with the lowest layer of litter samples collected from the sample plot. After loading the specified amount, the second square holding frame 1 was lowered from bottom to top and stacked on top of the lowest square holding frame 1. At this time, the second square holding net bag 2 naturally rested on the litter layer inside the lowest square holding net bag 2, and the tree trunk flow simulation circular pipe 5 corresponding to the second square holding net bag 2 was stacked on top of the lowest square holding frame 1. On the trunk flow simulation pipe 5, the litter corresponding to the sample plot layer is loaded into the second square holding net 2 to a specified amount. Under the action of gravity, the pin 10 of the second square holding net 2 slides down along the gap of the railing, that is, the litter layer in the second square holding net 2 naturally presses on the litter layer of the bottom square holding net 2. Then, the same operation is carried out to complete the loading of litter into the remaining square holding net 2 from bottom to top. After loading, all square holding frames are stacked on top of each other, and the trunk flow simulation bottom pipe 7, multiple trunk flow simulation pipes 5, and trunk flow simulation top pipe 6 are stacked from bottom to top. The different layers of square holding net 2 and their litter layers maintain the layered structure formed by the weight of each layer from bottom to top, simulating the layered structure naturally formed by different litter layers. The structure composed of the trunk flow simulation bottom pipe 7, multiple trunk flow simulation pipes 5, and trunk flow simulation top pipe 6 is used to simulate the trunk of the plantation. During the experiment, the weight of each litter layer at different times was measured. The specific process was as follows: all the square holding frames 1 were raised using the corresponding first lifting device 3, ensuring that the litter layers in the square holding net bags 2 were separated and did not come into contact. The weight data detected by the weight sensor at this time was the weight of the litter layer. The water holding rate of the current litter layer was calculated by using the pre-detected dry weight of the litter. The trend of water holding rate change could be obtained by detecting the weight change of the litter layer at multiple times. During the experiment, this device could also be used in an indoor environment with controlled temperature, humidity and light to more accurately simulate the natural temperature, humidity and light conditions of the artificial forest, thereby obtaining a more realistic simulation of the water holding rate change of the litter layer. To study the relationship between rainfall and the water holding capacity of litter layer in plantations, a through-rain simulated dripper 9 and a trunk flow simulated annular dripper 8 were activated and their flow rates were controlled. Through-rain fell on the litter, and trunk flow flowed from top to bottom onto the litter, forming a simulated plantation tree trunk composed of a simulated trunk flow bottom pipe 7, multiple simulated trunk flow circular pipes 5, and a simulated trunk flow top pipe 6, simulating the trunk flow in a real plantation scene. Subsequently, the first lifting device 3 was activated at different times to weigh each litter layer and calculate the water holding capacity of the litter at different times.

[0027] The specific steps for using this device are as follows: 1) Select research plots in tropical plantations, set up quadrats, and measure throughfall and trunk runoff; 2) Based on the degree of decomposition of litter, different litter layers are divided, from top to bottom, including the undecomposed layer, the semi-decomposed layer, and the decomposed layer. The undecomposed layer is composed of fresh litter from the plantation, maintaining its original shape, with no obvious color change and no trace of decomposition on the surface. The semi-decomposed layer is characterized by a noticeably darkened color, leaves without a complete outline, and most litter being pulverized. The decomposed layer is characterized by fragments, making it impossible to identify the original shape. The thickness of each litter layer is recorded, and samples of each litter layer are collected, fresh weight is measured, and dry weight is measured after drying at 80℃. The original moisture content is calculated. 3) Take samples from each litter layer and place them into different square holding net bags 2 according to the order of each litter layer in the sample plot, until the thickness of each litter layer is recorded in step 2); stack the square holding net bags 2 one on top of the other. 4) Adjust the temperature and humidity of the test area and start the test; During the test, at regular intervals, control the square holding frame 1 to rise from top to bottom, detect the weight of the fallen material in the corresponding square holding net bag 2 through the weight sensor, and calculate the water holding rate of the fallen material in each layer. The water holding rate calculation formula is: R=(M'-M) / M, where R is the water holding rate, M' is the wet weight of the fallen material, and M is the dry weight of the fallen material; After that, lower the square holding frame 1 back into place, and ensure that the adjacent square holding frames 1 are aligned and that the tree trunk flow simulation pipe 5, the tree trunk flow simulation top pipe 6, and the tree trunk flow simulation bottom pipe 7 are aligned. In step 4), when it is necessary to simulate rainfall, the tree trunk flow simulation ring dripper 8 and the penetrating rain simulation dripper 9 are activated and the flow rate is set. During the experiment, not only can the water holding rate of different layers of litter be calculated, but also the water absorption rate can be calculated. The water absorption rate formula is V=R' / t, where: V is the water absorption rate, t is the simulated rainfall time (h), and R' is the water holding capacity of the litter.

Claims

1. A device for testing the water-holding capacity of litter in tropical plantations, comprising a square holding frame (1), a square holding net (2), a first lifting device (3), a frame support base (4), a trunk flow simulation pipe (5), a trunk flow simulation top pipe (6), a trunk flow simulation bottom pipe (7), a trunk flow simulation annular dripper (8), and a penetrating rain simulation dripper (9), characterized in that... The square holding frame (1) has railings arranged at intervals on its sides. Pins (10) that can slide up and down along the gaps between the railings are provided. The top and bottom of the square holding frame (1) are open. There are at least two square holding frames (1), and multiple square holding frames (1) are stacked one on top of the other. Each square holding frame (1) contains a square holding net bag (2). The top of the side of the square holding net bag (2) is fixed to the end of the pin (10), and the other end of the pin (10) is T-shaped. The bottom of the square holding net bag (2) is... At least one circular hole (11) is provided. The square holding net (2) at the edge of the circular hole (11) extends upward to the top of the square holding net (2) to form a circular tube mesh structure (12). The trunk flow simulation circular tube (5) is fixedly provided with a guide (13) on its side. The guide (13) is provided with a sliding member (14) that can slide up and down along the guide (13). The outer side of the sliding member (14) is fixedly connected to the top of the circular tube mesh structure (12). Multiple square holding frames (1) are stacked up and down corresponding to the trunk flow simulation circular tube (5). Among the multiple square holding frames (1), the bottom of the lowest square holding frame (1) is provided with a frame support base (4), the top surface of the frame support base (4) is grid-shaped, and the top of the uppermost square holding frame (1) is provided with a penetrating rain simulated drip device (9), and the bottom of the penetrating rain simulated drip device (9) is provided with a drip head. Among the multiple tree trunk flow simulation pipes (5), the bottom of the lowest tree trunk flow simulation pipe (5) is provided with a tree trunk flow simulation bottom pipe (7), the top of the highest tree trunk flow simulation pipe (5) is provided with a tree trunk flow simulation top pipe (6), the outer side of the upper part of the tree trunk flow simulation top pipe (6) is provided with a tree trunk flow simulation annular dripper (8), and the bottom of the tree trunk flow simulation annular dripper (8) is provided with a ring of drip heads; Each square holding frame (1) is provided with a first support (15) on the outside. The first support (15) is connected to the first lifting device (3), and a weight sensor is provided between the first support (15) and the first lifting device (3).

2. The test device for water-holding capacity of tropical plantation litter according to claim 1, characterized in that... The square holding frame (1) has a first protrusion (16) on the top side and a first groove on the bottom side. The first protrusion (16) and the first groove correspond one-to-one. In the two adjacent square holding frames (1), the first protrusion (16) of the lower square holding frame (1) is inserted into the first groove of the upper square holding frame (1).

3. The test device for water-holding capacity of litter in tropical plantations according to claim 1, characterized in that... The top side of the simulated tree trunk flow pipe (5) and the top side of the simulated tree trunk flow pipe (7) are both provided with a second protrusion (17). The bottom side of the simulated tree trunk flow pipe (5) and the bottom side of the simulated tree trunk flow pipe (6) are both provided with a second groove. The second protrusion (17) of the simulated tree trunk flow pipe (5) corresponds one-to-one with the second groove. The second groove of the simulated tree trunk flow pipe (6) corresponds one-to-one with the second protrusion (17) of the simulated tree trunk flow pipe (5). The second protrusion (17) of the simulated tree trunk flow pipe (7) corresponds one-to-one with the second groove of the simulated tree trunk flow pipe (6). 17) Corresponding one-to-one with the second groove of the trunk flow simulation pipe (5), in the two adjacent trunk flow simulation pipes (5), the second boss (17) of the lower trunk flow simulation pipe (5) is inserted into the second groove of the upper trunk flow simulation pipe (5), the second boss (17) of the uppermost trunk flow simulation pipe (5) is inserted into the second groove of the trunk flow simulation top pipe (6), and the second boss (17) of the trunk flow simulation bottom pipe (7) is inserted into the second groove of the lowermost trunk flow simulation pipe (5).

4. The test device for water-holding capacity of tropical plantation litter according to claim 1, characterized in that... The penetrating rain simulation dripper (9) directly above the tree trunk flow simulation jacking pipe (6) has no drip head. A second support (18) is provided directly above the tree trunk flow simulation jacking pipe (6). The second support (18) is provided with a second lifting device (19). The second lifting device (19) is connected to the center of the top of the tree trunk flow simulation jacking pipe (6).

5. The test device for water-holding capacity of litter in tropical plantations according to claim 1, characterized in that... The top of the simulated trunk flow pipe (6) is closed, and the bottom of the simulated trunk flow pipe (7) is closed.

6. The test device for water-holding capacity of litter in tropical plantations according to claim 1, characterized in that... The frame support base (4) is a bottom-suspended base, and a water collection tank is provided below the frame support base (4).

7. The test device for water-holding capacity of litter in tropical plantations according to claim 1, characterized in that... The number of the square holding frames (1) is 2 or 3.

Images