LU501522B1

LU501522B1 - Method for measuring leaf area of plant

Info

Publication number: LU501522B1
Application number: LU501522A
Authority: LU
Inventors: Has Waqir BAO; Zhongwu Wang; Haifeng Bao; Saruul Kang
Original assignee: Univ Inner Mongolia Agri
Priority date: 2022-02-18
Filing date: 2022-02-18
Publication date: 2022-08-18

Abstract

The present disclosure provides a method for measuring plant leaf area, and belongs to the technical field of a study of physiological plant ecology. The method includes steps of collecting and photographing plant leaf, converting image format, determining TIC point coordinates, identifying picture with eCognition software, reading leaf length and width with scaleplate in ArcMap, topologizing, acquiring data, and obtaining leaf area. The method has advantages of low costs, flexible operation, accurate measurement, and time saving, problems of measuring and computing irregular and small leaf areas are solved, personal errors are reduced, and files are saved individually and read again; any leaf area is measured; field operations are convenient, and measurement of a large number of specimens is achieved; and linear and planar information is measured directly by computer. Errors caused by subjective factors are reduced; and vector files are saved and read separately for next use.

Description

METHOD FOR MEASURING LEAF AREA OF PLANT LU501522

TECHNICAL FIELD

[01] The present disclosure belongs to the technical field of physiological plant ecology, and particularly relates to a method for measuring a leaf area of a plant.

BACKGROUND ART

[02] A functional trait of a plant, as a result of a species to accommodate different environments in a long-term evolutionary process, is easy to observe and measure, which can indicate an accommodation and response of the plant to an external environment objectively. The functional trait of the plant can accommodate a change in a habitat and achieve a certain effect on an ecosystem function, which reflects an indicative function in the representational ecosystem function of the plant, and shows a relationship between an ecosystem process and the function. In a response process of the functional trait of the plant to an ecosystem, a leaf trait achieves a key effect, and it is indispensable for a measurement in a leaf area in the leaf trait.

[03] At present, the leaf area of the plant is measured depending on a portable laser leaf area meter or in the traditional method of counting grids. The leaf area meter has advantages of small volume and convenience for carrying, and the traditional method of counting the grids is easy to operate. Meanwhile, the measurement of the leaf area of the plant by the conventional portable laser leaf area meter or in the traditional method of counting the grids also has the following defects:

[04] (1) The portable laser leaf area meter is expensive in a price, high in maintenance costs, and long in maintenance time for any damage;

[05] (2) When the leaf area of a small plant is measured with the portable laser leaf area meter, inaccurate data may happen, for example, when a leaf area of Artemisia frigida is measured with the laser leaf area meter, there is a case of no data due to a small leaf, and the leaf is also easy to damage in the measuring process;

[06] (3) There is also a limit to the weather in terms of the meter, for example, the laser leaf area meter can'be used in rainy days or the humid weather during a field operation;

[07] (4) The traditional method of counting the grids is time-consuming. In addition, as the counting method varies from person to person, statistical data is also inaccurate.

[08] Therefore, the present application provides an ArcGIS technology-based method for measuring the leaf area of the plant.

SUMMARY

[09] To overcome defects in the prior art, the present disclosure provides a method for measuring a leaf area of a plant.

[10] In order to fulfill the above objective, the present disclosure provides the following 1 technical solution: LU501522

[11] | The method for measuring the leaf area of the plant, which includes the following steps:

[12] Step 1: collecting a plant leaf in a field;

[13] Step 2: photographing the collected plant leaf, and acquiring the original JPEG image file of the plant leaf;

[14] Step 3: importing the original JPEG image file into PCI Geomatica V8.2 software, and converting the file into a PIX file with the PCI Geomatica V8.2 software for editing in ArcMap;

[15] Step 4: determining coordinates of TIC points at a bottom left corner and a top right corner of an image in each PIX file under an Xpace command of the PCI Geomatica V8.2 software to determine a length and a width of the overall image in the PIX file;

[16] Step 5: with eCognition software, identifying the PIX file for the leaf automatically, acquiring a boundary line picture of each leaf, and exporting it as a vector file;

[17] Step 6: opening the vector file in the ArcMap, and reading two indexes of the leaf, that is the length and the width, in the vector file with a scaleplate in the ArcMap;

[18] Step 7: opening a boundary vector file of the leaf in ArcGIS, and computing the leaf area automatically with a geometry computation tool.

[19] Preferably, a method for photographing the collected plant leaf to acquire the original JPEG image file includes steps: paving coordinate paper on a camera shelf, placing the collected plant leaf on the coordinate paper, and adjusting a focus for photographing; or before photographing, squeezing a specimen, bringing the specimen back to a laboratory, photographing vertically, and acquiring the original JPEG image file.

[20] The method for measuring the leaf area of the plant, provided by the present disclosure, has the following beneficial effects:

[21] (1) The method is low in costs, flexible to operate, accurate in a measurement, and time- saving, problems of measuring and computing irregular and small leaf areas are solved, personal errors are reduced, and files can be saved individually and read again;

[22] (2) A leaf area index of any plant leaf can be measured;

[23] (3) Field operations are convenient, and the measurement of a large number of specimens can be achieved;

[24] (4) Linear and planar information is measured directly by a computer. The errors caused by subjective factors are reduced in the method;

[25] (5) Vector files that are created can be saved separately and read again for a next use.

2

BRIEF DESCRIPTION OF THE DRAWINGS LU501522

[26] FIG. 1 is a flow chart illustrating a measurement of a leaf area of a plant in the present disclosure;

[27] FIG. 2 is a paragraphed leaf in a step 2, saved as a JPEG image file;

[28] FIG. 3 is a leaf boundary line graph acquired by an automatic identification of a PIX file with eCognition software after a further processing of the original JPEG file with PCI Geomatica V8.2 software;

[29] FIG. 41s a modification of a boundary line on a vector file opened in ArcMap;

[30] FIG. S is a vector file that is outputted again;

[31] FIG. 6 is a computation of a leaf area with ArcMap.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[32] The implementations of the present disclosure will be further described with reference to the drawings: The following embodiments are not intended to limit the scope of protection of the present disclosure, but are merely and more clearly descriptive of the technical solution of the present disclosure. Embodiment 1

[33] With a development of a technology, a theory and application of ArcGIS are wider and wider in every area of ecology, including applications of the ArcGIS in landscape ecology, marine ecological environment monitoring, and a farmland ecosystem, a computation of an ecological carrying capacity, a spatial distribution map of an ecological risk, and other areas. Moreover, an ArcGIS technology is increasingly matured, which has become an indispensable technology in every area of the ecology. Therefore, in the embodiment, a computation of a leaf area of a plant is completed by means of the ArcGIS.

[34] The embodiment provides a method for measuring a leaf area of a plant, shown as FIGs. 1 to 6, which includes the following steps:

[35] Atstep 1, a plant leaf is collected in a field, and the collected leaf may any shapes, such as a flake shape, a strip shape, or a needle shape;

[36] Step 2: photographing the collected plant leaf, and acquiring the original JPEG image file of the plant leaf;

[37] In a specific operation: coordinate paper is paved on a camera shelf, the collected plant leaf is placed on the coordinate paper, and a focus is adjusted for photographing; or before a picture is taken, a specimen is squeezed and is brought back to a laboratory for vertical photographing, and the original JPEG image is acquired,

[38] Step 3: importing the original JPEG image file into PCI Geomatica V8.2 software, and converting the file into a PIX file with the PCI Geomatica V8.2 software for editing in ArcMap; 3

[39] Atastep 4, a length and a width of an overall image in the PIX file are determined, that is, coordinates of TIC points at a bottom left corner and a top right corner of the image in each LU501522 PIX file are determined under an Xpace command of the PCI Geomatica V8.2 software, and a unit (cm) is customized,

[40] Atastep 5, with eCognition software, the PIX file for the leaf is identified automatically, and a boundary line picture of each leaf is acquired, and is exported as a vector file;

[41] Step 6: opening the vector file in the ArcMap, and reading two indexes of the leaf, that is the length and the width, in the vector file with a scaleplate in the ArcMap;

[42] Atstep 7, the boundary vector file of the leaf is opened in ArcGIS, and a field is created in an Attribute, which is named as "Area"; a right click is implemented on the new field, "Geometry Computation” is selected, the leaf area is computed automatically based on coordinate values in the step 4, that is, a length value and a width value of the leaf in the step 6.

[43] The method for measuring the leaf area of the plant, provided by the embodiment, has advantages of low costs, flexible operation, accurate measurement, and time saving, problems of measuring and calculating irregular and small leaf areas are solved, personal errors are reduced, and files can be saved individually and read again; the leaf area of any plant leaf can be measured; field operations are convenient, and measurement of a large number of specimens can be achieved; and linear and planar information is measured directly by a computer. In the method, errors caused by subjective factors are reduced; and the vector files can be saved separately and read again for a next use. Based on provincial characteristics, as the plant leaves in grasslands in northern China, and especially, desert grasslands have characteristics of downsizing or degeneration into the needle shape, correct data is not easy to acquire with the portable laser leaf area meter. With a new method in the present disclosure, parameters of the plant leaf with any area can be measured accurately.

[44] The above embodiment is only the implementation of the present disclosure, but the scope of protection of the present disclosure is not limited thereto; and any simple change or equivalent replacement of the technical solution, made by a person skilled in the art obviously within the technical scope of the present disclosure, shall fall within the scope of protection of the present disclosure.

4

Claims

WHAT IS CLAIMED IS: LU501522

1. A method for measuring a leaf area of a plant, characterized in that it comprises the following steps of: Step 1: collecting a plant leaf in a field; Step 2: photographing the collected plant leaf, and acquiring the original JPEG image file of the plant leaf; Step 3: importing the original JPEG image file into PCI Geomatica V8.2 software, and converting the file into a PIX file with the PCI Geomatica V8.2 software for editing in ArcMap; Step 4: determining coordinates of TIC points at a bottom left corner and a top right corner of an image in each PIX file under an Xpace command of the PCI Geomatica V8.2 software to determine a length and a width of the overall image in the PIX file; Step 5: with eCognition software, identifying the PIX file for the leaf automatically, acquiring a boundary line picture of each leaf, and exporting it as a vector file; Step 6: opening the vector file in the ArcMap, and reading two indexes of the leaf, that is the length and the width, in the vector file with a scaleplate in the ArcMap; Step 7: opening a boundary vector file of the leaf in ArcGIS, and computing the leaf area automatically with a geometry computation tool.

2. The method for measuring the leaf area of the plant according to claim 1, characterized in that, a method for photographing the collected plant leaf to acquire the original JPEG image file comprises steps: paving coordinate paper on a camera shelf, placing the collected plant leaf on the coordinate paper, and adjusting a focus for photographing; or before photographing, squeezing a specimen, bringing the specimen back to a laboratory, photographing vertically, and acquiring the original JPEG image file.