Method for identifying taxus cuspidata vegetation water utilization

Abstract

The invention relates to the field of moisture detection, and particularly discloses a method for identifying taxus cuspidata vegetation moisture utilization. The method comprises the following steps: collecting xylem at the same position on taxus cuspidata at different growth stages as a sample, sampling soil and rainfall near a collection point, and extracting moisture in the plant xylem sample and the soil sample in a laboratory environment; the method comprises the following steps: detecting and comparing hydrogen and oxygen isotopes of plant sample moisture, soil sample moisture and rainfall sample moisture, and determining moisture utilization characteristics of tiny-population taxus cuspidata by using a stable isotope method through sample plot selection, sample collection and test and determination of plant moisture utilization sources and proportions. Therefore, the ecological stability of taxus cuspidata population can be better maintained.

Description

Technical Field

[0001] The invention belongs to the technical field of water detection, and in particular relates to a method for identifying water utilization of Taxus cuspidata vegetation. Background Art

[0002] Water is a key factor restricting vegetation growth. The growth and development of vegetation are closely related to available water resources. Soil moisture limitation will affect plant carbon and water cycles, hinder plant growth, increase plant mortality, change plant community structure and composition, and reduce primary total yield. Affected by growth status, groundwater level and soil conditions, season and other factors, it often leads to different proportions of water utilization by plants for potential water sources such as soil water and atmospheric precipitation, which has strong temporal and spatial heterogeneity, and plant water strategies change accordingly.

[0003] Current research on plant water utilization is mostly focused on plants at the same growth stage in the same season, which makes it difficult to reflect the characteristics of vegetation water utilization and its seasonal changes. When sampling in the field, due to differences in stable isotope composition within the same plant and the fractionation characteristics of water isotope samples, the research on plant water utilization strategies based on stable isotopes has extremely high requirements for samples. The collection, preservation and testing methods of samples directly affect the scientific validity of the research results, and scientific and unified sample collection and preservation methods play a significant role in enhancing the transferability of individual studies.

[0004] Taxus cuspidatus is an endangered plant under key protection in my country. It is difficult to renew its population under natural conditions and has relatively strict requirements for its growth environment. Exploring the water utilization response mechanism of Taxus cuspidatus under the background of global warming is a necessary means to protect and restore the Taxus cuspidatus population, and it is also a key link in the comprehensive implementation of biodiversity conservation work in the Northeast region. Summary of the invention

[0005] In order to overcome the shortcomings of the prior art, the purpose of the present invention is to provide a method for identifying water utilization of Taxus cuspidata vegetation, so as to explore the seasonal dynamic characteristics of the water source of Taxus cuspidata at different growth stages, and provide data support and scientific reference for the protection and restoration of Taxus cuspidata populations and the conservation of biodiversity in Northeast China.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A method for identifying water utilization of Taxus cuspidata vegetation comprises the following steps:

[0008] S1. On sunny days between 8:00 and 10:00 a.m., collect xylem from the same position on branches at the same height on the sunny side of Taxus cuspidata at different growth stages, place in sample bottles, seal and store at low temperature, and collect multiple samples from each tree;

[0009] S2. Soil samples are collected near the collection point, and the samples are collected in layers at multiple depths. The soil samples are collected to fill the sample bottles, and the samples are sealed and stored at low temperature;

[0010] S3. Place a precipitation collector in an unobstructed open space near the collection point to collect all precipitation greater than 2 mm during the growing season of Taxus cuspidata. Collect precipitation samples after the precipitation stops completely and store the samples in a sealed container at low temperature.

[0011] S4. Use a low-temperature vacuum extraction system to extract water from plant samples and soil samples and store them at low temperatures;

[0012] S5. Detect hydrogen and oxygen isotopes of water content in plant samples, soil samples and precipitation samples;

[0013] S6. Compare the hydrogen and oxygen isotopes of the water content in plant samples, soil samples and precipitation samples to determine the source relationship between the water content in plant samples, soil samples and precipitation samples.

[0014] Preferably, in S1, stems of Taxus cuspidata that have grown for more than two years are selected, two-year-old branches with a diameter of about 0.3 cm-0.5 cm are cut, the outer bark is removed, the xylem is retained, and 3 cm-4 cm of the xylem that is not directly contacted is selected as the sample.

[0015] Preferably, in S2, the soil sampling depths are 0 cm, 10 cm, 20 cm, 30 cm, 40 cm, 50 cm, 60 cm, 70 cm, 80 cm, 90 cm and 100 cm above the ground surface, respectively.

[0016] Preferably, in S3, a precipitation collector is used to collect rainwater, and the precipitation collector comprises a beaker 1, on which a short-handled funnel 2 for blocking the mouth of the beaker 1 is provided, and in which a ping-pong ball 3 for sealing is provided.

[0017] Preferably, the plant samples, soil samples and precipitation samples are all frozen and stored below -20°C.

[0018] Preferably, before testing, the plant samples, soil samples and precipitation samples are placed in an environment of 3-4°C for node thawing and refrigerated at low temperature.

[0019] Preferably, in S6, the comparison methods include direct comparison method, multivariate linear mixed model, IsoSource model and MixSIAR model.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention collects xylem at the same position on Taxus cuspidatus at different growth stages as samples, samples soil and precipitation near the collection points at the same time, extracts moisture from plant xylem samples and soil samples in a laboratory environment, detects and compares hydrogen and oxygen isotopes of moisture in plant samples, moisture in soil samples and moisture in precipitation samples, and uses a stable isotope method to determine the water utilization characteristics of a very small population of Taxus cuspidatus through sample site selection, sample collection and testing, and determination of plant water utilization sources and proportions, so as to better maintain the ecological stability of the Taxus cuspidatus population. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a block diagram of the method of the present invention;

[0023] Figure 2 It is a schematic diagram of the structure of the precipitation collector of the present invention;

[0024] In the picture: 1. Beaker; 2. Short-handled funnel; 3. Ping-pong ball. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Example:

[0027] See also Figure 1 - Figure 2 As shown, a method for identifying water utilization of Taxus cuspidata vegetation specifically comprises the following steps:

[0028] S1. On a sunny day between 8:00 and 10:00 a.m., on branches at the same height on the sunny side of Taxus cuspidata at different growth stages, samples can be collected from seedlings, saplings and mature trees respectively. The xylem at the same position can be collected and placed in a sample bottle. The samples are sealed and stored at low temperature. Multiple samples can be collected from each tree.

[0029] S2. Soil samples are collected near the collection point, and the samples are collected in layers at multiple depths. The soil samples are collected to fill the sample bottles, and the samples are sealed and stored at low temperature;

[0030] S3. Place a precipitation collector in an unobstructed open space near the collection point to collect all precipitation greater than 2 mm during the growing season of Taxus cuspidata. Collect precipitation samples after the precipitation stops completely and store the samples in a sealed container at low temperature.

[0031] S4. Use a low-temperature vacuum extraction system to extract water from plant samples and soil samples and store them at low temperatures;

[0032] S5. Detect hydrogen and oxygen isotopes of water content in plant samples, soil samples and precipitation samples;

[0033] S6. Compare the hydrogen and oxygen isotopes of the water content in plant samples, soil samples and precipitation samples to determine the source relationship between the water content in plant samples, soil samples and precipitation samples.

[0034] Xylem samples were collected from the same position on Taxus cuspidatus at different growth stages. Soil and precipitation near the collection points were sampled. Water was extracted from plant xylem and soil samples in a laboratory environment. The hydrogen and oxygen isotopes of plant sample water, soil sample water and precipitation sample water were tested and compared. The stable isotope method was used to determine the water utilization characteristics of extremely small populations of Taxus cuspidatus through sample site selection, sample collection and testing, and determination of the sources and proportions of plant water utilization, so as to better maintain the ecological stability of the Taxus cuspidatus population.

[0035] In the S1, in order to eliminate the isotope enrichment caused by stomatal transpiration, stems of Taxus cuspidata that have grown for more than two years are selected, two-year-old branches with a diameter of about 0.3 cm-0.5 cm are cut, the bark is quickly removed, the xylem is retained, and 3 cm-4 cm of xylem that is not directly touched is selected as the sample, which is stored in an ice box outside and frozen after being brought back to the laboratory.

[0036] In S2, the soil sampling depths are 0 cm, 10 cm, 20 cm, 30 cm, 40 cm, 50 cm, 60 cm, 70 cm, 80 cm, 90 cm and 100 cm above the ground surface, and the soil collection range is one meter around the tree roots.

[0037] In S3, a precipitation collector is used to collect rainwater. The precipitation collector includes a beaker 1. A short-handled funnel 2 for blocking the mouth of the beaker 1 is provided on the beaker 1. A ping-pong ball 3 for sealing is provided in the short-handled funnel 2. The precipitation collection range is one meter around the tree roots. When precipitation falls inside the short-handled funnel 2, the rainwater gathered inside the short-handled funnel 2 will float the ping-pong ball 3, and then the rainwater inside the short-handled funnel 2 will flow into the beaker 1 along the gap between the ping-pong ball 3 and the short-handled funnel 2 to complete the precipitation sample collection. When there is no precipitation, the ping-pong ball 3 is blocked at the drain outlet of the short-handled funnel 2 due to gravity to prevent the precipitation sample collected inside the beaker 1 from evaporating.

[0038] After being taken back to the laboratory, the plant samples, soil samples and precipitation samples were all frozen and stored in an environment below -20°C.

[0039] Before testing, plant samples, soil samples and precipitation samples were thawed and refrigerated at 3-4℃.

[0040] In S6, the comparison methods include direct comparison method, multivariate linear mixed model, IsoSource model and MixS IAR model.

[0041] Taking the plant-water relationship as the starting point, and Taxus cuspidatus at different growth stages as the research object, using stable isotope technology, we conducted research on hydrogen and oxygen stable isotopes in plant branch water, soil water, and atmospheric precipitation. We systematically explained the dynamic laws of water sources of Taxus cuspidatus at different growth stages (seedlings, saplings, and mature trees), and revealed the water utilization strategy and response mechanism of Taxus cuspidatus under the background of regional precipitation changes, in order to provide scientific understanding and basic data support for evaluating the impact of climate change on the population dynamics of Taxus cuspidatus and guiding forest management.

[0042] In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0043] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0045] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0046] In the drawings of the embodiments disclosed in the present invention, only the structures related to the embodiments disclosed in the present invention are involved, and other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of the present invention can be combined with each other.

Claims

1. A method for identifying water utilization of Taxus cuspidata vegetation, characterized in that: The specific steps include: S1. On sunny days between 8:00 and 10:00 a.m., collect xylem from the same position on branches at the same height on the sunny side of Taxus cuspidata at different growth stages, place in sample bottles, seal and store at low temperature, and collect multiple samples from each tree; S2. Soil samples are collected near the collection point, and the samples are collected in layers at multiple depths. The soil samples are collected to fill the sample bottles, and the samples are sealed and stored at low temperature; S3. Place a precipitation collector in an unobstructed open space near the collection point to collect all precipitation greater than 2 mm during the growing season of Taxus cuspidata. Collect precipitation samples after the precipitation stops completely and store the samples in a sealed container at low temperature. S4. Use a low-temperature vacuum extraction system to extract water from plant samples and soil samples and store them at low temperatures; S5. Detect hydrogen and oxygen isotopes of water content in plant samples, soil samples and precipitation samples; S6. Compare the hydrogen and oxygen isotopes of the water content in plant samples, soil samples and precipitation samples to determine the source relationship between the water content in plant samples, soil samples and precipitation samples.

2. The method for identifying water utilization of Taxus cuspidata vegetation according to claim 1, characterized in that: In S1, stems of Taxus cuspidata that have grown for more than two years are selected, two-year-old branches with a diameter of about 0.3 cm-0.5 cm are cut, the outer bark is removed, the wood is retained, and 3 cm-4 cm of the wood that is not directly touched is selected as the sample.

3. The method for identifying water utilization of Taxus cuspidata vegetation according to claim 1, characterized in that: In S2, the soil sampling depths are 0 cm, 10 cm, 20 cm, 30 cm, 40 cm, 50 cm, 60 cm, 70 cm, 80 cm, 90 cm and 100 cm above the ground surface, respectively.

4. The method for identifying water utilization of Taxus cuspidata vegetation according to claim 1, characterized in that: In S3, rainwater is collected using a precipitation collector, the precipitation collector comprising a beaker (1), the beaker (1) being provided with a short-handled funnel (2) for blocking the mouth of the beaker (1), and the short-handled funnel (2) being provided with a ping-pong ball (3) for sealing.

5. The method for identifying water utilization of Taxus cuspidata vegetation according to claim 1, characterized in that: The plant samples, soil samples and precipitation samples were all frozen and stored below -20°C.

6. The method for identifying water utilization of Taxus cuspidata vegetation according to claim 1, characterized in that: Before testing, plant samples, soil samples and precipitation samples were thawed and refrigerated at 3-4℃.

7. The method for identifying water utilization of Taxus cuspidata vegetation according to claim 1, characterized in that: In S6, the comparison methods include direct comparison method, multivariate linear mixed model, IsoSource model and MixSIAR model.

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