CN114455710A - A method for plant screening and community construction suitable for urban landscape water restoration - Google Patents

Abstract

The invention relates to a method for plant screening and community construction suitable for urban landscape water restoration. In the storage box of the wetland matrix: 1) each plant is planted in the storage box alone; 2) the plants with the same growth type are combined and planted in the storage box; including the following steps: 1) regularly add nutrients; 2) monitor plant growth and Water quality index; 3) Judging the competitiveness of different plant species according to the growth status of plants and the removal effect of nitrogen and phosphorus elements in the water, so as to screen. Six kinds of plants were mixed and planted in the storage box to build a community, and through the niche differences between different plants, in order to weaken the competition between species and promote the absorption and utilization of nitrogen and phosphorus in eutrophic water by plants.

Description

A method for plant screening and community construction suitable for urban landscape water restoration

technical field

The invention relates to the field of eutrophication water body restoration, in particular to a plant screening and community construction method suitable for urban landscape water body restoration.

Background technique

As an important part of urban water ecological environment, urban landscape water can optimize the living environment and is closely related to people's quality of life. Compared with natural water bodies such as lakes and rivers, most urban landscape water bodies are closed water bodies, which have the characteristics of small water area and poor mobility. With the development of industry and the increase of population density, a large amount of NO, NO ₂ and other gases and surface nutrients contained in automobile exhaust enter urban landscape water bodies along with rainwater and surface runoff, and also include the intrusion of domestic garbage, the input of these foreign nutrients As a result, the concentration of nitrogen and phosphorus in the water body is too high, resulting in eutrophication of the water body, the occurrence of algae and plankton blooms, the decrease of dissolved oxygen in the water, and the odor of the water body, which seriously affects the quality of life of residents and loses its ornamental value as a landscape water body.

Among the many methods to control the eutrophication of urban landscape water bodies, the traditional physical methods such as aeration and salvage are too expensive, and they can only cure the symptoms but not the root causes. Although the chemical method is effective, it is easy to cause secondary pollution. The phytoremediation in the biological method removes nitrogen and phosphorus in the water body through the absorption and assimilation of aquatic plants and the synergy with microorganisms. , is widely used in the ecological restoration of urban landscape water bodies.

The growth characteristics of aquatic plants are different, and there are differences in the tolerance and absorption and utilization capacity of nutrient elements in the water body. Therefore, the selection of aquatic plants greatly affects the purification effect of the water body. At the same time, the combination of plants will also affect the removal of nitrogen and phosphorus. On the one hand, plant combinations can lead to interspecific competition. Species with strong competitiveness will inhibit the growth of other species and obtain more resources to meet growth and reproduction. Species with weak competitiveness will quickly or gradually die out due to the acquisition of fewer resources. . Especially among species with similar ecological niches, competition (especially allelopathy) affects the survival of plants and the accumulation of biomass. If a large number of species with weaker competition ability are planted in large quantities, they will also cause mass death of plants. Thereby artificially increasing the input of exogenous nutrients in the water body. On the other hand, the combination of plants can improve the species diversity of the community, and some studies have shown that species diversity can lead to niche complementarity and improve the ability of the community to absorb nitrogen and phosphorus, thereby optimizing the effect of water purification. Niche complementarity means that due to differences in resource requirements and habitat utilization among species, resource allocation and niche differentiation among different plants occur, reducing the spatial, temporal, and nutrient types, forms and quantities of different plants. The competition intensity promotes the coexistence between plants and the stability of the community, thereby improving the primary productivity of the community and the utilization efficiency of resources. Therefore, in the practical application of water body remediation, the competition ability of species and the degree of niche differentiation among aquatic plants that build the community should be comprehensively considered.

Although the species diversity of the community has the potential to improve its absorption of nitrogen and phosphorus, the current application of aquatic plants to purify water mostly defaults to the combined advantages of submerged plants and other life forms. Shallow water bodies and viewing needs within the city. Compared with submerged plants, emerging plants can remove a large amount of nitrogen and phosphorus in water because of their large biomass and strong adaptability, and have high ornamental value. Transfer from the system is often used for the restoration of landscape water bodies or water bodies with a high degree of eutrophication. The invention selects six ornamental emergent plants, and provides an application paradigm for plant screening and community construction of urban landscape water body restoration based on the interspecific competition effect and resource utilization efficiency of plants.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a plant screening and community construction method suitable for urban landscape water body restoration, the purpose of which is to provide a realization scheme for plant selection and configuration when constructing a plant community for urban landscape water body ecological restoration.

The technical scheme of the present invention to solve the above-mentioned technical problems is as follows: a plant screening method suitable for urban landscape water restoration, characterized in that the reproduction of ornamental emergent plants scallion, cattail, iris, calamus, canna, and reliflower is collected. The materials are planted and cultivated in the storage box loaded with the constructed wetland matrix in the following ways:

1) Each plant is planted in the storage box separately;

2) Plant the same plant combination in the growth type in the storage box;

Include the following steps:

1) Regularly add nutrition;

2) Monitor plant growth and water quality indicators;

3) Judging the competitiveness of different plant species according to the growth status of plants and the removal effect of nitrogen and phosphorus elements in the water, so as to screen.

The constructed wetland matrix is mainly composed of river sand. Rinse the river sand with tap water for 5-6 times until the effluent is clear. Soak the cleaned sediment with 0.2mol/L dilute hydrochloric acid for 1-2 days, and then use tap water and distilled water in turn. Flush to remove soluble nutrients in the sediment to prevent the original nitrogen and phosphorus in the sediment from affecting the measurement results.

The size of the storage box is 63cm long x 45cm wide x 39cm high, and each storage box is planted with 12 plants, so the planting density is 43.5 plants/m ² , and the rhizomes of the plants are fixed in 8cm deep sand and cultivated During this period, the water level was maintained between 14cm-18cm.

The growth environment of the plants is the still water condition of the greenhouse, the initial state of the culture water is 10% Hoagland nutrient solution, the total nitrogen concentration is 12mg/L, the total phosphorus concentration is 4mg/L, and the volume is 30L; During the month, the nutrient solution was added every 5 days, and ammonium chloride (NH ₄ CL) and potassium dihydrogen phosphate (KH ₂ PO4) were used as the components of nitrogen and phosphorus in the nutrient solution. The amount is 70mg, and the total amount of phosphorus is 10mg. For different plant combinations, the principle of quantitatively adding nitrogen and phosphorus and distilling the volume to a uniform water level with distilled water is adopted.

The incubator was placed in a greenhouse for cultivation. The temperature was set to 30 °C during the period of 8:00-20:00, and the temperature was set to 25 °C during the period of 20:00-8:00, and the humidity was controlled at 50%; at 8 During the period of :00-20:00, the plants were supplemented with sodium lamps, and good ventilation was maintained during the cultivation period.

A method for constructing a plant community suitable for urban landscape water restoration, characterized in that propagating materials of ornamental emergent plants scallion, cattail, iris, calamus, canna, and jasperia are collected, and mixed planting and cultivating in artificial plants loaded with artificial In the storage box of the wetland matrix, a community is constructed, and the ecological niche difference between different plants is used to weaken the competition among species and promote the absorption and utilization of nitrogen and phosphorus in eutrophic water by plants.

Beneficial effect: Plants with the same growth type are planted in combination, and in the case of similar ecological niches, the growth conditions of the plants are compared, and the plants with stronger competitiveness are screened out. At the same time, plants of different growth types are matched to form niche differences between plant communities, resulting in complementary niches of different types of plants in resource allocation and utilization, thereby promoting the absorption and removal of nitrogen and phosphorus by the community. Starting from the interspecific competition relationship and resource utilization efficiency of plants, we provide solutions for plant selection and community construction in water ecological restoration technology: (1) Plants of the same growth type are combined to determine their competitiveness, so as to determine their competitiveness. Screening of plants; (2) Use plants of different growth types to build communities, and improve the stability of the community and the effect of water restoration through the differences in their niches. These two schemes can be used in combination in practical applications. First, the plants of the same growth type are screened, and then the selected plants are matched with different growth types to construct the community, which can promote the stability of the community and the diversity of the landscape to the greatest extent. , At the same time improve the water body repair effect.

Detailed ways

The principles and features of the present invention are described below, and the examples are only used to explain the present invention, but not to limit the scope of the present invention.

A plant screening method suitable for the restoration of urban landscape water bodies, characterized in that the propagating materials of the ornamental emergent plants scallion, cattail, iris, calamus, canna, and Zaili flower are collected, and are planted and cultivated in the following manners respectively. In the storage box of the constructed wetland matrix:

1) Each plant is planted in the storage box separately;

2) Plant the same plant combination in the growth type in the storage box;

Include the following steps:

1) Regularly add nutrition;

2) Monitor plant growth and water quality indicators;

3) Judging the competitiveness of different plant species according to the growth status of plants and the removal effect of nitrogen and phosphorus elements in the water, so as to screen.

The constructed wetland matrix is mainly composed of river sand. Rinse the river sand with tap water for 5-6 times until the effluent is clear. Soak the cleaned sediment with 0.2mol/L dilute hydrochloric acid for 1-2 days, and then use tap water and distilled water in turn. Flush to remove soluble nutrients in the sediment to prevent the original nitrogen and phosphorus in the sediment from affecting the measurement results.

The size of the storage box is 63cm long x 45cm wide x 39cm high, and each storage box is planted with 12 plants, so the planting density is 43.5 plants/m ² , and the rhizomes of the plants are fixed in 8cm deep sand and cultivated During this period, the water level was maintained between 14cm-18cm.

The growth environment of the plants is the still water condition of the greenhouse, the initial state of the culture water is 10% Hoagland nutrient solution, the total nitrogen concentration is 12mg/L, the total phosphorus concentration is 4mg/L, and the volume is 30L; During the month, the nutrient solution was added every 5 days, and ammonium chloride (NH ₄ CL) and potassium dihydrogen phosphate (KH ₂ PO4) were used as the components of nitrogen and phosphorus in the nutrient solution. The amount is 70mg, and the total amount of phosphorus is 10mg. For different plant combinations, the principle of quantitatively adding nitrogen and phosphorus and making up the volume with distilled water to a uniform water level is adopted.

The incubator was placed in a greenhouse for cultivation. The temperature was set to 30 °C during the period of 8:00-20:00, and the temperature was set to 25 °C during the period of 20:00-8:00, and the humidity was controlled at 50%; at 8 During the period of :00-20:00, the plants were supplemented with sodium lamps, and good ventilation was maintained during the cultivation period.

A method for constructing a plant community suitable for urban landscape water restoration, characterized in that propagating materials of ornamental emergent plants scallion, cattail, iris, calamus, canna, and jasperia are collected, and mixed planting and cultivating in artificial plants loaded with artificial In the storage box of the wetland matrix, a community is constructed, and the ecological niche difference between different plants is used to weaken the competition among species and promote the absorption and utilization of nitrogen and phosphorus in eutrophic water by plants.

The specific experimental steps are as follows:

Six common emergent plants, Schoenoplectus tabernaemontani, Typha orientalis, Iris tectorum, Acorus calamus, Cannaindica and Thalia dealbata, are selected in the present invention from the same nursery. base. Select individual plants with moderate size and similar body shape. According to the growth type of different types of plants, trim them to similar heights. Wash the roots and leaves of the plants with distilled water to remove residual nitrogen and phosphorus and other nutrients, weigh and record them. Fresh weight. At the same time, the number of leaves of canna, Zailihua, calamus and iris, and the number of ramets of water onion and cattail were recorded. The remaining plants were selected and cultivated outdoors to supplement the dead plants. A transparent storage box of length 63cm x width 45cm x height 39cm was selected as a container for plant growth, and an 8cm thick sand layer was laid in the storage box to fix the plants. Each storage box was planted with 12 plants, and the planting density was 43.5 plants/ m ² . In order to prevent the original nitrogen and phosphorus in the sediment from affecting the measurement results, the river sand was washed with tap water 5-6 times in the early stage until the water was clear, and the washed sediment was soaked in 0.2mol/L dilute hydrochloric acid for 1-2 days to remove Soluble nutrients in the sediment, and then rinsed with tap water and distilled water in turn.

The present invention provides three planting modes, which are: single planting, two-species combination and six-plant mixed planting. The configuration results of plants in different ways are as follows: In monoculture, each plant was replicated 3 times, totaling 18 storage boxes. In the two-species combination, three types of plants with the same growth types were planted in combination: large (Zarya and Canna), slender (water onion and cattail), and fan-shaped (water iris and water calamus), each combination of 6 In a single repetition, there are 6 plants of each type, a total of 18 storage boxes. Among the six plant mixtures, 2 of each plant were planted, for a total of 12 plants of 6 species, and 18 repetitions of storage boxes were set up. Therefore, in the three planting methods, the number of repetitions of each plant is 36, and there are 54 storage boxes in total.

According to different combinations, the numbered plants were evenly planted in random positions of the storage box, and the storage boxes were randomly placed on the four seedbeds in the greenhouse, and 30L of 10% Hoagland nutrient solution was added for calibration. line markers. The total nitrogen concentration of the initial culture water was 12 mg/L, the total phosphorus concentration was 4 mg/L, and the nutrient concentration was higher than the standard of surface water category V. Using the sand layer as a starting point, measure and record the initial plant height. The temperature was set to 30°C during the day (8:00-20:00), 25°C at night (20:00-8:00), the humidity was controlled at 50%, and the plants were supplemented with sodium lamps during the day. Maintain good ventilation during cultivation and keep the water level between 14cm-18cm.

Nitrogen and phosphorus were additionally added to all storage boxes during the incubation period. Ammonium chloride (NH ₄ CL) and potassium dihydrogen phosphate (KH ₂ PO4) were used as the nitrogen and phosphorus components in the nutrient solution, and the same amount of nutrient solution with the same concentration was added to all storage boxes every five days, and the added amount was total nitrogen 70mg, total phosphorus 10mg, after adding, dilute the volume to the corresponding 30L mark with distilled water, stir well, take 20ml water samples from each of the four corners and the center of the storage box, and mix a total of 100ml water samples evenly. After taking the water samples, measure the concentration of total nitrogen and total phosphorus on the same day. The detection method of total nitrogen is potassium persulfate ultraviolet spectrophotometry, and the detection method of total phosphorus is molybdenum antimony anti-spectrophotometry. Methods of Analysis (Fourth Edition).

After two months of cultivation, all plants were harvested and the roots were cleaned of sediment, flowering individuals and dead individuals were recorded, and the morphological indicators of the plants were measured. The measurement indicators include: 1 plant height, 2 fresh weight, 3 number of leaves, and 4 number of ramets. The six kinds of plants have different growth patterns, and there are differences in measurement indicators. The number of leaves was measured for Canna, Zailihua, Iris and Iris, and the number of ramets was counted for Cattail, Scallion and Canna.

After two months of cultivation, the results were as follows:

(1) In the combined planting of water onion and cattail, both grow well. The plant height, fresh weight and ramet growth of water onion in combination planting were all larger than those in single planting, and the fresh weight growth was significantly different between the two planting methods, indicating that water onion grows better in combination planting. However, there was no significant difference in the indicators of cattail in combination planting and single species value, which indicated that although the two had the same growth type, there was no fierce interspecific competition, and even had a certain promotion effect. In terms of removal of nitrogen and phosphorus, the single planting of water onion removes 720.22 mg of total nitrogen and 138.20 mg of total phosphorus; the single planting of cattail removes 647.95 mg of total nitrogen and 133.57 mg of total phosphorus. The nutrient removal ability of water onion is slightly stronger.

(2) In the combined planting of iris and iris, the growth of iris was significantly better than that of iris. In the single species value, the plant height, fresh weight and leaf growth of iris are all larger than those of the combination planting, and the plant height and fresh weight are significantly different in the two planting methods, which indicates that the interspecific competition is stronger in the combination planting. Calamus is in a dominant position, while iris is less competitive. In terms of removal of nitrogen and phosphorus, the single planting of iris removed 684.62 mg of total nitrogen and 139.20 mg of total phosphorus; the single planting of iris removed 712.23 mg of total nitrogen and 160.99 mg of total phosphorus. Calamus has slightly stronger nutrient removal ability.

(3) In the combined planting of Canna and Zailihua, both grow well, the growth of canna ramets and leaves is higher than that of single planting, but the growth of plant height and fresh weight is smaller than that of single planting. The plant height, fresh weight and leaf growth of Zailihua were smaller than those of monoculture. This shows that the growth of the two plants in the combined planting is inhibited to a certain extent compared with the single planting, so that the growth conditions of the two plants in the combined planting are both weaker than those of the single planting. In terms of the removal of nitrogen and phosphorus in water, canna monoculture removed 791.20 mg of total nitrogen and 189.26 mg of total phosphorus; Zailihua monoculture removed 754.91 mg of total nitrogen and 144.66 mg of total phosphorus. The nutrient removal ability of canna is slightly stronger.

(4) In the mixed planting of the six plants, the plant height and ramet growth of Scallion were lower than those of single planting, and the growth of fresh weight was higher than that of single planting, which indicated that the growth of Scallion was equal in single planting and mixed planting. The plant height, fresh weight, plant height growth and survival rate of cattail were significantly lower than those of monoculture, indicating that the growth of cattail was inhibited in the mixed planting of six species. The plant height, fresh weight and plant height growth of iris were significantly lower than those of single planting, while the growth of iris plant height and fresh weight were higher than those of single planting, while the growth of leaves was lower than that of single planting, indicating that the growth of iris in mixed species was better than that of single planting. iris. The plant height, fresh weight and plant height growth of Canna and Zailihua were significantly higher than those of single planting, which indicated that both grew well in mixed planting.

(5) The mixed planting of the six plants has the best effect on the removal of nitrogen and phosphorus in the water body. In the two-month cultivation, the total nitrogen absorbed and removed was 756.07 mg, and the total phosphorus was 173.30 mg, accounting for 93% of the total amount added. With 91%, significantly higher than the average of six plant monoculture or combination planting. Under the condition of continuous addition of nitrogen and phosphorus, the nitrogen and phosphorus in the water body decreased from the initial total nitrogen of 12 mg/L and total phosphorus of 4 mg/L to 1.93 mg/L and 0.56 mg/L, respectively, which indicated that the growth of the six emergent plants The differences in the types of plants open up the niches between species, which further leads to the complementation of the ecological niches of different species of plants in resource utilization, and promotes the absorption of nitrogen and phosphorus by the community as a whole.

(6) In monoculture, there are differences in the ability of the six plants to remove total nitrogen and total phosphorus from water. The ability to remove nitrogen from large to small is: Canna, Zailihua, Scallion, calamus, iris and cattail. The abilities from largest to smallest are: canna, calamus, zailihua, water onion, iris and calamus.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection of the present invention. within the range.

Claims (6)

1. a kind of plant screening method that is applicable to the restoration of urban landscape water body, it is characterized in that, collect the breeding material of ornamental emergent water plants scallion, cattail, iris, calamus, canna, reli flower, plant and cultivate in the following manner respectively. In the storage box loaded with the constructed wetland matrix: 1) Each plant is planted in the storage box separately; 2) Plant the same plant combination in the growth type in the storage box; Include the following steps: 1) Regularly add nutrition; 2) Monitor plant growth and water quality indicators; 3) Judging the competitiveness of different plant species according to the growth status of plants and the removal effect of nitrogen and phosphorus elements in the water, so as to screen. 2. a kind of plant screening method suitable for urban landscape water restoration according to claim 1, is characterized in that, the artificial wetland matrix is mainly made up of river sand, and the river sand is washed 5-6 times with tap water until the water is clarified, and the The cleaned sediment is soaked in 0.2mol/L dilute hydrochloric acid for 1-2 days, and then washed with tap water and distilled water in turn to remove the soluble nutrients in the sediment, so as to prevent the original nitrogen and phosphorus in the sediment from affecting the measurement results. 3. a kind of plant screening method suitable for urban landscape water body restoration according to claim 1, is characterized in that, the size specification of the storage box is length 63cm × width 45cm × height 39cm, and each storage box is all planted with 12 plants, Therefore, the planting density was 43.5 plants/m ² , the rhizomes of the plants were fixed in the 8cm-deep sediment, and the water level was maintained between 14cm-18cm during the cultivation period. 4. a kind of plant screening method suitable for urban landscape water body restoration according to claim 1, is characterized in that, the growth environment of plant is greenhouse still water condition, and the initial state of cultivating water body is 10% Hoagland nutrient solution, its The total nitrogen concentration was 12mg/L, the total phosphorus concentration was 4mg/L, and the volume was 30L; during the two-month period of plant cultivation, the nutrient solution was added every 5 days, and ammonium chloride and potassium dihydrogen phosphate were used as the nutrient solution For the composition of nitrogen and phosphorus, the total amount of nitrogen in the nutrient solution added each time is 70mg, and the total amount of phosphorus is 10mg. For different plant combinations, the principle of quantitatively adding nitrogen and phosphorus and distilling the volume to a uniform water level is adopted. 5. a kind of plant screening method suitable for urban landscape water body restoration according to claim 1, is characterized in that, incubator is placed in greenhouse to cultivate, and the time period temperature of 8:00-20:00 is set to 30 ℃ , during the time period of 20:00-8:00, the temperature was set to 25 °C, and the humidity was controlled at 50%; the sodium lamp was used to supplement the light for the plants during the time period of 8:00-20:00, and good ventilation was maintained during the cultivation period. 6. A plant community construction method suitable for urban landscape water body restoration is characterized in that, collecting the propagation materials of ornamental emergent water plants scallion, cattail, iris, calamus, canna, and reliflower, and mixed planting and cultivating in the loading In a storage box with a constructed wetland matrix, a community is constructed, and through the niche differences between different plants, in order to weaken the competition between species and promote the absorption and utilization of nitrogen and phosphorus in eutrophic water by plants.