PK purification ability of 57 plants
Whether urban landscaping can reduce PM _ 2.5 and pollution gas in the air or not, and how to scientifically build green space that can improve urban ecological environment is an important topic for landscaping departments. The reporter learned that Nanjing Municipal Bureau of Greening and Landscape Architecture, together with Institute of Botany, Chinese Academy of Sciences and Nanjing University of Information Science & Technology, conducted an interdisciplinary quantitative study for the first time on the reduction of air PM2.5 and pollution gases by common urban landscaping trees and indoor green plants. It is understood that this experiment uses real-time online monitoring in artificial simulation room to test 33 common landscaping tree species and 24 green plants.
Outdoor Group Players: Landscape Plants
Among the "tall people", Pterocarya stenoptera won the laurel crown, and Gardenia was "small in size and strong in ability"
Number of participants: 33 species (including 2 1 species of trees and 0/2 species of shrubs).
Test content: the reduction of three harmful gases, such as PM2.5, sulfide and nitride.
Among the 33 kinds of landscaping plants participating in the experiment, there are common street trees such as Paulownia, Cedar and Cinnamomum camphora in Nanjing, as well as "high-value" ornamental trees such as cherry blossoms, magnolia and plum blossoms, and "short" shrub varieties such as gardenia and Michelia. However, in competition with the tall and straight "arbor group" players, will the petite "shrub group" players suffer because of their short stature? According to the experts who participated in the experiment, their experimental data are divided into two types: single plant and unit leaf area. The latter set of experimental data will make some plants with small body and strong ability stand out from the competition.
By comprehensive comparison, Ubuntu, Ginkgo biloba and Magnolia grandiflora have the highest absorption effects on the three harmful substances.
■ Post-match comments:
Chinese ash
A well-deserved "all-round player"
Among the PM2.5 absorption rates that people are most concerned about, Liriodendron chinense, Buxus macrophylla and Pterocarya stenoptera occupy the top three per plant, and Pterocarya stenoptera also occupies the first place in the list of absorbing sulfur dioxide and nitrogen compounds, which can be said to be well-deserved air purification plants. In the data of harmful substances absorbed per unit leaf area, the relatively small gardenia greatly exceeds other plants.
Indoor group player: domestic green plants
The "dark horse" bamboo absorbs nearly 90 {BF} of formaldehyde, and the "seed player" aloe vera is at the bottom.
Number of participants: 24 kinds
Test content: indoor formaldehyde absorption
For indoor air, the biggest harmful substance is formaldehyde. Which plants are experts in absorbing formaldehyde? The experimenter injected 2ppm units of formaldehyde into the fog box to observe the absorption of formaldehyde by plants within two hours. Dazhu, Liriodendron chinense and Rhododendron occidentalis ranked in the top three respectively, among which Dazhu, a "dark horse player", performed well in absorbing formaldehyde by nearly 90 {BF}.
On the contrary, the rankings of some "seed players" who are usually placed high hopes are not satisfactory. For example, the well-known green radish, chlorophytum, rubber tree and so on. None of them are ranked in the front, but Aloe Vera, advertised as a "formaldehyde absorption expert", is even more disappointing, with each plant ranking at the bottom in terms of its ability to absorb formaldehyde. In terms of formaldehyde absorption efficiency per unit leaf area, aloe is still not high, ranking seventh from the bottom. And Brazil Iron topped the list, and Bambusa also entered the top five in this ranking.
■ Post-match comments:
aloe
Indoor green plants still have a place.
It seems that aloe vera is really not an expert in absorbing formaldehyde. So, should people "delete" aloe from the list of indoor green plants? The expert believes that the function of indoor plants can not be measured by the single effect of absorbing formaldehyde. We should also see that aloe, as a domestic green plant, has other contributions, such as the balance of water and the release of oxygen by photosynthesis, so it cannot be "killed with one stick".
Interpretation of doubts by garden department
Do street trees still "reuse" the smog absorption efficiency of Fatong?
The contestant "young" and "adult" Fatong is not bad.
It is worth noting that in the data of absorbing PM2.5 per unit leaf area, Platanus acerifolia, a symbol tree species in Nanjing, ranks sixth from the bottom, and the ranking of absorbing sulfur dioxide and nitride is also the bottom. Is the role of Fatong in greening really the same as that in ranking?
Researcher Yu of Botanical Garden of Chinese Academy of Sciences told the reporter that it is unfair to compare Fatong with a leaf. "You can have a look. The absorption capacity of sulfur dioxide and nitride per plant ranks in the top three, and PM2.5 ranks ninth. Although its efficiency is not high in the test of unit leaf area, its ability to remove haze as a whole plant is still very strong. "
Yu also told the reporter that because the plant of Fatong was too big, the experiment used a relatively small Fatong. "The fatong of urban roads is twenty or thirty meters high, and the whole factory will absorb more pollutants. In addition, we plant street trees to purify the air, and the shading function of Fraxinus mandshurica in summer is irreplaceable by other tree species. Therefore, planting Fatong is still a good choice. "
Will they be allowed to "divide their work and cooperate" according to the results of this competition?
Factories and roads will send different tree species to "stand guard"
Zang Liangting, director of the Science and Technology Department of Nanjing Bureau of Greening and Landscape Architecture, told the reporter that the garden department began to cooperate with Nanjing University of Information Science & Technology Institute of Botany to carry out this experiment last year, and the results announced this time increased more tree species and green plants. "According to these data, we will also make green scientifically at work and plant different tree species according to different polluted environments, such as planting garden plants with strong reducing ability in factories with heavy sulfur dioxide pollution and surrounding residential areas. For roads with large exhaust emissions and traffic flow, greening options have a strong ability to reduce nitrogen. "
Director Zang said that the design of pure lawn has been less and less used in the construction of green space in Nanjing. After understanding the efficacy of plants, we can choose trees and shrubs with strong air purification ability to "join hands" and plant these trees to eliminate pollutants in the air to the maximum extent and bring cleaner air to the public. (Source: China Daily)