Su Zequn, after listening to Lü Chuanting's speech, said that the current greening rate in Guangzhou has reached 35.5%, but many newly approved residential areas only have a 30% greening rate. Su joked with Lü Chuanting, who is from the planning department, saying: "In the future, don't approve any residential area with a greening rate of less than 35%."
Experts point out that Guangzhou commonly uses only about 50 types of greenery plants and species diversity should be strengthened.
"Why can't Guangzhou grow willow trees well? Why are there more and more cases of banyan trees having curled leaves? These are all related to pest infestations caused by species uniformity," said Xing Fuwu. He explained that all organisms in nature coexist and check each other. Different kinds of plant fruits attract different types of birds. While eating the fruit, these birds also help plants fight against pests. However, if the plant species are too uniform, fewer birds will appear, and the chance of plants getting pest diseases will relatively increase.
What harm does insufficient plant species diversity cause? Xing Fuwu pointed out that the large-scale pest infestations on white orchids and palm family plants in Guangzhou over the past two years were related to species uniformity. According to their observation studies, parks in Guangzhou that widely planted white orchids have all encountered a pest called "Egyptian scale insect." This insect likes to attach itself to the leaves of white orchids, and when the wind blows, it looks like dandruff floating around. In addition, white orchid trunks and branches are often harmed by "white orchid aphids." However, if two or three white orchids are reasonably mixed with multiple broadleaf tree species, the "Egyptian scale insect" and "white orchid aphid" would be less likely to be found.
Su Zequn also revealed that Guangzhou plans to increase flower forests in suburban scenic forests. Currently, the Guangzhou Forestry and Landscape Bureau has planned 30 themed "flower seas" distributed across ten districts and two cities in Guangzhou, with each "flower sea" blooming at different times. In the future, Guangzhou residents will have different flowers to enjoy every month.
After the "big change" for the Asian Games, Guangzhou has become more beautiful and greener. According to relevant research reports, Guangzhou's "heat island effect" is showing a yearly decreasing trend.
Banyan trees can be seen everywhere in Guangzhou, but experts say they are "a bit monotonous." Photo by Wu Weihong.
For the next five years, how will Guangzhou continue to add greenery? How will it create a "four-seasons flower city"? Yesterday, the expert seminar on the "12th Five-Year Plan Development Plan for Guangzhou's Forestry and Landscaping" was held. It is understood that during the "12th Five-Year Plan" period, Guangzhou will build an ecological corridor of "three verticals and five horizontals," promote the "wall removal and green exposure" of more than 60 parks, and construct 30 urban "flower seas." The seminar was presided over and addressed by Su Zequn, the standing committee member of the Guangzhou Municipal Committee and the executive vice mayor of Guangzhou.
Lü Chuanting said: "Guangzhou's greenery needs to develop from 'sporadic' to 'omnipresent.' It should build a green network just like building a road network, allowing greenery to integrate into living environments. Only then can such greenery truly enhance people's quality of life."
Each district must promote at least one park "wall removal" per year.
The plan will form an overall layout of "two enclosures, three verticals, and five horizontals."
Su Zequn pointed out that as the "Flower City," Guangzhou still lacks flowering plants, and urban landscaping should increase flowering plants. "Landscaping should use flowers where necessary. Some media asked whether spending 90 million yuan annually on flowers is too much. I think, as long as it meets the needs of our city and is financially sustainable, this money isn't excessive. More flowers in the city, I believe, most citizens will like."
"Five horizontals" refer to five east-west oriented ecological corridors, from north to south: "Northern Mountain Front Buffer Zone," "Pearl River Front and Rear Channels" ecological corridor, "Jinshan Avenue - Lotus Mountain" ecological corridor, "Shawan Water Channel - Seagull Island" ecological corridor, and "Hengli Water Channel - Fu Zhou Water Channel" ecological corridor.
Lu Chuanting, Director of the Guangzhou Urban Planning Compilation and Research Center, said that during the "11th Five-Year Plan" period, the green space rate in Guangzhou's built-up area only increased by 2 percentage points, but people felt that it became much greener. This was because the "wall removal and green exposure" introduced parks into the city, the demolition of illegal buildings to construct small green spaces made the greenery around residents increase, and the greening of government departments and units was opened to the public, turning "private gardens" into "public gardens." Although the amount of greenery added through various forms of landscaping wasn't very high, it achieved excellent ecological and landscape benefits.
Currently, the "wall removal and green exposure" projects in parks are mainly divided into three categories based on their own functional needs along specific sections: First, remove existing walls, using terrain shaping, planting flowering trees and shrubs, and herbaceous flowers of Lingnan gardens to renovate the slopes of green spaces between parks and main city roads, exposing the park's scenery, such as the Renmin Road section of Liuhu Lake Park; Second, utilize the original topography and geomorphology to transform solid walls into invisible fences, adding flowering plants, such as the Dongfeng Road section of Martyrs Cemetery; Third, beautify the landscape on the original ground, transforming dense outer green belts into transparent green belts, relocating dense outer trees and shrubs, reshaping the freed-up grounds' terrain, increasing the planting of flowering plants, and constructing garden paths and benches, etc., facilitating citizens' leisure and exercise, such as Zhujiang Park and the Dongxi Road section of Liuhu Lake Park.
Chief Researcher Xing Fuwu of the South China Botanical Garden of the Chinese Academy of Sciences said that Guangzhou, after the "big change," feels "much greener." But in his view, Guangzhou's greenery is somewhat monotonous. "Both sides of the Pearl River in Guangzhou are all banyan trees. Actually, there are many native tree species suitable for planting in waterfront areas. Why only think of planting banyan trees?"
"Three verticals" refer to three north-south oriented ecological corridors, from west to east: "Hongqi Li - Dafushi Mountain - Fangcun Flower and Fruit Area - Liuxi River" ecological corridor, "Jiaomen Water Channel - Nansha Port Expressway - Ten Thousand Mu Fruit Protection Area" ecological corridor, and "Simyang Ocean - Dongjiang River - Zengjiang River" ecological corridor.
Last year, Guangzhou successively demolished the walls of Zhujiang Park, Tianhe Park, Yuexiu Park, Liuhu Lake Park, and Martyrs Cemetery, making the parks seamlessly connect with the roads, achieving good landscape effects. According to the "12th Five-Year Plan," Guangzhou will continue to promote the "wall removal and green exposure" of urban parks, completing at least one per district each year. By calculation, in the next five years, Guangzhou will promote the "wall removal and green exposure" of at least 60 parks.
"There are too many banyan trees planted along both sides of the Pearl River, it's too monotonous!" Chief Researcher and Doctoral Supervisor Xing Fuwu of the South China Botanical Garden of the Chinese Academy of Sciences bluntly stated at yesterday's "Guangzhou Forestry and Landscaping '12th Five-Year Plan' Development Plan" seminar that Guangzhou commonly uses only about 50 types of greenery plants, while developed countries generally reach 500 to 1000 types, leading to Guangzhou being "green indeed, but monotonously green."
The initial draft of the "Guangzhou Forestry and Landscaping '12th Five-Year Plan' Development Plan" has been completed. The plan clearly states that by 2015 during the "12th Five-Year Plan" period, Guangzhou's forest coverage rate should reach 42%, the total volume of forest stockpile should reach 14.26 million cubic meters, the green space rate in the built-up area should reach 36%, the green coverage rate in the built-up area should reach 41.5%, and the per capita park green space area should reach 16.5 square meters.
"The decrease in the 'heat island effect' is inseparable from Guangzhou's recent efforts in surrounding the city with forests and increasing green areas," said Su Zequn. Guangzhou should further "develop potential," and while removing illegal buildings in old urban areas, use the freed-up land for greening. "We need to make the public realize that 'building illegal structures doesn't increase house area, but decreases green area.'"
"Two enclosures" include the outer and inner enclosures. The outer enclosure refers to establishing regional cooperation through continuous mountain bodies in the northern part of Guangzhou, coastal mudflats, coastal protective forests, farmland water networks in the southeastern part, and farmland forest networks, roads, and waterways in the western part. The inner enclosure forms a green city-surrounding belt along the second ring expressway - Ba River - Pearl River West Channel, encompassing seven districts of Guangzhou.
"Wall removal and green exposure" involves integrating some park green spaces along the main city roads with road greenery through comprehensive environmental and landscape improvements in the city, gradually dismantling the enclosed walls around some municipal parks so that pedestrians on the road can admire the beautiful garden landscapes within the walls, merging park landscapes with urban street views into one harmonious whole.
Xing Fuwu said that Guangzhou applies more than 300 types of plants for urban greening, but only about 50 types are common. Research results indicate that merely in Guangzhou, there are over 1500 types of wild plants applicable for greening, compared to which the common 50 types are just "a drop in the bucket," and most are foreign-introduced species.
The preliminary draft of the "Guangzhou Forestry and Landscaping '12th Five-Year Plan' Development Plan" explicitly states that during the '12th Five-Year Plan' period, by 2015, Guangzhou's forest coverage rate should reach 42%, the green space rate in the built-up area should reach 36%, the green coverage rate should reach 41.5%, and the per capita park green space area should reach 16.5 square meters.
It is understood that the "Guangzhou Forestry and Landscaping '12th Five-Year Plan' Development Plan" will incorporate expert suggestions, modify accordingly, and then be submitted to the Guangzhou Municipal Government for deliberation.
White orchids shedding "dandruff" due to species uniformity
"To improve species diversity, the role of the government is very important! Led by the government, promoting industry-university-research cooperation, forming a research, planning, construction, and nursery production industrial chain," Xing Fuwu urged that scientific research is the driving force behind promoting diversity, as all wild plants need to go through processes such as introduction, domestication, evaluation, and screening before they can be applied to greening. The government should increase investment in greening scientific research. "Once plant diversity enriches, Guangzhou can achieve the realm of 'flowers in all four seasons, bird songs, and floral fragrances,' making the Flower City even more beautiful."
According to the monitoring of the Chinese Academy of Forestry Sciences, the increase in quantity and improvement in quality of urban greenery have significantly enhanced Guangzhou's urban ecological carrying capacity. In recent years, the "heat island effect" has shown a yearly decreasing trend. The area with temperature differences greater than 1.2°C has stopped expanding, and the area with temperature differences greater than 1.6°C has started shrinking. The annual carbon dioxide fixation of the city's forest ecosystem reaches 194.991 million tons, accounting for 35.40% of the city's annual carbon dioxide emissions, while simultaneously releasing 141.812 million tons of oxygen. The current forest produces an annual water output of 7.638 billion tons, accounting for 58.11% of the city's total annual water output. The underground runoff in urban forest areas accounts for 49.63% of the city's total runoff. Annually, it purifies 102,900 tons of sulfur dioxide in the atmosphere, equivalent to 60.39% of the city's total sulfur dioxide emissions, absorbs 3,263.86 tons of fluorides, and actually retains 13,300 tons of dust, equivalent to 21.99% of the city's total industrial emissions.