Firmly believe that the green mountains do not put "pine"

This is a protracted "forest defense war".

In late autumn, the red maple leaves on the top of the mountain are a landscape, but if a pine tree turns yellow or even turns reddish brown, it is not a symbol of seasonal change, but a "disease": pine wood nematode disease.

Pine trees - Zhejiang afforestation pioneer tree species, the total area of pine forests in the province exceeds 50 million mu, accounting for almost half of the total forest area of the province. For every 1 cubic meter increase in forest stock, an additional 1.83 tons of carbon dioxide can be fixed accordingly. Not long ago, the central government issued a heavy document on carbon peaking and carbon neutrality, and by 2025, the forest coverage rate will reach 24.1%, and the forest stock will reach 18 billion cubic meters, laying a solid foundation for achieving carbon peaking and carbon neutrality.

Falling down a pine tree often takes decades or centuries to grow back. Since the invasion of pine wood nematodes in Ningbo Xiangshan County in 1991, the "struggle" with pine wood nematodes has lasted in Zhejiang for 30 years.

Race against time

Let the fallen pine trees be fewer

In the blink of an eye, the 56-year-old Wu Dacheng quickly jumped into the canopy. In the gap between the pine branches and the pine branches, he skillfully tied the rope, and the team members pulled the rope and applied force in the direction of the pine tree dumping, and within 5 minutes, the pine tree was sawn off and disposed of on the spot.

This is the daily routine of the forest pest and disease control team in Jingning County, Lishui, and when the reporter met them in Chengzhao Township, this team was already dealing with the third diseased tree of the day. Zhang Guangjin, the leader of the team, has led the team members to guard the 1.61 million mu of pine-related woodland in the county since 2009. The discovery of a diseased tree, the cleaning of a tree, from the first time the disaster in Jingning "emerged", this team of only 25 people at most, blocked the spread of the disaster in the county, making Jingning one of the most effective districts and counties in the province to prevent and control pine wood nematode disease.

Pine wood nematode disease is an infectious disease that is an invasive alien forest disaster. If a diseased tree is not cleaned up in a timely and thorough manner, it can easily spread into a disaster. In the 2012 State Forestry Administration's "Standards for the Infestation of Major Forest Pests", pine wood nematode disease was listed as the first plant disease among "important (typical) pests". What is more noteworthy is that the criteria for the occurrence of other pests are based on the percentage as a quantitative indicator, except for pine wood nematode disease, which is only defined and expressed in only 10 words of "pine wood nematode infection strain", which is characterized as "disaster".

"One plant is a disaster", which shows the great harm. Zhejiang's various measures are hoping to achieve the goal of "no disaster if there is a disease", so that the epidemic of pine wood nematode disease can be prevented and controlled. An important part of this is that on top of the prevention and control model of centralized cleaning in the winter and spring from October to March of the following year, the "increase" is the normalized governance model of death and cleanup.

The change of pattern is based on the understanding of biological laws. Shen Yuanhua, an expert at the Zhejiang Provincial Forest Disease and Pest Control Station, told reporters that one of the "culprits" of pine wood nematode disease is that pine brown tianniu likes to choose robust pine trees for food and supplement nutrition, and the pine wood nematodes carried on it can make pine trees die quickly.

"This combination of invasions has upset the natural balance established by the natural system." He told reporters that the Tianniu larvae parasitize on dead pine trees, usually after feathering in April and May of the following year, that is, after the "on-line" model of death and clearance, the disposal effect of various places has been significantly improved. The data shows that after the effective prevention and control in the spring of 2020, in the autumn of 2020 (according to the cleaning time, referring to November to March 2021), the disaster situation in Zhejiang Province appeared for the first time "inflection point", and the scope of clean-up and the intensity of clean-up reached the highest in the history of prevention and control in 30 years.

However, the phenomenon of large-scale dead pine trees in patches and contiguous areas has been effectively contained as only a "preliminary victory". Chen Weiping, deputy director of the Zhejiang Provincial Forest Disease and Pest Control Station, told reporters that in the past 30 years, pine wood nematode disease in Zhejiang Province has shown a trend of evolution from northeast to southwest. According to the epidemic monitoring, the first northeast of Zhejiang to be invaded, the current high incidence of the epidemic has been effectively contained, the degree of harm has been greatly reduced, but the pine forest resources are more abundant in the central and southwestern parts of Zhejiang, the future epidemic prevention and control situation is still very grim.

"The mountainous terrain in southwest Zhejiang is higher, and it will be more difficult to control than in the northeast." He said that pine wood nematodes have strong stress resistance and plasticity, and the rich pine forest resources and natural climate environment in Zhejiang Province are more suitable for the occurrence of pine wood nematode disease epidemics, and the race against time is still one of the keys to the prevention and control of pine wood nematode disease in Zhejiang in the next period of time.

Jingning has built a protective cordon with the participation and coordination of the whole people, and the 303 rangers and actively participating people in the county are the "eyes" for the prevention and control of pine wood nematode disease. Liu Liyuan, director of the forestry workstation in Wutong Township, Jingning County, has recently received 3 phone calls, all from the same village, and the "report" is the same tree. He quickly went to the site to survey and take samples and reported to the county forest plant quarantine station. Once there is a confirmed disaster situation, the phone of Zhang Guangjin, the leader of the exclusion team, will ring.

For more places, the latest implementation of the forest chief system in Zhejiang Province clearly proposes to establish and improve the local government responsibility system for the prevention and control of major forestry pests, and the prevention and control of pine wood nematode disease has been incorporated into the disaster prevention and mitigation and relief system, which has become an important component of the main task of the forest chief.

Improve the "granularity" of control

Prevention and control use digital weapons

Prevention and control work should be timely and of high quality. Since the discovery of the pine wood nematode disease epidemic in Zhejiang in 1991, most counties and cities with pine forests have been affected.

Before 2019, the epidemic situation of pine wood nematode disease in Liandu District of Lishui City doubled for three consecutive years, and the local government was determined to completely reverse the unfavorable situation of prevention and control.

Lishui is the area with the richest forest resources in Zhejiang. In the "Lishui Green and Low Carbon Demonstration Action Plan" previously released by Lishui City, the forest carbon sequestration and sink increase action has become one of the 20 local actions around the carbon peak system, and the realization of the value of forest carbon sinks and the innovation of carbon sink ecological product trading are based on the premise of preserving forest resources.

To preserve ecosystem resources, we first need to find out the "bottom of the family". In May last year, Liandu District pioneered the "Yunsen Defense" precision intelligent control integrated management platform in the province, using the purchase of social services, liandu district ecological forestry development center with the help of drones and shuttles, the forest resources of the whole district were carefully explored.

The increase in "granularity" can be controlled so that the cleanup of sick and dead trees can be targeted. Ye Mingwang, director of the Liancheng Forestry Work Center Station in Liandu District, said that the census of forest resources is only one month, and it is basically impossible to climb through the mountains and forests in the area under the jurisdiction of the workstation during this period. A "stupid approach" they had previously used was to monitor 5 sick and dead trees in an area and estimate them according to the "sampled" trees and total area. Now it's different, and the location of each sick and dead tree can be located.

"Remote areas in the past may have been difficult to find or clear in place, but since last year we have basically achieved full coverage." The relevant person in charge of the forest disease and pest prevention and quarantine station of the Liandu District Ecological Forestry Development Center told reporters that according to the epidemic area, the whole district is divided into three types of priority areas for treatment, and then according to the handling distance, the ground conditions, etc., the three cleaning difficulty levels of A, B and C are divided, and additional subsidies are provided for the cleaning of high difficulty and high-risk points. By the end of April 2021, the speed, quantity and quality of mountain field cleaning in the whole district are the highest in the calendar year.

The introduction of new technologies and the exploration of digital empowerment of prevention and control work are blossoming all over Zhejiang. In Jinhua Yongkang, the local comprehensive use of satellite remote sensing, UAV aerial surveys, interforestry sensors, ground manual surveys and other technologies to achieve all-weather monitoring of 140,000 acres of pine forests. In the helmet of Li Chengshi, head of the Forest Green Disease and Pest Control Service Department in Yongkang City, there is also a positioning chip hidden, and through GPS trace technology, the clean-up footprints of each member of the extermination team will be recorded in detail, and each diseased wood transport vehicle has also achieved digital management.

"We can superimpose the pine wood nematode disease epidemic data into a map of forest resources, draw a three-color map, realize the dynamic management of the diseased wood, and carry out statistical analysis of the pine wood nematode disease data and the management of the growth of the diseased wood." Wang Zhengming, director of the Forest Disease and Pest Control and Quarantine Station in Yongkang City, said that Yongkang also implements closed-loop management of the whole process of cleaning up the diseased wood, and these data will provide a basis for the preparation of the annual prevention and control plan.

"If we truly implement high-quality eradication, it is possible to achieve a cliff-like decline in the area and number of strains of pine wood nematode disease in the province within two to three years." Chen Weiping said that based on the exploration of various places, Zhejiang is building a provincial-level forest prevention platform, and the prevention and control work of the whole province has also changed from extensive and low-quality control to intensive, high-quality full-scale prevention and control.

Hold the landscape

The beauty of each is the best of both worlds, and the beauty of the United States is the same

Walking into the core scenic spot of Xikou in Fenghua, Ningbo, the lush masson pine forest on both sides of the ancient road is a rare scenery. Mao Lan, a forest insect-proof greening consultant at Xikou National Forest Park, pointed to an area for reporters: In 2000, 73 dead pine trees with a chest diameter of more than 45 centimeters were found here. From last year to now, the record of tree cutting in the scenic spot has remained zero.

For major scenic spots and key ecological areas, pine wood nematode disease has to be prevented. Taking Xikou Forest Park as an example, there are more than 80 pine trees in the area with an age of more than 100 years, more than 5,000 trees over 80 years old, and more than 20,000 trees over 50 years old, accounting for nearly 80% of the pine forest area. A "stroke" may cause continuous disasters, and because of this, the Huangshan Mountain Scenic Area in Anhui, which is famous for its Huangshan Pine, has been hanging a slogan saying "All pines and their products are strictly prohibited from entering" many years ago.

Of course, the significance of guarding the landscape lies not only in the landscape, but also in the emergence of a beautiful economy. "The scenic spot is famous for the pine tree landscape, if the pine trees are sick, how can the scenic spot attract tourists?" Mao Lan said that since 2003, the Xikou scenic spot has begun to "hang water" for pine trees, which is like vaccinating people, focusing on prevention. After 2006, the Xikou scenic spot went further, using a comprehensive prevention and treatment method, using immune injections, and "inviting" two organisms, namely flower velvet beetles and swollen leg bees that feed on pine brown tianniu.

"In the whole country, Zhejiang is the first province to start using injections to prevent pine wood nematode disease." Shen Yuanhua told reporters that the drug initially needed to be imported, and the price of a single drug was about 50 yuan, and now, the province has cultivated a number of pharmaceutical companies, and the cost of each drug has dropped to about 10 yuan. In 2017, Zhejiang also issued a special normative management document. Pine needles have indicators, files, and corresponding assessment rewards and punishments, in recent years, the province has been "vaccine" pine trees, the survival rate remains above 99%.

In many areas of the province that have been cleaned up, more broad-leaved trees and precious tree species have replaced the former pine trees and created a new green. But this is not a common approach. In the Ningbo Songlan Mountain Coastal Tourist Resort in Xiangshan County, the hills along the coast are clustered with greenery. These dwarf pine trees are the main force of wind and sand fixation in this scenic area, and their diminutive posture is not because of their young age, but because they grow on the seashore, the soil layer is thin, and the combination of coastal climate.

"In Zhejiang Province, there are many such coastal areas, and only pine trees can survive and grow in such a harsh environment, and once these pine trees are infected and die, some places will become barren mountains." Chen Weiping said that in the early stage of the epidemic of pine wood nematode disease found in Xiangshan, there was no corresponding prevention and control experience in various places, so it suffered great losses, and in the next few years, Zhejiang will strive to make up for the "short board" of pine wood nematode disease prevention and control in the island area, guard the green coastline, and further tap the advantages and potential of the sea.

The continuous prevention and control of pine wood nematode disease is not for the "independent" of Zhejiang, but for the ecological security of nearly 900 million mu of pine forest resources in the country. At the 2021 Yangtze River Delta Eco-Green Integrated Development Demonstration Zone Developer Conference held at the end of September this year, the three provinces of the Yangtze River Delta jointly signed the "Joint Announcement on mutual recognition and mutual recognition of forest pest quarantine in Shanghai, Jiangsu, Zhejiang and Anhui", and from now on, the quarantine requirements of forestry pests in Shanghai, Jiangsu, Zhejiang and Anhui provinces are required to implement mechanisms such as "one-time proposal, one-year validity", full coverage of quarantine registration, shared quarantine list of origin, joint quarantine traceability, and joint credit supervision.

The joint prevention and treatment of pine wood nematode disease in the three provinces of Jiangsu, Zhejiang and Anhui is the earliest regional joint prevention mechanism established in the country, which is still running well and the joint prevention and control objects of the joint defense area are constantly expanding. The relevant person in charge of the Forestry Bureau of Jiangsu Province said that the mutual recognition and interoperability mechanism will greatly improve the efficiency of forest transportation and quarantine and the level of quarantine supervision in the Yangtze River Delta region, and more than 1 million forestry production and operation entities will benefit from it.

Source: Zhejiang Daily