林地基本信息 Basic info
位置 Location： 库伦旗六家子镇三道洼 Sandaowa,Liujiazi,Kulunqi
树种 Species：杨树 Poplar
In the autumn of 2019, Liujiazi Tree Farm informed us that there had been large-scale tree pest and disease breakout in the forest where our 2010-1 forest site was located. It required emergency cutting down and later replanting. We sampled and examined the trees in the site on October 11. Among the randomly-sampled 1532 trees in the site, 513 trees had mild symptom or none, but the left 1019 trees all suffered moderate to severe tree disease (preliminarily estimated to be Agrobacterium tumefaciens). 67% of poplars in the forest were in serious condition.
图 1 树干上的冠瘿病 ——————————————图 2 树干枯朽，树皮脱落
Image 1. Agrobacterium tumefaciens on the trunk -------------------Image 2. Rotten trunk and tree bark peeling off
According to Low-Function Forest Improvement Technology Regulations LYT1690-2007, low-function forest is regarded as follows:
4.2.2 By suffering severe pest attack, drought, floods, or natural disaster such as heavy wind, snow or fire, the affected dead trees, including dying trees take up over 20% of the overall stands.
In this case, the forest was categorized into low-function forest and required cutting and replanting.
The city-level Forestry Bureau evaluated the forest regarding pest and disease according to Forest Disease and Insect Pest Prevention and Control Regulations. The Evaluation document is showed below. To prevent the disease from spreading, the tree farm executed the cutting work.
图 3 林地鉴定书
Image 3. Evaluation by Kulun Nature Resource Bureau Forest Station
图 4 六家子林场进行了人工采伐（12月10日）
Image 4. Liujiazi Tree Farm Excecuted Cutting Work (taken on December 10, 2019)