The dead surface combustibles of artificial coniferous forests in Chengde were focused in this paper.Predicting models between fuel loading and the stand and landform factors,as well as between water ratio of combusti...The dead surface combustibles of artificial coniferous forests in Chengde were focused in this paper.Predicting models between fuel loading and the stand and landform factors,as well as between water ratio of combustibles and weather factors were established with a regression analysis method.The models were effective in calculating fuel loading and water ratio.Fuel loading,water ratio and thickness of combustibles are regarded as the parameters of potential surface fire behavior.Based on a cluster analysis,the potential surface fire behavior of different forest lands was divided into 3 classes:strong,medium,or weak surface fire.The results indicated that most of artificial coniferous forests were in the status of medium surface fire,the risk of surface fire of mixed forests was lower than pure forests,and that of sapling forests and half-mature forests was higher than near-mature forests.展开更多
This study mainly investigatied the geographical distribution patterns of Dastarcus helophoroides in China and analyzed the thresholds of temperature and humidity in its distribution regions, to provide a theoretical ...This study mainly investigatied the geographical distribution patterns of Dastarcus helophoroides in China and analyzed the thresholds of temperature and humidity in its distribution regions, to provide a theoretical basis for employing %D.helophoroides% in controlling long-horned beetles. In China, %D.helophoroides% distributed in the regions from the north, Meihekou City(41°41′ N) of Jilin Province to south, Shenzhen City(22°38′ N) of Guangdong Province, and from west, Zhongning county(105°40′ E) of Ningxia Huizu Autonomous Region to east, Meihekou City(125°54′ E) of Jilin Province. The insect distributed widely in Guangdong, Jiangsu, Anhui, Hebi, Henan, Shanxi, Shandong, Ningxia, Shannxi, Beijing, Jilin and Liaoning. The annual mean temperature in the distribution regions was higher than 5.4 ℃, the average temperature in July was above 22.6 ℃, the average temperature in January is higher than -15.2 ℃, and the extreme low temperature was -36.8 ℃. The annual humidity in the distribution regions was above 47.2% and the annual precipitation was above 186.3 mm.展开更多
文摘The dead surface combustibles of artificial coniferous forests in Chengde were focused in this paper.Predicting models between fuel loading and the stand and landform factors,as well as between water ratio of combustibles and weather factors were established with a regression analysis method.The models were effective in calculating fuel loading and water ratio.Fuel loading,water ratio and thickness of combustibles are regarded as the parameters of potential surface fire behavior.Based on a cluster analysis,the potential surface fire behavior of different forest lands was divided into 3 classes:strong,medium,or weak surface fire.The results indicated that most of artificial coniferous forests were in the status of medium surface fire,the risk of surface fire of mixed forests was lower than pure forests,and that of sapling forests and half-mature forests was higher than near-mature forests.
文摘This study mainly investigatied the geographical distribution patterns of Dastarcus helophoroides in China and analyzed the thresholds of temperature and humidity in its distribution regions, to provide a theoretical basis for employing %D.helophoroides% in controlling long-horned beetles. In China, %D.helophoroides% distributed in the regions from the north, Meihekou City(41°41′ N) of Jilin Province to south, Shenzhen City(22°38′ N) of Guangdong Province, and from west, Zhongning county(105°40′ E) of Ningxia Huizu Autonomous Region to east, Meihekou City(125°54′ E) of Jilin Province. The insect distributed widely in Guangdong, Jiangsu, Anhui, Hebi, Henan, Shanxi, Shandong, Ningxia, Shannxi, Beijing, Jilin and Liaoning. The annual mean temperature in the distribution regions was higher than 5.4 ℃, the average temperature in July was above 22.6 ℃, the average temperature in January is higher than -15.2 ℃, and the extreme low temperature was -36.8 ℃. The annual humidity in the distribution regions was above 47.2% and the annual precipitation was above 186.3 mm.
