采用AFLP技术对平泉县的1个油松-落叶松混交林和2个油松纯林中油松毛虫(Dendrolimus tabulaeformis Tsai et Liu)的135个个体进行了遗传多样性和遗传结构的研究,并调查了3个油松林群落的各种环境条件。结果表明,纯林中油松毛虫种群的遗...采用AFLP技术对平泉县的1个油松-落叶松混交林和2个油松纯林中油松毛虫(Dendrolimus tabulaeformis Tsai et Liu)的135个个体进行了遗传多样性和遗传结构的研究,并调查了3个油松林群落的各种环境条件。结果表明,纯林中油松毛虫种群的遗传多样性高于混交林中的油松毛虫种群;林木生长状况为影响不同油松纯林群落中油松毛虫种群遗传多样性的重要因素;混交林对油松毛虫种群之间的基因流有阻断作用,油松毛虫种群的基因流大小与油松林之间的物种多度呈反相关。展开更多
植物与植食性昆虫在长期的协同进化过程中形成既复杂又微妙的关系。以往关于植物对昆虫的防御反应及机制的研究较为深入,但关于昆虫对植物抗性的反防御反应近年来才受到关注,尤其是昆虫对植物诱导抗性反应的研究已有明显进展(Mainguet ...植物与植食性昆虫在长期的协同进化过程中形成既复杂又微妙的关系。以往关于植物对昆虫的防御反应及机制的研究较为深入,但关于昆虫对植物抗性的反防御反应近年来才受到关注,尤其是昆虫对植物诱导抗性反应的研究已有明显进展(Mainguet et al.,2008;Zeng et al.,2008)。当植物产生防御物质时昆虫能利用自身代谢系统对食物中的有害物质进行解毒和排毒,大大削弱了植物的诱导抗性在害虫防治过程中的作用强度(王琛柱等,2007),所以,在研究植物与昆虫之间的作用关系时,对昆虫本身防御机制的研究是必不可少的。展开更多
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
文摘采用AFLP技术对平泉县的1个油松-落叶松混交林和2个油松纯林中油松毛虫(Dendrolimus tabulaeformis Tsai et Liu)的135个个体进行了遗传多样性和遗传结构的研究,并调查了3个油松林群落的各种环境条件。结果表明,纯林中油松毛虫种群的遗传多样性高于混交林中的油松毛虫种群;林木生长状况为影响不同油松纯林群落中油松毛虫种群遗传多样性的重要因素;混交林对油松毛虫种群之间的基因流有阻断作用,油松毛虫种群的基因流大小与油松林之间的物种多度呈反相关。
文摘植物与植食性昆虫在长期的协同进化过程中形成既复杂又微妙的关系。以往关于植物对昆虫的防御反应及机制的研究较为深入,但关于昆虫对植物抗性的反防御反应近年来才受到关注,尤其是昆虫对植物诱导抗性反应的研究已有明显进展(Mainguet et al.,2008;Zeng et al.,2008)。当植物产生防御物质时昆虫能利用自身代谢系统对食物中的有害物质进行解毒和排毒,大大削弱了植物的诱导抗性在害虫防治过程中的作用强度(王琛柱等,2007),所以,在研究植物与昆虫之间的作用关系时,对昆虫本身防御机制的研究是必不可少的。
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.