论文部分内容阅读
对安徽省国外松大面积衰退和枯死原因的调查研究表明 ,造成这种衰退和枯死的现象是多方面因素共同作用的结果 ,是一种林木衰退病 .该衰退病的发生原因 :1)诱发因素 :温度年较差较大、年降雨量分布不均匀、土壤粘重板结或容重过大、地势低洼积水、土壤瘠薄、林分密度过大 ;2 )激化因素 :干旱严重重复发生、割脂过早过度、霜冻、食叶害虫等害虫危害 ;松针褐斑病等病害侵害 ;3)促进因素 :松枯梢病菌、根腐病菌、立木腐朽病菌、天牛、小蠹虫等病虫害危害 .
A survey of the causes of large-area dilapidation and withering in large-scale areas outside Anhui Province shows that the causes of such decline and withering are the result of a combination of various factors and are a kind of tree decline disease. The causes of this decline disease are as follows: 1) Factors: the annual temperature difference is relatively large, uneven distribution of annual rainfall, soil bulk density or bulk density, low lying water, barren soil, forest density is too large; 2) exacerbating factors: severe drought repeated occurrence of cutting Fat too early, frost, leaf pests and other pests; pine needles brown spot disease and other diseases; 3) promoting factors: pine withered pathogen, root rot bacteria, rotten bacteria, beetles, beetles and other pests and diseases hazards.