摘要
【目的】明确天然赤松次生林空间结构对松赤枯病害发生程度的影响,探索以调控空间结构指标为手段的松赤枯病生态控制技术,为营林实践提供指导。【方法】在昆嵛山天然赤松次生林中设立6 hm2样地,测定松赤枯病寄主树种赤松、黑松和多脂松的空间结构指标——树种角尺度、大小比数、混交度和发病率,分析各空间结构指标与发病程度之间的关联性。以发病率作为松赤枯病的病害发生程度,对每个样株分上、中、下层,从东、南、西、北4个方向各随机剪取1个枝条检查病斑,病害发病率直接采用病斑长度比值来计算。【结果】1)赤松的所有空间结构指标都与松赤枯病发生程度之间呈负相关关系,其中胸径大小比数(R2=0.962,P=0.003)和树高大小比数(R2=0.794,P=0.043)与松赤枯病发生程度相关性显著,而角尺度和混交度与其无显著相关性。2)黑松胸径大小比数和混交度与松赤枯病发生程度之间呈负相关性,树高大小比数和角尺度与其呈正相关性,但所有相关性均不显著。3)多脂松所有空间结构指标都与松赤枯病发生程度之间呈负相关性,其中只有混交度与其相关性显著(R2=0.810,P=0.037)。4)3个树种中赤松和多脂松赤枯病发生程度与空间结构的相关性强于黑松;不同空间结构指标相比较,混交度和大小比数与赤枯病的相关性强于角尺度。【结论】混交度和大小比数对昆嵛山松赤枯病的生态调控功效明显优于角尺度。森林经营实践中可通过尽量增大寄主松属树种大小比数和增加寄主松属树种的混交度,以达到控制松赤枯病的目的;而角尺度不宜作为调控指标。同时,针对3个树种对赤枯病的抗病差异性,对病害疫区进行林分改造时多选择种植黑松,控制多脂松的比例,以增强生态系统对赤枯病的抵御能力。
[Objective ]This study was to ascertain the impact of spatial structure on damaging degree of a natural secondary Japanese Red Pine forest in Kunyushan caused by pine needle blight,and provide academic direction for ecological control of forest pest.[Method]A six-hectares plot was set out in Kunyushan natural secondary Japanese Red Pine forest,three indexes,including mingling degree,neighborhood comparison and uniform angle,were selected and measured.The relationship between spatial structure and damaging degree of pine needle blight was analyzed.The disease incidence of host plants was used as damaging degree caused by pine needle blight based on a preliminary survey.To investigate the disease incidence,twelve twigs were pruned off randomly from four different directions（east,west,south and north） in the upper,middle and lower crown of each sample tree.Scab on needles of twigs caused by pine needle blight was observed.Disease incidence was calculated as the following formula,disease incidence（%） = length of scab/total length of needles × 100%.[Result]1） For pine needle blight on P.densiflora,all spatial structure indexes were negatively correlated with damaging degree,among which the two neighborhood comparison indexes of diameter atbreast height（R^2= 0.962,P = 0.003） and tree height（R^2= 0.794,P = 0.043） were significantly correlate with damaging degree,and no significant relationship was found between damaging degree and Uniform angle index or mingling degree index.2） For pine needle blight on P.thunbergii Parl,there was a negative linear relationship between damaging degree and mingling degree index（or diameter at breast height of neighbourhood comparison index）,and the other spatial structure indexes were positively related with damaging degree,but all the relationship were not significant.3） For pine needle blight on P.resinosa Ait,all spatial structure indexes were negative related with damaging degree,among which only the mingling degree index was significantly related.4） In terms of host species,correlation between spatial structure with P.densiflora or P.resinosa was stronger than that with P.thunbergii.In terms of spatial structure,mingling degree and neighbourhood comparison were found stronger than uniform angle.[Conclusion]Among the spatial structure indexes,mingling degree and neighbourhood comparison were proved superior to uniform angle for regulating Kunyushan Web-spinning Sawfly ecologically.The relationship between spatial structure and damaging degree can be utilized,and to adapt ecological methods of rational planting and selective cutting for controlling pine needle blight damage during the course of forest management.For P.densiflora,mingling degree should be controlled beyond 0.5 to decrease damage; for P.thunbergii it should be controlled on a tolerable level; and for P.resinosa,mingling degree of middle level should be avoided.On the other hand,to take account of the difference of disease resistance among the above host plants,in order to strengthen resistance ability to pine needle blight of the ecosystem,a higher proportion of P.thunbergii and less P.resinosa should be planted for stand improvement.
出处
《林业科学》
EI
CAS
CSCD
北大核心
2016年第8期60-67,共8页
Scientia Silvae Sinicae
基金
国家自然科学基金项目(31270682)
国家林业局公益性行业科研专项(201204501)
国家林业局山东昆嵛山森林生态系统定位观测研究站监测运行补助项目
关键词
松赤枯病
空间结构
角尺度
大小比数
混交度
发生程度
pine needle blight
spatial structure
uniform angle
neighbourhood comparison
mingling degree
damaging degree
