三峡库区松材线虫病扩张速度对人为活动的响应

松材线虫病是我国森林重要的检疫性病害,除自然媒介天牛传播,人为因素介导的传播在松材线虫病扩散和蔓延中起着至关重要的作用。选择在我国松材线虫病的重点发生区域三峡库区,研究马尾松林景观格局和以人为活动强度为主要因子的松材线虫病扩散规律,尝试揭示松材线虫病扩散机制。结果显示三峡库区的疫点数在近年有上升趋势,各地区发病率得到一定控制;在疫区和非疫区,马尾松林斑块聚合度最大的是非疫区的大渡口,为98.6406;斑块分离度最大的是非疫区的秭归,为0.9318;方差分析结果显示马尾松林景观格局和松材线虫病之间没有相关性。进一步研究了松材线虫病和人为活动强度的联系,结果显示松材线虫病发病率和地区路网密度、人口总量具有较强的相关性,和地区GDP、货运周转量相关性小。宜昌的松材线虫病发病率和路网密度的相关系数为0.985,和人口总数的相关系数为0.866;重庆的松材线虫病发病率和路网密度相关系数为0.924,和人口总数相关系数为0.999;其次基于路网密度和人口总数,对三峡库区松材线虫病疫情在未来十年进行了预测,结果显示随着路网密度和人口总数的扩增,宜昌松材线虫病也将呈现逐步增大的趋势,R~2值为0.919和0.637;重庆发生趋势一致,R~2值为0.976和0.992。

A correlation of pine wood nematode dispersal rate with human activities-a case study in the Three Gorges Reservoir Area

The pine wood nematode is a major quarantine pest in China, in addition to the vector insect Monochamus alternatus Hope, and humans play an important role in the proliferation and dispersal of these pests. This study was carried out in a concentrated pinewood nematode area of the Three Gorges reservoir. The landscape of region dominated by Pinus massoniana was analyzed based on the intensity of the effect of humans for diffusion processes, which are the key factors to the dispersal of the pinewood nematode, in an attempt to reveal dispersal mechanisms. The results showed the number of epidemic towns increased, but the incidence rate of the pinewood nematode was controlled. For P. massoniana in epidemic or non-epidemic towns, the largest aggregation index was 98.6406 in Dadukou, which is a non-epidemic town; the largest division index was 0.9318 in Zigui, which is a non-epidemic town; and the results of the variance analysis showed that there was no correlation between the P. massoniana distribution pattern and the pinewood nematode. We further studied the correlation between humans and the pinewood nematode, and the results showed the incidence rate was correlated with the density of road networks and the total population, and had little correlation with the GDP or rotation volume of goods transport. In Yichang, a factorial analysis showed that the correlation coefficient of the incidence rate and density of the road network was 0.985, and the correlation coefficient of the rate and total population was 0.866. In Chongqing, a factorial analysis showed that the correlation coefficient of the rate and density of the road network was 0.924, the correlation coefficient of the rate and total population was 0.999. Then, in view of the density of the road network and total population, it was predicted that the incident rate of the pinewood nematode in Yichang will increase during the next decade as the density of the road network and total population increases, with R² values of 0.919 and 0.637, respectively. Results from Chongqing were consistent with R² values of 0.976 and 0.992, respectively.