【作者】 王静；

【导师】 梁军；

【作者基本信息】 中国林业科学研究院 ， 森林保护学， 2012， 博士

【摘要】 杨树溃疡病（Botryosphaeria dothidea Mong.）、烂皮病（Valsa sordid Nit.）为主的寄主主导性病害是制约杨树栽培及发展的主要因素。本研究以北方杨树人工林为研究对象，从区域－林分－个体不同层次分析人工林杨树干部病害发生与各因素间的关系。利用景观病理学原理和方法对区域尺度下杨树人工林干部病害发生特征开展了研究，解析在区域尺度下人工林病害发生与寄主本身及其群体特征间的关系。在林分水平上，选取林木相对指标（个体与群体平均比率）、树冠形状、营养空间利用状况三大类指标讨论其对溃疡病发生程度的影响。并以最小结构单元为基础，通过对胸径、树高和冠幅的大小比数作为空间结构指标来描述单木之间的空间关系以及这种空间结构对树木个体病害发生的影响，对以营林措施为导向的病害生态控制具有重要的意义。主要研究结果如下：（1）在区域尺度下(100km~2)，杨树人工林林龄、密度及郁闭度对林分平均发病率均存在极显著差异，林分发病率与林龄(1-12龄)呈极显著的正相关关系(R=0.72, p <0.01)，与林分密度也呈极显著正相关关系(R~2=0.3638, p=0.0037)，即林分发病率分别随着林龄增长、林分密度增加而呈线性增长；同时随着林分郁闭度升高，林分平均发病率也随之增高。（2）区域内人工林不同种植方式和林分类型对病害发生也存在显著影响。林分发病率在孤立斑块的低于纯林、混交林和其他林分(主要为四旁绿化林)，但这些种植方式内林木发病率没有显著差异，同时均显著高于农田间作的林木发病率。位于不同地理位置的林分间的发病株率存在显著差异（F=3.30，p=0.021），林分中与村庄距离最近的林分内杨树发病株率显著高于其他几种位置类型。精细管理林分的林木发病株率和林木发病指数（DSI）显著低于粗放管理的林分。（3）发病指数（DSI）在不同品种间差异是极显著的。其中107杨的平均DSI最低(DSI%<4%)；三倍体毛白杨的DSI最高，平均达10.48％，显著高于其他所有品种。总体上，中林46、廊坊杨、毛白杨、I-69杨和108杨等品种之间的DSI差异不显著，但均显著低于三倍体毛白杨。（4）欧美杨107和108的相对胸径、相对树高、相对冠幅、树冠伸展度、完满度和投影比与溃疡病发病指数的相关性都随着林分密度的减少，呈现明显减弱的趋势，树冠伸展度指标对发病株率的影响比其它指标更显著，树冠体积和生长空间竞争指数与溃疡病发病指数的相关性均随林分密度的减少，呈现明显减弱的趋势。而欧美杨DN113杨树溃疡病病害发生情况与这些指标基本无显著性相关。（5）多元回归方程检验结果，除了相对冠幅和树冠完满度外，其它竞争指标对杨树的发病株率均存在显著作用，并具有综合性。其中，林分密度、相对胸径、相对树高、伸展度、冠长率、树冠体积、生长空间指数和生长空间竞争指数对发病的影响是极显著的；林分密度、相对树高、相对冠幅、树冠伸展度和生长空间指数与发病株率均呈显著负相关，说明林分的发病率随着这些指标的升高而减小。方程拟合达到极显著水平（R~2=0.615, p＜0.001）。（6）采用胸径、树高和冠幅大小比数分析其与杨树人工林溃疡病发生程度的关系。结果表明，在株行距为3m×2m的林地中，欧美杨107、108和DN113溃疡病发病指数与这些指标大小比数的相关性极显著，且均呈极显著性负相关，但随着密度的减小，其相关性越来越弱，当株行距达到3m×4m时，杨树溃疡病病害的发生基本不受林木个体优势度强弱的影响。（7）107杨、108杨和DN113杨溃疡病感病情况在不同指标个体优势度间均存在极显著差异。3个品种的发病程度在优势木（1）和亚优势木（0.75）与绝对劣势木（0）存在明显差异，劣势木（0.25）的发病程度明显高于优势木（1），说明处于优势状态下的树木相比处于劣势不容易受到病害的侵害；劣势木的发病程度普遍高于中庸木；在劣势木与绝对劣势木之间，虽然感病情况存在差异，但欧美杨107的差异并不明显。以树高和冠幅作为变量参数，欧美杨108和DN113的发病程度在优势木、亚优势木和中庸木间无显著差异。更多还原

【Abstract】 Host-based disease, mainly including poplar canker and rotten skin disease, is the mainconstraints of plantation and development of poplar. In this study, aiming to short-rotationpoplar plantation forest in the northern China, it analyzed relations between diseaseoccurrences and various factors at different layers of region—stand—individual. By usingprinciples and methods of landscape pathology, researches on the characteristics of diseasehappened to poplar stem at the regional scale, and relations between disease occurrence andhost itself as well as community characteristics were analyzed. At the stand level, relative index(average ratio of individual and community), crown shape, spatial utilization of nutrition wereselected to discuss the impact on occurrence of poplar canker due to above indicators. At theindividual level, the neighborhood comparison among diameter at breast height, tree height andthe size of tree crown was used to describe the spatial relations among single trees and impactson disease occurrence due to the spatial structure, which has important significance on forestmanagement measurement oriented eco-control of tree disease.At the regional level (100km~2), the impacts of density and canopy cover on averagedisease occurrence of poplar is significant. The disease occurrence of stand has positivecorrelation with plantation age (1-12years)(R=0.72, p<0.01), as well as stand density(R~2=0.3638, p=0.0037). It indicates that the disease occurrence of stand increased with theincreasing of plantation age and stand density. Meanwhile, with the increasing of stand canopycover, the average disease occurrence of stand increased too.Both plantation type and stand type have significant impacts on disease occurrence. Thedisease occurrence of stand in isolated patches is lower than in the pure forest, mixed forestand other type of stands. And the disease occurrence among in the pure forest, mixed forest andother type of stands has no significant difference, but higher than which of corpes. The diseaseoccurrence rate of trees located in different geographic situation is significantly different(F=3.30，p=0.021). The disease occurrence of poplars near the village is higher than of which located in other places. The disease occurrence rate and DSI of fine managed stand issignificantly lower than stand with extensive management.DSI among different types of poplar is extremely different. Of which the average DSI ofpoplar107is the lowest (DSI%<4%); and the DSI of triploid Chinese white poplar is thehighest, up to10.48%, higher than other kinds. Overall, the difference of DSI amongP.euramricana (Dode) Guineir cv.’zhonglin-46’, poplar Langfang, Chinese white poplar，P.deltoid bartr. CI. Lux I-69/55and poplar108are slight，but significantly lower than triploidChinese white poplar.The correlation between relative diameter，relative height，relative crown，branchstretching，crown round degree，crown projection ratio and canker occurrence index of poplar107and108would significantly decline with the decrease of stand density. The impact ofbranch stretching on disease occurrence is more significant than other indicators. Thecorrelation between crown volume and growth space competition index and canker occurrencehas the trend of decreasing with the decrease of stand density. The canker occurrence of DN113poplar has no correlation with those indicators.From the result of multiple regression equation, except relative crown and crown rounddegree, other indicators have significant correlation with disease occurrence, with integrationreaction. Of which, the impact of stand density，relative diameter，relative height，branchstretching, crown volume，growth space index and growth space competition index on diseaseoccurrence is significant. The stand density，relative height，relative crown，branch stretchingand growth space index has significant negative correlation with disease occurrence, whichmeans the disease occurrence rate decreases with the increase of those indicators. The equationfitted very well (R~2=0.615, P＜0.001).The correlation between canker occurrence of poplar plantation and neighborhoodcomparison of diameter at breast height, tree height and the size of tree crown was analyzed.The result shows that poplar107,108and DN113in the same density, the occurrence of cankerhas significant negative correlation with neighborhood comparison of diameter at breast height,tree height and the size of tree crown. And the correlation decreased with the declining of the density. When the planting space reaches to3m×4m, the occurrence of canker would not beimpact by individual dominance.There is significant difference of canker occurrence of poplar107,108and DN113underdifferent indicator. The disease occurrence of three kinds of poplar in dominant tree (1) andco-dominant tree (0.75) and absolutely suppressed tree (0) is significantly different. Theoccurrence of suppressed tree (0.25) is obviously higher than dominant tree (1); it indicates thatthe trees under dominant situation would be less impacted by disease than suppressed trees; theoccurrence of suppressed tree is generally higher than intermediate trees. There exist a certaindifference of disease occurrence between suppressed trees and absolutely suppressed trees, butno significant difference for poplar107. Considering the variable of height and crown, thedisease occurrence of poplar108and DN113among dominant, co-dominant and intermediatetrees have no significant difference.更多还原