The Loss Assessment Of The Populus×euramericana Canker Disease

Poplar is a very important economic species and its the economic, ecological and socialbenefits are significantly. populus×euramericana canker disease is a new disease whichdamage poplar trunks and branches. The disease develops quickly and harms serious. In May2005, the disease was first found in Puyang City, Henan Province. In2006, the diseaseoccurred serious in Heze City and Yanzhou City, Shandong Province. In2009, the disease hascaused serious economic losses in Tianjin City. In order to assess the harm and loss of thedisease, different incidence levels of the poplar was used as the research object in Heze City,Cao County. The wood qualities, leaf photosynthesises, diameters, heights and timbers ofvolume growth on healthy plants and infected plants had been studied within the sample plot.The main results were as following:1. The impact of disease on wood propertiesAfter the populus×euramericana canker disease harmed to poplar plantation, the woodbasic density and dry density were reduced by7.8%and5.49%respectively. The tangentialshrinkage, radial shrinkage rate and volume shrinkage rate increased by3.53%,1.257%,5.72%. Organic extract content and acid insoluble lignin content increased by32.9%and3.96%, holocellulose content decreased by6.67%. The dry density, organic extract content,holocellulose, acid insoluble lignin content reached the significant difference level betweenthe health wood and damaged wood.2. The impact of disease on leaf photosynthesisThe impact of the populus×euramericana canker disease on leaf photosynthesis waswidely. With the increase of photosynthetic active radiation (PAR), the photosynthetic rate(Pn) and the water use efficiency (WUE) was both increased, the intercellular CO2concentration (CI) was decreased, the light use efficiency (LUE) first was increased andthen decreased of both the healthy plants and infected plants leaves. The apparent quantumyield of the healthy plants and infected plants leaves were reached to0.044and0.031respectively. The leaf light compensation point (LCP) of the infected plants leaf was82.06μmol/(m~2s) and higher than the healthy plants significantly. The light saturationpoint (LSP) of the healthy plants and infected plants leaves were equal to1600μmol/(m~2 s); The healthy plants transpiration rate was always higher than the infected plants.3. The impact of disease on the amount of poplar’s each growth factor and lossassessmentThe poplar each growth factor was caused serious impact by the occurrence ofpopulus×euramericana canker disease. When the disease occurring grade was respectivelyup to three, two and two, the diameter, height and timber of volume had already beeninfluenced extremely significant. According to the relation between different grades and lossrate, we set up the loss rate-estimating model of the diameter, height and timber of volumerespectively. The model belonged to linear model and were D(%)=18.5656X-16.0926, H(%)=16.286X-9.1817, V(%)=11.09X-11.853. In addition, we assessed the lost of poplarplantation per hectare. The result indicated that the economic losses rate reaches25.45%, theannual economic losses can reach to4950yuan.