The Research On The Effect Of Prescribed Burning On Bursaphelenchus Xylophilus

Pine wilt disease has damaged the natural landscape and forest ecology in China,posing a serious threat to the sustainable management of China’s forestry industry and causing significant losses to the national economy and people’s livelihood.At present,the main means to prevent and control pine wilt disease are physical,chemical and biological control,but there are limitations in various control theories and techniques,and it is of great theoretical and practical importance to study more economical,practical and effective pine wilt disease control techniques.In this paper,we investigate the mechanism of low-intensity fire disturbance on Monochamus alternatus and pine wilt disease from the perspective of prescribed burning,and study the control effect of pine wilt disease to povide a theoretical basis for controlling the spread of pine wilt disease.The study’s specifics and outcomes are listed below.(1)Analysis of the impact of prescribed burning on the number of Monochamus alternatus and Bursaphelenchus xylophilus:the study used independent sample t-test to expore the impact of burning on the trapping amount of Monochamus altern atus and the number of Bursaphelenchus xylophilus in the control and test plots.No significant disparity(P>0.05)was revealed between the control and experimental sample plots in regards to the amount of males,females and total Monochamus alternatus,as well as the quantity of Bursaphelenchus xylophilus before the fire.However,there were significant differences in the amount of trapping between the two types of sample plots after fire(P<0.001).The total trapping amount of males,females and Monochamus alternatus in the test plots decreased by 75.04%,68.25%and 71.64%respectively,and the amount of Bursaphelenchus xylophiluss decreased by 69.18%,72.36%and 71.03%respectively.(2)Analysis of the control effect of prescribed burning in different stands:the average control effect is reflected by calculating the population decline rate of the Monochamus alternatus and its carrying Bursaphelenchus xylophilus,and correcting the population decline rate.Exploring if there is any disparity between the Monochamus alternatus trapping amount and the Bursaphelenchus xylophilus quantity between unprescribed and prescribed burning sample plots,a univariate analysis of variance is employed.Multivariate analysis of variance was used to compare the control effect of prescribed burning in different stands.The results showed that there was a significant difference in the number of Monochamus alternatus between different stand types and different fire treatments(P<0.001),and the interaction effect between the sample plot type and whether or not to burn had a significant effect on the number of Monochamus alternatus(P<0.001).After the prescribed burning treatment,the average control effects of male,female and total Monochamus alternatus beetles in the three types of forests are all satisfied:infected and uncontrollable forest>healthy forest>infected and controlled forest.There were significant differences in Bursaphelenchus xylophilus numbers between fire treatments(P<0.001),but no significant differences in Bursaphelenchus xylophilus numbers within stand types(P>0.05),and the interaction effect between sample type and whether or not to fire had no significant effect on Bursaphelenchus xylophilus numbers(P>0.05).The best control effect of the infected and uncontrolled stands is maintained at 60%～64%,and the second is that there is no significant difference between the control effect of the infected and healthy stands,which is basically stable at 51%～55%.(3)Short-term and long-tern effects of prescribed burning to control pine wilt disease:continuously record the trapping amount and the number of Monochamus alternatus and Bursaphelenchus xylophiluss in the sample plots of Pinus massoniana plantation before and after the prescribed burning,calculate its population decline rate and correct population decline rate,and draw the corresponding quantitative change curve.The results showed that from the perspective of short-term impact,the impact of prescribed burning on the number of Monochamus alternatus was immediate.Within 10 days after the fire,the number of Monochamus alternatus among the three types of stands decreased most significantly.The short-term effect on the number of Bursaphelenchus xylophilus does not appear immediately after the fire.The decrease was most obvious within 20 days after the fire.From the perspective of long-term impact,the number of males,females and total Monochamus alternatus and the number of Bursaphelenchus xylophilus carried by each of the three types of stands were significantly lower than those before the fire within three years.In addition,there will be a significant decline in the first year after the fire,and a small fluctuation in the next two years.The control effect of prescribed burning on pine wilt disease is sustainable and effective within three years.