The Distribution And Analysis Of Influence Factors Of Parocneria Orienta In Sichuan With Species Ditribution Model

Parocneria orienta is one of the most important cypress pests in Sichuan.It is the main monitoring object of forestry pests in Sichuan province.According to incomplete statistics,the area is up to 3 million 500 thousand mu in recent years.It has caused serious harm to the cypress forest in Sichuan province.In this paper,we will establish the distribution pattern of species in Sichuan and compare the spatial distribution,temporal and climatic factors.Based on the annual distribution data and23 environmental factors of the moth of Parocneria orienta in Sichuan in the past2012-2016 years,three species distribution models of MAXENT,BIOCLIM and DOMAIN were selected to screen out the important factors of the occurrence of the moth of Parocneria orienta,and the potential distribution areas of the moth of the moth of Parocneria orienta were predicted and the level of adaptation was classified.The receiver operating characteristic curve was used to verify the results of species distribution models.The main results are as follows:The total area of Parocneria orienta has declined in the past 5 years.The total area in 2016 was 282685 Mu compared with the total area in 2012,accounting for7.43% of the total area in the period of the period.The moth of Parocneria orienta is located in the longitude from West Sichuan to 103.202 E,East Sichuan to 108.103 E,in the latitude of North Sichuan to 32.445 degrees N,and from south to 27.877 N,concentrated near the altitude of 400 meters,and in the dual factor analysis of time and space,the harmful regions are significantly different from the longitude,but at latitude and altitude.There is no significant difference in time change.The AUC values of the three models combined with 19 climatic factors are 0.860,0.848 and0.837 respectively.The three models have high accuracy,and the maximum entropy model has the highest accuracy.The high yield areas of the three models are distributed in Mianyang,Guangyuan,Nanchong and Bazhong.Therefore,according to the results of the probability density model,the distribution of Parocneria orienta is mainly concentrated in the counties of EasternSichuan.In the three large areas of Ganzi,ABA and Liangshan in Western Sichuan,the growth and development of Parocneria orienta are not suitable,and they are greatly influenced by the latitude and altitude of the spatial factors.According to the evaluation index of AUC value,the prediction results of the distribution area of the moth of Parocneria orienta were more accurate.The results showed that the main factors affecting the distribution of the moth were temperature,the next was the rainfall,the average temperature in July,the lowest temperature in July,the lowest temperature in June,the lowest temperature in August,and the isothermal(tavg-7,tmin-7,tmin-6,tmin-8,bio-3)is an important environmental factor that affects the distribution of Parocneria orienta.