The Response Of Four Forest Pests To Climate Change In Beijing

In recent years,with the continuously global warming,disastrous weather also appears frequently,which has aroused great concern of human beings.Climate changes have also resulted in the increasing generation and the early occurrence period of forest pests,the expansion of the occurrence and distribution area.In consequences,it became increasingly fierce,which has brought extremely adverse effects to the development of forestry.Because of the forest pests’ changing temperature features,their occurrence is closely related to the climate of their living environment.It is of great significance to study the response of forest pests to the climate change for the better prediction.By using correlation analysis method and regression analysis method,this paper studies the rule of climate change in Beijing from 2007 to 2018,and discusses the relationship between climate change and the occurrence area of forest pests in Beijing from 2008 to 2018,the occurrence area and initial stage of four forest pests from 2011 to 2018(Drosicha corpulenta,Apocheima cinerarius,Semiothisa cinerearia,Hyphantria cunea).The main results are as following:1.The average annual temperature,the average annual minimum temperature,the average annual maximum temperature,the annual precipitation and the annual sunshine hours are all increasing in Beijing,while the average annual relative humidity is decreasing.2.There is a significant positive correlation between the total area and mild area of forest pests and the annual average relative humidity in Beijing.3.There is no significant correlation between the occurrence area of Drosicha corpulenta and all climatic factors;the total occurrence area of Apocheima cinerarius is positively correlated with the precipitation in May and the average lowest air temperature in June,while the slight occurrence area is negatively correlated with the precipitation in January;the total occurrence area and the slight occurrence area of Semiothisa cinerearia are negatively correlated with the average relative humidity in August;The occurrence area of Hyphantria cunea was positively correlated with the average temperature in September and precipitation in August.4.There is a negative significant correlation between the initial stage of Drosicha corpulenta and the average maximum temperature in March.For every 1℃ increase in average temperature in February,the onset of Apocheima cinerarius is at least 2d earlier.For every 1℃ increase in average temperature in January,the onset of Apocheima cinerarius is at least 1d earlier.For every 1℃ increase in the average maximum temperature in April,the onset date of Semiothisa cinerearia is about 5.9 days earlier.For every1℃ increase in the average maximum temperature in March,the onset of the Hyphantria cunea was about3.4d earlier.In Beijing,the total occurrence area of forest pests is mainly affected by the average relative humidity,and the factors affecting the occurrence area of single pest are different,while the onset of pests is greatly affected by the temperature,and with the increase of temperature,the onset has different degrees of advance.