Abstract:

Objective: This study aims to clarify the relationship between landscape patterns and population density and adulthood occurrence period of Monochamus alternatus, which may lay the theoretical foundation for formulating the technical measures to control the population of M. alternatus with landscape patterns. Method: With the method of landscape ecology, the population number of M. alternatus in Pinus massoniana stands in 4 townships of Shunchang County, Fujian Province was monitored by the trapping method. The occurrence period of M. alternatus adulthood was divided into three periods and time dynamic model was established. ARCGIS, ENVI and FRAGSTATS software were used to extract and divide the landscape information and calculate the landscape index. The correlations between the landscape index at the Class-level and the landscape-level and the population density and adulthood occurrence period of M. alternatus were analyzed. Result: A total of 139 321 M. alternatus were captured in the four study areas. The peak period (T) in Pushang Town ended the earliest, the peak period (P) and the late period (L) in Shuangxi Subdistrict ended the earliest, while Dagan Town ended the latest in these two periods. At the patch type level, the population density of M. alternatus was significantly positively correlated with the area of forest patch and the number of roads patch, and the correlation coefficient was 0.952 and 0.959, respectively. The population density of M. alternatus was significantly negatively correlated with farmland patch area (R=-0.963) and the division index of roads (R=-0.968). At the landscape-level, the total area of landscape was significant positively correlated with the population density of M. alternatus (R=0.970), and the population density of M. alternatus decreased with the increase of the landscape richness, with a correlation coefficient of -0.958. The density and aggregation of forest patch had an important impact on the different period of adult occurrence. The peak period of adult occurrence had a strong positive correlation with the density and area of road patches. The density and area of urban, farmland and water patches were negatively correlated with the occurrence period of M. alternatus adults, but the total area of landscape was significant positively correlated with the different occurrence periods of adults. Conclusion: The area of forest patch and the number of roads patch are significantly positively correlated with the density of M. alternatus, but there was a negative correlation between division of road patch and the patch area of farmland and the density in this species. The density of forest patch and road patch is positively correlated with the end time of thriving, peak and late period of M. alternatus, while the density and area of urban, farmland and water patches are negatively correlated. In general, landscape pattern cannot only affect the population density of M. alternatus, but also affect the temporal dynamics of the occurrence of the population.

Key words: Monochamus alternatus, landscape patterns, landscape index, population density, adult stage