Abstract: In this paper,twelve investigations were conducted on the structural feature of arthropod community in a plum orchard,and a cluster analysis was made on the temporal dynamics of the community.The total community could be clustered into 5 clusters (D=0.2000),i.e.,that in March,in June,in July,in November,and in other months.The natural enemy and pest-neutral subcommunities could be also clustered into 5 clusters,respectively.For natural enemy sub-community,the clusters (D=0.2000) were that in March,in July,in August,in September and October,and in other months,and for pestneutral sub-community,they (D=0.1000) were that in April,in July,in June,in November,and in other months.The results of cluster analysis partly reflected the seasonal differences of total community and sub-communities, while the temporal overlaps of cluster results reflected the complexity of community structure.Based on the optimization cut-apart,both the total community and the sub-communities were divided into 5 stages,i.e.,6 April as the first stage,27 April to 8 June as the second stage,27 June to 27 August as the third stage,21 September to 19 October as the forth stage,and 22 November as the fifth stage.

Key words: ⁹⁵Zr, Marine environment, Marine organism, Sediment