The Community Ecology Of Soil Animal And Arthropod At Nanfeng Citrus Orchards In Jiangxi

The community ecology of soil animal and arthropod in theNanfeng citrus orchards was studied during 2003～2005 inJiangxi Province. The major results were summarized below:1. Soil animal communities were investigated in threedifferent sample stations in the citrus orchards of Nanfengcounty, Jiangxi Province, China. 1035 individuals werecollected in the sample stations. A total of 141 species werefound belonging to 97 families in 26 orders of 4 sorts. TheCommunity indices: the dominance(C), evenness (E), richness(D), diversity (H) and similarity coefficient (q) of soilanimal communities were analyzed. Also, both stratificationpattern and horizontal pattern of soil animals in the areas wereexamined. The results showed that Acaraina, Araneae andDorylaimida were the dominants in the three stations. The Acommunity had the highest diversity index. The C communityshowed the highest dominance. The similarity coefficientbetween the A and C community was the least. On the verticaldistribution of individuals and species of soil animals, itdecreased with increasing of the depth in soil and there wasfeature of soil animal congregating to surface horizon.2. The species component and species richness, dominance, ecological concentration, diversity and evenness of arthropodcommunity in the grand and vegetation of the citrus orchardsin Nanfeng County were studied in detail. The result showed thatthere were 100 species of arthropods, including 50 pests, 42natural enemies and 8 moderate insects. And their percentagesto the whole community were 50％, 42％, 8％respectively. Therichness was 22～43. The ecological concentration was 0.1155～0.8131. The diversity was 0.5961～2.7263. And the evennesswas 0.1929～0.7324. During the period of July, 15 to October,27, the index of ecological concentration was low, the diversityand evenness were high. So the structure of arthropod communitywas rational.3. From three inspects of time, space and two dimension oftime=space, the meaning of the niche width, data and nicheoverlap data of spider dominance species and destination pestswere analyzed in the Nanfeng orange gardens in Jiangxi province.Before growing up the fruit in orange tree, the time-space nichewidth order of the spider was: Pirata subpiraticus (0.4330),Clubiona reichlini (0.3529), Tetragnatha squamata (0.3085) andUmmeliata insecticeps (0.2199).The niche width of Piratasubpiraticus and Clubiona reichlini was bigger. It indicatedthey had better ability to adapt to environment and utilize time resource. After growing up the fruit in orange tree's,the orderof the spider in time-space niche width was: Clubiona reichlini(0.6774), Tetragnatha squamata (0.6135), Pirata subpiraticus(0.5349) and Ummeliata insecticeps (0.3887). The niche widthof Clubiona reichlini and Tetragnatha squamata was bigger. Itindicated they had good ability to adapt to environment andutilize time resource. The aim of the paper was to provide sometheoretic reference for controlling pest by ecosystem in theNanfeng orange gardens.4. According to the community feature of the Nanfengcitrus orchard, it put out the model of restoration-rebuildingfor the ecosystem of citrus orchards in Nanfeng by restoringthe population and number of natural enemy, building aprotective forest web and implementing the model of 'pig-firedamp-fruit'.