滨海沙地木麻黄人工林生态系统分解者类型分析

Analysis on Decomposer in Artificial Casuarina eguisetifolia Ecosystem in Coastal Sandy

对2种林龄木麻黄人工林土壤微生物和土壤动物的数量及种类进行分析,结果表明:2种林分中土壤微生物数量差异较大,16年生人工林中放线菌所占比例最大,为50.65%;25年生人工林中细菌所占比例最大,为64.26%。细菌、真菌在2种人工林中表现出随着林龄增长而增加的趋势,放线菌则相反。土壤功能细菌中氨化细菌所占比例最大,16年生和25年生分别为91.61%、86.42%;随林龄增大,自生固氮菌的数量急剧增加,而有机磷分解菌、硝化细菌和纤维分解菌3类功能细菌数量逐渐减少。2种林分中共出现表层土壤动物6目13科22种。

The quantity and species of decomposers including the microorganisms and animals in the soil of Casuarina eguisetifolia plantation ecosystem in two different ages on Dongshan island of Fujian Province were studied. The results showed that there were significant differences in the quantity of soil microorganisms be- tween the plantations with different ages. Actinomycetes accounted for 50.65 % of the total in the 16 years old plantation, which was the largest percentage, Bacteri accounted for 64.26% in the 25 years old plantation, which was the largest percentage. The quantity of bacteria and fungi showed growing tendency with the in- crease of plantation age, whereas actinomycetes changed with a contrary tendency. Ammonifier accounted for the largest proportion among the functional bacteria in both of the two different aged Casuarina eguisetifolia plantation ecosystem, which was 91.61% in 16 years old plantation, and 86.42% in 25 years old planta- tion. The number of Azotobacteria increased sharply with the increase of age, but the number of organic phosphors decomposing microbes, nitrogen fixing bacteria and cellulose decomposing bacteria tapered off. There were 22 species belonging to 13 families and 7 orders of soil animals in the surface layer in the Casuarina eguisetifolia plantation ecosystem with two different ages.