Changes of grass root system, soil fauna and soil microflora in the process of decaying of crushed wood fragments.

作者调查了青森县山区木屑堆积的荒草地土壤中的草根系统、土壤动物和土壤微生物区系的变化。取得的结果如下：1.研究结果。虽然弹尾目和粉虱的数量从建立时的10^*4/m^2下降到10^*3/m^2，但在建立3个月后又有所增加。建库后表层粉螨比例由20%增加到50%。建立前土壤中细菌、放线菌和真菌的数量分别为10^*6、10^*6和10^*4/g。它们在成立后增长了10倍。多林试验区的数量少于少林试验区。干土中细菌、放线菌、真菌和纤维素分解菌的数量分别为10^*7-8、10*5-6和10^*6-7/g。从5月到10月，它们逐渐增加。试验区的纤维素分解菌数量明显多于没有碎木片的试验区。埋藏在表层土壤中的纤维素纸，无论是在试验田还是在实验室调节温湿度的条件下，在50-60天内几乎都会分解。腐解率在20-30天和40-50天增加了两倍。细菌、放线菌、真菌和微生物生物量C的数量均增加了2倍，但纤维素分解菌的数量仅在20-30天增加，在40-50天减少。从春季到秋季，粉虱、弹尾目和线虫的数量分别为10^*4-5、10^*3-5和10^*4-7/m^2，粉虱和线虫数量逐渐增加。虽然各层都有线虫，但只在表层观察到螨类和弹尾目动物。将观察到的线虫的生态类型划分为淡水生存和湿润土壤生存。

The author investigated the change of grass root system, soil fauna and soil microflora in the ploughless pasture soil rich in crushed wood fragments in a mountainous region in Aomori Prefecture. The results obtained are as follows.1. Though the numbers of Collembola and Acari decreased from 10^*4/m^2 to 10^*3/m^2 in the establishment, they increased again 3 months after the establishment. The proportion of Acari increased from 20% to 50% in the surface layer after the establishment.2. The numbers of bacteria, actinomycetes and fungi were 10^*6, 10^*6 and 10^*4/g of dried soil respectively before the establishment. They increased 10times after the establishment. The numbers of them in the much wood test plot were less than those in the less wood plot.3. The numbers of bacteria and actinomycetes, fungi and cellulose decomposing microbe were 10^*7 -8, 10^*5 -6, and 10^*6 -7/g of dried soil respectively. They increased from May to October gradually. The numbers of cellulose decomposing microbe in the test plot were more than those without crushed wood fragments.4. Cellulose papers buried in the surface soil were almost decomposed in 50-60 days either in the test field or in the laboratory regulated temperature and humidity. The decomposing rate increased two times, 20-30 and 40 -50 days. Though the numbers of bacteria, actinomycetes, fungi and microbial biomass C increased in both 2 times, those of cellulose decomposing microbe increased only in 20-30 days and decreased in 40 -50 days.5. The numbers of Acari, Collembola and Nematoda were 10^*4 -5, 10^*3 - 5 and 10^*4-7 /m^2 respectively and those of Acari and Nematoda increased gradually from spring to autumn. Though Nematoda were observed in every layer, Acari and Collembola were observed only in the surface layer. The ecological type of the Nematoda observed were classified to live by the fresh water and in wet soils.