互花米草(Spartina alterniflora)草场土壤微生物生态分布及某些酶活性的研究

种植互花米草的盐沼土中,细菌、放线菌和真菌的数量比对照盐沼土中多。就不同深度来说,15—30厘米土层中,细菌数最多。细菌总数的增减趋势是:夏秋两季最多,冬春两季较少。在各生理类群中,氨化细菌占优势;固氮细菌、硝化细菌次之;反硝化细菌和硫酸盆还原细菌最少。内源呼吸作用强度、添加葡萄糖后的呼吸作用强度、氧化丙酮酸的能力和氧化多酚化合物的能力皆显示出同样的趋势,即三年生草场土壤中生物活性最强,光滩土壤中生物活性最弱。在光滩土壤中,脲酶和过氧化氢酶活性很低,而种植互花米草的土壤中这两种酶活性较强,但与种植年限和季节变化无显著相关性。

A STUDY ON ECOLOGICAL DISTRIBUTION OF MICROOGANISMS AND SOME BIOCHEMICAL CHARACTERISTICS IN THE SPARTINA ALTERNIFLORA MARSH SOIL

To find out the interrelationships between S,alterniflora and ils particular ecological environment, comparative studies on ecological distribution of soil microbes in one-,two- and three-year-old, S.altermflora marsh soil of Binghai,Jiangsu,were carried out in a 2-year-duration (1985-1986). Respiration Quotient(RQ), enzyme activity and their interrelationships were also determined. In the soil of S.alternif-lora planting salt marsh, numbers of bacteria, actinomycetcs and microfungi were found more than in unvegetated soil. The number of bacteria varied with depth, ma-ximun occuring in 15-30 cm from the top soil in summer and autum, alternated with relatively small numbeis during spring and winter. Ammonifying bacteria predominate with less azotobacter and nitrifying bacteria and the least denitrifying bacteria and sulfate reducing bacteria. RQ were measured for endogenous respiration, respiration by-adding glucose, the capacity of oxidizing pyruvic acid and polyphonel compounds. Results showed similar trends, i.e.,the highest RQ occuring in 3 years old S,alterniflord marsh soil. Urease and perhydrogenase activities were very low in barren unvegetate soil whereas their activities were observed to be rather high without significant variations in one-, two- and three-year-old marsh soil and without seasonal variation.