东北羊草草原不同生境土壤微生物与土壤理化性质关系研究-植物学专业毕业论文.docx

中 文摘要
本论文主要以东北羊草草原不同放牧梯度的羊草群落土壤为研究对象,对土壤微生物数量,微生物量,土壤呼吸以及土壤酶活性(包括过氧化氢酶、多酚氧化酶和蔗糖酶)和土壤理化因子进行了测定,得出了季节动态曲线并对它们之间的相互关系进行了统计分析。
,试验结果表明,保护区和不同放牧梯度以及盐碱滩的土壤微生物学特
性辛吐壤理化性质都不相同,随着放牧程度的加重,微生物数量、微生物
量、土壤呼吸速率和土壤酶活性均呈下降趋势。但是在羊草草原不同生境土壤中,土壤微生物的数量、生物量、土壤呼吸强度以及三种土壤酶活性、土壤养分的测定结果表现了相似的规律,土壤微生物数量和微生物量、土壤呼吸速率、土壤酶活性都有季节变化,均呈单峰曲线,最大值出现在7、 8月份。
t-检验结果表明,保护区与不同放牧梯度的土壤之间相比较,微生物学特性有显著或极显著差异。相关分析表明,土壤微生物量与土壤水分、土壤温度、土壤有机质、土壤全氮、全磷、速效氮成显著或极显著正相关, 与PH值呈负相关,与速效磷相关性不明显。
不同生境土壤的蔗糖酶活性与土壤微生物量呈显著相关。微生物量与过氧化氢酶也呈显著或极显著相关,而与多酚氧化酶的相关性不显著。对蔗糖酶的活性和土壤呼吸强度进行回归分析,二者亦呈线性正相关。y
关键词:革草草原,生境,微生物数量,土壤酶活性,土壤呼吸速率
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Abstract
The report is focusing on typical Leymus munity which was grazed in different intensity in the leymus chinensis grassland in northeast determjned the soi 1 anisms amount,microbial biomass,soll respiration rate and activity of soil enzyme(soil catalase, incertase and polyphenol oxidase),environmental factors as well after examination of that particular studied and analyzed the relationship between them due to the different season.
The consequence of examinations showed that soil anism, soil chemical properties are different between the protecting,grazing and soil salinity quality of anism amount,microbial biomass,soll respiration rate and activity of soil enzyme have been reducing by the raising of grazing soil anism amount,microbial biomass, respiration rate and soi 1 enzyme showed a single—peak curve reached at the top between July and August during the year.
According to the results of significance test that soil microbial biomass was positively correlated with soil moisture,soil temperature,anic matter content,total-N and—P。and available- correlations between them have reached significant or extremely significant the
correlation between microbial binmass and soil PH showed
was no significant correlation between microbial biomass and available-P.
Soll microbial biomass in different environment was signi