柏木低效林经济林改造模式土壤微生物及酶活性动态研究

发布时间：2018-01-18 23:52

本文关键词： 低效林经济林改造土壤微生物土壤酶土壤养分　出处：《四川农业大学》2014年硕士论文　论文类型：学位论文

【摘要】：近年来,由于自然环境破坏和人为活动干扰等因素造成的低效林分面积日益扩大的问题,引起了国内外专家的重视。低效林不仅影响林业可持续发展,降低了森林整体质量和功能,还阻碍了行业和区域的经济与社会的健康发展,因此川中丘陵区大面积的柏木低效林亟需进行改造与重建。德阳市属长江上游区域,对其低效林分进行改造,提高其保水保土的防护效益,是长江防护林工程建设中必不可少的重要环节,也是“川中丘陵区人工林生态系统结构优化与功能提升技术"专题的重点研究内容之一。本文以德阳市旌阳区柏木低效林为对照,通过野外调查和室内分析,研究以花椒为主的经济林改造初期土壤微生物数量、土壤酶活性及养分含量状况,探讨土壤微生物、酶活性与土壤养分的关系以及土壤质量变化,为低效林的经济林改造模式提供理论基础,研究结果表明：1.花椒改造模式土壤pH值低于对照,差异极显著。经济林改造模式下土壤全钾、速效钾、有效磷含量均极显著高于柏木低效林,有机质和其他养分含量差异不显著。花椒、核桃经济林改造模式土壤养分含量差异均不显著。土壤各养分含量垂直分布规律一致,均随着土层的加深逐渐减少。2.土壤细菌占微生物总数量的75%以上,放线菌次之,真菌最少。与柏木低效林相比,经济林改造模式土壤微生物各类群均有所提高。土壤微生物总量以及细菌、真菌、放线菌数量存在一致的垂直分布规律,均随着土层加深迅速下降,主要集中在上层。各微生物类群数量在夏季和秋季多于春季和冬季。花椒、核桃改造模式与柏木低效林细菌数量均在秋季最多,花椒改造模式与对照林地细菌数量冬季最少,核桃改造模式则在春季最少；花椒改造模式与对照样地放线菌数量秋季最多,冬季最少,而核桃改造模式放线菌数量夏季最多,春季最少；花椒、核桃改造模式与对照样地土壤真菌数量均在秋季最多,但花椒、核桃改造模式放线菌数量春季最少,柏木低效林冬季最少；微生物总数季节动态规律与细菌数量一致。3.核桃改造模式与对照相比较,土壤过氧化氢酶、脲酶活性差异不显著,但磷酸酶活性显著低于对照；花椒改造模式与对照相比,三种土壤酶活性差异均不显著。随土层深度的增加,三种酶的活性都呈现减弱的趋势,其活性主要集中在上层。改造模式与对照林地土壤过氧化氢酶活性均在夏季最高,但前者在冬季最低,后者在春季最低；花椒改造模式土壤脲酶活性夏季最高,冬季最低,而核桃改造模式和对照林地其活性秋季最高,冬季最低；土壤磷酸酶活性均为夏季最高,冬季最低。4.施用无机化肥在短期内对土壤有机质含量没有显著影响,土壤全氮、碱解氮、有效磷含量随着相应肥料的施用量增加而增加,土壤全磷、全钾、速效钾含量随着相应肥料施用量的增加呈现先上升后下降的趋势。土壤细菌数量随着氮肥的施用量先增加后减少,少量的磷、钾肥可提高细菌数量,过量则会抑制细菌活动,无机化肥的施用会减少土壤放线菌、真菌数量。施用无机肥在短期内可显著提高土壤酶活性,但随着其施用量的增加其活性会降低。5.细菌数量与有效磷含量极显著负相关,与速效钾含量极显著正相关；放线菌数量与全磷、全氮、水解氮含量显著或极显著正相关；真菌数量与有机质、全氮、水解氮、有效磷含量呈显著或极显著正相关。土壤过氧化氢酶活性与全氮含量呈极显著相关关系；脲酶活性与全氮、速效钾含量呈显著相关关系；磷酸酶活性与全磷、有效磷、全氮、碱解氮、速效钾含量呈显著或极显著相关关系。细菌、放线菌数量与三种酶活性均呈显著或极显著正相关,真菌数量与磷酸酶活性显著相关,与过氧化氢酶活性极显著相关。6.经济林改造模式土壤全氮含量与放线菌、真菌数量以及土壤酶活性的相关性最为显著,说明土壤全氮含量对土壤生物学性质影响较大。真菌数量和磷酸酶活性与大部分土壤养分含量显著或极显著相关,说明土壤真菌数量和磷酸酶活性可更好的评价土壤肥力水平。
[Abstract]:In recent years, due to the destruction of natural environment and human disturbance factors such as low stand area growing problem, attracted the attention of domestic and foreign experts. The forest not only affect the sustainable development of forestry, the forest reduces the overall quality and function, but also hinders the healthy development of economic and social sectors and regions, so the transformation with the reconstruction of large area in hilly area of Sichuan cypress forest to Deyang city. The upper reaches of the Yangtze River region, the transformation of the inefficient stand, improve the soil and water conservation benefit protection, is an important part of the Yangtze River shelterbelt project construction is essential, "in the hilly area of central Sichuan structure optimization and the function of artificial forest ecosystem" one of the key research contents to enhance the technical topic. This paper takes Deyang City Jingyang District cypress forest as the control, through field investigation and laboratory analysis, the research mainly to pepper The economic transformation of the initial forest soil microbial biomass, soil enzyme activity and nutrient status, to explore the relationship between soil microorganism, enzyme activity and soil nutrient and soil quality changes and provide a theoretical basis for the transformation of mode of economic forest forest, the results showed that: 1. pepper transformation model of soil pH value is lower than the control, significant differences in economic forest. The transformation mode of soil total potassium, available potassium, available phosphorus content was significantly higher than that of Cupressus funebris forest, organic matter and other nutrient content had no significant difference. The Chinese prickly ash, walnut forest transformation model of soil nutrient content had no significant difference. The vertical distribution of soil nutrient content were decreased with soil depth.2. soil bacteria accounted for more than 75% of the total number of bacteria, actinomycetes and fungi. Compared with cypress forest, economic forest transformation groups have different soil microorganisms Increased. The total amount of soil microbes and bacteria, fungi, actinomycetes in vertical distribution were consistent, with the deepening of soil layer decreased rapidly, mainly concentrated in the upper layer. The number of microbes in summer and autumn than in spring and winter. The Chinese prickly ash, walnut and cypress forest transformation mode of the number of bacteria were the highest in autumn, pepper transformation the control mode and the number of bacteria in winter forest at least, is the least in spring walnut transformation mode; pepper transformation pattern and the control of Actinomyces in autumn most, least in winter, and the walnut transformation pattern of Actinomyces most in summer, less in spring; the Chinese prickly ash, walnut transformation pattern and control the number of fungi samples were the highest in autumn however, Chinese prickly ash, walnut transformation mode of actinomycetes in spring cypress forest at least in winter; the total number of microorganisms and bacteria consistent seasonal dynamics of nuclear.3. Peach transformation model compared with the control, soil catalase, urease activity had no significant difference, but the phosphatase activity was significantly lower than the control; pepper transformation model compared with the control, three kinds of soil enzyme activities were not significantly different. With the increase of soil depth, the activity of the three enzymes showed a weakening trend, its activity is mainly concentrated on the the upper. The transformation pattern and control soil catalase activity were highest in summer, but the lowest in winter and the lowest in spring; pepper transformation mode of soil urease activity was highest in summer, lowest in winter, while the nuclear transformation pattern and its control of peach forest activity were highest in autumn and lowest in winter; the soil phosphatase activity was highest in summer and winter the lowest.4. chemical fertilizer had no significant effect on soil organic matter content in the short term, soil total nitrogen, available nitrogen, available phosphorus content with corresponding fertilizer application amount Increased soil total phosphorus, total potassium, available potassium content with the corresponding amount of fertilizer increased and then decreased. The number of soil bacteria with the amount of nitrogen fertilizer increased first and then decreased, a small amount of phosphorus and potassium can improve the quantity of bacteria, excess can inhibit bacterial activity, inorganic fertilizer will reduce the number of actinomycetes, fungi significantly increased soil enzyme activity. The application of inorganic fertilizer in the short term, but with the increase of application rates of the activity of.5. can reduce the number of bacteria and the content of available phosphorus significantly negatively correlated with available potassium content was significantly positive correlation; the number of actinomycetes and the total phosphorus, total nitrogen hydrolysis, nitrogen content was significant or extremely significant positive correlation; the number of fungi and organic matter, total nitrogen, hydrolyzable nitrogen, a significant or extremely significant positive correlation. The content of available phosphorus in soil catalase activity and total nitrogen content showed significant correlation; urea Enzyme activity and total nitrogen, there was a significant correlation between potassium content; phosphatase activity and total phosphorus, available phosphorus, total nitrogen, alkali hydrolyzable nitrogen, significant or very significant correlation. The content of available potassium bacteria, actinomycetes and three kinds of enzyme activity were significant or highly significant positive correlation, significant correlation and the number of fungi phosphatase activity and catalase activity was significantly related to.6. economic forest transformation soil total nitrogen content and actinomycetes, fungi and soil enzyme activities were the most significant correlation, indicating the soil total nitrogen content has greater effect on soil biological properties. The number of fungi and phosphatase activity and soil nutrient content was most significant or extremely significant correlation, indicating the level of evaluation of soil fertility and soil fungi quantity and phosphatase activities could be better.

【学位授予单位】：四川农业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：S714

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