大兴安岭落叶松林火烧迹地土壤微生物群落特性的研究
文献类型：学位论文
| 作者 | 白爱芹 |
| 学位类别 | 硕士 |
| 答辩日期 | 2011 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 傅伯杰 ; 曲来叶 |
| 关键词 | 地形 fire severity 恢复时间 rehabilitation year 火烧程度 seasonal changes 土壤微生物群落 soil fertility 土壤养分 soil microorganism community |
| 其他题名 | Study of Soil Microbial Community Characteristics on Burned Area of Larch Forests in Daxing’anling Mountains |
| 中文摘要 | 大兴安岭林区是我国最大的林区和重要的木材供应基地，对于区域气候、水文条件有重要影响。然而,近些年来,该地区的火灾次数和面积不断上升，并时有大火和特大火出现。森林火灾之后土壤的恢复状况直接影响着植被的更新过程，因此对于火烧迹地土壤质量的监测十分重要。土壤微生物作为指示土壤质量的一个重要指标，是近年来国内外研究的热点。本文以大兴安岭兴安落叶林火灾后恢复初期的不同火烧程度、不同地形、不同恢复时间的火烧迹地及其对照样地的土壤微生物为研究对象，结合季节变化，对土壤微生物生物量分布、群落结构和功能进行了考察，以揭示不同火烧迹地植被恢复过程中土壤微生物群落变化规律及影响因素，为火烧后森林生态系统的管理提供直接依据。研究所取得的一些主要结论如下： 1）火后6年的重度火烧迹地土壤微生物生物量、代谢活性和碳源利用能力显著高于对照样地，这与森林火烧后土壤养分和水分条件的改变密切相关，火烧显著促进了土壤微生物的生长，提高了其活性，是影响火烧迹地土壤微生物群落特征的重要因素，但对土壤微生物群落多样性没有显著的影响。 2）火后6年的重度和中度火烧迹地的土壤微生物生物量、代谢活性没有显著差异，在对不同碳源的利用能力存在差异，这可能与火烧迹地地上草本植物在这段时间迅速的更新有关。 3）土壤微生物的生物量、群落结构、代谢活性和多样性受平地和坡地的地形差异的显著影响。平地的土壤养分、水分、微生物生物量都要高于坡地。但坡地土壤微生物的多样性指数和代谢能力高于平地。在植被恢复的过程中坡地的土壤养分和水分条件可能是限制植被恢复速度的关键因素。 4）坡向明显影响土壤微生物生物量，不同坡向的土壤水分含量是导致土壤微生物碳库差异的主要原因。土壤微生物群落结构和多样性与坡向的关系不密切。 5）在植被恢复5年、6年和8年的过程中，土壤物理化学指标均与其对照样地逐年接近。土壤养分指标TN、TC、SOC、AN、SM比对照样地要高，呈现逐年下降的趋势。 6）MBC/MBN季节变化明显，在六月份和九月份的变化明显不同，这可能与不同季节土壤碳源的输入差异有关。 7）在不同的恢复时间，仅生物多样性指数H¢表现出较明显的随恢复时间增加而增加的规律，其他指标如生物量、代谢活性和结构变化受恢复时间的影响比较复杂，这可能与样地间差异过大有关，因而建议恢复时间影响土壤微生物的研究采取对相同样地每年跟踪调查取样的方式，空间代替时间的方法在土壤微生物的群落特征的研究，至少在恢复初期的研究中不建议使用。 |
| 英文摘要 | Daxing’anling is one of the biggest forest region in China and serves as an important wood resource base. However, forest fire occurred frequently and the loss was severe in recent years. Soil restoration quality in burned areas could effect vegetation restoration directly. It is thus important to monitor soil quality. Soil microorganism, one of the most important indicators of soil quality, recently became a research hotspot. We focused on the response of all microbial populations to changes in the soil environment in Daxing’anling burned areas. The purpose of this study is to examine the effects of differential fire severities, terrains of the burned areas and years of vegetation restoration on soil microbial biomass distribution, soil microbial community structure, soil microbial functional diversity and their seasonal changes in the these areas. Fumigated extraction and Biolog methods were used to detect soil microbial biomass, soil microbial community structure and soil microbial functional diversity respectively. The results were shown as follows: 1） The soil microorganism biomass, metabolic activities and carbon use efficiency, except biodiversity, were significantly influenced by forest fire those of them were higher in burned areas than unburned areas. They have close relationships with soil fertility and soil water content. Forest fire increased the growth and metabolites soil microorganism 2） The carbon use efficiency was affected by the serverity of forest fire, however, there were no significantly differences of soil microorganism biomass and activities between the serious and medium forest fire. It may due to the quick rehabilitation of herbs. 3） The soil microorganism biomass, community structure, metabolic activity and function diversity were significantly influenced by topography, i.e. flat site or slope site. It may be related to the marked higher soil fertility and soil water content at flat site than slope site. However, the biodiversity index and carbon use efficiency were higher at slope site. 4） The slope direction could affect the soil microorganism biomass, which may due to the differences of soil water content between western slop and southern slop. 5） The soil carbon, nitrogen soil organic content, available nitrogen and soil water content were declined and the differences between burned area and their control area were decreased from five year, six year to eight year. 6) The seasonal change of MBC/MBN was clear differences between June and September, which may closely related to the input of litter fall. 7) Only soil biodiversity index H¢ was increased with the rehabilitation year, other parameters have no clear trend with rehabilitation year. We suggest the soil samples should be continually conducted in the same area and sampling every year to avoid differences among sites. |
| 源URL | [http://ir.rcees.ac.cn/handle/311016/35078]  |
| 专题 | 生态环境研究中心_城市与区域生态国家重点实验室 |
| 推荐引用方式 GB/T 7714 | 白爱芹. 大兴安岭落叶松林火烧迹地土壤微生物群落特性的研究[D]. 北京. 中国科学院研究生院. 2011. |
入库方式： OAI收割
来源：生态环境研究中心
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