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經營模式對毛竹林土壤細菌、真菌群落結構和豐度的影響

發(fā)布時間:2018-03-25 00:02

  本文選題:毛竹林 切入點:粗放經營 出處:《浙江農林大學》2017年碩士論文


【摘要】:毛竹是中國亞熱帶地區(qū)重要的人工林,目前我國的毛竹林采用兩種經營模式:粗放和集約經營。毛竹林粗放經營對土壤養(yǎng)分循環(huán)和微生物的群落結構產生重要影響。本研究以土壤細菌和真菌為對象,在毛竹主產區(qū)分別選擇兩處不同栽培年限的粗放和集約經營毛竹林樣地,分別采集0-20cm和20-40cm土壤,通過熒光定量PCR技術分析了土壤細菌和真菌的豐度;PCR-DGGE技術和T-RFLP技術分析了土壤細菌和真菌的群落結構變化和多樣性指數。旨在揭示毛竹林長期粗放或集約經營過程中土壤細菌和真菌的群落結構和豐度隨經營時間增加的變化規(guī)律。取得的主要研究結果如下:(1)粗放經營毛竹林發(fā)展過程中,安吉土壤細菌豐度隨著毛竹種植時間不斷下降,而安吉土壤真菌以及長興土壤細菌和真菌在毛竹純林5年時豐度均顯著增加,之后隨種植地點的不同出現不同的變化規(guī)律。土壤細菌和真菌的群落結構均發(fā)生明顯變化,且細菌結構對毛竹種植時間的響應更敏感,表層土壤細菌群落表現出抵抗干擾、恢復到初始結構的趨勢。對DGGE結果的冗余分析的第一、二軸對樣地變化的解釋率大多低于65%,不同地點、不同土層驅動土壤微生物結構隨時間變化的主要因子缺乏一致性,說明除本研究分析的5個土壤指標外還有其他性質驅動微生物結構的變化,是多因子共同作用導致細菌和真菌的變化。對T-RFLP結果的冗余分析說明,影響土壤細菌和真菌的群落結構的因素依次是地區(qū)、土層和毛竹種植時間,說明毛竹林土壤細菌表現為明顯的地域差異。(2)集約經營毛竹林發(fā)展過程中,土壤養(yǎng)分表現為富集現象。遂昌和長興兩地細菌和真菌的豐度表現出不同的變化規(guī)律,遂昌土壤細菌隨時間增加豐度變化不大,僅亞表層土壤在25年時顯著上升;而真菌則在前15年時隨時間增加而下降,15年后又上升。長興土壤細菌呈現出穩(wěn)定的周期性變化,而真菌則在集約經營5年時發(fā)生變化,5年之后豐度保持穩(wěn)定。說明土壤細菌和真菌的豐度變化規(guī)律有明顯的地域性差異,隨時間的增加細菌的數量更趨向于穩(wěn)定,而真菌的數量在長時間的集約經營后上升。PCR-DGGE結果表明,集約經營后的發(fā)展過程中細菌的多樣性變化發(fā)生在經營中后期,而真菌的群落結構變化發(fā)生在經營前期。真菌受到環(huán)境因子的影響大于細菌,且細菌表現出抵抗干擾、恢復群落結構的能力。對T-RFLP結果的冗余分析表明,影響同一地區(qū)細菌、真菌結構的理化性質較為統(tǒng)一,其中pH在細菌和真菌的群落變化過程中起到了關鍵作用;地域差異對細菌和真菌群落的影響大于不同土層之間的影響,而不同土層的影響大于不同經營時間的影響。
[Abstract]:Phyllostachys pubescens is an important plantation in subtropical China. At present, there are two kinds of management models of Phyllostachys pubescens forest in China: extensive and intensive management. Extensive management of Phyllostachys pubescens forest has an important effect on soil nutrient cycling and microbial community structure. In the main production area of Phyllostachys pubescens, two extensive and intensive plots with different cultivation years were selected to collect 0-20cm and 20-40cm soil, respectively. The abundance of soil bacteria and fungi was analyzed by fluorescence quantitative PCR and T-RFLP. The community structure change and diversity index of soil bacteria and fungi were analyzed in order to reveal the long-term extensive or intensive management of Phyllostachys pubescens forest. The community structure and abundance of soil bacteria and fungi increased with the management time. The main results were as follows: 1) during the extensive management of Phyllostachys pubescens forest, The bacterial abundance of Anji soil decreased with the planting time of Phyllostachys pubescens, while the soil fungi and fungi in Anji soil and Changxing soil increased significantly in 5 years of pure bamboo forest. The community structure of soil bacteria and fungi changed obviously, and the bacterial structure was more sensitive to the planting time of Phyllostachys pubescens, and the bacterial community in surface soil showed resistance to interference. In the redundancy analysis of DGGE results, the rate of interpretation of the variation of soil samples was mostly lower than 65. In different sites, the main factors driving soil microbial structure in different soil layers were not consistent with each other over time. In addition to the five soil indicators analyzed in this study, there are other properties that drive the change of microbial structure, which is caused by the interaction of many factors. The redundancy analysis of T-RFLP results shows that, The factors influencing the community structure of soil bacteria and fungi were region, soil layer and planting time of Phyllostachys pubescens, which indicated that soil bacteria in Phyllostachys pubescens forest showed obvious regional difference. 2) during the development process of intensive management of Phyllostachys pubescens forest. The abundance of bacteria and fungi in Suichang and Changxing showed different changes. The abundance of bacteria in Suichang soil changed little with time, but the subsurface soil increased significantly in 25 years. However, fungi decreased with time in the first 15 years, and then increased 15 years later. The bacteria in Changxing soil showed stable periodic changes. But fungi changed during intensive management for 5 years and kept stable after 5 years, which indicated that the variation of soil bacteria and fungi abundance had obvious regional difference, and the number of bacteria tended to be stable with the increase of time. The number of fungi increased after intensive management for a long time. The results of PCR-DGGE showed that the diversity of bacteria in the development process of intensive management occurred in the middle and late stage of operation. The changes of fungal community structure occurred in the early stage of operation. The fungi were affected by environmental factors more than bacteria, and bacteria showed the ability to resist interference and restore the community structure. The redundancy analysis of T-RFLP results showed that the bacteria affected the same area. The physical and chemical properties of fungal structure were uniform, and pH played a key role in the change of bacterial and fungal communities, and the influence of geographical differences on bacterial and fungal communities was greater than that on different soil layers. The influence of different soil layer is greater than that of different management time.
【學位授予單位】:浙江農林大學
【學位級別】:碩士
【學位授予年份】:2017
【分類號】:S795.7;S714.3

【參考文獻】

相關期刊論文 前10條

1 張飛英;劉亞群;徐瑞英;周瑛;;長期施肥下毛竹林土壤的肥力質量研究[J];浙江林業(yè)科技;2016年04期

2 馬云波;牛聰P,

本文編號:1660621


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