民勤人工梭梭林土壤微生物時空異質(zhì)性與土壤非生物因子關(guān)系研究
發(fā)布時間：2018-10-13 15:14
【摘要】：土地沙化是目前我國面臨的嚴(yán)重的生態(tài)環(huán)境問題之一。營造人工固沙林是當(dāng)前防治土地沙化和恢復(fù)生態(tài)的有效措施之一。本文通過對甘肅民勤沙區(qū)不同年代營造的梭梭人工林植被、土壤微生物、土壤物理性質(zhì)及土壤養(yǎng)分等因子變化的觀測與分析研究,應(yīng)用空間代替時間的研究方法分析人工林土壤微生物的時空異質(zhì)性特征及其與土壤因子的相互關(guān)系,以期為我國西北干旱沙區(qū)防沙治沙和生態(tài)恢復(fù)建設(shè)提供科學(xué)依據(jù)。研究結(jié)果表明:1)流動沙地建立人工梭梭固沙林后,有效恢復(fù)了沙地的植被與生態(tài),物種多樣性不斷豐富,植被組成由造林初期單一的人工灌木結(jié)構(gòu)逐漸向草本植物占優(yōu)勢的草本-灌木結(jié)構(gòu)演替。2)土壤中真菌、細(xì)菌、放線菌的數(shù)目以及微生物量碳含量呈現(xiàn)出先增加后緩慢降低的趨勢,在造林30年后達(dá)到峰值。3)不同林齡人工梭梭固沙林地土壤顆粒組成存在顯著差異(P0.05);成土作用明顯。5個年代樣地土壤含水量、pH表現(xiàn)出明顯的層次性特征。另外,距離樹干越近,土壤的pH值、含水量、粘、粉粒含量越大,沙粒含量越小。4)不同林齡梭梭人工固沙林土壤有機(jī)碳、氮、磷養(yǎng)分大量回歸,表現(xiàn)為:土壤表層土壤的有機(jī)碳和氮磷全量明顯高于中、下層;且隨林齡的增長而增長;水平方向上,土壤有機(jī)碳和全磷在樹干附近的含量要明顯低于樹冠下,全氮、有效磷和有效氮則表現(xiàn)出明顯的齡級效應(yīng)。5)因子分析顯示,土壤各因子含量均隨著梭梭人工林林齡的增長而增長。水平方向上在距樹干0-50cm內(nèi)養(yǎng)分占150cm范圍內(nèi)69.95%。垂直方向上,0-5cm土壤表層所存儲的土壤養(yǎng)分最多;土壤養(yǎng)分含量與土層呈現(xiàn)出明顯的負(fù)效應(yīng)。6)土壤三大菌群以及微生物量碳與土壤pH值、有機(jī)碳、全氮、含水率、粘粒、粉粒的含量表現(xiàn)出極顯著正相關(guān)關(guān)系,與土壤砂粒含量、碳氮比表現(xiàn)出負(fù)相關(guān)關(guān)系,與土壤全磷、有效磷、有效氮、硝態(tài)氮、氨態(tài)氮之間的相關(guān)性不顯著。說明流動沙地建立人工梭梭林后,植被得到有效恢復(fù),促進(jìn)了成土過程,為微生物的發(fā)育提供了生境。
[Abstract]:Land desertification is one of the serious ecological environmental problems in China. Creating artificial sand fixation forest is one of the effective measures to control land desertification and restore ecology. In this paper, the changes of plant vegetation, soil microbes, soil physical properties and soil nutrients in different years of Haloxylon ammodendron plantation in Minqin Sandy area, Gansu Province, were observed and analyzed. The spatiotemporal heterogeneity of soil microorganism in artificial forest and its relationship with soil factors were analyzed by using the method of space instead of time in order to provide scientific basis for sand control and ecological restoration in arid sandy region of northwest China. The results showed that: 1) the vegetation and ecology of the sandy land were restored effectively after the establishment of the sand fixation forest of Haloxylon ammodendron on the mobile sandy land, and the species diversity was continuously rich. Vegetation composition from a single artificial shrub structure in the early stage of afforestation to herbaceous shrub structure succession. 2) soil fungi, bacteria, The number of actinomycetes and microbial biomass carbon content increased first and then decreased slowly. The peak value was reached after 30 years of afforestation. 3) there were significant differences in soil particle composition among different forest ages (P0.05); soil formation was obvious. The soil moisture content of five plots showed obvious stratification characteristics with pH. In addition, the closer to the trunk, the greater the soil pH value, water content, clay content and silt content, and the smaller the sand content. 4) the soil organic carbon, nitrogen and phosphorus nutrients were regressed in different forest ages of Haloxylon ammodendron artificial sand fixation forest. The results showed that the total amount of organic carbon and nitrogen and phosphorus in the topsoil was significantly higher than that in the middle and lower layers, and increased with the increase of forest age. In the horizontal direction, the contents of soil organic carbon and total phosphorus near the tree trunk were significantly lower than those under the tree crown. Available phosphorus and available nitrogen showed obvious age effect. 5) Factor analysis showed that the content of soil factors increased with the increase of forest age of Haloxylon ammodendron plantation. In horizontal direction, the nutrient content in 0-50cm was 69.95% in the range of 150cm. In the vertical direction, the soil nutrient stored in the surface layer of 0-5cm was the most, and the soil nutrient content and soil layer showed obvious negative effect. There was a significant positive correlation between the content of silt and soil sand content, C / N ratio, but no significant correlation with soil total phosphorus, available nitrogen, nitrate nitrogen and ammonia nitrogen. The results showed that after the establishment of the artificial Haloxylon ammodendron forest in the moving sandy land, the vegetation was restored effectively, the soil-forming process was promoted, and the habitat was provided for the development of microbes.
【學(xué)位授予單位】：甘肅農(nóng)業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：S714.3
本文編號：2269081
[Abstract]:Land desertification is one of the serious ecological environmental problems in China. Creating artificial sand fixation forest is one of the effective measures to control land desertification and restore ecology. In this paper, the changes of plant vegetation, soil microbes, soil physical properties and soil nutrients in different years of Haloxylon ammodendron plantation in Minqin Sandy area, Gansu Province, were observed and analyzed. The spatiotemporal heterogeneity of soil microorganism in artificial forest and its relationship with soil factors were analyzed by using the method of space instead of time in order to provide scientific basis for sand control and ecological restoration in arid sandy region of northwest China. The results showed that: 1) the vegetation and ecology of the sandy land were restored effectively after the establishment of the sand fixation forest of Haloxylon ammodendron on the mobile sandy land, and the species diversity was continuously rich. Vegetation composition from a single artificial shrub structure in the early stage of afforestation to herbaceous shrub structure succession. 2) soil fungi, bacteria, The number of actinomycetes and microbial biomass carbon content increased first and then decreased slowly. The peak value was reached after 30 years of afforestation. 3) there were significant differences in soil particle composition among different forest ages (P0.05); soil formation was obvious. The soil moisture content of five plots showed obvious stratification characteristics with pH. In addition, the closer to the trunk, the greater the soil pH value, water content, clay content and silt content, and the smaller the sand content. 4) the soil organic carbon, nitrogen and phosphorus nutrients were regressed in different forest ages of Haloxylon ammodendron artificial sand fixation forest. The results showed that the total amount of organic carbon and nitrogen and phosphorus in the topsoil was significantly higher than that in the middle and lower layers, and increased with the increase of forest age. In the horizontal direction, the contents of soil organic carbon and total phosphorus near the tree trunk were significantly lower than those under the tree crown. Available phosphorus and available nitrogen showed obvious age effect. 5) Factor analysis showed that the content of soil factors increased with the increase of forest age of Haloxylon ammodendron plantation. In horizontal direction, the nutrient content in 0-50cm was 69.95% in the range of 150cm. In the vertical direction, the soil nutrient stored in the surface layer of 0-5cm was the most, and the soil nutrient content and soil layer showed obvious negative effect. There was a significant positive correlation between the content of silt and soil sand content, C / N ratio, but no significant correlation with soil total phosphorus, available nitrogen, nitrate nitrogen and ammonia nitrogen. The results showed that after the establishment of the artificial Haloxylon ammodendron forest in the moving sandy land, the vegetation was restored effectively, the soil-forming process was promoted, and the habitat was provided for the development of microbes.
【學(xué)位授予單位】：甘肅農(nóng)業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：S714.3
【參考文獻(xiàn)】
相關(guān)期刊論文 前3條
1 朱震達(dá);中國土地荒漠化的概念、成因與防治[J];第四紀(jì)研究;1998年02期
2 彭少麟,趙平;跨越邊界的生態(tài)恢復(fù)——第十三屆國際恢復(fù)生態(tài)學(xué)大會綜述[J];生態(tài)學(xué)報;2001年12期
3 王新平,李新榮,肖洪浪,張景光,張志山;干旱半干旱地區(qū)人工固沙灌木林生態(tài)系統(tǒng)演變特征[J];生態(tài)學(xué)報;2005年08期
，本文編號：2269081
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