氮添加对杨树人工林土壤微生物结构的影响
发布时间：2018-10-05 15:46
【摘要】：人类活动导致陆地生态系统中的活性氮沉降量不断增加,氮沉降增加已经对森林生态系统特征和过程产生了很大影响。土壤微生物是森林生态系统中重要的组成部分,研究氮沉降增加对土壤微生物的影响对于探索生态系统碳贮存及养分循环变化具有十分重要的意义。本研究以江苏东台林场10年生和17年生杨树人工林为研究样地,人工施加氮肥模拟大气氮沉降增加,应用磷脂脂肪酸(PLFA)技术,探讨了不同水平氮添加对杨树生长季(5月~10月)过程中土壤微生物生物量及群落结构组成的影响,并结合土壤理化性质的分析,初步探索了影响土壤微生物变化的因素。所得主要结果如下:1、短期(3 a)氮添加未对10年生和17年生杨树人工林土壤总有机碳、总氮、C/N、土壤含水率有明显的影响,但土壤pH有降低的趋势。2、10年生杨树人工林中,微生物总生物量及各微生物类群(细菌、革兰氏阴性细菌、革兰氏阳性细菌、真菌、放线菌、丛枝菌根真菌)生物量在生长季中期(8月份)达到最高。而17年生人工林中,生长季初期(6月份)和中期(8月份)微生物总生物量、细菌、丛枝菌根真菌生物量相当,均高于生长季后期(10月份);真菌、放线菌生物量生长季中期(8份)最高。3、在10年生杨树人工林生长季,短期超高水平氮添加(300 kg?hm-2?a-1)使微生物总生物量、细菌、革兰氏阴性细菌、真菌生物量降低。在17年生杨树人工林生长季,短期氮添加对微生物总生物量及不同微生物类群(细菌、革兰氏阴性细菌、革兰氏阳性细菌、真菌、放线菌、丛枝菌根真菌)生物量的影响较小且没有明显的规律。4、在10年生杨树人工林生长季,土壤有机碳是影响土壤微生物生物量的主要因素。氮添加后微生物生物量下降很可能是受碳限制的影响。在17年生杨树人工林生长季,土壤水分是影响微生物生物量的重要因素,但当土壤水分充足时,土壤C/N是限制微生物生长的因素。5、短期氮添加使10年生杨树人工林生长季土壤微生物结构发往了变化,表现为占主导地位的微生物类群生物量下降。除个别样地外,短期氮添加使17年生杨树人工林生长季微生物群落结构发生了变化。
[Abstract]:The amount of active nitrogen deposition in terrestrial ecosystems is increasing due to human activities, and the increase of nitrogen deposition has had a great impact on the characteristics and processes of forest ecosystems. Soil microorganism is an important part of forest ecosystem. It is very important to study the effect of nitrogen deposition on soil microorganism in order to explore carbon storage and nutrient cycling in ecosystem. In this study, 10-year-old and 17-year-old poplar plantations in Dongtai Forest Farm, Jiangsu Province, were used to simulate the increase of atmospheric nitrogen deposition by applying nitrogen fertilizer. The phospholipid fatty acid (PLFA) technique was applied to simulate the increase of atmospheric nitrogen deposition. The effects of different nitrogen levels on soil microbial biomass and community structure during the growing season of poplar (May ~ October) were studied. The factors affecting soil microbial changes were preliminarily explored based on the analysis of soil physical and chemical properties. The main results were as follows: (1) the short-term (3 a) nitrogen addition had a significant effect on soil total organic carbon (TOC), total nitrogen (TN) C / N, soil moisture content in 10 years old and 17 year old poplar plantations, but soil pH had a decreasing trend of 0.2, 10 years old poplar plantations. The total biomass and the biomass of various microbial groups (bacteria, Gram-negative bacteria, Gram-positive bacteria, fungi, actinomycetes, arbuscular mycorrhizal fungi) reached the highest in the middle of growing season (August). In 17 years old plantation, the total biomass of microorganisms, bacteria and arbuscular mycorrhizal fungi in the early growth season (June) and the middle (August) were similar, which were higher than those in the late growing season (October). The biomass of actinomycetes was the highest in the middle of growth season (8 parts). In the growth season of 10 year old poplar plantation, the short term super high level nitrogen was added (300 kg?). Hm-2? A) the total microbial biomass, bacteria, Gram-negative bacteria and fungal biomass were decreased. In the growth season of 17 years old poplar plantation, the total biomass and different microbial groups (bacteria, Gram-negative bacteria, Gram-positive bacteria, Fungi, Actinomycetes) were added in short-term nitrogen. The effect of arbuscular mycorrhizal fungi on biomass was small and there was no obvious regularity. In the growing season of 10 years old poplar plantation, soil organic carbon was the main factor affecting soil microbial biomass. The decrease of microbial biomass after nitrogen addition is probably affected by carbon limitation. Soil moisture is an important factor affecting microbial biomass during the growth season of 17 years old poplar plantation, but when soil moisture is sufficient, Soil C / N was the limiting factor of microbial growth. Short-term nitrogen supplementation changed the soil microbial structure in the growing season of 10 year old poplar plantation, which showed that the dominant microbial biomass decreased. The microbial community structure of 17 year old poplar plantation was changed with the addition of short term nitrogen except for a few plots.
【学位授予单位】：南京林业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S792.11;S714
[Abstract]:The amount of active nitrogen deposition in terrestrial ecosystems is increasing due to human activities, and the increase of nitrogen deposition has had a great impact on the characteristics and processes of forest ecosystems. Soil microorganism is an important part of forest ecosystem. It is very important to study the effect of nitrogen deposition on soil microorganism in order to explore carbon storage and nutrient cycling in ecosystem. In this study, 10-year-old and 17-year-old poplar plantations in Dongtai Forest Farm, Jiangsu Province, were used to simulate the increase of atmospheric nitrogen deposition by applying nitrogen fertilizer. The phospholipid fatty acid (PLFA) technique was applied to simulate the increase of atmospheric nitrogen deposition. The effects of different nitrogen levels on soil microbial biomass and community structure during the growing season of poplar (May ~ October) were studied. The factors affecting soil microbial changes were preliminarily explored based on the analysis of soil physical and chemical properties. The main results were as follows: (1) the short-term (3 a) nitrogen addition had a significant effect on soil total organic carbon (TOC), total nitrogen (TN) C / N, soil moisture content in 10 years old and 17 year old poplar plantations, but soil pH had a decreasing trend of 0.2, 10 years old poplar plantations. The total biomass and the biomass of various microbial groups (bacteria, Gram-negative bacteria, Gram-positive bacteria, fungi, actinomycetes, arbuscular mycorrhizal fungi) reached the highest in the middle of growing season (August). In 17 years old plantation, the total biomass of microorganisms, bacteria and arbuscular mycorrhizal fungi in the early growth season (June) and the middle (August) were similar, which were higher than those in the late growing season (October). The biomass of actinomycetes was the highest in the middle of growth season (8 parts). In the growth season of 10 year old poplar plantation, the short term super high level nitrogen was added (300 kg?). Hm-2? A) the total microbial biomass, bacteria, Gram-negative bacteria and fungal biomass were decreased. In the growth season of 17 years old poplar plantation, the total biomass and different microbial groups (bacteria, Gram-negative bacteria, Gram-positive bacteria, Fungi, Actinomycetes) were added in short-term nitrogen. The effect of arbuscular mycorrhizal fungi on biomass was small and there was no obvious regularity. In the growing season of 10 years old poplar plantation, soil organic carbon was the main factor affecting soil microbial biomass. The decrease of microbial biomass after nitrogen addition is probably affected by carbon limitation. Soil moisture is an important factor affecting microbial biomass during the growth season of 17 years old poplar plantation, but when soil moisture is sufficient, Soil C / N was the limiting factor of microbial growth. Short-term nitrogen supplementation changed the soil microbial structure in the growing season of 10 year old poplar plantation, which showed that the dominant microbial biomass decreased. The microbial community structure of 17 year old poplar plantation was changed with the addition of short term nitrogen except for a few plots.
【学位授予单位】：南京林业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S792.11;S714
【参考文献】
相关期刊论文 前10条
1 王国兵;阮宏华;唐燕飞;何容;;森林土壤微生物生物量动态变化研究进展[J];安徽农业大学学报;2009年01期
2 常运华;刘学军;李凯辉;吕金岭;宋韦;;大气氮沉降研究进展[J];干旱区研究;2012年06期
3 李德军,莫江明,方运霆,江远清;木本植物对高氮沉降的生理生态响应[J];热带亚热带植物学报;2004年05期
4 王晖;莫江明;鲁显楷;薛t熁，
本文编号：2253963
本文链接：https://www.wllwen.com/kejilunwen/nykj/2253963.html
