不同杉木林经营模式土壤微生物多样性及碳、氮库比较研究

发布时间：2018-05-22 14:10

本文选题：不同杉木林经营模式 + 土壤微生物功能多样性　；参考：《福建农林大学》2017年硕士论文

【摘要】：杉木是我国南方特有的,且已有千年历史的重要用材树种之一,在我国南方林业生产中不仅能提供木材和多种林副产品,而且在保护生态环境、维持森林生态系统平衡方面具有十分重要的地位和作用。随着杉木人工林造林规模的不断扩大,纯林化、针叶化和多代连栽的现象日益严重,已造成较为严重的水土流失、地力衰退等现象,直接制约当前杉木人工林的可持续发展。近些年来对于杉木人工林地力衰退问题已有许多报道,但更多学者还主要集中在有关机制方面的研究,而对杉木人工林地力衰退防治技术体系还没有进行具体而深入的研究。虽然目前有些学者们也提出了一些防治技术措施或者对策(如营造杉阔混交林、林下套种阔叶树和林地施肥等),但由于这些技术措施在实际经营中需要大量的人力物力,且实施难度较大,经济成本较高等原因,还难以得到推广应用,大多数还仍然停留在理论层面上。因此,如何从整个生态系统角度出发,充分利用自然力,来构建近自然的杉木林经营模式,已成为当前杉木人工林地力衰退防治的一个迫切需要解决的重大课题。有鉴于此,本课题组在长时间的杉木研究过程中,针对杉木人工林营林所存在的各类生态问题,根据国内外研究者提出的人工林经营新的理论与方法,对杉木人工林生态系统实施近自然化经营,建立了两种近自然杉木林经营模式(老龄林和萌芽林),同时在其相邻之处建立了二代杉木人工林2(不炼山)、二代杉木人工林1(炼山)和天然林作为研究的系列样地,主要研究不同杉木林经营模式对土壤微生物功能多样性、土壤微生物结构多样性、土壤碳库和土壤氮库的影响,为深入揭示杉木人工林地力衰退机制以及退化的杉木林生态系统的恢复和重建提供科学理论依据。主要研究结果如下:(1)以不同杉木林经营模式为研究对象,应用Biolog生态板研究土壤微生物功能多样性,结果表明,当培养144h后不同杉木林经营模式土壤Biolog生态板AWCD值在0-10 cm和10-20 cm均以萌芽林最高,二代杉木人工林1最低,表明5种不同经营模式中萌芽林的土壤微生物群落碳源代谢能力最大,二代杉木人工林1最小。在0-10 cm和10-20 cm土层不同杉木林经营模式土壤微生物群落对多聚物、羧酸类、氨基酸类碳源的利用能力均高于其他3种碳源的利用能力。在0-10 cm土层不同杉木林经营模式的6类碳源的累积利用情况高于10-20 cm土层。在0-10 cm和10-20 cm土层上,二代杉木人工林1的Shannon-wiener指数均最小,表明二代杉木人工林1利用的土壤微生物碳源种类较少且较不均匀。(2)应用PLFA技术对不同杉木林经营模式土壤微生物结构多样性进行分析,结果表明从不同经营模式土壤中共检测到17种微生物群落磷脂脂肪酸生物标记,且不同经营模式土壤各类型微生物群落磷脂脂肪酸含量存在一定差异,各菌群的磷脂脂肪酸含量以细菌最高,放线菌最低,其中放线菌仅在天然林(0.51 nmol·g-1)中被检测出来。不同杉木林经营模式土壤总磷脂脂肪酸含量存在显著性差异(P0.05),土壤总磷脂脂肪酸含量在33.15-10.48 nmol·g-1之间,含量排序为:天然林二代杉木人工林2萌芽林老龄林二代杉木人工林1。土壤真菌磷脂脂肪酸含量存在显著性差异(P0.05),不同杉木林经营模式中其它土壤菌群磷脂脂肪酸含量均不存在显著性差异(P0.05)。(3)不同杉木林经营模式中,二代杉木人工林2的真菌/细菌值最大为0.67,老龄林的真菌/细菌值最小为0.38,说明二代杉木人工林2更能有效地提高土壤真菌的含量所占的比例。不同杉木林经营模式土壤G+/G-的值在2.70-0.46之间,其中,天然林的G+/G-值最大,萌芽林的G+/G-值最小。不同杉木林经营模式土壤微生物群落磷脂脂肪酸Pielou指数之间差异较小,说明各经营模式土壤微生物分布均匀度差异较小。不同杉木林经营模式土壤微生物群落磷脂脂肪酸Simposon指数天然林最大,而萌芽林与老龄林较小,说明天然林土壤的一些优势磷脂脂肪酸的相对含量较高,萌芽林与老龄林土壤的一些优势磷脂脂肪酸的相对含量较低。(4)不同杉木林经营模式土壤全C含量和土壤C储量均不存在显著差异(P0.05)。总体上不同杉木林经营模式土壤C储量呈现出:二代杉木人工林1二代杉木人工林2天然林萌芽林老龄林的大小顺序。不同杉木林经营模式土壤DOC含量仅在0-10cm 土层存在极显著差异(P0.01),土壤DOC含量在各土层上均以萌芽林土壤DOC含量最高。各土壤层次上,不同杉木林经营模式土壤MBC含量均存在极显著差异(P0.01),萌芽林和老龄林土壤MBC的含量均最高,其次为天然林,二代杉木人工林2和二代杉木人工林1的土壤MBC的含量均较低。表明萌芽林和老龄林更有利于土壤微生物的繁殖和生长,提高了土壤MBC含量,从而使林地土壤肥力得以恢复和改善,尤其是萌芽林模式。土壤全C含量、土壤C储量、土壤DOC含量、土壤MBC的含量均随土层的加深而逐渐降低,具有明显的土壤垂直分布特征。(5)在各土层上,不同杉木林经营模式土壤全N含量和土壤N储量皆不存在显著差异(P0.05)。土壤N储量以二代杉木人工林1与二代杉木人工林2较高,萌芽林与老龄林较低。不同杉木林经营模式土壤铵态氮含量变化范围在20.83-10.23 mg·kg-1。且土壤铵态氮含量差异不显著(P0.05)。不同杉木林经营模式土壤硝态氮含量变化范围18.72-2.24 mg·kg-1。各土层上均以萌芽林与老龄林含量较高。不同经营模式土壤DON含量变化范围在16.08-1.76mg·kg-1。不同经营模式土壤DON含量仅在20-40 cm 土层存在显著差异(P0.05)。不同经营模式土壤MBN含量存在极显著差异(P0.01),土壤MBN含量在78.1-10.6 mg·kg-1之间。从各土壤层次来看,土壤MBN含量呈现萌芽林、老龄林和天然林土壤MBN的含量较高,二代杉木人工林2和二代杉木人工林1的土壤MBN的含量较低。不同杉木林经营模式土壤全N含量、土壤N储量、土壤铵态氮含量、土壤硝态氮含量、土壤DON含量、土壤MBN含量均随土层的加深而逐渐降低,有明显的土壤垂直分布特征。(6)不同杉木林经营模式在0-10 cm土层上的综合得分排序为:萌芽林、老龄林与二代杉木人工林2高于二代杉木人工林1。在10-20 cm 土层上的综合得分排序为:萌芽林、老龄林与二代杉木人工林1高于二代杉木人工林2。在20-40 cm 土层上的综合得分排序为:萌芽林、二代杉木人工林1和二代杉木人工林2高于老龄林。在40-60 cm 土层上的综合得分排序为:萌芽林、二代杉木人工林1、二代杉木人工林2高于老龄林。总体来看各土层上的综合得分均以萌芽林最高,说明各经营模式中以萌芽林的土壤肥力与土壤恢复能力最好,萌芽林可为今后杉木林地力维持提供借鉴与参考。
[Abstract]:Cunninghamia lanceolata is one of the most important timber tree species in the south of China. It can not only provide wood and a variety of forest by-products in the forestry production in the south of China, but also play an important role in protecting the ecological environment and maintaining the balance of forest ecosystem. With the continuous expansion of the plantation of Chinese fir plantation, the forest production is expanding. The phenomenon of large, pure forest, coniferous and multi generation continuous planting is becoming more and more serious, which has caused serious soil erosion and soil erosion, which directly restricts the sustainable development of Chinese fir plantation. In recent years, many reports have been reported on the decline of Chinese fir plantation force, but more scholars have mainly concentrated on the related mechanisms. However, there is no specific and in-depth study on the technology system for the prevention and control of the decline and control of Chinese fir forestland force decline. Although some scholars have also put forward some measures for prevention and control, such as the construction of the mixed forest, the broad-leaved tree and the fertilizing in the woodland, but the technical measures need a lot of practical management. Human and material resources are difficult to implement, and the economic cost is high, and it is still difficult to be popularized. Most of them still remain on the theoretical level. Therefore, how to make full use of the natural force from the angle of the whole ecosystem to construct the near natural Chinese fir forest management model has become the prevention and control of the force decline of the Chinese fir plantation. In view of this, in the course of the long time study of Chinese fir plantation, we have set up two of the ecological problems of the Chinese fir plantation forest, based on the new theories and methods of plantation management proposed by the researchers at home and abroad, and set up the natural management of the ecological system of Chinese fir plantation. At the same time, the two generation of Chinese fir plantation 2 (non smelting mountain), the two generation of Chinese fir plantation 1 (smelting mountain) and natural forest were used as a series of research plots, and the diversity of soil microbial function and soil microbial structure diversity were mainly studied in different Cunninghamia lanceolata Forest Management models. The effects of soil carbon storage and soil nitrogen pool provide scientific theoretical basis for revealing the mechanism of force decline of Chinese fir plantation and the restoration and reconstruction of degraded Chinese fir forest ecosystem. The main results are as follows: (1) using different Shan Mulin management models as the research object, the application of Biolog ecological board to study the diversity of soil microbial function, The results showed that the AWCD values of soil Biolog ecosystem on 0-10 cm and 10-20 cm were the highest in 0-10 cm and 10-20 cm, and the two generation of Cunninghamia lanceolata plantation was the lowest. It showed that the carbon source metabolism of the soil microbial communities in the 5 different management patterns was the largest, and the two generation of fir wood 1 was the smallest. In the 0-10 cm and 10-20 cm soil layers. The utilization of soil microbial communities to polymers, carboxylic acids and amino acid carbon sources in different Chinese fir forest management models were higher than those of the other 3 carbon sources. The cumulative utilization of 6 types of carbon sources in the 0-10 cm soil layer of different Cunninghamia lanceolata management models was higher than the 10-20 cm soil layer. On the 0-10 cm and 10-20 cm soil layers, two generation of Chinese fir plantation 1 The Shannon-wiener index was the least, indicating that the soil microbial carbon source of the two generation of Chinese fir plantation 1 was less and less uniform. (2) the diversity of soil microbial structure in different Chinese fir forest management models was analyzed by PLFA technology. The results showed that phosphatidylcholine fatty acids from 17 microbial communities were detected from different management models. The content of phospholipid and fatty acids in various microbial communities in different types of soil was different, and the content of phospholipid fatty acids in each group was the highest and the actinomycetes were the lowest. The actinomycetes were detected only in the natural forest (0.51 nmol. G-1). The content of total phosphatidic fatty acids in soil of different fir forest management models existed Significant difference (P0.05), the content of total phosphatidic fatty acids in soil was between 33.15-10.48 nmol and g-1. The content of the content was: the two generation of Chinese Fir Plantation in the natural forest 2 sprout forest aged two generation of Chinese fir plantation and 1. soil fungi phospholipid fatty acid content was significant difference (P0.05). There was no significant difference in content (P0.05). (3) in different Chinese fir forest management models, the maximum value of fungi / bacteria in 2 of the two generation of Chinese fir plantation was 0.67, and the minimum value of fungi / bacteria was 0.38 in the aged forest, indicating that the two generation of Chinese fir plantation 2 could effectively increase the proportion of soil fungi in the soil of different Cunninghamia lanceolata forest management model soil G+/G-. Among them, the G+/G- value of natural forest is the largest and the G+/G- value of the sprout forest is the smallest. The difference of phosphatide and fatty acid Pielou index between the soil microorganism community of different Chinese fir forest management mode is small, which indicates that the distribution uniformity of soil microbes in different management modes is small. The phospholipid fat of soil microbial community in different Chinese fir forest management mode is different. The Simposon index of fatty acid is the largest in natural forest, but the germination forest and the aged forest are smaller. It shows that the relative content of some dominant phosphatidic fatty acids in the natural forest soil is higher, and the relative content of some dominant phosphatidic fatty acids in the germination forest and the aged forest soil is low. (4) there is no significant C content in soil and the C reserves in different Chinese fir forest management models. The difference (P0.05). In general, the soil C reserves of different fir forest management models are as follows: two generation Cunninghamia lanceolata plantation 1 two generation Cunninghamia lanceolata plantation 2 natural forest budding forest aging forest size order. The soil DOC content of different Chinese fir forest management mode is only very significant difference in the 0-10cm soil layer (P0.01), and the soil DOC content is in the germination forest soil on the soil layers. Soil DOC content was the highest in soil levels. There were significant differences in soil MBC content in different Chinese fir forest management models (P0.01). The content of soil MBC in sprout and aged forests was the highest, followed by natural forest. The content of MBC in the 2 and two Chinese fir plantation of the two generation of Chinese fir plantation was lower, indicating that the germination and aging forests were more favorable. The breeding and growth of soil microbes increased the MBC content of soil, thus restoring and improving the soil fertility of forestland, especially the sprout forest model. The total C content of soil, the C reserves of soil, the content of the soil DOC and the content of the soil MBC gradually decreased with the depth of the soil layer, and the soil vertical distribution characteristics were obvious. (5) on the various soil layers, There was no significant difference between the total N content of soil and the soil N reserves in the management mode of the same Chinese fir forest (P0.05). The soil N reserves were higher in the two generation Cunninghamia lanceolata plantation 1 and the two generation Cunninghamia lanceolata plantation, and the sprout forest and the aged forest were lower. The soil ammonium nitrogen content of different Chinese fir forest management models was in the 20.83-10.23 mg kg-1. and the soil ammonium nitrogen content was poor. The variation range of soil nitrate nitrogen content in different Chinese fir forest management models (18.72-2.24 mg / kg-1.), the content of soil DON content in the different management models of different management models in the different management models of different management patterns in the different management models of different management modes in the different management models of the different management models in the 20-40 cm soil layer (P0.05). The soil MBN content in different management models was significantly different (P0.01), and the soil MBN content was between 78.1-10.6 mg. Kg-1. From the soil level, the content of MBN content appeared in the soil, and the content of MBN in the aged forest and natural forest soil was higher. The content of MBN in the two generation of Chinese fir plantation and the two generation of Chinese fir plantation 1 was lower. Different Shan Mulin was different. The total N content of soil, soil N reserves, soil ammonium nitrogen content, soil nitrate nitrogen content, soil DON content, soil MBN content gradually decrease with soil depth, and have obvious soil vertical distribution characteristics. (6) the comprehensive scoring of different Chinese fir forest management patterns on the 0-10 cm soil layer is the germination forest, the aged forest and the two generation of fir trees. The comprehensive score of 2 higher than two generation Cunninghamia lanceolata plantation 1. on the 10-20 cm soil layer: germination forest, aged forest and two generation Cunninghamia lanceolata plantation 1 higher than two generation of Chinese fir plantation 2. on the 20-40 cm soil layer, the comprehensive score is: germination forest, two generation Cunninghamia lanceolata plantation 1 and two generation of Cunninghamia lanceolata Plantations are higher than the aging forest. In the 1. layers of soil layer. The comprehensive scores were as follows: the germination forest, the two generation of Chinese fir plantation 1, the two generation of Chinese fir plantation 2 higher than the aged forest. In general, the comprehensive scores on the soil layers were the highest in the sprout forest, which indicated that the soil fertility and the soil recovery ability of the sprout forest were the best in each management model, and the germination forest could provide reference and reference for the maintenance of Chinese fir woodland force in the future. Exam.
【学位授予单位】：福建农林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S791.27

【参考文献】