首页 > 硕士 > 农学 > 正文

基质添加对土壤种子库特征的影响研究

The Feature Analysis of Soil Seed Bank by Adding Substrates

作者: 专业:环境管理与经济 导师:李洪远 年度:2015 学位:硕士  院校: 南开大学

Keywords

soil seed bank, substrates, germination curve, regression analysis, CCA analysis

        土壤种子库来源于地面植被,是土壤中全部的活性种子及土壤上层掉落物的总和。土壤种子库具有潜在的植被恢复能力,在植被重建及生态恢复中发挥了非常重要的作用。土壤种子库应用于植被恢复的案例多集中于欧洲、澳洲、日本等地区,也有许多典型的成功案例,例如用土壤种子库在日本屋久岛林道坡面的植被恢复、日本箕面国定公园大坝施工造成裸地的植被恢复等。但国内土壤种子库的研究角度多集中于探究土壤种子库的基础特征,主要包括密度、组成、多样性指数、相似性指数等方面,而关于植被恢复的实践工程研究非常少。本研究借鉴日本土壤种子库的实践经验,创新性地探究基质添加对土壤种子库特征的影响。选择的有机基质(草炭土与稻壳炭),无机基质(活性炭、珍珠岩、蛭石),混合基质(草炭土与珍珠岩混合,稻壳炭与蛭石混合),探究不同类型的基质与表土以不同比例混合时,土壤种子库的特征情况,研究结果如下所示:对土壤种子库密度的促进作用上,混合基质)无机基质>有机基质。所有的试验组中,混合基质对于种子库萌发数量的促进作用最为明显,这可能是由于混合基质由有机基质和无机基质组成,其中有机基质能够为土壤种子库提供营养物质,而无机基质能够保持一定的水分与空间,有利于植物根系生长。混合基质试验组与单一基质试验组差异性非常显著,但是混合基质(草炭土+珍珠岩及稻壳炭+蛭石)两组之间的差异性并不显著。与表土的混合比例上,30%的混合比例能够很好地增加土壤种子库的密度,而有机:无机的配比上,1:1的混合比例效果最好。在促进土壤种子库的多样性水平上,混合基质也表现出了明显的优势,大部分组能够显著提高多样性水平,有机基质试验组在促进群落多样性水平上的优势不明显。对于Shannon指数,30%是最好的混合比例。而对于Simpson指数和Pielou指数,10%是最好的混合比例。土壤种子库的萌发曲线大致呈现“S”型,经历了萌发平稳期—迅速增长期—稳定期,不同试验组在各个时期所经历的时间不同。萌发曲线最好的仍然是混合基质组,其萌发曲线明显优于单一基质。混合基质组中,草炭+珍珠岩及稻壳炭+蛭石都在30%的混合比例时,萌发效果最好。从混合比例来看,1:1的混合比例最优。通过土壤种子库萌发数量与时间的回归分析,发现三次模型对萌发曲线较好的几个组的模拟效果最佳。同时探究了草炭土+珍珠岩30%1:1以及稻壳炭+蛭石30%1:1的萌发率与时间的关系,发现其萌发格局呈现不规则的抛物形状,并且呈现明显的二峰、三峰格局。对生长势的促进作用则是混合基质优于有机基质优于无机基质,群落的生长势好,既需要有机基质为群落提供营养物质,又需要无机基质来保持土壤水分及为根系生长提供更多的空间。混合基质从比例来看,30%、40%的混合比例都是较优组合,而从有机:无机配比来看,1:2的比例更优。生长势最好的七个组,生长势与时间的回归方程拟合效果都非常好,而且用三次多项式、四次多项式都能够很好地解释植物生长势随着时间的变化规律。通过分析Kendall、Spearman、Pearson指数,发现生长势与密度的相关系数较大,而且都显著相关。但生长势与其它指标之间的关系系数较小,相关关系不明显。通过CCA排序分析,萌发物种呈现出明显的三个聚类。其中第一聚类分布有效钾(K)及有效磷(P)含量较高的地方,而第二聚类则分布在土壤含水率较高的区域,说明该类植物对土壤水分要求比较高,该类植物多喜欢潮湿的环境,第三聚类植物大多数都是一些中性植物,能够广泛地适应各种类型的生境,土壤理化因子中,K、P是重要的环境因子。而排序在水分含量较高区域的多为草炭+珍珠岩混合的试验组,排序在K、P元素较高的地方则为稻壳炭+蛭石混合的试验组。添加基质能够明显促进土壤理化性质的改良,而土壤有机元素对土壤种子库有很明显的影响,尤其是N、P、K等元素对植物群落的密度、生长势都有非常明显的影响,其回归方程为Height=-2.807-0.084 C+2.455 N-0.106P+0.491K; Density=51.712+0.829 C-16.867 N-1.999P-4.568K.
    A soil seed bank is a collection of viable seeds present in the soil and on its surface with regeneration potential. The seed bank is an important resource for plant community conservation in terms of regeneration and serves as a supplement of the vegetation; With increasing environmental degeneration, soil seed banks are considered as playing a more important role in restoration of vegetation.The project cases using SSBs for vegetation restoration were mainly carried out in Japan, Australia and some European countries. The typical cases examined were:The topsoil spraying for the Mino River Dam natural recovery; the revegetation method using topsoil seed banks in Yakushima Island. However in China, the focus on SSBs are mainly about the fundamental features of SSBs, such as:density, composition, diversity and so on.So in this paper, the effect of adding substrates for SSBs was explored. Concerning on the Engineering use of the soil seed bank, three inorganic substrates (perlite, vermiculite, acticarbon) and two organic substrates (peat, rice husk charcoal) and two mixed matrix(peat-perlite and rice husk charcoal-vermiculite) were selected for germination experiment to explore the characteristic of SSBs with different types of substrates with different proportions. The conclusions were as follows:The regular pattern for density of SSBs were showed as:mixed substrates> inorganic substrates> organic substrates. For all experimental groups, groups adding mixed substrates showed the most obvious effect in promoting the density of SSBs. This was mainly because the mixed substrates were contained with both organic substrates and inorganic substrates,which could provide nutrients for soil as well as maintain moisture and space for roots.The difference between mixed substrates and single substrates was very obvious.while the difference between the two mixed substrates was not so significant. The mixing ratio of 30% will be good way to promote the density of soil seed bank, and for the organic:inorganic ratio,the ratio of 1:1 was more suitable. For improving the diversity of SSBs, the mixed substrates could significantly improve the diversity of communities, and the organic substrates played little role in improving the diversity.And for Shannon Index,the best ratio was 30%,while for the Simpson index and Pielou index.the preferable proportion were both 10%.The germination curve generally presented "S" shape, with smooth-growing period- rapid-growing period-stable period,but the time for each period differed depended on different substrates.The best germination curves were also presented in the mixed substrates.which had obvious advantages than single substrates.Among all the groups,the peat-perlite and rice husk charcoal-vermiculite both with 30% were the best groups for germination. And for the organic:inorganic ratio,the ratio of 1:1 was more suitable. Six groups with good germination were selected from single and mixed substrates for the regression analysis between germination amount and time. And the cubic equations were found the best model to explain the regression. Also the relationship between germination rate and time were explored, the irregular parabolic shape of germination pattern with two or three peaks were also found.For promoting plants growth potential,the orders were:the mixed substrates> organic substrates> inorganic substrates.Best growth potential needed organic substrates to provide nutrients and inorganic substrates to maintain soil moisture and keep more space for plant roots. And for the mixing proportion, the 30%,40% mixing ratio were preferable, and for the organic:inorganic ratio,the ratio of 1:2 was more suitable. Seven well-growth groups were selected to explore the regression analysis between growth potential of communities and time, and the cubic equation and biquadratic equation could well explain the growth conditions. By analyzing the Kendall, Spearman, Pearson Index, the correlation coefficient between growth potential and density was very high and was significantly related. But the correlation between growth potential and other indexes were not so obvious.The ordination analysis was carried out between community feature and physical and chemical properties of soil,and three clustings were found. The first clusterings was distributed in the K, P elements region,which demonstrated these plants can adapt to the fertile soil. The second clustering was located in the region with high soil moisture, indicating that these plants could adapt to the moist environment.The third clustings plants could widely adapt to various types of habitats. Among all these factors, K、P were the most important environmental factors. Quadrats distributed in K,P region were mainly experimental groups of peat-perlite,while quadrats distributed in high water content area were mainly group of rice husk charcoal-vermiculite. The adding of substrates could effectively improve the soil properties.the organic elements of soil could have very significant impact on SSBs. The elements of N、P、K could improve the growth potential and density of soil seed bank.The regression equation were: Height=-2.807-0.084 C+2.455 N-0.106P+0.491K; Density=51.712+0.829 C-16.867 N-1.999P-4.568K.
        

基质添加对土壤种子库特征的影响研究

摘要5-7
Abstract7-9
第一章 绪论12-22
    第一节 研究背景12-14
    第二节 国内外土壤种子库研究现状14-18
        1.2.1 国内研究现状14-16
        1.2.2 国外研究进程16-18
    第三节 研究目的与意义18-19
    第四节 研究内容与技术路线图19-22
        1.4.1 研究内容19-20
        1.4.2 技术路线图20-22
第二章 研究方法22-29
    第一节 取样区域介绍22
    第二节 基质材料介绍22-23
    第三节 研究方法23-29
        2.3.1 取样方法23-24
        2.3.2 试验设计24-26
        2.3.3 萌发试验26-27
        2.3.4 数据处理27-29
第三章 基质添加对土壤种子库基本特征影响分析29-43
    第一节 单一基质对土壤种子库密度的影响29-31
    第二节 混合基质对土壤种子库密度的影响31-34
    第三节 土壤种子库密度的差异性分析34-37
    第四节 土壤种子库的多样性分析37-43
第四章 基质添加对土壤种子库萌发的影响43-59
    第一节 萌发数量与基质关系分析43-51
    第二节 萌发数量与时间关系的回归分析51-59
第五章 基质添加对生长势的影响分析59-72
    第一节 植物群落生长势情况的分析59-66
    第二节 基质与植物生长势的函数关系66-69
    第三节 生长势与多样性指数及密度的关系分析69-72
第六章 基质添加对土壤理化性质的影响分析72-79
    第一节 基于土壤理化性质的土壤种子库的排序分析72-76
    第二节 土壤理化性质与生长势和密度的关系76-79
第七章 结论与讨论79-82
    第一节 研究结论79-80
    第二节 主要创新点80
    第三节 需进一步探究的问题80-82
参考文献82-87
附录87-94
致谢94-95
个人简历、在学期间发表的学术论文与研究成果95-96
        下载全文需50


本文地址:

上一篇:北京农民种植西瓜选择行为研究
下一篇:最后一页

分享到: 分享基质添加对土壤种子库特征的影响研究到腾讯微博           收藏
评论排行
公告