城市化对中国东南海岸区沿河流的森林—大气—表层河水氮污染和循环影响
发布时间：2024-06-01 00:22
当前沿海地区可持续地提供多样的生态系统服务受到日益关注,导致全球范围内越来越多的沿海地区正在经历快速的城市化进程,进而带来环境氮(N)污染问题。由于氮饱和度将对沿海生态系统及其相关服务产生特别深远的影响,因而了解其如何应对不断增长的城市化进程是重要的。尽管先前的研究已经调查了城市化对全球不同生态系统中氮饱和度模式的影响,但这些研究结果揭示了不同城市化研究结果具有相互冲突的格局(增加,减少或没有明确的模式)。因此,了解氮污染的潜在机制及其对沿海生态系统影响具有重要的生态学和社会意义。本文以中国南部福州闽江口流经市区的白龙江(BJR)和郊区的乌龙江(WJR)河岸森林为研究对象,研究城市化对氮污染的影响及N元素在森林-大气-地表水的生物地球化学循环。具体研究内容和结果如下:(1)基于15N稳定同位素技术,探索沿BJR和WJR的亚热带沿岸森林土壤N有效性和循环模式。本研究内容分析了不同土层土壤、叶片的氮变量,包括土壤和叶片的氮浓度,同位素丰度以及土壤氮矿化速率。BJR森林的土壤总氮浓度,无机氮浓度(铵和硝酸盐),氮矿化速率(净氮矿化和净硝化)和土壤δ15
【文章页数】：118 页
【学位级别】：博士
【文章目录】：
Dedication
List of Abbreviations and Acronyms
摘要
Abstract
1 General introduction
1.1 Coastal areas are a magnet for people from non-coastal areas
1.2 Urbanization of coastal areas around the world
1.3 Urbanization of coastal areas across China
1.4 Urbanization and nitrogen pollution globally,across China and in coastal areas
1.4.1 Atmospheric nitrogen deposition to terrestrial and aquatic ecosystems in relation to urbanization
1.4.2 Urbanization as an influence on nitrogen pollution in forest ecosystems
1.4.3 Nitrogen pollution of river ecosystems as a consequence of urbanization
1.5 Study rationale,objectives,questions and technical route
1.5.1 Study rationale
1.5.2 Study objectives
1.5.3 Study questions
1.5.4 Study technical route
1.6 Thesis structure
2 Differential patterns of nitrogen and δ 15N in soil and foliar along two urbanized rivers in a subtropical coastal city of southern China
2.1 Introduction
2.2 Materials and Methods
2.2.1 Study site descriptions
2.2.2 Collection and pre-treatment of plant and soil samples
2.2.3 Chemical and δ 15N analysis of plant and soil samples
2.2.4 Statistical analysis
2.3 Results
2.3.1 Soil p H,N contents,and net N mineralization and nitrification rates
2.3.2 Soil 15N natural abundance,and plant N concentration and 15N natural abundance
2.3.3 Relationships of soilδ 15N and soil N availability and plantδ 15N
2.4 Discussion
2.4.1 Effect of urbanization on soil N contents and N transformation rates
2.4.2 Effect of urbanization on soil and foliarδ 15N
2.5 Conclusions
3 Soil carbon and nitrogen availability are key determinants of soil microbial biomass and respiration in forests along urbanized rivers of southern China
3.1 Introduction
3.2 Materials and Methods
3.2.1 Study sites
3.2.2 Soil sampling and treatment
3.2.3 Chemical analysis of soil samples
3.2.4 Statistical analysis
3.3 Results
3.3.1 Soil chemical properties
3.3.2 Soil microbial biomass and microbial quotient
3.3.3 Soil microbial respiration rate and metabolic quotient
3.3.4 Correlations between soil chemical and microbial properties
3.4 Discussion
3.5 Conclusions
4 Increasing importance of nitrate-nitrogen and organic nitrogen concentrations in bulk and throughfall precipitation across urban forests in southern China
4.1 Introduction
4.2 Materials and Methods
4.2.1 Study sites
4.2.2 Sample collections and laboratory analysis
4.2.3 Data analysis
4.3 Results
4.3.1 Patterns of nitrogen concentrations in BP and TP across rivers and seasons
4.3.2 Relationships between precipitation,soil and foliar N variables
4.4 Discussion
4.5 Conclusions
5 Patterns of nitrogen concentrations and their controls in two southern China urban river ecosystems
5.1 Introduction
5.2 Materials and Methods
5.2.1 Study site descriptions
5.2.2 Sampling procedures and analytical methods
5.2.3 Statistical analysis
5.3 Results
5.3.1 Spatial pattern of nitrogen concentrations in river waters
5.3.2 Temporal pattern of nitrogen concentrations in river waters
5.3.3 Relationships between surface water,precipitation and soil N variables
5.4 Discussion
5.5 Conclusions
6 Conclusions and recommendations
6.1 Conclusions
6.2 Recommendations
6.2.1 Management options to reduce nitrogen pollution in urban areas
6.2.2 Future research perspectives
References
Biographical Sketch
Published papers and other Academic Achievements during the Program
Preface and Acknowledgements
本文编号：3985291
【文章页数】：118 页
【学位级别】：博士
【文章目录】：
Dedication
List of Abbreviations and Acronyms
摘要
Abstract
1 General introduction
1.1 Coastal areas are a magnet for people from non-coastal areas
1.2 Urbanization of coastal areas around the world
1.3 Urbanization of coastal areas across China
1.4 Urbanization and nitrogen pollution globally,across China and in coastal areas
1.4.1 Atmospheric nitrogen deposition to terrestrial and aquatic ecosystems in relation to urbanization
1.4.2 Urbanization as an influence on nitrogen pollution in forest ecosystems
1.4.3 Nitrogen pollution of river ecosystems as a consequence of urbanization
1.5 Study rationale,objectives,questions and technical route
1.5.1 Study rationale
1.5.2 Study objectives
1.5.3 Study questions
1.5.4 Study technical route
1.6 Thesis structure
2 Differential patterns of nitrogen and δ 15N in soil and foliar along two urbanized rivers in a subtropical coastal city of southern China
2.1 Introduction
2.2 Materials and Methods
2.2.1 Study site descriptions
2.2.2 Collection and pre-treatment of plant and soil samples
2.2.3 Chemical and δ 15N analysis of plant and soil samples
2.2.4 Statistical analysis
2.3 Results
2.3.1 Soil p H,N contents,and net N mineralization and nitrification rates
2.3.2 Soil 15N natural abundance,and plant N concentration and 15N natural abundance
2.3.3 Relationships of soilδ 15N and soil N availability and plantδ 15N
2.4 Discussion
2.4.1 Effect of urbanization on soil N contents and N transformation rates
2.4.2 Effect of urbanization on soil and foliarδ 15N
2.5 Conclusions
3 Soil carbon and nitrogen availability are key determinants of soil microbial biomass and respiration in forests along urbanized rivers of southern China
3.1 Introduction
3.2 Materials and Methods
3.2.1 Study sites
3.2.2 Soil sampling and treatment
3.2.3 Chemical analysis of soil samples
3.2.4 Statistical analysis
3.3 Results
3.3.1 Soil chemical properties
3.3.2 Soil microbial biomass and microbial quotient
3.3.3 Soil microbial respiration rate and metabolic quotient
3.3.4 Correlations between soil chemical and microbial properties
3.4 Discussion
3.5 Conclusions
4 Increasing importance of nitrate-nitrogen and organic nitrogen concentrations in bulk and throughfall precipitation across urban forests in southern China
4.1 Introduction
4.2 Materials and Methods
4.2.1 Study sites
4.2.2 Sample collections and laboratory analysis
4.2.3 Data analysis
4.3 Results
4.3.1 Patterns of nitrogen concentrations in BP and TP across rivers and seasons
4.3.2 Relationships between precipitation,soil and foliar N variables
4.4 Discussion
4.5 Conclusions
5 Patterns of nitrogen concentrations and their controls in two southern China urban river ecosystems
5.1 Introduction
5.2 Materials and Methods
5.2.1 Study site descriptions
5.2.2 Sampling procedures and analytical methods
5.2.3 Statistical analysis
5.3 Results
5.3.1 Spatial pattern of nitrogen concentrations in river waters
5.3.2 Temporal pattern of nitrogen concentrations in river waters
5.3.3 Relationships between surface water,precipitation and soil N variables
5.4 Discussion
5.5 Conclusions
6 Conclusions and recommendations
6.1 Conclusions
6.2 Recommendations
6.2.1 Management options to reduce nitrogen pollution in urban areas
6.2.2 Future research perspectives
References
Biographical Sketch
Published papers and other Academic Achievements during the Program
Preface and Acknowledgements
本文编号：3985291
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