Date of Award
5-2024
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
College/School
College of Science and Mathematics
Department/Program
Earth and Environmental Studies
Thesis Sponsor/Dissertation Chair/Project Chair
Jennifer Krumins
Committee Member
Nina Goodey
Committee Member
Huan Feng
Committee Member
Richard Pouyat
Abstract
In terrestrial biomes, soils possess the highest amount of carbon and nitrogen stocks that regulate biogeochemical processes and provide ecosystem services. The amount of carbon and nitrogen stored in soils, as a balance of nutrient influxes and outfluxes, is controlled by various environmental and soil factors, while at the same time soil carbon and nitrogen stocks can be subject to anthropogenic impacts, like nutrient storage in urban soils. To inform a better, general understanding of carbon and nitrogen distribution in urban soils, the present dissertation gathers four articles (from Chapters 2 to 5, respectively) addressing different aspects of the issue, and Chapter 1 Summarizing Report provides an overview of these articles and introduces the structure of the present dissertation. Based on a meta-analysis in carbon stocks comparison between natural and urban soils, Chapter 2 indicates that from global perspective urban soils store a lower amount of carbon compared to natural soils. Moreover, the amount of carbon storage in urban soils is less variable than the carbon in natural soils, suggesting a homogenous effect of human activities on in urban soils and environments. Given that the wetland soil carbon data are not well-representative in the research work included in Chapter 2, Chapter 3 bridges this gap and focuses on the relationship between varied degrees of anthropogenic impacts (levels of population density are used) and carbon storage in mangrove soils. It is found that the two variables are negatively associated with each other, while this relationship is weak when resolving together with typical environmental factors like temperature and precipitation. Various human activities across different levels of population density can complicate the relationship. Speaking to the soil nitrogen, Chapter 4 compares the amount of nitrogen stocks and mechanisms among natural, agricultural, and urban soils through a global scale of literature search. Urban soils store the highest amount of nitrogen among the three habitats, while natural and agricultural soils support a similar amount of soil nitrogen. Moreover, the effects of climatic and soil factors on soil nitrogen stocks are reduced in agricultural and urbans, suggesting the nitrogen storage in anthropogenic soils may be more subject to anthropogenic factors, like fertilizer use and nitrogen deposition, which overwhelm natural factors. Under the environmental context of low carbon and high nitrogen stocks in urban soils, Chapter 5 serves as a review article that organizes major ecological mechanisms and human activities that change the carbon and nitrogen distribution in urban soils. Furthermore, integrating soil nutrient distribution into Urban Ecology, this chapter discusses potential environmental consequences as well as human health concerns. This whole presentation provides a better understanding of carbon and nitrogen distribution in natural and anthropogenic soils and serves a critical reference for soil and environmental sustainability for all.
File Format
Recommended Citation
Chien, Shih-Chieh, "A Global Analysis of Carbon and Nitrogen Stocks in Natural and Anthropogenic Soils" (2024). Theses, Dissertations and Culminating Projects. 1485.
https://digitalcommons.montclair.edu/etd/1485