TY - BOOK

T1 - The large scale understanding of natural organic matter

T2 - processes and application

AU - Adams, Jess

PY - 2017

Y1 - 2017

N2 - Natural biogeochemical cycles of the macronutrient elements carbon (C), nitrogen(N) and phosphorus (P) have been transformed by food and fuel production,through atmospheric pollution and climate change. Further, land disturbance hasled to considerable losses of nutrients from terrestrial ecosystems. Thisinvestigation aims to explore and address several barriers to understanding naturalorganic matter cycling across terrestrial and aquatic ecosystems.Soil organic matter (SOM) turnover models are often constrained by C and N,while data on organic P is lacking. Twenty UK soils were used to provide the firstinvestigation of organic P in density fractionated SOM pools. Organic matter in themineral fraction was considerably more enriched in oP. Stoichiometric ratiosagreed with a new classification model, which provides important constraints formodels of nutrient cycles.Radiocarbon (14C) measurements of aquatic OM indicates sources and turnover ondifferent timescales. Here, the first analysis of particulate O14C in UK riverssuggested topsoil was the major source. Significantly depleted material was foundin a catchment with historical mining activity. Global, temporal analysis ofdissolved O14C enabled quantification of different OM sources, and highlighted theimportance of assessing the data against the changing atmospheric 14C signal. Newdissolved O14C data for rural, arable and urban catchments were more depletedthan the global averages.In industry, there is a growing need to manage aquatic nutrient enrichment throughrapid and reliable monitoring. A model of UV absorbance was tested againstfreshwaters that were biased towards eutrophic conditions. The resultsdemonstrated the weak absorbing components of algal DOM, and new variablemodel parameters were introduced, which quantified the contribution of algalDOM. This could have implications on model predictions of DOC concentration,and a generally applicable spectroscopic model is questionable.This investigation considerably expands the dataset available for modelling largescale biogeochemical cycles, highlights the importance of an integrated approach,and considers the implications involved with applied modelled predictions ofaquatic DOC.

AB - Natural biogeochemical cycles of the macronutrient elements carbon (C), nitrogen(N) and phosphorus (P) have been transformed by food and fuel production,through atmospheric pollution and climate change. Further, land disturbance hasled to considerable losses of nutrients from terrestrial ecosystems. Thisinvestigation aims to explore and address several barriers to understanding naturalorganic matter cycling across terrestrial and aquatic ecosystems.Soil organic matter (SOM) turnover models are often constrained by C and N,while data on organic P is lacking. Twenty UK soils were used to provide the firstinvestigation of organic P in density fractionated SOM pools. Organic matter in themineral fraction was considerably more enriched in oP. Stoichiometric ratiosagreed with a new classification model, which provides important constraints formodels of nutrient cycles.Radiocarbon (14C) measurements of aquatic OM indicates sources and turnover ondifferent timescales. Here, the first analysis of particulate O14C in UK riverssuggested topsoil was the major source. Significantly depleted material was foundin a catchment with historical mining activity. Global, temporal analysis ofdissolved O14C enabled quantification of different OM sources, and highlighted theimportance of assessing the data against the changing atmospheric 14C signal. Newdissolved O14C data for rural, arable and urban catchments were more depletedthan the global averages.In industry, there is a growing need to manage aquatic nutrient enrichment throughrapid and reliable monitoring. A model of UV absorbance was tested againstfreshwaters that were biased towards eutrophic conditions. The resultsdemonstrated the weak absorbing components of algal DOM, and new variablemodel parameters were introduced, which quantified the contribution of algalDOM. This could have implications on model predictions of DOC concentration,and a generally applicable spectroscopic model is questionable.This investigation considerably expands the dataset available for modelling largescale biogeochemical cycles, highlights the importance of an integrated approach,and considers the implications involved with applied modelled predictions ofaquatic DOC.

KW - carbon cycling

KW - nitrogen

KW - Phosphorus

KW - Soil

KW - radiocarbon

KW - freshwater

KW - Transport and fate

U2 - 10.17635/lancaster/thesis/134

DO - 10.17635/lancaster/thesis/134

M3 - Doctoral Thesis

PB - Lancaster University

ER -