Determining patterns in the composition of dissolved organic matter in fresh waters according to land use and management

Yates, Christopher A.; Johnes, Penny J.; Brailsford, Francesca L.; Evans, Christopher D. ORCID: https://orcid.org/0000-0002-7052-354X; Evershed, Richard P.; Glanville, Helen C.; Jones, Davey L.; Lloyd, Charlotte E.M.; Marshall, Miles R.; Owen, Alun T.. 2023 Determining patterns in the composition of dissolved organic matter in fresh waters according to land use and management [in special issue: Dissolved organic matter in freshwaters] Biogeochemistry, 164 (1). 143-162. https://doi.org/10.1007/s10533-022-00964-2

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Official URL: http://dx.doi.org/10.1007/s10533-022-00964-2

Abstract/Summary

In fresh waters, the origins of dissolved organic matter (DOM) have been found to exert a fundamental control on its reactivity, and ultimately, its ecosystem functional role. A detailed understanding of landscape scale factors that control the export of DOM to aquatic ecosystems is, therefore, pivotal if the effects of DOM flux to fresh waters are to be fully understood. In this study we present data from a national sampling campaign across the United Kingdom in which we explore the variability in DOM composition in three broad landscape types defined by similar precipitation, geology, land use and management, hydrology, and nutrient enrichment status. We characterised samples from fifty-one sites, grouping them into one of three major underlying classifications: circumneutral streams underlain by clay and mudstone (referred to as ‘clay’), alkaline streams underlain by Cretaceous Chalk or by Carboniferous or Jurassic Limestone (‘limestone’), and acidic streams in peatland catchments underlain by a range of low permeability lithologies (‘peat’). DOM composition was assessed through organic matter stoichiometry (organic carbon: organic nitrogen; organic carbon: organic phosphorus; C/N(P)DOM) and metrics derived from ultra-violet (UV)/visible spectroscopic analysis of DOM such as specific UV absorption (a254 nm; SUVA254). We found similar SUVA254, C/NDOM and DOM/a254 relationships within classifications, demonstrating that despite a large degree of heterogeneity within environments, catchments with shared environmental character and anthropogenic disturbance export DOM with a similar composition and character. Improving our understanding of DOM characterisation is important to help predict shifts in stream ecosystem function, and ecological responses to enrichment or mitigation efforts and how these may result in species composition shifts and biodiversity loss in freshwater ecosystems.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	https://doi.org/10.1007/s10533-022-00964-2
UKCEH and CEH Sections/Science Areas:	Soils and Land Use (Science Area 2017-) Unaffiliated
ISSN:	0168-2563
Additional Information. Not used in RCUK Gateway to Research.:	Open Access paper - full text available via Official URL link.
Additional Keywords:	dissolved organic matter, carbon, nitrogen, phosphorus, nutrient stoichiometry
NORA Subject Terms:	Ecology and Environment Hydrology Agriculture and Soil Science
Date made live:	25 Jan 2024 09:46 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/536771

Item Type:

Publication - Article

Digital Object Identifier (DOI):

https://doi.org/10.1007/s10533-022-00964-2

UKCEH and CEH Sections/Science Areas:

Soils and Land Use (Science Area 2017-)
Unaffiliated

ISSN:

0168-2563

Additional Information. Not used in RCUK Gateway to Research.:

Open Access paper - full text available via Official URL link.

Additional Keywords:

dissolved organic matter, carbon, nitrogen, phosphorus, nutrient stoichiometry