Riparian Zone Heterogeneity Influences the Amount and Fate of Biodegradable Dissolved Organic Carbon at the Land-Water Interface
(2025) In Journal of Geophysical Research: Biogeosciences 130(5).- Abstract
The transport of biodegradable dissolved organic carbon (bDOC) across land-water boundaries is central to supporting the ecological and biogeochemical functioning of freshwater ecosystems. Yet, we know little about how the generation and supply of terrestrial bDOC to streams and lakes is regulated by the physical, biological, and hydrological properties of the riparian interface. Here, we assessed how terrestrial, groundwater, and aquatic bDOC differ along flowpaths connecting riparian soils to a headwater boreal stream. We further tested how bDOC generation and supply differs among interfaces with distinct hydrogeomorphologies, as reflected by differences in soil properties, groundwater dynamics, and hydrological connectivity to the... (More)
The transport of biodegradable dissolved organic carbon (bDOC) across land-water boundaries is central to supporting the ecological and biogeochemical functioning of freshwater ecosystems. Yet, we know little about how the generation and supply of terrestrial bDOC to streams and lakes is regulated by the physical, biological, and hydrological properties of the riparian interface. Here, we assessed how terrestrial, groundwater, and aquatic bDOC differ along flowpaths connecting riparian soils to a headwater boreal stream. We further tested how bDOC generation and supply differs among interfaces with distinct hydrogeomorphologies, as reflected by differences in soil properties, groundwater dynamics, and hydrological connectivity to the stream. We found that bDOC quantity declined sharply from terrestrial sources, to groundwater, to aquatic systems, and that these differences were associated with changes in the optical and chemical properties of the dissolved organic matter pool. However, bDOC generation and potential transport in groundwater varied across site types and reflected local differences in soil organic matter storage, depth to groundwater, and soil microbial community activity. Interface zones with organic-rich soils but weak hydrological connections had a large capacity to produce bDOC, but likely only laterally contributed organic resources during floods. By contrast, sites with stronger lateral hydrological connectivity served as persistent conduits for organic resources generated further upslope, even if the capacity to generate bDOC locally was weak. Overall, our results illustrate how hydrogeomorphic heterogeneity at the land-water interface can add spatial and temporal complexity to the generation and transfer of bDOC from soils to the inland water continuum.
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- author
- Reidy, Melissa ; Berggren, Martin LU ; Lupon, Anna ; Laudon, Hjalmar and Sponseller, Ryan A.
- organization
- publishing date
- 2025-05
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- bDOC, boreal, hydrogeomorphology, riparian zone
- in
- Journal of Geophysical Research: Biogeosciences
- volume
- 130
- issue
- 5
- article number
- e2024JG008471
- publisher
- John Wiley & Sons Inc.
- external identifiers
-
- scopus:105005230551
- ISSN
- 2169-8953
- DOI
- 10.1029/2024JG008471
- language
- English
- LU publication?
- yes
- additional info
- Publisher Copyright: © 2025. The Author(s).
- id
- 50b56607-ef96-460a-9892-b7bd6b70d065
- date added to LUP
- 2025-08-06 15:21:27
- date last changed
- 2025-08-06 15:26:06
@article{50b56607-ef96-460a-9892-b7bd6b70d065,
abstract = {{<p>The transport of biodegradable dissolved organic carbon (bDOC) across land-water boundaries is central to supporting the ecological and biogeochemical functioning of freshwater ecosystems. Yet, we know little about how the generation and supply of terrestrial bDOC to streams and lakes is regulated by the physical, biological, and hydrological properties of the riparian interface. Here, we assessed how terrestrial, groundwater, and aquatic bDOC differ along flowpaths connecting riparian soils to a headwater boreal stream. We further tested how bDOC generation and supply differs among interfaces with distinct hydrogeomorphologies, as reflected by differences in soil properties, groundwater dynamics, and hydrological connectivity to the stream. We found that bDOC quantity declined sharply from terrestrial sources, to groundwater, to aquatic systems, and that these differences were associated with changes in the optical and chemical properties of the dissolved organic matter pool. However, bDOC generation and potential transport in groundwater varied across site types and reflected local differences in soil organic matter storage, depth to groundwater, and soil microbial community activity. Interface zones with organic-rich soils but weak hydrological connections had a large capacity to produce bDOC, but likely only laterally contributed organic resources during floods. By contrast, sites with stronger lateral hydrological connectivity served as persistent conduits for organic resources generated further upslope, even if the capacity to generate bDOC locally was weak. Overall, our results illustrate how hydrogeomorphic heterogeneity at the land-water interface can add spatial and temporal complexity to the generation and transfer of bDOC from soils to the inland water continuum.</p>}},
author = {{Reidy, Melissa and Berggren, Martin and Lupon, Anna and Laudon, Hjalmar and Sponseller, Ryan A.}},
issn = {{2169-8953}},
keywords = {{bDOC; boreal; hydrogeomorphology; riparian zone}},
language = {{eng}},
number = {{5}},
publisher = {{John Wiley & Sons Inc.}},
series = {{Journal of Geophysical Research: Biogeosciences}},
title = {{Riparian Zone Heterogeneity Influences the Amount and Fate of Biodegradable Dissolved Organic Carbon at the Land-Water Interface}},
url = {{http://dx.doi.org/10.1029/2024JG008471}},
doi = {{10.1029/2024JG008471}},
volume = {{130}},
year = {{2025}},
}