Network Connectivity and Local Hydrology Drive DOM Composition in a Nonperennial Stream.

Saved in:
Bibliographic Details
Title: Network Connectivity and Local Hydrology Drive DOM Composition in a Nonperennial Stream.
Authors: Flynn, Sarah M.1,2 (AUTHOR) s.m.flynn@ku.edu, Hale, Rebecca L.3 (AUTHOR), Seybold, Erin2,4 (AUTHOR), Plont, Stephen5 (AUTHOR), Busch, Michelle2 (AUTHOR), Sommerville, Alexi2,4 (AUTHOR), Brown, Connor L.2,4 (AUTHOR), Burgin, Amy J.6 (AUTHOR) burginam@iastate.edu
Source: Journal of Geophysical Research. Biogeosciences. May2026, Vol. 131 Issue 5, p1-19. 19p.
Subject Terms: *Dissolved organic matter, *Hydrology, *Carbon cycle, *Biogeochemistry, *Streamflow, Fluorescence spectroscopy, Ephemeral streams
Abstract: Nonperennial streams are dynamic sites of biogeochemical processing, yet much remains to be learned about how hydrologic connectivity at different spatial and temporal scales impacts the composition of dissolved organic matter (DOM). We characterized spatial and temporal patterns of DOM composition in a nonperennial prairie stream network using 3 years of hydrologic data and fluorescence spectroscopy of surface water. Principal component analyses revealed that humic, terrestrial components explained the most variance in DOM composition. These components were highest at sites in the headwaters. In contrast, autochthonous DOM was relatively greater at sites with persistent local‐scale surface water and flowing conditions. Network and local controls (i.e., the degree to which surface water is connected across the network and site‐level water persistence and flow metrics, respectively) interacted to alter DOM composition, with their combined influence depending on the hydrologic phase. High connectivity promoted mixing and transport that diluted local autochthonous signals, whereas low or transitional flows enhanced retention, autochthonous activity, and microbial processing. These findings suggest that hydrologic fragmentation in nonperennial systems modulates not only DOM source and transformation but also its downstream bioavailability, with implications for carbon cycling under shifting climate and flow regimes. Plain Language Summary: Nonperennial streams dry at some point in time or space. They are widespread and increasingly common with climate change, but we know relatively little about how they affect water quality and carbon cycling. We examined the types of dissolved organic matter found in stream water across a nonperennial prairie watershed in Kansas. We collected water samples throughout the watershed over 3 years during both wet and dry conditions. Our results showed that when the stream was fully connected and flowing, the composition of DOM was relatively well mixed and uniform across the network. However, when water levels were lower and the stream became fragmented, the types of DOM varied depending on whether the site had flowing water, was an isolated pool, or had recently dried. Sites with continuous water had more autochthonous and microbially degraded DOM, whereas sites that had recently dried or contained isolated pools had DOM primarily derived from leaching of soil and plant material. This study highlights that organic matter composition can alter significantly across drying stream networks, especially at sites where water persists throughout time through microbial processing. Understanding these dynamics is important for predicting how carbon and nutrients move through freshwater systems in a changing climate. Key Points: Network connectivity transports dissolved organic matter, while local hydrology governs the transformation of dissolved organic matterNetwork‐scale dry downs increased the humic and terrestrial components of dissolved organic matterAutochthonous dissolved organic matter increased with local water persistence [ABSTRACT FROM AUTHOR]
Copyright of Journal of Geophysical Research. Biogeosciences is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: GreenFILE
FullText Text:
  Availability: 0
Header DbId: 8gh
DbLabel: GreenFILE
An: 194137182
AccessLevel: 6
PubType: Academic Journal
PubTypeId: academicJournal
PreciseRelevancyScore: 0
IllustrationInfo
Items – Name: Title
  Label: Title
  Group: Ti
  Data: Network Connectivity and Local Hydrology Drive DOM Composition in a Nonperennial Stream.
– Name: Author
  Label: Authors
  Group: Au
  Data: <searchLink fieldCode="AR" term="%22Flynn%2C+Sarah+M%2E%22">Flynn, Sarah M.</searchLink><relatesTo>1,2</relatesTo> (AUTHOR)<i> s.m.flynn@ku.edu</i><br /><searchLink fieldCode="AR" term="%22Hale%2C+Rebecca+L%2E%22">Hale, Rebecca L.</searchLink><relatesTo>3</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Seybold%2C+Erin%22">Seybold, Erin</searchLink><relatesTo>2,4</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Plont%2C+Stephen%22">Plont, Stephen</searchLink><relatesTo>5</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Busch%2C+Michelle%22">Busch, Michelle</searchLink><relatesTo>2</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Sommerville%2C+Alexi%22">Sommerville, Alexi</searchLink><relatesTo>2,4</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Brown%2C+Connor+L%2E%22">Brown, Connor L.</searchLink><relatesTo>2,4</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Burgin%2C+Amy+J%2E%22">Burgin, Amy J.</searchLink><relatesTo>6</relatesTo> (AUTHOR)<i> burginam@iastate.edu</i>
– Name: TitleSource
  Label: Source
  Group: Src
  Data: <searchLink fieldCode="JN" term="%22Journal+of+Geophysical+Research%2E+Biogeosciences%22">Journal of Geophysical Research. Biogeosciences</searchLink>. May2026, Vol. 131 Issue 5, p1-19. 19p.
– Name: Subject
  Label: Subject Terms
  Group: Su
  Data: *<searchLink fieldCode="DE" term="%22Dissolved+organic+matter%22">Dissolved organic matter</searchLink><br />*<searchLink fieldCode="DE" term="%22Hydrology%22">Hydrology</searchLink><br />*<searchLink fieldCode="DE" term="%22Carbon+cycle%22">Carbon cycle</searchLink><br />*<searchLink fieldCode="DE" term="%22Biogeochemistry%22">Biogeochemistry</searchLink><br />*<searchLink fieldCode="DE" term="%22Streamflow%22">Streamflow</searchLink><br /><searchLink fieldCode="DE" term="%22Fluorescence+spectroscopy%22">Fluorescence spectroscopy</searchLink><br /><searchLink fieldCode="DE" term="%22Ephemeral+streams%22">Ephemeral streams</searchLink>
– Name: Abstract
  Label: Abstract
  Group: Ab
  Data: Nonperennial streams are dynamic sites of biogeochemical processing, yet much remains to be learned about how hydrologic connectivity at different spatial and temporal scales impacts the composition of dissolved organic matter (DOM). We characterized spatial and temporal patterns of DOM composition in a nonperennial prairie stream network using 3 years of hydrologic data and fluorescence spectroscopy of surface water. Principal component analyses revealed that humic, terrestrial components explained the most variance in DOM composition. These components were highest at sites in the headwaters. In contrast, autochthonous DOM was relatively greater at sites with persistent local‐scale surface water and flowing conditions. Network and local controls (i.e., the degree to which surface water is connected across the network and site‐level water persistence and flow metrics, respectively) interacted to alter DOM composition, with their combined influence depending on the hydrologic phase. High connectivity promoted mixing and transport that diluted local autochthonous signals, whereas low or transitional flows enhanced retention, autochthonous activity, and microbial processing. These findings suggest that hydrologic fragmentation in nonperennial systems modulates not only DOM source and transformation but also its downstream bioavailability, with implications for carbon cycling under shifting climate and flow regimes. Plain Language Summary: Nonperennial streams dry at some point in time or space. They are widespread and increasingly common with climate change, but we know relatively little about how they affect water quality and carbon cycling. We examined the types of dissolved organic matter found in stream water across a nonperennial prairie watershed in Kansas. We collected water samples throughout the watershed over 3 years during both wet and dry conditions. Our results showed that when the stream was fully connected and flowing, the composition of DOM was relatively well mixed and uniform across the network. However, when water levels were lower and the stream became fragmented, the types of DOM varied depending on whether the site had flowing water, was an isolated pool, or had recently dried. Sites with continuous water had more autochthonous and microbially degraded DOM, whereas sites that had recently dried or contained isolated pools had DOM primarily derived from leaching of soil and plant material. This study highlights that organic matter composition can alter significantly across drying stream networks, especially at sites where water persists throughout time through microbial processing. Understanding these dynamics is important for predicting how carbon and nutrients move through freshwater systems in a changing climate. Key Points: Network connectivity transports dissolved organic matter, while local hydrology governs the transformation of dissolved organic matterNetwork‐scale dry downs increased the humic and terrestrial components of dissolved organic matterAutochthonous dissolved organic matter increased with local water persistence [ABSTRACT FROM AUTHOR]
– Name: AbstractSuppliedCopyright
  Label:
  Group: Ab
  Data: <i>Copyright of Journal of Geophysical Research. Biogeosciences is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.)
PLink https://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=8gh&AN=194137182
RecordInfo BibRecord:
  BibEntity:
    Identifiers:
      – Type: doi
        Value: 10.1029/2025JG009568
    Languages:
      – Code: eng
        Text: English
    PhysicalDescription:
      Pagination:
        PageCount: 19
        StartPage: 1
    Subjects:
      – SubjectFull: Dissolved organic matter
        Type: general
      – SubjectFull: Hydrology
        Type: general
      – SubjectFull: Carbon cycle
        Type: general
      – SubjectFull: Biogeochemistry
        Type: general
      – SubjectFull: Streamflow
        Type: general
      – SubjectFull: Fluorescence spectroscopy
        Type: general
      – SubjectFull: Ephemeral streams
        Type: general
    Titles:
      – TitleFull: Network Connectivity and Local Hydrology Drive DOM Composition in a Nonperennial Stream.
        Type: main
  BibRelationships:
    HasContributorRelationships:
      – PersonEntity:
          Name:
            NameFull: Flynn, Sarah M.
      – PersonEntity:
          Name:
            NameFull: Hale, Rebecca L.
      – PersonEntity:
          Name:
            NameFull: Seybold, Erin
      – PersonEntity:
          Name:
            NameFull: Plont, Stephen
      – PersonEntity:
          Name:
            NameFull: Busch, Michelle
      – PersonEntity:
          Name:
            NameFull: Sommerville, Alexi
      – PersonEntity:
          Name:
            NameFull: Brown, Connor L.
      – PersonEntity:
          Name:
            NameFull: Burgin, Amy J.
    IsPartOfRelationships:
      – BibEntity:
          Dates:
            – D: 01
              M: 05
              Text: May2026
              Type: published
              Y: 2026
          Identifiers:
            – Type: issn-print
              Value: 21698953
          Numbering:
            – Type: volume
              Value: 131
            – Type: issue
              Value: 5
          Titles:
            – TitleFull: Journal of Geophysical Research. Biogeosciences
              Type: main
ResultId 1