Leaf-litter leachate is distinct in optical properties and bioavailability to stream heterotrophs

Adam S. Wymore, Zacchaeus G. Compson, William H. McDowell, Jody D. Potter, Bruce A Hungate, Thomas G Whitham, Jane C Marks

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

Dissolved organic C (DOC) leached from leaf litter contributes to the C pool of stream ecosystems and affects C cycling in streams. We studied how differences in leaf-litter chemistry affect the optical properties and decomposition of DOC. We used 2 species of cottonwoods (Populus) and their naturally occurring hybrids that differ in leaf-litter phytochemistry and decomposition rate. We measured DOC and nutrient concentration in leaf leachates and determined the effect of DOC quality on heterotrophic respiration in 24-h incubations with stream sediments. Differences in DOC composition and quality were characterized with fluorescence spectroscopy. Rapidly decomposing leaves with lower tannin and lignin concentrations leached ~40 to 50% more DOC and total dissolved N than did slowly decomposing leaves. Rates of heterotrophic respiration were 25 to 50% higher on leachate from rapidly decomposing leaf types. Rates of heterotrophic respiration were related to metrics of aromaticity. Specifically, rates of respiration were correlated negatively with the Fluorescence Index and positively with Specific Ultraviolet Absorbance (SUVA254) and T280 tryptophan-like fluorescence peak. These results reveal that leaf-litter DOC is distinctly different from ambient streamwater DOC. The relationships between optical characteristics of leaf leachate and bioavailability are opposite those found in streamwater DOC. Differences in phytochemistry among leaf types can influence stream ecosystems with respect to DOC quantity, composition, and rates of stream respiration. These patterns suggest that the relationship between the chemical structure of DOC and its biogeochemistry is more complex than previously recognized. These unique properties of leaflitter DOC will be important when assessing the effects of terrestrial C on aquatic ecosystems, especially during leaf fall.

Original languageEnglish (US)
Pages (from-to)857-866
Number of pages10
JournalFreshwater Science
Volume34
Issue number3
DOIs
StatePublished - Sep 1 2015

Fingerprint

heterotrophs
optical properties
leachates
leaf litter
plant litter
optical property
bioavailability
leachate
respiration
breathing
leaves
phytochemistry
streamwater
plant biochemistry
fluorescence emission spectroscopy
fluorescence
decomposition
degradation
fluorescence spectroscopy
ecosystems

Keywords

  • Dissolved organic carbon
  • Fluorescence spectroscopy
  • Leaf litter
  • Populus

ASJC Scopus subject areas

  • Ecology
  • Aquatic Science
  • Ecology, Evolution, Behavior and Systematics

Cite this

Leaf-litter leachate is distinct in optical properties and bioavailability to stream heterotrophs. / Wymore, Adam S.; Compson, Zacchaeus G.; McDowell, William H.; Potter, Jody D.; Hungate, Bruce A; Whitham, Thomas G; Marks, Jane C.

In: Freshwater Science, Vol. 34, No. 3, 01.09.2015, p. 857-866.

Research output: Contribution to journalArticle

Wymore, Adam S. ; Compson, Zacchaeus G. ; McDowell, William H. ; Potter, Jody D. ; Hungate, Bruce A ; Whitham, Thomas G ; Marks, Jane C. / Leaf-litter leachate is distinct in optical properties and bioavailability to stream heterotrophs. In: Freshwater Science. 2015 ; Vol. 34, No. 3. pp. 857-866.
@article{9553027ccfa147648ac7410a53eed500,
title = "Leaf-litter leachate is distinct in optical properties and bioavailability to stream heterotrophs",
abstract = "Dissolved organic C (DOC) leached from leaf litter contributes to the C pool of stream ecosystems and affects C cycling in streams. We studied how differences in leaf-litter chemistry affect the optical properties and decomposition of DOC. We used 2 species of cottonwoods (Populus) and their naturally occurring hybrids that differ in leaf-litter phytochemistry and decomposition rate. We measured DOC and nutrient concentration in leaf leachates and determined the effect of DOC quality on heterotrophic respiration in 24-h incubations with stream sediments. Differences in DOC composition and quality were characterized with fluorescence spectroscopy. Rapidly decomposing leaves with lower tannin and lignin concentrations leached ~40 to 50{\%} more DOC and total dissolved N than did slowly decomposing leaves. Rates of heterotrophic respiration were 25 to 50{\%} higher on leachate from rapidly decomposing leaf types. Rates of heterotrophic respiration were related to metrics of aromaticity. Specifically, rates of respiration were correlated negatively with the Fluorescence Index and positively with Specific Ultraviolet Absorbance (SUVA254) and T280 tryptophan-like fluorescence peak. These results reveal that leaf-litter DOC is distinctly different from ambient streamwater DOC. The relationships between optical characteristics of leaf leachate and bioavailability are opposite those found in streamwater DOC. Differences in phytochemistry among leaf types can influence stream ecosystems with respect to DOC quantity, composition, and rates of stream respiration. These patterns suggest that the relationship between the chemical structure of DOC and its biogeochemistry is more complex than previously recognized. These unique properties of leaflitter DOC will be important when assessing the effects of terrestrial C on aquatic ecosystems, especially during leaf fall.",
keywords = "Dissolved organic carbon, Fluorescence spectroscopy, Leaf litter, Populus",
author = "Wymore, {Adam S.} and Compson, {Zacchaeus G.} and McDowell, {William H.} and Potter, {Jody D.} and Hungate, {Bruce A} and Whitham, {Thomas G} and Marks, {Jane C}",
year = "2015",
month = "9",
day = "1",
doi = "10.1086/682000",
language = "English (US)",
volume = "34",
pages = "857--866",
journal = "Freshwater Science",
issn = "2161-9549",
publisher = "The Society for Freshwater Science",
number = "3",

}

TY - JOUR

T1 - Leaf-litter leachate is distinct in optical properties and bioavailability to stream heterotrophs

AU - Wymore, Adam S.

AU - Compson, Zacchaeus G.

AU - McDowell, William H.

AU - Potter, Jody D.

AU - Hungate, Bruce A

AU - Whitham, Thomas G

AU - Marks, Jane C

PY - 2015/9/1

Y1 - 2015/9/1

N2 - Dissolved organic C (DOC) leached from leaf litter contributes to the C pool of stream ecosystems and affects C cycling in streams. We studied how differences in leaf-litter chemistry affect the optical properties and decomposition of DOC. We used 2 species of cottonwoods (Populus) and their naturally occurring hybrids that differ in leaf-litter phytochemistry and decomposition rate. We measured DOC and nutrient concentration in leaf leachates and determined the effect of DOC quality on heterotrophic respiration in 24-h incubations with stream sediments. Differences in DOC composition and quality were characterized with fluorescence spectroscopy. Rapidly decomposing leaves with lower tannin and lignin concentrations leached ~40 to 50% more DOC and total dissolved N than did slowly decomposing leaves. Rates of heterotrophic respiration were 25 to 50% higher on leachate from rapidly decomposing leaf types. Rates of heterotrophic respiration were related to metrics of aromaticity. Specifically, rates of respiration were correlated negatively with the Fluorescence Index and positively with Specific Ultraviolet Absorbance (SUVA254) and T280 tryptophan-like fluorescence peak. These results reveal that leaf-litter DOC is distinctly different from ambient streamwater DOC. The relationships between optical characteristics of leaf leachate and bioavailability are opposite those found in streamwater DOC. Differences in phytochemistry among leaf types can influence stream ecosystems with respect to DOC quantity, composition, and rates of stream respiration. These patterns suggest that the relationship between the chemical structure of DOC and its biogeochemistry is more complex than previously recognized. These unique properties of leaflitter DOC will be important when assessing the effects of terrestrial C on aquatic ecosystems, especially during leaf fall.

AB - Dissolved organic C (DOC) leached from leaf litter contributes to the C pool of stream ecosystems and affects C cycling in streams. We studied how differences in leaf-litter chemistry affect the optical properties and decomposition of DOC. We used 2 species of cottonwoods (Populus) and their naturally occurring hybrids that differ in leaf-litter phytochemistry and decomposition rate. We measured DOC and nutrient concentration in leaf leachates and determined the effect of DOC quality on heterotrophic respiration in 24-h incubations with stream sediments. Differences in DOC composition and quality were characterized with fluorescence spectroscopy. Rapidly decomposing leaves with lower tannin and lignin concentrations leached ~40 to 50% more DOC and total dissolved N than did slowly decomposing leaves. Rates of heterotrophic respiration were 25 to 50% higher on leachate from rapidly decomposing leaf types. Rates of heterotrophic respiration were related to metrics of aromaticity. Specifically, rates of respiration were correlated negatively with the Fluorescence Index and positively with Specific Ultraviolet Absorbance (SUVA254) and T280 tryptophan-like fluorescence peak. These results reveal that leaf-litter DOC is distinctly different from ambient streamwater DOC. The relationships between optical characteristics of leaf leachate and bioavailability are opposite those found in streamwater DOC. Differences in phytochemistry among leaf types can influence stream ecosystems with respect to DOC quantity, composition, and rates of stream respiration. These patterns suggest that the relationship between the chemical structure of DOC and its biogeochemistry is more complex than previously recognized. These unique properties of leaflitter DOC will be important when assessing the effects of terrestrial C on aquatic ecosystems, especially during leaf fall.

KW - Dissolved organic carbon

KW - Fluorescence spectroscopy

KW - Leaf litter

KW - Populus

UR - http://www.scopus.com/inward/record.url?scp=84953750580&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84953750580&partnerID=8YFLogxK

U2 - 10.1086/682000

DO - 10.1086/682000

M3 - Article

VL - 34

SP - 857

EP - 866

JO - Freshwater Science

JF - Freshwater Science

SN - 2161-9549

IS - 3

ER -