Elevated Atmospheric CO sub(2) Alters Leaf Litter Quality for Stream Ecosystems: An In Situ Leaf Decomposition Study

Rising atmospheric carbon dioxide is known to affect terrestrial vegetation but little is known about possible indirect effects on aquatic ecosystems from altered leaf litter quality. Trembling aspen seedlings were exposed to ambient or elevated atmospheric CO sub(2) for 6 months, then senesced leav...

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Bibliographic Details
Published in:Hydrobiologia 2003-03, Vol.495 (1-3), p.203-203
Main Authors: Tuchman, Nancy C, Wahtera, Kirk A, Wetzel, Robert G, Teeri, James A
Format: Article
Language:English
Online Access:Get full text
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Summary:Rising atmospheric carbon dioxide is known to affect terrestrial vegetation but little is known about possible indirect effects on aquatic ecosystems from altered leaf litter quality. Trembling aspen seedlings were exposed to ambient or elevated atmospheric CO sub(2) for 6 months, then senesced leaves were collected and analyzed for chemical differences. Leaves growing in elevated CO sub(2) had significantly higher phenolic compounds, lignin levels, and carbon:nitrogen ratios, but lower foliar nitrogen. Leaf aggregates from both treatments were kept in a headwater stream for 4 months and the microbial activity, macroinvertebrate composition, and leaf decomposition were monitored. Exposure to higher CO sub(2) lowered microbial community respiration and increased leaf decomposition rates. The chemical changes from elevated CO sub(2) negatively affect the early stages of decay when microorganisms have a strong influence. Effects on the macroinvertebrate role were not conclusive.
ISSN:0018-8158