Controls of organic carbon processing in boreal headwater streams
Thesis (M.S.) University of Alaska Fairbanks, 2023 Carbon emissions from headwater streams are derived from both terrestrial inputs and in-stream microbial processing of organic carbon, but the relative importance of metabolic processes in boreal streams remains uncertain. Determining the factors th...
Main Author: | |
---|---|
Other Authors: | , , |
Format: | Thesis |
Language: | English |
Published: |
2023
|
Subjects: | |
Online Access: | http://hdl.handle.net/11122/14633 |
id |
ftunivalaska:oai:scholarworks.alaska.edu:11122/14633 |
---|---|
record_format |
openpolar |
spelling |
ftunivalaska:oai:scholarworks.alaska.edu:11122/14633 2023-11-05T03:41:14+01:00 Controls of organic carbon processing in boreal headwater streams Iannucci, Frances Marie Jones, Jeremy B. Jr. Arp, Christopher D. Muscarella, Mario E. 2023-08 http://hdl.handle.net/11122/14633 en_US eng http://hdl.handle.net/11122/14633 Department of Biology and Wildlife Water Carbon content Interior Alaska Rivers Stream chemistry Organic compound content Taiga ecology Master of Science in Biological Sciences Thesis ms 2023 ftunivalaska 2023-10-12T18:03:18Z Thesis (M.S.) University of Alaska Fairbanks, 2023 Carbon emissions from headwater streams are derived from both terrestrial inputs and in-stream microbial processing of organic carbon, but the relative importance of metabolic processes in boreal streams remains uncertain. Determining the factors that regulate organic carbon processing will aid in predicting how the carbon balance of boreal streams will respond to future environmental change. In this study, I addressed the question: what controls organic carbon uptake in boreal headwater streams draining catchments with discontinuous permafrost? I hypothesized that organic carbon uptake is collectively regulated by organic carbon lability, phosphorus availability, and temperature, with discharge modulating each of these conditions. I tested these hypotheses using a combination of laboratory resource manipulation experiments and ecosystem metabolism measurements throughout the Caribou-Poker Creeks Research Watershed (CPCRW) in Interior Alaska, USA. In the laboratory experiments, respiration and dissolved organic carbon (DOC) loss were both co-limited by the supply of labile carbon and phosphorus, but temperature and residence time acted as stronger controls of DOC loss. Ecosystem respiration (ER) was largely predicted by discharge and between-site variance, although some within-site variance was explained by gross primary production (GPP) and temperature. Between sites, both ER and GPP were inversely related to watershed permafrost extent, with an inverse relationship between temperature and permafrost extent providing the most plausible explanation for this pattern. These results provide some of the first evidence of a functional response to permafrost thaw in stream ecosystems and suggest that the contribution of metabolism to stream carbon emissions may increase as climate change progresses. Bonanza Creek Long Term Ecological Research program (NSF award #DEB-1026415), NSF award #DEB-1926632, the Society for Freshwater Science, Alaska EPSCoR (NSF award ... Thesis Caribou-Poker Creeks Research Watershed permafrost taiga Alaska University of Alaska: ScholarWorks@UA |
institution |
Open Polar |
collection |
University of Alaska: ScholarWorks@UA |
op_collection_id |
ftunivalaska |
language |
English |
topic |
Water Carbon content Interior Alaska Rivers Stream chemistry Organic compound content Taiga ecology Master of Science in Biological Sciences |
spellingShingle |
Water Carbon content Interior Alaska Rivers Stream chemistry Organic compound content Taiga ecology Master of Science in Biological Sciences Iannucci, Frances Marie Controls of organic carbon processing in boreal headwater streams |
topic_facet |
Water Carbon content Interior Alaska Rivers Stream chemistry Organic compound content Taiga ecology Master of Science in Biological Sciences |
description |
Thesis (M.S.) University of Alaska Fairbanks, 2023 Carbon emissions from headwater streams are derived from both terrestrial inputs and in-stream microbial processing of organic carbon, but the relative importance of metabolic processes in boreal streams remains uncertain. Determining the factors that regulate organic carbon processing will aid in predicting how the carbon balance of boreal streams will respond to future environmental change. In this study, I addressed the question: what controls organic carbon uptake in boreal headwater streams draining catchments with discontinuous permafrost? I hypothesized that organic carbon uptake is collectively regulated by organic carbon lability, phosphorus availability, and temperature, with discharge modulating each of these conditions. I tested these hypotheses using a combination of laboratory resource manipulation experiments and ecosystem metabolism measurements throughout the Caribou-Poker Creeks Research Watershed (CPCRW) in Interior Alaska, USA. In the laboratory experiments, respiration and dissolved organic carbon (DOC) loss were both co-limited by the supply of labile carbon and phosphorus, but temperature and residence time acted as stronger controls of DOC loss. Ecosystem respiration (ER) was largely predicted by discharge and between-site variance, although some within-site variance was explained by gross primary production (GPP) and temperature. Between sites, both ER and GPP were inversely related to watershed permafrost extent, with an inverse relationship between temperature and permafrost extent providing the most plausible explanation for this pattern. These results provide some of the first evidence of a functional response to permafrost thaw in stream ecosystems and suggest that the contribution of metabolism to stream carbon emissions may increase as climate change progresses. Bonanza Creek Long Term Ecological Research program (NSF award #DEB-1026415), NSF award #DEB-1926632, the Society for Freshwater Science, Alaska EPSCoR (NSF award ... |
author2 |
Jones, Jeremy B. Jr. Arp, Christopher D. Muscarella, Mario E. |
format |
Thesis |
author |
Iannucci, Frances Marie |
author_facet |
Iannucci, Frances Marie |
author_sort |
Iannucci, Frances Marie |
title |
Controls of organic carbon processing in boreal headwater streams |
title_short |
Controls of organic carbon processing in boreal headwater streams |
title_full |
Controls of organic carbon processing in boreal headwater streams |
title_fullStr |
Controls of organic carbon processing in boreal headwater streams |
title_full_unstemmed |
Controls of organic carbon processing in boreal headwater streams |
title_sort |
controls of organic carbon processing in boreal headwater streams |
publishDate |
2023 |
url |
http://hdl.handle.net/11122/14633 |
genre |
Caribou-Poker Creeks Research Watershed permafrost taiga Alaska |
genre_facet |
Caribou-Poker Creeks Research Watershed permafrost taiga Alaska |
op_relation |
http://hdl.handle.net/11122/14633 Department of Biology and Wildlife |
_version_ |
1781697569835974656 |