The role of nutrients for stream ecosystem function in Arctic landscapes : drivers of productivity under environmental change
Arctic and sub-Arctic freshwaters are currently experiencing substantial ecosystem changes due to the effects of global warming. Global warming effects on these freshwaters include increasing water temperatures, altered hydrological patterns, shifts in riparian vegetation and changes in the export o...
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Umeå universitet, Institutionen för ekologi, miljö och geovetenskap
2020
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ftsprs:oai:DiVA.org:polar-8607 2024-09-09T19:18:34+00:00 The role of nutrients for stream ecosystem function in Arctic landscapes : drivers of productivity under environmental change Myrstener, Maria 2020 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:polar:diva-8607 eng eng Umeå universitet, Institutionen för ekologi, miljö och geovetenskap Umeå : Umeå universitet orcid:0000-0003-0943-641X http://urn.kb.se/resolve?urn=urn:nbn:se:polar:diva-8607 urn:isbn:978-91-7855-445-4 urn:isbn:978-91-7855-446-1 info:eu-repo/semantics/openAccess Nutrients Stream Arctic Boreal Primary productivity Algae Biofilm Nutrient limitation Nitrogen Phosphorus Physical Geography Naturgeografi Doctoral thesis, comprehensive summary info:eu-repo/semantics/doctoralThesis text 2020 ftsprs 2024-08-15T03:00:15Z Arctic and sub-Arctic freshwaters are currently experiencing substantial ecosystem changes due to the effects of global warming. Global warming effects on these freshwaters include increasing water temperatures, altered hydrological patterns, shifts in riparian vegetation and changes in the export of nutrients and carbon from soils. How these alterations to the physical and chemical hab-itat will affect stream ecosystem functioning largely depends on the responses by autotrophic pro-ducers and heterotrophic primary consumers. In this thesis, I explore how key stream ecosystem processes such as metabolic rates and nutrient cycling vary as a function of climate and landscape drivers, particularly light, temperature, and nutrient and carbon availability. To do this I leveraged natural gradients in vegetation, altitude, disturbance, and precipitation throughout the year in northern Sweden, as well as long- and short-term manipulations of nutrient availability. I also synthesized nutrient limitation data from lakes and streams to more holistically assess the re-sponses of boreal to Arctic freshwaters to changes in nutrients and climate variables. I found that nutrient availability, and especially nitrogen (N), is a main driver of spatial and temporal patterns of biofilm productivity, whole system metabolic rates, and short term N uptake in Arctic and sub-Arctic streams. I also show the importance of light and temperature constraints during early spring and late autumn, which set the limit for the aquatic growing season and annual productivity pat-terns. I present a first comparison of combined drivers of lake and stream responses to nutrient addition, which points to a shared importance of N and phosphorus (P) rather than light or tem-perature in driving the magnitude of nutrient limitation across these systems. Ultimately, I pro-pose that across large ranges in habitat variables, widespread nutrient limitation of Arctic fresh-waters constrain other climate change effects on ecosystem functions. The results presented ... Doctoral or Postdoctoral Thesis Arctic Climate change Global warming Northern Sweden Swedish Polar Research Secretariat: Swedish Polar Bibliography (DiVA) Arctic |
institution |
Open Polar |
collection |
Swedish Polar Research Secretariat: Swedish Polar Bibliography (DiVA) |
op_collection_id |
ftsprs |
language |
English |
topic |
Nutrients Stream Arctic Boreal Primary productivity Algae Biofilm Nutrient limitation Nitrogen Phosphorus Physical Geography Naturgeografi |
spellingShingle |
Nutrients Stream Arctic Boreal Primary productivity Algae Biofilm Nutrient limitation Nitrogen Phosphorus Physical Geography Naturgeografi Myrstener, Maria The role of nutrients for stream ecosystem function in Arctic landscapes : drivers of productivity under environmental change |
topic_facet |
Nutrients Stream Arctic Boreal Primary productivity Algae Biofilm Nutrient limitation Nitrogen Phosphorus Physical Geography Naturgeografi |
description |
Arctic and sub-Arctic freshwaters are currently experiencing substantial ecosystem changes due to the effects of global warming. Global warming effects on these freshwaters include increasing water temperatures, altered hydrological patterns, shifts in riparian vegetation and changes in the export of nutrients and carbon from soils. How these alterations to the physical and chemical hab-itat will affect stream ecosystem functioning largely depends on the responses by autotrophic pro-ducers and heterotrophic primary consumers. In this thesis, I explore how key stream ecosystem processes such as metabolic rates and nutrient cycling vary as a function of climate and landscape drivers, particularly light, temperature, and nutrient and carbon availability. To do this I leveraged natural gradients in vegetation, altitude, disturbance, and precipitation throughout the year in northern Sweden, as well as long- and short-term manipulations of nutrient availability. I also synthesized nutrient limitation data from lakes and streams to more holistically assess the re-sponses of boreal to Arctic freshwaters to changes in nutrients and climate variables. I found that nutrient availability, and especially nitrogen (N), is a main driver of spatial and temporal patterns of biofilm productivity, whole system metabolic rates, and short term N uptake in Arctic and sub-Arctic streams. I also show the importance of light and temperature constraints during early spring and late autumn, which set the limit for the aquatic growing season and annual productivity pat-terns. I present a first comparison of combined drivers of lake and stream responses to nutrient addition, which points to a shared importance of N and phosphorus (P) rather than light or tem-perature in driving the magnitude of nutrient limitation across these systems. Ultimately, I pro-pose that across large ranges in habitat variables, widespread nutrient limitation of Arctic fresh-waters constrain other climate change effects on ecosystem functions. The results presented ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Myrstener, Maria |
author_facet |
Myrstener, Maria |
author_sort |
Myrstener, Maria |
title |
The role of nutrients for stream ecosystem function in Arctic landscapes : drivers of productivity under environmental change |
title_short |
The role of nutrients for stream ecosystem function in Arctic landscapes : drivers of productivity under environmental change |
title_full |
The role of nutrients for stream ecosystem function in Arctic landscapes : drivers of productivity under environmental change |
title_fullStr |
The role of nutrients for stream ecosystem function in Arctic landscapes : drivers of productivity under environmental change |
title_full_unstemmed |
The role of nutrients for stream ecosystem function in Arctic landscapes : drivers of productivity under environmental change |
title_sort |
role of nutrients for stream ecosystem function in arctic landscapes : drivers of productivity under environmental change |
publisher |
Umeå universitet, Institutionen för ekologi, miljö och geovetenskap |
publishDate |
2020 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:polar:diva-8607 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Climate change Global warming Northern Sweden |
genre_facet |
Arctic Climate change Global warming Northern Sweden |
op_relation |
orcid:0000-0003-0943-641X http://urn.kb.se/resolve?urn=urn:nbn:se:polar:diva-8607 urn:isbn:978-91-7855-445-4 urn:isbn:978-91-7855-446-1 |
op_rights |
info:eu-repo/semantics/openAccess |
_version_ |
1809758621235412992 |