Warming alters photosynthetic rates of sub-boreal peatland vegetation

Boreal peatlands are important in the global carbon cycle. Despite covering only 3% of the global land area, peatlands store approximately one third of all soil carbon. Temperature is one of the major drivers in peatland carbon cycling as it affects both plant production and CO2 fluxes from soils. H...

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Main Author: Aljaste, Arvo
Format: H2
Language:Inglés
Published: SLU/Southern Swedish Forest Research Centre 2011
Subjects:
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author Aljaste, Arvo
author_browse Aljaste, Arvo
author_facet Aljaste, Arvo
author_sort Aljaste, Arvo
collection Epsilon Archive for Student Projects
description Boreal peatlands are important in the global carbon cycle. Despite covering only 3% of the global land area, peatlands store approximately one third of all soil carbon. Temperature is one of the major drivers in peatland carbon cycling as it affects both plant production and CO2 fluxes from soils. However, it is relatively unknown how boreal peatland plant photosynthesis is affected by higher temperatures. Therefore, we measured plant photosynthetic rates under two different warming treatments in a poor fen in Northern Michigan. Eighteen plots were established that were divided into three treatments: control, open-top chamber (OTC) warming and infrared (IR) lamp warming. Previous work at this site has shown that there was a significant increase in canopy and peat temperature with IR warming (5°C and 1.4°C respectively), while the OTC’s had mixed overall warming. Plots were divided equally into lawns and hummocks. We measured mid-day carbon dioxide (CO2) uptake on sedges (Carex utriculata), shrubs (Chamaedaphne calyculata) and Sphagnum mosses. Sphagnum moss net primary production (NPP) was also measured with cranked wires and compared with CO2 uptake. Our results indicate that there was no significant difference in sedge CO2 uptake, while shrub CO2 uptake significantly decreased with warming. A significant increase occurred in Sphagnum moss gross ecosystem production (GEP), ecosystem respiration (ER) and net ecosystem exchange (NEE). Contrary to the positive CO2 exchange of Sphagnum, overall NPP decreased significantly in hummocks with both warming treatments. The results of the study indicate that temperature partly limits the photosynthetic capacity of plants in sub-boreal peatlands, but not all species respond similarly to higher temperatures.
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institution Swedish University of Agricultural Sciences
language Inglés
publishDate 2011
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spelling RepoSLU28712012-04-20T14:20:43Z Warming alters photosynthetic rates of sub-boreal peatland vegetation Aljaste, Arvo Peatlands CO2 uptake Climate change microtopography Boreal peatlands are important in the global carbon cycle. Despite covering only 3% of the global land area, peatlands store approximately one third of all soil carbon. Temperature is one of the major drivers in peatland carbon cycling as it affects both plant production and CO2 fluxes from soils. However, it is relatively unknown how boreal peatland plant photosynthesis is affected by higher temperatures. Therefore, we measured plant photosynthetic rates under two different warming treatments in a poor fen in Northern Michigan. Eighteen plots were established that were divided into three treatments: control, open-top chamber (OTC) warming and infrared (IR) lamp warming. Previous work at this site has shown that there was a significant increase in canopy and peat temperature with IR warming (5°C and 1.4°C respectively), while the OTC’s had mixed overall warming. Plots were divided equally into lawns and hummocks. We measured mid-day carbon dioxide (CO2) uptake on sedges (Carex utriculata), shrubs (Chamaedaphne calyculata) and Sphagnum mosses. Sphagnum moss net primary production (NPP) was also measured with cranked wires and compared with CO2 uptake. Our results indicate that there was no significant difference in sedge CO2 uptake, while shrub CO2 uptake significantly decreased with warming. A significant increase occurred in Sphagnum moss gross ecosystem production (GEP), ecosystem respiration (ER) and net ecosystem exchange (NEE). Contrary to the positive CO2 exchange of Sphagnum, overall NPP decreased significantly in hummocks with both warming treatments. The results of the study indicate that temperature partly limits the photosynthetic capacity of plants in sub-boreal peatlands, but not all species respond similarly to higher temperatures. SLU/Southern Swedish Forest Research Centre 2011 H2 eng https://stud.epsilon.slu.se/2871/
spellingShingle Peatlands
CO2 uptake
Climate change
microtopography
Aljaste, Arvo
Warming alters photosynthetic rates of sub-boreal peatland vegetation
title Warming alters photosynthetic rates of sub-boreal peatland vegetation
title_full Warming alters photosynthetic rates of sub-boreal peatland vegetation
title_fullStr Warming alters photosynthetic rates of sub-boreal peatland vegetation
title_full_unstemmed Warming alters photosynthetic rates of sub-boreal peatland vegetation
title_short Warming alters photosynthetic rates of sub-boreal peatland vegetation
title_sort warming alters photosynthetic rates of sub-boreal peatland vegetation
topic Peatlands
CO2 uptake
Climate change
microtopography