Assessing the dynamics of vegetation productivity in circumpolar regions with different satellite indicators of greenness and photosynthesis
High-latitude treeless ecosystems represent spatially highly heterogeneous landscapes with small net carbon fluxes and a short growing season. Reliable observations and process understanding are critical for projections of the carbon balance of the climate-sensitive tundra. Space-borne remote sensin...
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ftubpotsdam:oai:kobv.de-opus4-uni-potsdam:51372 2023-05-15T15:14:06+02:00 Assessing the dynamics of vegetation productivity in circumpolar regions with different satellite indicators of greenness and photosynthesis Walther, Sophia Guanter, Luis (Prof. Dr.) Heim, Birgit Jung, Martin Duveiller, Gregory Wolanin, Aleksandra Sachs, Torsten 2018 https://publishup.uni-potsdam.de/opus4-ubp/frontdoor/index/index/docId/51372 https://doi.org/10.5194/bg-15-6221-2018 eng eng https://publishup.uni-potsdam.de/opus4-ubp/frontdoor/index/index/docId/51372 https://doi.org/10.5194/bg-15-6221-2018 https://creativecommons.org/licenses/by/4.0/ info:eu-repo/semantics/closedAccess CC-BY ddc:550 Institut für Geowissenschaften article doc-type:article 2018 ftubpotsdam https://doi.org/10.5194/bg-15-6221-2018 2022-08-21T22:36:41Z High-latitude treeless ecosystems represent spatially highly heterogeneous landscapes with small net carbon fluxes and a short growing season. Reliable observations and process understanding are critical for projections of the carbon balance of the climate-sensitive tundra. Space-borne remote sensing is the only tool to obtain spatially continuous and temporally resolved information on vegetation greenness and activity in remote circumpolar areas. However, confounding effects from persistent clouds, low sun elevation angles, numerous lakes, widespread surface inundation, and the sparseness of the vegetation render it highly challenging. Here, we conduct an extensive analysis of the timing of peak vegetation productivity as shown by satellite observations of complementary indicators of plant greenness and photosynthesis. We choose to focus on productivity during the peak of the growing season, as it importantly affects the total annual carbon uptake. The suite of indicators are as follows: (1) MODIS-based vegetation indices (VIs) as proxies for the fraction of incident photosynthetically active radiation (PAR) that is absorbed (fPAR), (2) VIs combined with estimates of PAR as a proxy of the total absorbed radiation (APAR), (3) sun-induced chlorophyll fluorescence (SIF) serving as a proxy for photosynthesis, (4) vegetation optical depth (VOD), indicative of total water content and (5) empirically upscaled modelled gross primary productivity (GPP). Averaged over the pan-Arctic we find a clear order of the annual peak as APAR <= GPP < SIF < VIs/VOD. SIF as an indicator of photosynthesis is maximised around the time of highest annual temperatures. The modelled GPP peaks at a similar time to APAR. The time lag of the annual peak between APAR and instantaneous SIF fluxes indicates that the SIF data do contain information on light-use efficiency of tundra vegetation, but further detailed studies are necessary to verify this. Delayed peak greenness compared to peak photosynthesis is consistently found across ... Article in Journal/Newspaper Arctic Tundra University of Potsdam: publish.UP Arctic Biogeosciences 15 20 6221 6256 |
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Open Polar |
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University of Potsdam: publish.UP |
op_collection_id |
ftubpotsdam |
language |
English |
topic |
ddc:550 Institut für Geowissenschaften |
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ddc:550 Institut für Geowissenschaften Walther, Sophia Guanter, Luis (Prof. Dr.) Heim, Birgit Jung, Martin Duveiller, Gregory Wolanin, Aleksandra Sachs, Torsten Assessing the dynamics of vegetation productivity in circumpolar regions with different satellite indicators of greenness and photosynthesis |
topic_facet |
ddc:550 Institut für Geowissenschaften |
description |
High-latitude treeless ecosystems represent spatially highly heterogeneous landscapes with small net carbon fluxes and a short growing season. Reliable observations and process understanding are critical for projections of the carbon balance of the climate-sensitive tundra. Space-borne remote sensing is the only tool to obtain spatially continuous and temporally resolved information on vegetation greenness and activity in remote circumpolar areas. However, confounding effects from persistent clouds, low sun elevation angles, numerous lakes, widespread surface inundation, and the sparseness of the vegetation render it highly challenging. Here, we conduct an extensive analysis of the timing of peak vegetation productivity as shown by satellite observations of complementary indicators of plant greenness and photosynthesis. We choose to focus on productivity during the peak of the growing season, as it importantly affects the total annual carbon uptake. The suite of indicators are as follows: (1) MODIS-based vegetation indices (VIs) as proxies for the fraction of incident photosynthetically active radiation (PAR) that is absorbed (fPAR), (2) VIs combined with estimates of PAR as a proxy of the total absorbed radiation (APAR), (3) sun-induced chlorophyll fluorescence (SIF) serving as a proxy for photosynthesis, (4) vegetation optical depth (VOD), indicative of total water content and (5) empirically upscaled modelled gross primary productivity (GPP). Averaged over the pan-Arctic we find a clear order of the annual peak as APAR <= GPP < SIF < VIs/VOD. SIF as an indicator of photosynthesis is maximised around the time of highest annual temperatures. The modelled GPP peaks at a similar time to APAR. The time lag of the annual peak between APAR and instantaneous SIF fluxes indicates that the SIF data do contain information on light-use efficiency of tundra vegetation, but further detailed studies are necessary to verify this. Delayed peak greenness compared to peak photosynthesis is consistently found across ... |
format |
Article in Journal/Newspaper |
author |
Walther, Sophia Guanter, Luis (Prof. Dr.) Heim, Birgit Jung, Martin Duveiller, Gregory Wolanin, Aleksandra Sachs, Torsten |
author_facet |
Walther, Sophia Guanter, Luis (Prof. Dr.) Heim, Birgit Jung, Martin Duveiller, Gregory Wolanin, Aleksandra Sachs, Torsten |
author_sort |
Walther, Sophia |
title |
Assessing the dynamics of vegetation productivity in circumpolar regions with different satellite indicators of greenness and photosynthesis |
title_short |
Assessing the dynamics of vegetation productivity in circumpolar regions with different satellite indicators of greenness and photosynthesis |
title_full |
Assessing the dynamics of vegetation productivity in circumpolar regions with different satellite indicators of greenness and photosynthesis |
title_fullStr |
Assessing the dynamics of vegetation productivity in circumpolar regions with different satellite indicators of greenness and photosynthesis |
title_full_unstemmed |
Assessing the dynamics of vegetation productivity in circumpolar regions with different satellite indicators of greenness and photosynthesis |
title_sort |
assessing the dynamics of vegetation productivity in circumpolar regions with different satellite indicators of greenness and photosynthesis |
publishDate |
2018 |
url |
https://publishup.uni-potsdam.de/opus4-ubp/frontdoor/index/index/docId/51372 https://doi.org/10.5194/bg-15-6221-2018 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Tundra |
genre_facet |
Arctic Tundra |
op_relation |
https://publishup.uni-potsdam.de/opus4-ubp/frontdoor/index/index/docId/51372 https://doi.org/10.5194/bg-15-6221-2018 |
op_rights |
https://creativecommons.org/licenses/by/4.0/ info:eu-repo/semantics/closedAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.5194/bg-15-6221-2018 |
container_title |
Biogeosciences |
container_volume |
15 |
container_issue |
20 |
container_start_page |
6221 |
op_container_end_page |
6256 |
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1766344600624037888 |