Do volcanic eruptions enhance or diminish net primary production? Evidence from tree rings
Low growth rates of atmospheric CO2 were observed following the 1991 Pinatubo (Luzon) volcanic eruption. One hypothesis for this CO2 anomaly is that since diffuse light is more efficiently used by forests than direct light, the increase in the diffuse fraction of sunlight due to scattering by volcan...
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Language: | English |
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ftcdlib:qt57j5c3dm 2023-05-15T16:39:28+02:00 Do volcanic eruptions enhance or diminish net primary production? Evidence from tree rings Krakauer, Nir Y Randerson, James T n/a - n/a 2003-12-01 application/pdf http://www.escholarship.org/uc/item/57j5c3dm english eng eScholarship, University of California qt57j5c3dm http://www.escholarship.org/uc/item/57j5c3dm Attribution (CC BY): http://creativecommons.org/licenses/by/3.0/ CC-BY Krakauer, Nir Y; & Randerson, James T. (2003). Do volcanic eruptions enhance or diminish net primary production? Evidence from tree rings. Global Biogeochemical Cycles, 17(4), n/a - n/a. doi:10.1029/2003GB002076. UC Irvine: Department of Earth System Science, UCI. Retrieved from: http://www.escholarship.org/uc/item/57j5c3dm Physical Sciences and Mathematics boreal forest carbon sink diffuse light NPP Pinatubo tree rings carbon sequestration growth response primary production tree ring volcanic eruption Asia Central Luzon Eurasia Mount Pinatubo Philippines Southeast Asia Zambales article 2003 ftcdlib https://doi.org/10.1029/2003GB002076 2016-04-02T18:29:20Z Low growth rates of atmospheric CO2 were observed following the 1991 Pinatubo (Luzon) volcanic eruption. One hypothesis for this CO2 anomaly is that since diffuse light is more efficiently used by forests than direct light, the increase in the diffuse fraction of sunlight due to scattering by volcanic sulfur aerosol in the years following the eruption substantially increased forest net primary production (NPP). However, other observations suggest a decrease in northern forest NPP because of the cooler conditions following the eruption. Here we used a global database of dated tree ring widths (which correlate with forest NPP) to test this hypothesis. Ice core records of sulfur deposition allowed us to identify the timing and magnitude of 23 Pinatubo-scale eruptions since 1000 CE. We found a significant decrease in ring width for trees in middle to high northern latitudes (north of 45°N) following eruption sulfur peaks. Decreases in tree ring widths were in the range of 2–8% and persisted for ∼8 years following sulfur peaks, with minima at around 4–6 years. Ring width changes at lower latitudes in the Northern Hemisphere (30°N to 45°N) and in the Southern Hemisphere (30°S to 56°S) were not significant. In the tropics (30°N to 30°S) the paucity of tree ring records did not permit the evaluation of NPP changes. Given that elevated aerosol levels and summer cooling last only ∼2–3 years after an eruption, the persistence of declines in northern tree growth for up to 8 years after eruptions implies some additional mechanism that links these shorter-lived global eruption effects to sustained changes in tree physiology, biogeochemistry, or microclimate. At least for this sample of trees, the beneficial effect of aerosol light scattering appears to be entirely offset by the deleterious effect of eruption-induced climate change. Article in Journal/Newspaper ice core University of California: eScholarship Global Biogeochemical Cycles 17 4 n/a n/a |
institution |
Open Polar |
collection |
University of California: eScholarship |
op_collection_id |
ftcdlib |
language |
English |
topic |
Physical Sciences and Mathematics boreal forest carbon sink diffuse light NPP Pinatubo tree rings carbon sequestration growth response primary production tree ring volcanic eruption Asia Central Luzon Eurasia Mount Pinatubo Philippines Southeast Asia Zambales |
spellingShingle |
Physical Sciences and Mathematics boreal forest carbon sink diffuse light NPP Pinatubo tree rings carbon sequestration growth response primary production tree ring volcanic eruption Asia Central Luzon Eurasia Mount Pinatubo Philippines Southeast Asia Zambales Krakauer, Nir Y Randerson, James T Do volcanic eruptions enhance or diminish net primary production? Evidence from tree rings |
topic_facet |
Physical Sciences and Mathematics boreal forest carbon sink diffuse light NPP Pinatubo tree rings carbon sequestration growth response primary production tree ring volcanic eruption Asia Central Luzon Eurasia Mount Pinatubo Philippines Southeast Asia Zambales |
description |
Low growth rates of atmospheric CO2 were observed following the 1991 Pinatubo (Luzon) volcanic eruption. One hypothesis for this CO2 anomaly is that since diffuse light is more efficiently used by forests than direct light, the increase in the diffuse fraction of sunlight due to scattering by volcanic sulfur aerosol in the years following the eruption substantially increased forest net primary production (NPP). However, other observations suggest a decrease in northern forest NPP because of the cooler conditions following the eruption. Here we used a global database of dated tree ring widths (which correlate with forest NPP) to test this hypothesis. Ice core records of sulfur deposition allowed us to identify the timing and magnitude of 23 Pinatubo-scale eruptions since 1000 CE. We found a significant decrease in ring width for trees in middle to high northern latitudes (north of 45°N) following eruption sulfur peaks. Decreases in tree ring widths were in the range of 2–8% and persisted for ∼8 years following sulfur peaks, with minima at around 4–6 years. Ring width changes at lower latitudes in the Northern Hemisphere (30°N to 45°N) and in the Southern Hemisphere (30°S to 56°S) were not significant. In the tropics (30°N to 30°S) the paucity of tree ring records did not permit the evaluation of NPP changes. Given that elevated aerosol levels and summer cooling last only ∼2–3 years after an eruption, the persistence of declines in northern tree growth for up to 8 years after eruptions implies some additional mechanism that links these shorter-lived global eruption effects to sustained changes in tree physiology, biogeochemistry, or microclimate. At least for this sample of trees, the beneficial effect of aerosol light scattering appears to be entirely offset by the deleterious effect of eruption-induced climate change. |
format |
Article in Journal/Newspaper |
author |
Krakauer, Nir Y Randerson, James T |
author_facet |
Krakauer, Nir Y Randerson, James T |
author_sort |
Krakauer, Nir Y |
title |
Do volcanic eruptions enhance or diminish net primary production? Evidence from tree rings |
title_short |
Do volcanic eruptions enhance or diminish net primary production? Evidence from tree rings |
title_full |
Do volcanic eruptions enhance or diminish net primary production? Evidence from tree rings |
title_fullStr |
Do volcanic eruptions enhance or diminish net primary production? Evidence from tree rings |
title_full_unstemmed |
Do volcanic eruptions enhance or diminish net primary production? Evidence from tree rings |
title_sort |
do volcanic eruptions enhance or diminish net primary production? evidence from tree rings |
publisher |
eScholarship, University of California |
publishDate |
2003 |
url |
http://www.escholarship.org/uc/item/57j5c3dm |
op_coverage |
n/a - n/a |
genre |
ice core |
genre_facet |
ice core |
op_source |
Krakauer, Nir Y; & Randerson, James T. (2003). Do volcanic eruptions enhance or diminish net primary production? Evidence from tree rings. Global Biogeochemical Cycles, 17(4), n/a - n/a. doi:10.1029/2003GB002076. UC Irvine: Department of Earth System Science, UCI. Retrieved from: http://www.escholarship.org/uc/item/57j5c3dm |
op_relation |
qt57j5c3dm http://www.escholarship.org/uc/item/57j5c3dm |
op_rights |
Attribution (CC BY): http://creativecommons.org/licenses/by/3.0/ |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1029/2003GB002076 |
container_title |
Global Biogeochemical Cycles |
container_volume |
17 |
container_issue |
4 |
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n/a |
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1766029811944259584 |