Plant trait response of tundra shrubs to permafrost thaw and nutrient addition
Plant traits reflect growth strategies and trade-offs in response to environmental conditions. Because of climate warming, plant traits might adapt, altering ecosystem functions and vegetation–climate interactions. Despite important feedbacks of plant trait changes in tundra ecosystems with regional...
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ftcopernicus:oai:publications.copernicus.org:bgd82444 2023-05-15T15:19:06+02:00 Plant trait response of tundra shrubs to permafrost thaw and nutrient addition Iturrate-Garcia, Maitane Heijmans, Monique M. P. D. Cornelissen, J. Hans C. Schweingruber, Fritz H. Niklaus, Pascal A. Schaepman-Strub, Gabriela 2020-02-07 application/pdf https://doi.org/10.5194/bg-2019-498 https://www.biogeosciences-discuss.net/bg-2019-498/ eng eng doi:10.5194/bg-2019-498 https://www.biogeosciences-discuss.net/bg-2019-498/ eISSN: 1726-4189 Text 2020 ftcopernicus https://doi.org/10.5194/bg-2019-498 2020-02-10T15:42:01Z Plant traits reflect growth strategies and trade-offs in response to environmental conditions. Because of climate warming, plant traits might adapt, altering ecosystem functions and vegetation–climate interactions. Despite important feedbacks of plant trait changes in tundra ecosystems with regional climate, with a key role for shrubs, information on responses of shrub functional traits is limited. Here, we investigate the effects of experimentally increased permafrost thaw depth and (possibly thaw-associated) soil nutrient availability on plant functional traits and strategies of arctic shrubs in northeastern Siberia. We hypothesize that shrubs will generally shift their strategy from efficient conservation to faster acquisition of resources through adaptation of leaf and stem traits in a coordinated whole-plant fashion. Thereto we ran a 4-year permafrost thaw and nutrient fertilization experiment with a fully factorial block design and six treatment combinations – permafrost thaw (control, unheated cable, heated cable) x fertilization (no-nutrient addition, nutrient addition). We measured ten leaf and stem traits related to growth, defence and the resource economics spectrum in four shrub species, which were sampled in the experimental plots. The plant trait data were statistically analysed using linear mixed-effect models and principal component analysis (PCA). The response to increased permafrost thaw was not significant for most shrub traits. However, all shrubs responded to the fertilization treatment, despite decreased thaw depth and soil temperature in fertilized plots. Shrubs tended to grow taller, but did not increase their stem density or bark thickness. We found a similar coordinated trait response for all four species at leaf and plant level, i.e. they shifted from a conservative towards a more acquisitive resource economy strategy upon fertilization. In accordance, results point towards a lower investment into defence mechanisms, and hence increased shrub vulnerability to herbivory and climate extremes. Compared to biomass and height only, detailed data involving individual plant organ traits such as leaf area and nutrient contents or stem water content can contribute to a better mechanistic understanding of feedbacks between shrub growth strategies, permafrost thaw and carbon and energy fluxes. In combination with observational data, these experimental tundra trait data allow for a more realistic representation of tundra shrubs in dynamic vegetation models and robust prediction of ecosystem functions and related climate-vegetation-permafrost feedbacks. Text Arctic permafrost Tundra Siberia Copernicus Publications: E-Journals Arctic |
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Copernicus Publications: E-Journals |
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English |
description |
Plant traits reflect growth strategies and trade-offs in response to environmental conditions. Because of climate warming, plant traits might adapt, altering ecosystem functions and vegetation–climate interactions. Despite important feedbacks of plant trait changes in tundra ecosystems with regional climate, with a key role for shrubs, information on responses of shrub functional traits is limited. Here, we investigate the effects of experimentally increased permafrost thaw depth and (possibly thaw-associated) soil nutrient availability on plant functional traits and strategies of arctic shrubs in northeastern Siberia. We hypothesize that shrubs will generally shift their strategy from efficient conservation to faster acquisition of resources through adaptation of leaf and stem traits in a coordinated whole-plant fashion. Thereto we ran a 4-year permafrost thaw and nutrient fertilization experiment with a fully factorial block design and six treatment combinations – permafrost thaw (control, unheated cable, heated cable) x fertilization (no-nutrient addition, nutrient addition). We measured ten leaf and stem traits related to growth, defence and the resource economics spectrum in four shrub species, which were sampled in the experimental plots. The plant trait data were statistically analysed using linear mixed-effect models and principal component analysis (PCA). The response to increased permafrost thaw was not significant for most shrub traits. However, all shrubs responded to the fertilization treatment, despite decreased thaw depth and soil temperature in fertilized plots. Shrubs tended to grow taller, but did not increase their stem density or bark thickness. We found a similar coordinated trait response for all four species at leaf and plant level, i.e. they shifted from a conservative towards a more acquisitive resource economy strategy upon fertilization. In accordance, results point towards a lower investment into defence mechanisms, and hence increased shrub vulnerability to herbivory and climate extremes. Compared to biomass and height only, detailed data involving individual plant organ traits such as leaf area and nutrient contents or stem water content can contribute to a better mechanistic understanding of feedbacks between shrub growth strategies, permafrost thaw and carbon and energy fluxes. In combination with observational data, these experimental tundra trait data allow for a more realistic representation of tundra shrubs in dynamic vegetation models and robust prediction of ecosystem functions and related climate-vegetation-permafrost feedbacks. |
format |
Text |
author |
Iturrate-Garcia, Maitane Heijmans, Monique M. P. D. Cornelissen, J. Hans C. Schweingruber, Fritz H. Niklaus, Pascal A. Schaepman-Strub, Gabriela |
spellingShingle |
Iturrate-Garcia, Maitane Heijmans, Monique M. P. D. Cornelissen, J. Hans C. Schweingruber, Fritz H. Niklaus, Pascal A. Schaepman-Strub, Gabriela Plant trait response of tundra shrubs to permafrost thaw and nutrient addition |
author_facet |
Iturrate-Garcia, Maitane Heijmans, Monique M. P. D. Cornelissen, J. Hans C. Schweingruber, Fritz H. Niklaus, Pascal A. Schaepman-Strub, Gabriela |
author_sort |
Iturrate-Garcia, Maitane |
title |
Plant trait response of tundra shrubs to permafrost thaw and nutrient addition |
title_short |
Plant trait response of tundra shrubs to permafrost thaw and nutrient addition |
title_full |
Plant trait response of tundra shrubs to permafrost thaw and nutrient addition |
title_fullStr |
Plant trait response of tundra shrubs to permafrost thaw and nutrient addition |
title_full_unstemmed |
Plant trait response of tundra shrubs to permafrost thaw and nutrient addition |
title_sort |
plant trait response of tundra shrubs to permafrost thaw and nutrient addition |
publishDate |
2020 |
url |
https://doi.org/10.5194/bg-2019-498 https://www.biogeosciences-discuss.net/bg-2019-498/ |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic permafrost Tundra Siberia |
genre_facet |
Arctic permafrost Tundra Siberia |
op_source |
eISSN: 1726-4189 |
op_relation |
doi:10.5194/bg-2019-498 https://www.biogeosciences-discuss.net/bg-2019-498/ |
op_doi |
https://doi.org/10.5194/bg-2019-498 |
_version_ |
1766349286714376192 |