Fine-Root Traits Reveal Contrasting Ecological Strategies in European Beech and Norway Spruce During Extreme Drought
Trees adjust multiple structural and functional organ-specific characteristics, “traits”, to cope with diverse soil conditions. Studies on traits are widely used to uncover ecological species adaptability to varying environments. However, fine-root traits are rarely studied for methodological reason...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2020-08-01
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| Series: | Frontiers in Plant Science |
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| Online Access: | https://www.frontiersin.org/article/10.3389/fpls.2020.01211/full |
| _version_ | 1819226573178404864 |
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| author | Petia Simeonova Nikolova Petia Simeonova Nikolova Taryn L. Bauerle Karl-Heinz Häberle Helmut Blaschke Ivano Brunner Rainer Matyssek |
| author_facet | Petia Simeonova Nikolova Petia Simeonova Nikolova Taryn L. Bauerle Karl-Heinz Häberle Helmut Blaschke Ivano Brunner Rainer Matyssek |
| author_sort | Petia Simeonova Nikolova |
| collection | DOAJ |
| description | Trees adjust multiple structural and functional organ-specific characteristics, “traits”, to cope with diverse soil conditions. Studies on traits are widely used to uncover ecological species adaptability to varying environments. However, fine-root traits are rarely studied for methodological reasons. We analyzed the adaptability of the fine-root systems of European beech and Norway spruce to extreme drought within species-specific tree groups at Kranzberger Forst (Germany), focusing on the seasonality of morphological, physiological, and biochemical key traits in view of carbon (C) and nitrogen dynamics. We hypothesized that fine roots of both species adjust to seasonal drought: with beech representing a “fast” (i.e. with fast C turnover), and spruce a “slow” (i.e. with long-term C retention) ecological strategy. We identified three functional fine-root categories, based on root function (absorptive or transport fine roots), and mycorrhizal status of the absorptive fine-roots (mycorrhizal or non-mycorrhizal). Solely the non-mycorrhizal absorptive roots adjusted in a species-specific manner supporting fine-root ecological strategy hypothesis. During drought, beech produced thin ephemeral (absorptive non-mycorrhizal) fine roots with high specific fine-root area and high respiratory activity, representing fast C turnover and enabling effective resource exploitation. These adjustments reflect a “fast” ecological strategy. Conversely, spruce absorptive fine roots did not respond to the soil moisture deficit by growth but instead increased root suberization. Drastically lowered respiratory activity of this functional category facilitated C retention and structural persistence during drought, indicating a “slow” ecological strategy in spruce. Absorptive mycorrhizal fine roots maintained respiration throughout the drought event in both tree species, but in spruce this was the only fine-root category with high respiration. This suggests, that spruce relies heavily on mycorrhizal associations as a method of drought resistance. Accumulation of non-structural carbohydrates and high C concentrations were observed in the transport fine roots of both species, indicating drought-induced osmotic protection of these roots. Thus, functional classification enabled us to determine that fine-root branches of each species are not tied to one sole ecological strategy. The suggested approach helps to better understand the complex interplay between structure and function belowground. |
| first_indexed | 2024-12-23T10:27:38Z |
| format | Article |
| id | doaj.art-eb4d11cd459f4caaa50fa41070cc848f |
| institution | Directory Open Access Journal |
| issn | 1664-462X |
| language | English |
| last_indexed | 2024-12-23T10:27:38Z |
| publishDate | 2020-08-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Plant Science |
| spelling | doaj.art-eb4d11cd459f4caaa50fa41070cc848f2022-12-21T17:50:32ZengFrontiers Media S.A.Frontiers in Plant Science1664-462X2020-08-011110.3389/fpls.2020.01211550517Fine-Root Traits Reveal Contrasting Ecological Strategies in European Beech and Norway Spruce During Extreme DroughtPetia Simeonova Nikolova0Petia Simeonova Nikolova1Taryn L. Bauerle2Karl-Heinz Häberle3Helmut Blaschke4Ivano Brunner5Rainer Matyssek6Forest Resources and Management, Swiss Federal Research Institute WSL, Birmensdorf, SwitzerlandEcophysiology of Plants, TUM School of Life Sciences, Technische Universität München, Freising, GermanySchool of Integrative Plant Science, Cornell University, Ithaca, NY, United StatesEcophysiology of Plants, TUM School of Life Sciences, Technische Universität München, Freising, GermanyEcophysiology of Plants, TUM School of Life Sciences, Technische Universität München, Freising, GermanyForest Soils and Biogeochemistry, Swiss Federal Research Institute WSL, Birmensdorf, SwitzerlandEcophysiology of Plants, TUM School of Life Sciences, Technische Universität München, Freising, GermanyTrees adjust multiple structural and functional organ-specific characteristics, “traits”, to cope with diverse soil conditions. Studies on traits are widely used to uncover ecological species adaptability to varying environments. However, fine-root traits are rarely studied for methodological reasons. We analyzed the adaptability of the fine-root systems of European beech and Norway spruce to extreme drought within species-specific tree groups at Kranzberger Forst (Germany), focusing on the seasonality of morphological, physiological, and biochemical key traits in view of carbon (C) and nitrogen dynamics. We hypothesized that fine roots of both species adjust to seasonal drought: with beech representing a “fast” (i.e. with fast C turnover), and spruce a “slow” (i.e. with long-term C retention) ecological strategy. We identified three functional fine-root categories, based on root function (absorptive or transport fine roots), and mycorrhizal status of the absorptive fine-roots (mycorrhizal or non-mycorrhizal). Solely the non-mycorrhizal absorptive roots adjusted in a species-specific manner supporting fine-root ecological strategy hypothesis. During drought, beech produced thin ephemeral (absorptive non-mycorrhizal) fine roots with high specific fine-root area and high respiratory activity, representing fast C turnover and enabling effective resource exploitation. These adjustments reflect a “fast” ecological strategy. Conversely, spruce absorptive fine roots did not respond to the soil moisture deficit by growth but instead increased root suberization. Drastically lowered respiratory activity of this functional category facilitated C retention and structural persistence during drought, indicating a “slow” ecological strategy in spruce. Absorptive mycorrhizal fine roots maintained respiration throughout the drought event in both tree species, but in spruce this was the only fine-root category with high respiration. This suggests, that spruce relies heavily on mycorrhizal associations as a method of drought resistance. Accumulation of non-structural carbohydrates and high C concentrations were observed in the transport fine roots of both species, indicating drought-induced osmotic protection of these roots. Thus, functional classification enabled us to determine that fine-root branches of each species are not tied to one sole ecological strategy. The suggested approach helps to better understand the complex interplay between structure and function belowground.https://www.frontiersin.org/article/10.3389/fpls.2020.01211/fullecological strategyextreme droughtFagus sylvaticafine-root classificationfine-root traitsmorphology |
| spellingShingle | Petia Simeonova Nikolova Petia Simeonova Nikolova Taryn L. Bauerle Karl-Heinz Häberle Helmut Blaschke Ivano Brunner Rainer Matyssek Fine-Root Traits Reveal Contrasting Ecological Strategies in European Beech and Norway Spruce During Extreme Drought Frontiers in Plant Science ecological strategy extreme drought Fagus sylvatica fine-root classification fine-root traits morphology |
| title | Fine-Root Traits Reveal Contrasting Ecological Strategies in European Beech and Norway Spruce During Extreme Drought |
| title_full | Fine-Root Traits Reveal Contrasting Ecological Strategies in European Beech and Norway Spruce During Extreme Drought |
| title_fullStr | Fine-Root Traits Reveal Contrasting Ecological Strategies in European Beech and Norway Spruce During Extreme Drought |
| title_full_unstemmed | Fine-Root Traits Reveal Contrasting Ecological Strategies in European Beech and Norway Spruce During Extreme Drought |
| title_short | Fine-Root Traits Reveal Contrasting Ecological Strategies in European Beech and Norway Spruce During Extreme Drought |
| title_sort | fine root traits reveal contrasting ecological strategies in european beech and norway spruce during extreme drought |
| topic | ecological strategy extreme drought Fagus sylvatica fine-root classification fine-root traits morphology |
| url | https://www.frontiersin.org/article/10.3389/fpls.2020.01211/full |
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