Testing a dual isotope model to track carbon and water gas exchanges in a Mediterranean forest
Due to climate change, drier summers have been observed over the last ten years in Mediterranean areas. Increasing drought levels may have a different weight in influencing the stomatal versus photosynthetic activity of forests, altering the water-use efficiency (i.e., WUE, the amount of carbon gain...
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| Format: | Article |
| Language: | English |
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Italian Society of Silviculture and Forest Ecology (SISEF)
2009-03-01
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| Series: | iForest - Biogeosciences and Forestry |
| Subjects: | |
| Online Access: | https://iforest.sisef.org/contents/?id=ifor0491-002 |
| _version_ | 1817999359433768960 |
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| author | Ripullone F Guerrieri MR Saurer M Siegwolf R Jäggi M Guarini R Magnani F |
| author_facet | Ripullone F Guerrieri MR Saurer M Siegwolf R Jäggi M Guarini R Magnani F |
| author_sort | Ripullone F |
| collection | DOAJ |
| description | Due to climate change, drier summers have been observed over the last ten years in Mediterranean areas. Increasing drought levels may have a different weight in influencing the stomatal versus photosynthetic activity of forests, altering the water-use efficiency (i.e., WUE, the amount of carbon gain per water lost) and, consequently, the global carbon balance. By combining leaf gas exchanges and leaf carbon/oxygen isotope measurements, we tested under Mediterranean conditions a semi-quantitative dual isotope model to track adjustments in stomatal conductance (gs) and maximum CO2 assimilation at saturating light (Amax) in response to changes in air and soil water availability. The experiment was established at Allumiere site (Rome, Italy) over the course of two consecutive years. There, we modified the amount of precipitation reaching the soil on water depleted (D) and watered (W) replicate plots (~100 m2) of an Arbutus unedo L. forest using a system of rain gutters and sprinklers, respectively. Changes in soil water availability affected gs and Amax in parallel. As an application of the model, we found that, in response to reduced air and soil water availability, constant carbon (δ13C) and increasing oxygen (δ18O) isotope values were consistent with a parallel decline of either gs and Amax. As a result of parallel decline, WUE did not differ or only slightly differed between treatments, in contrast with most of the studies that found a wide-spread increase of WUE in response to enhanced drought. This study highlights the potentiality of the dual isotope model to provide insights of forest ecosystem functioning in Mediterranean environments. |
| first_indexed | 2024-04-14T03:07:44Z |
| format | Article |
| id | doaj.art-f9f2bd0d3e87456788d8207d34fc8cd5 |
| institution | Directory Open Access Journal |
| issn | 1971-7458 1971-7458 |
| language | English |
| last_indexed | 2024-04-14T03:07:44Z |
| publishDate | 2009-03-01 |
| publisher | Italian Society of Silviculture and Forest Ecology (SISEF) |
| record_format | Article |
| series | iForest - Biogeosciences and Forestry |
| spelling | doaj.art-f9f2bd0d3e87456788d8207d34fc8cd52022-12-22T02:15:42ZengItalian Society of Silviculture and Forest Ecology (SISEF)iForest - Biogeosciences and Forestry1971-74581971-74582009-03-0121596610.3832/ifor0491-002491Testing a dual isotope model to track carbon and water gas exchanges in a Mediterranean forestRipullone F0Guerrieri MR1Saurer M2Siegwolf R3Jäggi M4Guarini R5Magnani F6Dept. of Crop System, Forestry and Environmental Sciences, University of Basilicata (Italy)Dept. of Crop System, Forestry and Environmental Sciences, University of Basilicata (Italy)Paul Scherrer Institut, Laboratory of Atmospheric Chemistry, Stable Isotope and Ecosystem Fluxes (Switzerland)Paul Scherrer Institut, Laboratory of Atmospheric Chemistry, Stable Isotope and Ecosystem Fluxes (Switzerland)Paul Scherrer Institut, Laboratory of Atmospheric Chemistry, Stable Isotope and Ecosystem Fluxes (Switzerland)Dept. of Crop System, Forestry and Environmental Sciences, University of Basilicata (Italy)Dept. of Plant Cultivation, University of Bologna (Italy)Due to climate change, drier summers have been observed over the last ten years in Mediterranean areas. Increasing drought levels may have a different weight in influencing the stomatal versus photosynthetic activity of forests, altering the water-use efficiency (i.e., WUE, the amount of carbon gain per water lost) and, consequently, the global carbon balance. By combining leaf gas exchanges and leaf carbon/oxygen isotope measurements, we tested under Mediterranean conditions a semi-quantitative dual isotope model to track adjustments in stomatal conductance (gs) and maximum CO2 assimilation at saturating light (Amax) in response to changes in air and soil water availability. The experiment was established at Allumiere site (Rome, Italy) over the course of two consecutive years. There, we modified the amount of precipitation reaching the soil on water depleted (D) and watered (W) replicate plots (~100 m2) of an Arbutus unedo L. forest using a system of rain gutters and sprinklers, respectively. Changes in soil water availability affected gs and Amax in parallel. As an application of the model, we found that, in response to reduced air and soil water availability, constant carbon (δ13C) and increasing oxygen (δ18O) isotope values were consistent with a parallel decline of either gs and Amax. As a result of parallel decline, WUE did not differ or only slightly differed between treatments, in contrast with most of the studies that found a wide-spread increase of WUE in response to enhanced drought. This study highlights the potentiality of the dual isotope model to provide insights of forest ecosystem functioning in Mediterranean environments.https://iforest.sisef.org/contents/?id=ifor0491-002Carbon assimilationDroughtIsotope modelArbutus unedoStomatal conductanceWater-use efficiency |
| spellingShingle | Ripullone F Guerrieri MR Saurer M Siegwolf R Jäggi M Guarini R Magnani F Testing a dual isotope model to track carbon and water gas exchanges in a Mediterranean forest iForest - Biogeosciences and Forestry Carbon assimilation Drought Isotope model Arbutus unedo Stomatal conductance Water-use efficiency |
| title | Testing a dual isotope model to track carbon and water gas exchanges in a Mediterranean forest |
| title_full | Testing a dual isotope model to track carbon and water gas exchanges in a Mediterranean forest |
| title_fullStr | Testing a dual isotope model to track carbon and water gas exchanges in a Mediterranean forest |
| title_full_unstemmed | Testing a dual isotope model to track carbon and water gas exchanges in a Mediterranean forest |
| title_short | Testing a dual isotope model to track carbon and water gas exchanges in a Mediterranean forest |
| title_sort | testing a dual isotope model to track carbon and water gas exchanges in a mediterranean forest |
| topic | Carbon assimilation Drought Isotope model Arbutus unedo Stomatal conductance Water-use efficiency |
| url | https://iforest.sisef.org/contents/?id=ifor0491-002 |
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