| 1. |
- Atkin, Owen K, et al.
(författare)
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Using temperature-dependent changes in leaf scaling relationships to quantitatively account forthermal acclimation of respiration in a coupled global climate-vegetation model
- 2008
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Ingår i: Global Change Biology. - : Wiley. - 1354-1013. ; 14, s. 2709-2726
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Tidskriftsartikel (refereegranskat)abstract
- The response of plant respiration (R) to temperature is an important component of the biosphere's response to climate change. At present, most global models assume that R increases exponentially with temperature and does not thermally acclimate. Although we now know that acclimation does occur, quantitative incorporation of acclimation into models has been lacking. Using a dataset for 19 species grown at four temperatures (7, 14, 21, and 28 °C), we have assessed whether sustained differences in growth temperature systematically alter the slope and/or intercepts of the generalized log–log plots of leaf R vs. leaf mass per unit leaf area (LMA) and vs. leaf nitrogen (N) concentration. The extent to which variations in growth temperature account for the scatter observed in log–log R–LMA–N scaling relationships was also assessed. We show that thermal history accounts for up to 20% of the scatter in scaling relationships used to predict R, with the impact of thermal history on R–LMA–N generalized scaling relationships being highly predictable. This finding enabled us to quantitatively incorporate acclimation of R into a coupled global climate–vegetation model. We show that accounting for acclimation of R has negligible impact on predicted annual rates of global R, net primary productivity (NPP) or future atmospheric CO2 concentrations. However, our analysis suggests that accounting for acclimation is important when considering carbon fluxes among thermally contrasting biomes (e.g. accounting for acclimation decreases predicted rates of R by up to 20% in high-temperature biomes). We conclude that acclimation of R needs to be accounted for when predicting potential responses of terrestrial carbon exchange to climatic change at a regional level.
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| 2. |
- Atkinson, Lindsey J, et al.
(författare)
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Impact of growth temperature on scaling relationships linking photosynthetic metabolism to leaf functional traits
- 2010
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Ingår i: Functional Ecology. - : Wiley-Blackwell. - 0269-8463 .- 1365-2435. ; 24:6, s. 1181-1191
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Tidskriftsartikel (refereegranskat)abstract
- 1. Scaling relationships linking photosynthesis (A) to leaf traits are important for predicting vegetation patterns and plant-atmosphere carbon fluxes. Here, we investigated the impact of growth temperature on such scaling relationships.2. We assessed whether changes in growth temperature systematically altered the slope and/or intercepts of log-log plots of A vs leaf mass per unit leaf area (LMA), nitrogen and phosphorus concentrations for 19 contrasting plant species grown hydroponically at four temperatures (7, 14, 21 and 28 degrees C) in controlled environment cabinets. Responses of 21 degrees C-grown pre-existing (PE) leaves experiencing a 10 day growth temperature (7, 14, 21 and 28 degrees C) treatment, and newly-developed (ND) leaves formed at each of the four new growth temperatures, were quantified. Irrespective of the growth temperature treatment, rates of light-saturated photosynthesis (A) were measured at 21 degrees C.3. Changes in growth temperature altered the scaling between A and leaf traits in pre-existing (PE) leaves, with thermal history accounting for up to 17% and 31% of the variation on a mass and area basis, respectively. However, growth temperature played almost no role in accounting for scatter when comparisons were made of newly-developed (ND) leaves that form at each growth temperature.4. Photosynthetic nitrogen and phosphorus use efficiency (PNUE and PPUE, respectively) decreased with increasing LMA. No systematic differences in temperature-mediated reductions in PNUE or PPUE of PE leaves were found among species.5. Overall, these results highlight the importance of leaf development in determining the effects of sustained changes in growth temperature on scaling relationships linking photosynthesis to other leaf traits.
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| 3. |
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| 4. |
- Campbell, Catherine D, 1976-, et al.
(författare)
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Acclimation of photosynthesis and respiration is asynchronous in response to changes in temperature regardless of plant functional group
- 2007
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Ingår i: New Phytologist. - : Wiley-Blackwell Publishing Inc.. - 0028-646X .- 1469-8137. ; 176:2, s. 375-389
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Tidskriftsartikel (refereegranskat)abstract
- • Gas exchange, fluorescence, western blot and chemical composition analyses were combined to assess if three functional groups (forbs, grasses and evergreen trees/shrubs) differed in acclimation of leaf respiration (R) and photosynthesis (A) to a range of growth temperatures (7, 14, 21 and 28°C).• When measured at a common temperature, acclimation was greater for R than for A and differed between leaves experiencing a 10-d change in growth temperature (PE) and leaves newly developed at each temperature (ND). As a result, the R : A ratio was temperature dependent, increasing in cold-acclimated plants. The balance was largely restored in ND leaves. Acclimation responses were similar among functional groups.• Across the functional groups, cold acclimation was associated with increases in nonstructural carbohydrates and nitrogen. Cold acclimation of R was associated with an increase in abundance of alternative and/or cytochrome oxidases in a species-dependent manner. Cold acclimation of A was consistent with an initial decrease and subsequent recovery of thylakoid membrane proteins and increased abundance of proteins involved in the Calvin cycle.• Overall, the results point to striking similarities in the extent and the biochemical underpinning of acclimation of R and A among contrasting functional groups differing in overall rates of metabolism, chemical composition and leaf structure.
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| 5. |
- Gallego-Sala, Angela V., et al.
(författare)
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Latitudinal limits to the predicted increase of the peatland carbon sink with warming
- 2018
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Ingår i: Nature Climate Change. - : Springer Science and Business Media LLC. - 1758-678X .- 1758-6798. ; 8:10, s. 907-
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Tidskriftsartikel (refereegranskat)abstract
- The carbon sink potential of peatlands depends on the balance of carbon uptake by plants and microbial decomposition. The rates of both these processes will increase with warming but it remains unclear which will dominate the global peatland response. Here we examine the global relationship between peatland carbon accumulation rates during the last millennium and planetary-scale climate space. A positive relationship is found between carbon accumulation and cumulative photosynthetically active radiation during the growing season for mid- to high-latitude peatlands in both hemispheres. However, this relationship reverses at lower latitudes, suggesting that carbon accumulation is lower under the warmest climate regimes. Projections under Representative Concentration Pathway (RCP)2.6 and RCP8.5 scenarios indicate that the present-day global sink will increase slightly until around AD 2100 but decline thereafter. Peatlands will remain a carbon sink in the future, but their response to warming switches from a negative to a positive climate feedback (decreased carbon sink with warming) at the end of the twenty-first century.
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| 6. |
- Lin, Yan-Shih, et al.
(författare)
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Optimal stomatal behaviour around the world
- 2015
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Ingår i: Nature Climate Change. - : Springer Science and Business Media LLC. - 1758-678X .- 1758-6798. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- Stomatal conductance (gs) is a key land-surface attribute as it links transpiration, the dominant component of global land evapotranspiration, and photosynthesis, the driving force of the global carbon cycle. Despite the pivotal role of gs in predictions of global water and carbon cycle changes, a globalscale database and an associated globally applicable model of gs that allow predictions of stomatal behaviour are lacking. Here,we present a database of globally distributed gs obtained in the field for a wide range of plant functional types (PFTs) and biomes. We find that stomatal behaviour differs among PFTs according to their marginal carbon cost of water use, as predicted by the theory underpinning the optimal stomatal model1 and the leaf and wood economics spectrum2,3.We also demonstrate a global relationship with climate. These findings provide a robust theoretical framework for understanding and predicting the behaviour of gs across biomes and across PFTs that can be applied to regional, continental and global-scale modelling of ecosystem productivity, energy balance and ecohydrological processes in a future changing climate.
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| 7. |
- Lin, Yan-Shih, et al.
(författare)
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Optimal stomatal behaviour around the world
- 2015
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Ingår i: Nature Climate Change. - 1758-6798 .- 1758-678X. ; 5:5, s. 459-464
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Tidskriftsartikel (refereegranskat)abstract
- Stomatal conductance (g(s)) is a key land-surface attribute as it links transpiration, the dominant component of global land evapotranspiration, and photosynthesis, the driving force of the global carbon cycle. Despite the pivotal role of g(s) in predictions of global water and carbon cycle changes, a global-scale database and an associated globally applicable model of g(s) that allow predictions of stomatal behaviour are lacking. Here, we present a database of globally distributed g(s) obtained in the field for a wide range of plant functional types (PFTs) and biomes. We find that stomatal behaviour differs among PFTs according to their marginal carbon cost of water use, as predicted by the theory underpinning the optimal stomatal model(1) and the leaf and wood economics spectrum(2,3). We also demonstrate a global relationship with climate. These findin g(s) provide a robust theoretical framework for understanding and predicting the behaviour of g(s) across biomes and across PFTs that can be applied to regional, continental and global-scale modelling of ecosystem productivity, energy balance and ecohydrological processes in a future changing climate.
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| 8. |
- Zaragoza-Castells, Joana, et al.
(författare)
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Does growth irradiance affect temperature dependence and thermal acclimation of leaf respiration? Insights from a Mediterranean tree with long-lived leaves.
- 2007
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Ingår i: Plant Cell & Environment. - : Wiley. - 0140-7791 .- 1365-3040. ; 30:7, s. 820-33
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the response of leaf respiration (R) to changes in irradiance and temperature is a prerequisite for predicting the impacts of climate change on plant function and future atmospheric CO2 concentrations. Little is known, however, about the interactive effects of irradiance and temperature on leaf R. We investigated whether growth irradiance affects the temperature response of leaf R in darkness (Rdark) and in light (Rlight) in seedlings of a broad-leaved evergreen species, Quercus ilex. Two hypotheses concerning Rdark were tested: (1) the Q10 (i.e. the proportional increase in R per 10 °C rise in temperature) of leaf Rdark is lower in shaded plants than in high-light-grown plants, and (2) shade-grown plants exhibit a lower degree of thermal acclimation of Rdark than plants exposed to higher growth irradiance. We also assessed whether light inhibition of Rlight differs between leaves exposed to contrasting temperatures and growth irradiances, and whether the degree of thermal acclimation of Rlight is dependent on growth irradiance. We showed that while growth irradiance did impact on photosynthesis, it had no effect on the Q10 of leaf Rdark. Growth irradiance had little impact on thermal acclimation when fully expanded, pre-existing leaves were exposed to contrasting temperatures for several weeks. When Rlight was measured at a common irradiance, Rlight/Rdark ratios were higher in shaded plants due to homeostasis of Rlight between growth irradiance treatments and to the lower Rdark in shaded leaves. We also showed that Rlight does not acclimate to the same degree as Rdark, and that Rlight/Rdark decreases with increasing measuring and growth temperatures, irrespective of the growth irradiance. Collectively, we raised the possibility that predictive carbon cycle models can assume that growth irradiance and photosynthesis do not affect the temperature sensitivity of leaf Rdark of long-lived evergreen leaves, thus simplifying incorporation of leaf R into such models.
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