Balance between carbon gain and loss in warmer environments: impacts on photosynthesis and leaf respiration in four temperate tree species

Tree Physiology, Год журнала: 2024, Номер 44(7)

Опубликована: Июнь 21, 2024

Abstract The temperature sensitivities of photosynthesis and respiration remain a key uncertainty in predicting how forests will respond to climate warming. We grew seedlings four temperate tree species, including Betula platyphylla, Fraxinus mandshurica, Juglans mandshurica Tilia amurensis, at three regimes (ambient, +2 °C, +4 °C daytime air temperature). investigated net (Anet25), maximum rate RuBP-carboxylation (Vcmax25) RuBP-regeneration (Jmax25), stomatal conductance (gs25), mesophyll (gm25), leaf (Rleaf) dark (Rdark25) light (Rlight25) 25 all species. Additionally, we examined the Anet, Vcmax, Jmax, Rdark Rlight F. mandshurica. Our findings showed that warming-induced decreases Anet25, Vcmax25 Jmax25 were more prevalent late-successional species T. amurensis. Warming had negative impacts on gs25 Overall, Anet25 was positively correlated with across growth temperatures. However, positive correlation between observed only under warming conditions, negatively associated vapor pressure deficit. This implies deficit-induced decrease responsible for decline higher optimum Anet increased by 0.59 per 1.0 rise temperature. While elevated thermal optima it did not affect other sensitivity parameters Vcmax Jmax. Rdark25 affected any Rlight25 stimulated response curves altered warming, implying lack acclimation. ratios amurensis These results suggest Rleaf acclimate synchronously these

Язык: Английский

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Linking leaf dark respiration to leaf traits and reflectance spectroscopy across diverse forest types

New Phytologist, Год журнала: 2024, Номер unknown

Опубликована: Ноя. 19, 2024

Summary Leaf dark respiration ( R ), an important yet rarely quantified component of carbon cycling in forest ecosystems, is often simulated from leaf traits such as the maximum carboxylation capacity V cmax mass per area (LMA), nitrogen (N) and phosphorus (P) concentrations, terrestrial biosphere models. However, validity these relationships across types remains to be thoroughly assessed. Here, we analyzed variability its associations with other three temperate, subtropical tropical forests China, evaluating effectiveness spectroscopy a superior monitoring alternative. We found that magnesium calcium concentrations were more significant explaining cross‐site than commonly used like LMA, N P but univariate trait– always weak r 2 ≤ 0.15) forest‐specific. Although multivariate improved model performance, outperformed relationships, accurately predicted = 0.65) pinpointed factors contributing variability. Our findings reveal few novel greater scalability regarding , challenging use empirical process models emphasize potential promising alternative for estimating which could ultimately improve modeling plant respiration.

Язык: Английский

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Thermal acclimation of stem respiration reduces global carbon burden

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2024, Номер unknown

Опубликована: Фев. 28, 2024

Abstract Stem respiration is a key driver of carbon flux from ecosystems to the atmosphere, yet its response global warming remains poorly constrained. In particular it has been proposed that stem acclimates changing temperatures, which could have large implications for cycling under climate change, but no theory exists predict acclimated rates. Here, we hypothesized physiologically linked transpiration in order maintain hydraulic continuity. We then use linkage, combined with Eco-evolutionary optimality theory, develop theoretical prediction temperature sensitivity both and instantaneous respiration. Leveraging an extensive dataset, observe sensitivities across geographical seasonal variations are consistent this prediction. Our findings reveal contributes approximately quarter above-ground auto-trophic respiration, estimated annual emission around 11.20 ± 5.88 Pg C—comparable total anthropogenic emissions. Importantly, incorporating thermal acclimation into projections significantly reduces predicted land ecosystem emissions by 4.41 9.56 C SSP126 SSP585 scenarios, respectively, 21st century.

Язык: Английский

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Solar-Induced Fluorescence Responds Earlier than Vegetation Indices to the 2019 North China Plain Drought

Опубликована: Янв. 1, 2024

Язык: Английский

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