Asymmetric temperature effect on leaf senescence and its control on ecosystem productivity

PNAS Nexus, Год журнала: 2024, Номер 3(11)

Опубликована: Окт. 23, 2024

Widespread autumn cooling occurred in the northern hemisphere (NH) during period 2004-2018, primarily due to strengthening of Pacific Decadal Oscillation and Siberian High. Yet, while there has been considerable focus on warming impacts, effects natural leaf senescence plant productivity have largely overlooked. This gap knowledge hinders our understanding how vegetation adapts acclimates complex climate change. In this study, we utilize over 36,000 situ phenological time series from 11,138 European sites dating back 1950s, 30 years satellite greenness data (1989-2018), demonstrate that dates (LSD) forests responded more strongly than autumn. Specifically, a 1 °C increase temperature caused 7.5 ± 0.2 days' delay LSD, whereas decrease led an advance LSD with 3.3 0.1 days (

Язык: Английский

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Leaf warming in the canopy of mature tropical trees reduced photosynthesis due to downregulation of photosynthetic capacity and reduced stomatal conductance

New Phytologist, Год журнала: 2024, Номер unknown

Опубликована: Дек. 7, 2024

Summary Tropical forests play a large role in the global carbon cycle by annually absorbing 30% of our annual emissions. However, these have evolved under relatively stable temperature conditions and may be sensitive to current climate warming. Few experiments investigated effects warming on large, mature trees better understand how higher temperatures affect situ . We targeted four tree species ( Endiandra microneura , Castanospermum australe Cleistanthus myrianthus Myristica globosa ) Australian tropical rainforest warmed leaves canopy 4°C for 8 months. measured response curves photosynthesis respiration, determined critical chloroplast function based Chl fluorescence. Both stomatal conductance were strongly reduced 48 35%, respectively, with While was likely vapour pressure deficit, biochemistry responded via V cmax25 (−28%) J max25 (−29%). There no shift T opt photosynthesis. Concurrently, respiration rates at common did not change warming, suggesting limited respiratory thermal acclimation. This combination physiological responses leaf suggest sink future forests.

Язык: Английский

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Tree post‐drought recovery: scenarios, regulatory mechanisms and ways to improve

Biological reviews/Biological reviews of the Cambridge Philosophical Society, Год журнала: 2024, Номер 99(5), С. 1595 - 1612

Опубликована: Апрель 5, 2024

Efficient post-drought recovery of growth and assimilation enables a plant to return its undisturbed state functioning. Unlike annual plants, trees suffer not only from the current drought, but also cumulative impacts consecutive water stresses which cause adverse legacy effects on survival performance. This review provides an integrated assessment ecological, physiological molecular evidence photosynthesis in trees, with view informing breeding better ability recover stress. Suppression processes can result stress damage controlled downshift as part tree acclimation water-limited conditions. In latter case, could potentially be activated by turning off controlling mechanisms, several obstacles make this unlikely. Tree phenology, specifically photoperiodic constraints, limit photosynthesis, targeting these constraints may represent promising way breed enhanced post-drought. The mechanisms photoperiod-dependent regulation shoot, secondary root are reviewed. Finally, limitations trade-offs altering discussed.

Язык: Английский

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Drought shortens subtropical understory growing season by advancing leaf senescence

Global Change Biology, Год журнала: 2024, Номер 30(5)

Опубликована: Май 1, 2024

Abstract Subtropical forests, recognized for their intricate vertical canopy stratification, exhibit high resistance to extreme drought. However, the response of leaf phenology drought in species‐rich understory remains poorly understood. In this study, we constructed a digital camera system, amassing over 360,000 images through 70% throughfall exclusion experiment, explore phenology. The results revealed significant advancement senescence under drought, with 11.75 and 15.76 days start end leaf‐falling event, respectively. Pre‐season temperature primarily regulated development phenology, whereas soil water dominated variability Under conditions, sensitivities emergence decreased from −13.72 −11.06 °C −1 , insignificance observed emergence. Consequently, treatment shortened both length growing season (15.69 days) peak growth (9.80 plants. Moreover, study identified diverse responses among intraspecies interspecies particularly during phase. These findings underscore pivotal role availability shaping patterns, especially subtropical forests.

Язык: Английский

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Do red and yellow autumn leaves make use of different photoprotective strategies during autumn senescence?

Physiologia Plantarum, Год журнала: 2024, Номер 176(3)

Опубликована: Май 1, 2024

Our goal was to determine whether anthocyanin-producing species (red) use different photoprotective strategies cope with excess light during fall senescence compared non-anthocyanin-producing (yellow). In a previous study, we found that yellow retained the PsbS protein in late autumn, while red did not. Specifically, tested hypothesis make less of zeaxanthin and PsbS-mediated thermal dissipation, as they rely on anthocyanins for photoprotection. We monitored four (Acer ginnala, Rhus typhnia, Parenthocissus quinquefolia, Viburnum dentatum) negundo, Ostrya virginiana, Vitis riparia, Zanthoxylum americanum) throughout autumn analyzed pigments, content, chlorophyll fluorescence. at higher levels, had dark retention relative species. All lutein pool xanthophyll cycle pigments amounts than other carotenoids autumn. data support strategy senescence, therefore zeaxanthin-mediated dissipation. also species-specific variation particular combination used.

Язык: Английский

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