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Sun H, Wang WJ, Liu Z, Wang L, Bao SG, Ba S, Cong Y. Woody encroachment induced earlier and extended growing season in boreal wetland ecosystems. FRONTIERS IN PLANT SCIENCE 2024; 15:1413896. [PMID: 38812732 PMCID: PMC11133685 DOI: 10.3389/fpls.2024.1413896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Accepted: 04/30/2024] [Indexed: 05/31/2024]
Abstract
Woody plant encroachment (WPE), a widespread ecological phenomenon globally, has significant impacts on ecosystem structure and functions. However, little is known about how WPE affects phenology in wetland ecosystems of middle and high latitudes. Here, we investigated the regional-scale effects of WPE on the start (SOS), peak (POS), end (EOS), and length (GSL) of the growing season in boreal wetland ecosystems, and their underlying mechanisms, using remote sensing dataset during 2001-2016. Our results showed that WPE advanced the annual SOS and POS, while delaying EOS and extending GSL in boreal wetlands with these impacts increasing over time. When boreal wetland ecosystems were fully encroached by woody plants, the SOS and POS were advanced by 12.17 and 5.65 days, respectively, the EOS was postponed by 2.74 days, and the GSL was extended by 15.21 days. We also found that the impacts of WPE on wetland SOS were predominantly attributed to the increased degree of WPE (α), while climatic factors played a more significant role in controlling the POS and EOS responses to WPE. Climate change not only directly influenced phenological responses of wetlands to WPE but also exerted indirect effects by regulating soil moisture and α. Winter precipitation and spring temperature primarily determined the effects of WPE on SOS, while its impacts on POS were mainly controlled by winter precipitation, summer temperature, and precipitation, and the effects on EOS were mainly determined by winter precipitation, summer temperature, and autumn temperature. Our findings offer new insights into the understanding of the interaction between WPE and wetland ecosystems, emphasizing the significance of considering WPE effects to ensure accurate assessments of phenology changes.
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Affiliation(s)
- Hongchao Sun
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, China
- University of Chinese Academy of Sciences, College of Resources and Environment, Beijing, China
| | - Wen J. Wang
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, China
| | - Zhihua Liu
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Lei Wang
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, China
| | - Suri G. Bao
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, China
- University of Chinese Academy of Sciences, College of Resources and Environment, Beijing, China
| | - Shengjie Ba
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, China
- School of Geographical Sciences, Northeast Normal University, Changchun, China
| | - Yu Cong
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, China
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Bouchnak I, Coulon D, Salis V, D’Andréa S, Bréhélin C. Lipid droplets are versatile organelles involved in plant development and plant response to environmental changes. FRONTIERS IN PLANT SCIENCE 2023; 14:1193905. [PMID: 37426978 PMCID: PMC10327486 DOI: 10.3389/fpls.2023.1193905] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Accepted: 05/23/2023] [Indexed: 07/11/2023]
Abstract
Since decades plant lipid droplets (LDs) are described as storage organelles accumulated in seeds to provide energy for seedling growth after germination. Indeed, LDs are the site of accumulation for neutral lipids, predominantly triacylglycerols (TAGs), one of the most energy-dense molecules, and sterol esters. Such organelles are present in the whole plant kingdom, from microalgae to perennial trees, and can probably be found in all plant tissues. Several studies over the past decade have revealed that LDs are not merely simple energy storage compartments, but also dynamic structures involved in diverse cellular processes like membrane remodeling, regulation of energy homeostasis and stress responses. In this review, we aim to highlight the functions of LDs in plant development and response to environmental changes. In particular, we tackle the fate and roles of LDs during the plant post-stress recovery phase.
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Affiliation(s)
- Imen Bouchnak
- Centre National de la Recherche Scientifique (CNRS), University of Bordeaux, Laboratoire de Biogenèse Membranaire UMR5200, Villenave d’Ornon, France
| | - Denis Coulon
- Centre National de la Recherche Scientifique (CNRS), University of Bordeaux, Laboratoire de Biogenèse Membranaire UMR5200, Villenave d’Ornon, France
| | - Vincent Salis
- Université Paris-Saclay, Institut national de recherche pour l'agriculture, l'alimentation et l'environnement (INRAE), AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), Versailles, France
| | - Sabine D’Andréa
- Université Paris-Saclay, Institut national de recherche pour l'agriculture, l'alimentation et l'environnement (INRAE), AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), Versailles, France
| | - Claire Bréhélin
- Centre National de la Recherche Scientifique (CNRS), University of Bordeaux, Laboratoire de Biogenèse Membranaire UMR5200, Villenave d’Ornon, France
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Desai AR, Murphy BA, Wiesner S, Thom J, Butterworth BJ, Koupaei‐Abyazani N, Muttaqin A, Paleri S, Talib A, Turner J, Mineau J, Merrelli A, Stoy P, Davis K. Drivers of Decadal Carbon Fluxes Across Temperate Ecosystems. JOURNAL OF GEOPHYSICAL RESEARCH. BIOGEOSCIENCES 2022; 127:e2022JG007014. [PMID: 37502709 PMCID: PMC10369927 DOI: 10.1029/2022jg007014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 11/18/2022] [Accepted: 11/21/2022] [Indexed: 07/29/2023]
Abstract
Long-running eddy covariance flux towers provide insights into how the terrestrial carbon cycle operates over multiple timescales. Here, we evaluated variation in net ecosystem exchange (NEE) of carbon dioxide (CO2) across the Chequamegon Ecosystem-Atmosphere Study AmeriFlux core site cluster in the upper Great Lakes region of the USA from 1997 to 2020. The tower network included two mature hardwood forests with differing management regimes (US-WCr and US-Syv), two fen wetlands with varying levels of canopy sheltering and vegetation (US-Los and US-ALQ), and a very tall (400 m) landscape-level tower (US-PFa). Together, they provided over 70 site-years of observations. The 19-tower Chequamegon Heterogenous Ecosystem Energy-balance Study Enabled by a High-density Extensive Array of Detectors 2019 campaign centered around US-PFa provided additional information on the spatial variation of NEE. Decadal variability was present in all long-term sites, but cross-site coherence in interannual NEE in the earlier part of the record became weaker with time as non-climatic factors such as local disturbances likely dominated flux time series. Average decadal NEE at the tall tower transitioned from carbon source to sink to near neutral over 24 years. Respiration had a greater effect than photosynthesis on driving variations in NEE at all sites. Declining snowfall offset potential increases in assimilation from warmer springs, as less-insulated soils delayed start of spring green-up. Higher CO2 increased maximum net assimilation parameters but not total gross primary productivity. Stand-scale sites were larger net sinks than the landscape tower. Clustered, long-term carbon flux observations provide value for understanding the diverse links between carbon and climate and the challenges of upscaling these responses across space.
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Affiliation(s)
- Ankur R. Desai
- Department of Atmospheric and Oceanic SciencesUniversity of Wisconsin–MadisonMadisonWIUSA
| | - Bailey A. Murphy
- Department of Atmospheric and Oceanic SciencesUniversity of Wisconsin–MadisonMadisonWIUSA
| | - Susanne Wiesner
- Department of Plant and Earth ScienceUniversity of Wisconsin–River FallsRiver FallsWIUSA
| | - Jonathan Thom
- Space Science and Engineering CenterUniversity of Wisconsin–MadisonMadisonWIUSA
| | - Brian J. Butterworth
- Cooperative Institute for Research in Environmental SciencesCU BoulderBoulderCOUSA
- NOAA Physical Sciences LaboratoryBoulderCOUSA
| | | | - Andi Muttaqin
- Department of Atmospheric and Oceanic SciencesUniversity of Wisconsin–MadisonMadisonWIUSA
| | - Sreenath Paleri
- Department of Atmospheric and Oceanic SciencesUniversity of Wisconsin–MadisonMadisonWIUSA
| | - Ammara Talib
- Department of Civil and Environmental EngineeringUniversity of Wisconsin–MadisonMadisonWIUSA
| | - Jess Turner
- Freshwater & Marine SciencesUniversity of Wisconsin–MadisonMadisonWIUSA
| | - James Mineau
- Department of Atmospheric and Oceanic SciencesUniversity of Wisconsin–MadisonMadisonWIUSA
| | - Aronne Merrelli
- Department of Climate and Space Sciences and EngineeringUniversity of MichiganAnn ArborMIUSA
| | - Paul Stoy
- Department of Plant and Earth ScienceUniversity of Wisconsin–River FallsRiver FallsWIUSA
| | - Ken Davis
- Department of MeteorologyPennsylvania State UniversityUniversity ParkPAUSA
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del Barrio RA, Orioli GA, Brendel AS, Lindström LI, Pellegrini CN, Campoy JA. Persian Walnut ( Juglans regia L.) Bud Dormancy Dynamics in Northern Patagonia, Argentina. FRONTIERS IN PLANT SCIENCE 2022; 12:803878. [PMID: 35185955 PMCID: PMC8850472 DOI: 10.3389/fpls.2021.803878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 12/22/2021] [Indexed: 06/14/2023]
Abstract
Temperate deciduous fruit trees survive winter temperatures by entering a dormant phase in their aerial meristematic organs. Release from bud dormancy occurs after chill requirements (CR) have been satisfied, whereas bud burst/flowering follows heat requirement (HR) fulfillment. The physiological basis behind these metrics remains elusive. In this study, we are presenting the first multidisciplinary dormancy progression analysis in northern Patagonia, linking (1) forcing/field phenology, (2) bud anatomical development, and (3) soluble sugar (sucrose, glucose, and fructose) dynamics in Juglans regia L. CR and HR were determined for 'Chandler' and 'Franquette,' two walnut cultivars with markedly different CR, in artificial chill/forced heat trials (three seasons) and in-field chill/forced heat tests (five seasons) using excised twigs either with or without apical buds (non-decapitated and decapitated). The soluble sugar dynamics of 'Chandler' (high-performance liquid chromatography) and the anatomical changes of the buds (light microscopy) of the two cultivars were analyzed during endo-ecodormancy progression in one and two seasons, respectively. The CR defined by artificial chill tests proved to be an overestimation compared to the field determinations. Moreover, HR was the main driver in the phenology dynamics, as expected for a high-chill region. 'Chandler' showed an average of 10.3 field chill portions (CP) and 2,163 Growing Degree Hours (GDH°C) less than 'Franquette' for dormancy release and bud burst, respectively. These results were consistent with the transition of the shoot apex from the vegetative to the reproductive phase and the soluble sugar profile. The decrease in sucrose between 15 and 30 days after CR fulfillment could be a reliable biological marker for endodormancy release in walnut, while the increase in fructose and glucose is likely an osmolyte and cellulosic carbon source in pre-sprouting. In addition, we discuss the effect of paradormancy thanks to our apical bud experiment (with or without). Our results improve the current understanding of endo-ecodormancy progression in walnut and provide insightful results for walnut production (i.e., cultivation practices such as pruning) as well as for further application in dormancy modeling, to infer the ideotypes that should be bred for future climate conditions.
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Affiliation(s)
| | | | | | | | | | - José Antonio Campoy
- Univ. Bordeaux, INRAE, Biologie du Fruit et Pathologie, UMR 1332, Villenave-d’Ornon, France
- Department of Chromosome Biology, Max Planck Institute for Plant Breeding Research, Cologne, Germany
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Partanen J, Häkkinen R, Sutinen S, Viherä-Aarnio A, Zhang R, Hänninen H. Endodormancy release in Norway spruce grafts representing trees of different ages. TREE PHYSIOLOGY 2021; 41:631-643. [PMID: 32031217 DOI: 10.1093/treephys/tpaa001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 01/03/2020] [Indexed: 06/10/2023]
Abstract
Studies addressing endodormancy release in adult trees are usually carried out using twigs detached from the trees in the experiments. Potential problems caused by cutting the root-shoot connection when detaching the twigs can be avoided by using grafts as the experimental material. We studied the effects of chilling on the endodormancy release in Norway spruce (Picea abies (L.) Karst.) grafts where twigs of 16-, 32- and 80-year-old trees were used as the scions. The grafts were first exposed to chilling in natural conditions and then samples of them were transferred at intervals to a regrowth test in forcing conditions in a greenhouse. The bud burst percentage, BB%, in the forcing conditions generally increased from zero to near 100% with increasing previous chilling accumulation from mid-October until mid-November, indicating that endodormancy was released in almost all of the grafts by mid-November. The days to bud burst, DBB, decreased in the forcing conditions with successively later transfers until the next spring. Neither BB% nor DBB was dependent on the age of the scion. However, in the early phase of ecodormancy release, the microscopic internal development of the buds was more advanced in the grafts representing the 16-year-old than in those representing the 32- or 80-year-old trees. In conclusion, our findings suggest that no major change in the environmental regulation of endodormancy release in Norway spruce takes place when the trees get older. Taken together with earlier findings with Norway spruce seedlings, our results suggest that regardless of the seedling or tree age, the chilling requirement of endodormancy release is met in late autumn. The implications of our findings for Norway spruce phenology under climatic warming and the limitations of our novel method of using grafts as a proxy of trees of different ages are discussed.
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Affiliation(s)
- Jouni Partanen
- Natural Resources Institute Finland (Luke), Juntintie 154, FI-77600 Suonenjoki, Finland
| | - Risto Häkkinen
- Natural Resources Institute Finland (Luke), PO Box: 2, FI-00791 Helsinki, Finland
| | - Sirkka Sutinen
- Natural Resources Institute Finland (Luke), Yliopistokatu 6, FI-80100 Joensuu, Finland
| | - Anneli Viherä-Aarnio
- Natural Resources Institute Finland (Luke), PO Box: 2, FI-00791 Helsinki, Finland
| | - Rui Zhang
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, 666 Wusu Street, Hangzhou 311300, China
| | - Heikki Hänninen
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, 666 Wusu Street, Hangzhou 311300, China
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Piao S, Liu Q, Chen A, Janssens IA, Fu Y, Dai J, Liu L, Lian X, Shen M, Zhu X. Plant phenology and global climate change: Current progresses and challenges. GLOBAL CHANGE BIOLOGY 2019; 25:1922-1940. [PMID: 30884039 DOI: 10.1111/gcb.14619] [Citation(s) in RCA: 365] [Impact Index Per Article: 73.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 02/25/2019] [Indexed: 05/06/2023]
Abstract
Plant phenology, the annually recurring sequence of plant developmental stages, is important for plant functioning and ecosystem services and their biophysical and biogeochemical feedbacks to the climate system. Plant phenology depends on temperature, and the current rapid climate change has revived interest in understanding and modeling the responses of plant phenology to the warming trend and the consequences thereof for ecosystems. Here, we review recent progresses in plant phenology and its interactions with climate change. Focusing on the start (leaf unfolding) and end (leaf coloring) of plant growing seasons, we show that the recent rapid expansion in ground- and remote sensing- based phenology data acquisition has been highly beneficial and has supported major advances in plant phenology research. Studies using multiple data sources and methods generally agree on the trends of advanced leaf unfolding and delayed leaf coloring due to climate change, yet these trends appear to have decelerated or even reversed in recent years. Our understanding of the mechanisms underlying the plant phenology responses to climate warming is still limited. The interactions between multiple drivers complicate the modeling and prediction of plant phenology changes. Furthermore, changes in plant phenology have important implications for ecosystem carbon cycles and ecosystem feedbacks to climate, yet the quantification of such impacts remains challenging. We suggest that future studies should primarily focus on using new observation tools to improve the understanding of tropical plant phenology, on improving process-based phenology modeling, and on the scaling of phenology from species to landscape-level.
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Affiliation(s)
- Shilong Piao
- Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing, China
- Key Laboratory of Alpine Ecology and Biodiversity, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
- Center for Excellence in Tibetan Earth Science, Chinese Academy of Sciences, Beijing, China
| | - Qiang Liu
- Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Anping Chen
- Department of Biology, Colorado State University, Fort Collins, Colorado
| | - Ivan A Janssens
- Department of Biology, University of Antwerp, Wilrijk, Belgium
| | - Yongshuo Fu
- Department of Biology, University of Antwerp, Wilrijk, Belgium
- College of Water Sciences, Beijing Normal University, Beijing, China
| | - Junhu Dai
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Science, Beijing, China
| | - Lingli Liu
- Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Xu Lian
- Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Miaogen Shen
- Key Laboratory of Alpine Ecology and Biodiversity, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
- Center for Excellence in Tibetan Earth Science, Chinese Academy of Sciences, Beijing, China
| | - Xiaolin Zhu
- Department of Land Surveying and Geo-Informatics, The Hong Kong Polytechnic University, Kowloon, Hong Kong
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Carneros E, Yakovlev I, Viejo M, Olsen JE, Fossdal CG. The epigenetic memory of temperature during embryogenesis modifies the expression of bud burst-related genes in Norway spruce epitypes. PLANTA 2017; 246:553-566. [PMID: 28577177 PMCID: PMC5561168 DOI: 10.1007/s00425-017-2713-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 05/23/2017] [Indexed: 05/05/2023]
Abstract
Epigenetic memory affects the timing of bud burst phenology and the expression of bud burst-related genes in genetically identical Norway spruce epitypes in a manner usually associated with ecotypes. In Norway spruce, a temperature-dependent epigenetic memory established during embryogenesis affects the timing of bud burst and bud set in a reproducible and predictable manner. We hypothesize that the clinal variation in these phenological traits, which is associated with adaptation to growth under frost-free conditions, has an epigenetic component. In Norway spruce, dehydrins (DHNs) have been associated with extreme frost tolerance. DHN transcript levels decrease gradually prior to flushing, a time when trees are highly sensitive to frost. Furthermore, EARLY BUD BREAK 1 genes (EBB1) and the FT-TFL1-LIKE 2-gene (PaFTL2) were previously suggested to be implied in control of bud phenology. Here we report an analysis of transcript levels of 12 DHNs, 3 EBB1 genes and FTL2 in epitypes of the same genotype generated at different epitype-inducing temperatures, before and during spring bud burst. Earlier flushing of epitypes originating from embryos developed at 18 °C as compared to 28 °C, was associated with differential expression of these genes between epitypes and between buds and last year's needles. The majority of these genes showed significantly different expressions between epitypes in at least one time point. The general trend in DHN expression pattern in buds showed the expected reduction in transcript levels when approaching flushing, whereas, surprisingly, transcript levels peaked later in needles, mainly at the moment of bud burst. Collectively, our results demonstrate that the epigenetic memory of temperature during embryogenesis affects bud burst phenology and expression of the bud burst-related DHN, EBB1 and FTL2 genes in genetically identical Norway spruce epitypes.
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Affiliation(s)
- Elena Carneros
- Norwegian Institute of Bioeconomy Research, 1431, Ås, Norway
- Department of Life Sciences, University of Alcalá, Ctra. de Barcelona km 33.600, 28805, Alcalá De Henares, Madrid, Spain
| | - Igor Yakovlev
- Norwegian Institute of Bioeconomy Research, 1431, Ås, Norway
| | - Marcos Viejo
- Department of Plant Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, 1432, Ås, Norway
| | - Jorunn E Olsen
- Department of Plant Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, 1432, Ås, Norway
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Schiestl-Aalto P, Mäkelä A. Temperature dependence of needle and shoot elongation before bud break in Scots pine. TREE PHYSIOLOGY 2017; 37:316-325. [PMID: 28008084 DOI: 10.1093/treephys/tpw120] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 12/01/2016] [Indexed: 06/06/2023]
Abstract
Knowledge about the early part of needle growth is deficient compared with what is known about shoot growth. It is however important to understand growth of different organs to be able to estimate the changes in whole tree growth in a changing environment. The onset of growth in spring has been observed to occur over some certain threshold value of momentary temperature or temperature accumulation. We measured the length growth of Scots pine (Pinus sylvestris L.) needles and shoots from March until bud break over 3 years. We first compared needle growth with concurrent shoot growth. Then, we quantified threshold temperature of growth (i) with a logistic regression based on momentary temperatures and (ii) with the temperature sum accumulation method. Temperature sum was calculated with combinations of various time steps, starting dates and threshold temperature values. Needle elongation began almost concurrently with shoot elongation and proceeded linearly in relation to shoot growth until bud break. When studying the threshold temperature for growth, the method with momentary temperature effect on growth onset yielded ambiguous results in our conditions. The best fit of an exponential regression between needle growth or length and temperature sum was obtained with threshold temperatures -1 to +2 °C, with several combinations of starting date and time step. We conclude that although growth onset is a momentary event the process leading to it is a long-term continuum where past time temperatures have to be accounted for, rather than a sudden switch from quiescence to active growth. Further, our results indicate that lower temperatures than the commonly used +5 °C are sufficient for actuating the growth process.
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Affiliation(s)
- Pauliina Schiestl-Aalto
- Department of Forest Sciences, University of Helsinki, P.O. Box 27, FI-00014 Helsinki, Finland
| | - Annikki Mäkelä
- Department of Forest Sciences, University of Helsinki, P.O. Box 27, FI-00014 Helsinki, Finland
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9
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Viherä-Aarnio A, Sutinen S, Partanen J, Häkkinen R. Internal development of vegetative buds of Norway spruce trees in relation to accumulated chilling and forcing temperatures. TREE PHYSIOLOGY 2014; 34:547-56. [PMID: 24876293 DOI: 10.1093/treephys/tpu038] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The timing of budburst of temperate trees is known to be controlled by complicated interactions of temperature and photoperiod. To improve the phenological models of budburst, better knowledge of the internal bud development preceding budburst in relation to environmental cues is needed. We studied the effect of accumulated chilling and forcing temperatures on the internal development of vegetative buds preceding budburst in Norway spruce [Picea abies (L.) Karst.]. Branches from 17-year-old trees of southern Finnish origin were transferred eight times at 1- to 2-week intervals from October to December 2007 from the field at Punkaharju (61°48'N, 29°20'E) to the greenhouse with forcing conditions (day length 12 h, +20 °C). After seven different durations of forcing, the developmental phase and primordial shoot growth of the buds were analysed at the stereomicroscopic level. Air temperature was recorded hourly throughout the study period. The accumulated chilling unit sum had a significant effect on the temperature sum that was required to attain a certain developmental phase; a higher amount of chilling required a lower amount of forcing. The variation in the rate of development of different buds within each sample branch in relation to the chilling unit and forcing temperature sum was low. Regarding primordial shoot growth, there was also an inverse relation between accumulated chilling and forcing, i.e., a higher accumulated chilling unit sum before forcing required a lower temperature sum to initiate primordial shoot growth and resulted in a stronger effect of accumulated forcing. A second-order regression model with an interaction of chilling and forcing explained the variation of primordial shoot growth with high precision (R(2) = 0.88). However, further studies are required to determine the final parameter values to be used in phenological modelling.
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Affiliation(s)
- Anneli Viherä-Aarnio
- Finnish Forest Research Institute, Vantaa Research Unit, PO Box 18, FI-01301 Vantaa, Finland
| | - Sirkka Sutinen
- Finnish Forest Research Institute, Joensuu Research Unit, PO Box 68, FI-80101 Joensuu, Finland
| | - Jouni Partanen
- Finnish Forest Research Institute, Suonenjoki Research Unit, Juntintie 154, FI-77600 Suonenjoki, Finland
| | - Risto Häkkinen
- Finnish Forest Research Institute, Vantaa Research Unit, PO Box 18, FI-01301 Vantaa, Finland
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10
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Basler D, Körner C. Photoperiod and temperature responses of bud swelling and bud burst in four temperate forest tree species. TREE PHYSIOLOGY 2014; 34:377-88. [PMID: 24713858 DOI: 10.1093/treephys/tpu021] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Spring phenology of temperate forest trees is optimized to maximize the length of the growing season while minimizing the risk of freezing damage. The release from winter dormancy is environmentally mediated by species-specific responses to temperature and photoperiod. We investigated the response of early spring phenology to temperature and photoperiod at different stages of dormancy release in cuttings from four temperate tree species in controlled environments. By tracking bud development, we were able to identify the onset of bud swelling and bud growth in Acer pseudoplatanus L., Fagus sylvatica L., Quercus petraea (Mattuschka) Liebl. and Picea abies (L.) H. Karst. At a given early stage of dormancy release, the onset and duration of the bud swelling prior to bud burst are driven by concurrent temperature and photoperiod, while the maximum growth rate is temperature dependent only, except for Fagus, where long photoperiods also increased bud growth rates. Similarly, the later bud burst was controlled by temperature and photoperiod (in the photoperiod sensitive species Fagus, Quercus and Picea). We conclude that photoperiod is involved in the release of dormancy during the ecodormancy phase and may influence bud burst in trees that have experienced sufficient chilling. This study explored and documented the early bud swelling period that precedes and defines later phenological stages such as canopy greening in conventional phenological works. It is the early bud growth resumption that needs to be understood in order to arrive at a causal interpretation and modelling of tree phenology at a large scale. Classic spring phenology events mark visible endpoints of a cascade of processes as evidenced here.
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Affiliation(s)
- David Basler
- Institute of Botany, University of Basel, Schönbeinstrasse 6, CH-4056 Basel, Switzerland
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11
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Sutinen S, Partanen J, Viherä-Aarnio A, Häkkinen R. Development and growth of primordial shoots in Norway spruce buds before visible bud burst in relation to time and temperature in the field. TREE PHYSIOLOGY 2012; 32:987-97. [PMID: 22874832 DOI: 10.1093/treephys/tps063] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The timing of bud development in ecodormancy is critical for trees in boreal and temperate regions with seasonally alternating climates. The development of vegetative buds and the growth of primordial shoots (the primordial shoot ratio) in Norway spruce were followed by the naked eye and at stereo and light microscopic levels in fresh-cut and fixed buds obtained by regular field samplings during the spring of 2007, 2008 and 2009. Buds were collected from 15 randomly selected trees (all 16 years old in 2007) of one southern Finnish half-sib family. The air temperature was recorded hourly throughout the observation period. In 2008 and 2009, initial events in the buds, seen as accumulation of lipid droplets in the cortex area, started in mid-March and were depleted in late April, simultaneously with the early development of vascular tissue and primordial needles. In mid-April 2007, however, the development of the buds was at least 10 days ahead as a result of warm spells in March and early April. Variation in the timing of different developmental phases within and among the sample trees was negligible. There was no clear one-to-one correspondence between the externally visible and the internal development of the buds. The dependence of the primordial shoot ratio on different types of temperature sum was studied by means of regression analysis. High coefficients of determination (R(2) ≈ 95%) were attained with several combinations of the starting time (beginning of the year/vernal equinox), the threshold value (from -3 to +5 °C), and the time step (hour/day) used in the temperature summation, i.e., the prediction power of the primordial shoot ratio models turned out to be high, but the parameter estimate values were not unambiguous. According to our results, temperature sums describe the growth of the primordial shoot inside the bud before bud burst. Thus, the results provide a realistic interpretation for the present phenological models of bud development that are based on temperature sums and external observations of bud burst only, and they also provide new tools for improving the models.
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Affiliation(s)
- Sirkka Sutinen
- Finnish Forest Research Institute, Joensuu Research Unit, PO Box 68, FI-80101 Joensuu, Finland.
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