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O'Connell BP, Wiley E. Heatwaves do not limit recovery following defoliation but alter leaf drought tolerance traits. PLANT, CELL & ENVIRONMENT 2024; 47:482-496. [PMID: 37877185 DOI: 10.1111/pce.14750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 09/20/2023] [Accepted: 10/16/2023] [Indexed: 10/26/2023]
Abstract
As heatwave frequency increases, they are more likely to coincide with other disturbances like insect defoliation. But it is unclear if high temperatures after defoliation impact canopy recovery or leaf traits which may affect response to further stressors like drought. To examine these stressor interactions, we subjected defoliated (DEF) and undefoliated (UNDEF) oak saplings to a simulated spring heatwave of +10°C for 25 days. We measured gas exchange, leaf area recovery, carbohydrate storage, turgor loss point (ΨTLP ), and minimum leaf conductance (gmin ). During the heatwave, stem respiration exhibited stronger thermal acclimation in DEF than UNDEF saplings, while stomatal conductance and net photosynthesis increased. The heatwave did not affect leaf area recovery or carbohydrate storage of DEF saplings, but reflush leaves had higher gmin than UNDEF leaves, and this was amplified by the heatwave. Across all treatments, higher gmin was associated with higher daytime stomatal conductance and a lower ΨTLP . The results suggest defoliation stress may not be exacerbated by higher temperatures. However, reflush leaves are less conservative in their water use, limiting their ability to minimise water loss. While lower ΨTLP could help DEF trees maintain gas exchange under mild drought, they may be more vulnerable to dehydration under severe drought.
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Affiliation(s)
| | - Erin Wiley
- Department of Biology, University of Central Arkansas, Conway, Arkansas, USA
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Hart AT, Landhäusser SM, Wiley E. Tracing carbon and nitrogen reserve remobilization during spring leaf flush and growth following defoliation. TREE PHYSIOLOGY 2024:tpae015. [PMID: 38281259 DOI: 10.1093/treephys/tpae015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2024]
Abstract
Woody plants rely on the remobilization of carbon (C) and nitrogen (N) reserves to support growth and survival when resource demand exceeds supply at seasonally predictable times like spring leaf flush and following unpredictable disturbances like defoliation. However, we have a poor understanding of how reserves are regulated and whether distance between source and sink tissues affects remobilization. This leads to uncertainty about which reserves-and how much-are available to support plant functions like leaf growth. To better understand the source of remobilized reserves and constraints on their allocation, we created aspen saplings with organ-specific labeled reserves by using stable isotopes (13C,15N) and grafting unlabeled or labeled stems to labeled or unlabeled root stocks. We first determined which organs had imported root or stem-derived C and N reserves after spring leaf flush. We then further tested spatial and temporal variation in reserve remobilization and import by comparing 1) upper and lower canopy leaves, 2) early and late leaves, and 3) early flush and re-flush leaves after defoliation. During spring flush, remobilized root C and N reserves were preferentially allocated to sinks closer to the reserve source (i.e., lower vs upper canopy leaves). However, the reduced import of 13C in late versus early leaves indicates reliance on C reserves declined over time. Following defoliation, re-flush leaves imported the same proportion of root N as spring flush leaves, but they imported a lower proportion of root C. This lower import of reserve C suggests that, after defoliation, leaf re-flush rely more heavily on current photosynthate, which may explain the reduced leaf mass recovery of re-flush canopies (31% of initial leaf mass). The reduced reliance on reserves occurred even though roots retained significant starch concentrations (~5% dry wt), suggesting aspen prioritizes the maintenance of root reserves at the expense of fast canopy recovery.
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Affiliation(s)
- Ashley T Hart
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada
| | - Simon M Landhäusser
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada
| | - Erin Wiley
- Department of Biology, University of Central Arkansas, Conway, Arkansas, USA
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Gaytán Á, Abdelfattah A, Faticov M, Moreira X, Castagneyrol B, Van Halder I, De Frenne P, Meeussen C, Timmermans BGH, Ten Hoopen JPJG, Rasmussen PU, Bos N, Jaatinen R, Pulkkinen P, Söderlund S, Gotthard K, Pawlowski K, Tack AJM. Changes in the foliar fungal community between oak leaf flushes along a latitudinal gradient in Europe. JOURNAL OF BIOGEOGRAPHY 2022; 49:2269-2280. [PMID: 36636040 PMCID: PMC9828548 DOI: 10.1111/jbi.14508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 08/19/2022] [Accepted: 09/07/2022] [Indexed: 06/17/2023]
Abstract
AIM Leaves support a large diversity of fungi, which are known to cause plant diseases, induce plant defences or influence leaf senescence and decomposition. To advance our understanding of how foliar fungal communities are structured and assembled, we assessed to what extent leaf flush and latitude can explain the within- and among-tree variation in foliar fungal communities. LOCATION A latitudinal gradient spanning c. 20 degrees in latitude in Europe. TAXA The foliar fungal community associated with a foundation tree species, the pedunculate oak Quercus robur. METHODS We examined the main and interactive effects of leaf flush and latitude on the foliar fungal community by sampling 20 populations of the pedunculate oak Quercus robur across the tree's range. We used the ITS region as a target for characterization of fungal communities using DNA metabarcoding. RESULTS Species composition, but not species richness, differed between leaf flushes. Across the latitudinal gradient, species richness was highest in the central part of the oak's distributional range, and foliar fungal community composition shifted along the latitudinal gradient. Among fungal guilds, the relative abundance of plant pathogens and mycoparasites was lower on the first leaf flush, and the relative abundance of plant pathogens and saprotrophs decreased with latitude. CONCLUSIONS Changes in community composition between leaf flushes and along the latitudinal gradient were mostly a result of species turnover. Overall, our findings demonstrate that leaf flush and latitude explain 5%-22% of the small- and large-scale spatial variation in the foliar fungal community on a foundation tree within the temperate region. Using space-for-time substitution, we expect that foliar fungal community structure will change with climate warming, with an increase in the abundance of plant pathogens and mycoparasites at higher latitudes, with major consequences for plant health, species interactions and ecosystem dynamics.
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Affiliation(s)
- Álvaro Gaytán
- Department of Ecology, Environment and Plant SciencesStockholm UniversityStockholmSweden
- Bolin Center for Climate ResearchStockholm UniversityStockholmSweden
| | - Ahmed Abdelfattah
- Leibniz Institute for Agricultural Engineering and Bioeconomy (ATB)PotsdamGermany
| | - Maria Faticov
- Department of BiologySherbrooke UniversitySherbrookeQuebecCanada
| | | | | | | | | | | | | | | | - Pil U. Rasmussen
- The National Research Centre for the Working EnvironmentCopenhagenDenmark
| | - Nick Bos
- Section for Ecology and EvolutionUniversity of CopenhagenCopenhagenDenmark
| | - Raimo Jaatinen
- Natural Resources Institute Finland, Haapastensyrjä Breeding StationLäyliäinenFinland
| | - Pertti Pulkkinen
- Natural Resources Institute Finland, Haapastensyrjä Breeding StationLäyliäinenFinland
| | - Sara Söderlund
- Department of Ecology, Environment and Plant SciencesStockholm UniversityStockholmSweden
| | - Karl Gotthard
- Bolin Center for Climate ResearchStockholm UniversityStockholmSweden
- Department of ZoologyStockholm UniversityStockholmSweden
| | - Katharina Pawlowski
- Department of Ecology, Environment and Plant SciencesStockholm UniversityStockholmSweden
| | - Ayco J. M. Tack
- Department of Ecology, Environment and Plant SciencesStockholm UniversityStockholmSweden
- Bolin Center for Climate ResearchStockholm UniversityStockholmSweden
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Gaytán Á, Moreira X, Castagneyrol B, Van Halder I, De Frenne P, Meeussen C, Timmermans BGH, Ten Hoopen JPJG, Rasmussen PU, Bos N, Jaatinen R, Pulkkinen P, Söderlund S, Covelo F, Gotthard K, Tack AJM. The co-existence of multiple oak leaf flushes contributes to the large within-tree variation in chemistry, insect attack and pathogen infection. THE NEW PHYTOLOGIST 2022; 235:1615-1628. [PMID: 35514157 PMCID: PMC9545873 DOI: 10.1111/nph.18209] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 05/03/2022] [Indexed: 06/14/2023]
Abstract
Many plant species produce multiple leaf flushes during the growing season, which might have major consequences for within-plant variation in chemistry and species interactions. Yet, we lack a theoretical or empirical framework for how differences among leaf flushes might shape variation in damage by insects and diseases. We assessed the impact of leaf flush identity on leaf chemistry, insect attack and pathogen infection on the pedunculate oak Quercus robur by sampling leaves from each leaf flush in 20 populations across seven European countries during an entire growing season. The first leaf flush had higher levels of primary compounds, and lower levels of secondary compounds, than the second flush, whereas plant chemistry was highly variable in the third flush. Insect attack decreased from the first to the third flush, whereas infection by oak powdery mildew was lowest on leaves from the first flush. The relationship between plant chemistry, insect attack and pathogen infection varied strongly among leaf flushes and seasons. Our findings demonstrate the importance of considering differences among leaf flushes for our understanding of within-tree variation in chemistry, insect attack and disease levels, something particularly relevant given the expected increase in the number of leaf flushes with climate change.
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Affiliation(s)
- Álvaro Gaytán
- Department of Ecology, Environment and Plant SciencesStockholm UniversitySvante Arrhenius väg 20AStockholmSweden
| | - Xoaquín Moreira
- Misión Biológica de Galicia (MBG‐CSIC)Apdo. 2836080Pontevedra, GaliciaSpain
| | | | | | - Pieter De Frenne
- Forest & Nature LaboratoryGhent UniversityGeraardsbergsesteenweg 267BE‐9090Gontrode‐MelleBelgium
| | - Camille Meeussen
- Forest & Nature LaboratoryGhent UniversityGeraardsbergsesteenweg 267BE‐9090Gontrode‐MelleBelgium
| | - Bart G. H. Timmermans
- Department of AgricultureLouis Bolk InstituteKosterijland 3‐53981 AJBunnikthe Netherlands
| | | | - Pil U. Rasmussen
- The National Research Centre for the Working Environment2100CopenhagenDenmark
| | - Nick Bos
- Section for Ecology & EvolutionUniversity of Copenhagen2200CopenhagenDenmark
| | - Raimo Jaatinen
- Natural Resources Institute Finland, Haapastensyrjä Breeding StationFI‐16200LäyliäinenFinland
| | - Pertti Pulkkinen
- Natural Resources Institute Finland, Haapastensyrjä Breeding StationFI‐16200LäyliäinenFinland
| | - Sara Söderlund
- Department of Ecology, Environment and Plant SciencesStockholm UniversitySvante Arrhenius väg 20AStockholmSweden
| | - Felisa Covelo
- Departamento de Sistemas FísicosQuímicos y NaturalesUniversidad Pablo de OlavideCarretera de Utrera km. 141013SevilleSpain
| | - Karl Gotthard
- Department of ZoologyStockholm UniversitySvante Arrhenius väg 18BSE‐106 91StockholmSweden
| | - Ayco J. M. Tack
- Department of Ecology, Environment and Plant SciencesStockholm UniversitySvante Arrhenius väg 20AStockholmSweden
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Löiez S, Piper FI. Phenology explains different storage remobilization in two congeneric temperate tree species with contrasting leaf habit. TREE PHYSIOLOGY 2022; 42:501-512. [PMID: 34542156 DOI: 10.1093/treephys/tpab124] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 08/02/2021] [Accepted: 09/08/2021] [Indexed: 06/13/2023]
Abstract
The dependence of trees on carbon and nutrient storage is critical to predicting the forest vulnerability under climate change, but whether evergreen and deciduous species differ in their use and allocation of stored resources during spring phenology is unclear. Using a high temporal resolution, we evaluated the role of spring phenology and shoot growth as determinants of the carbon and nutrient storage dynamics in contrasting leaf habits. We recorded the phenology and shoot elongation and determined the concentrations of total non-structural carbohydrates (NSCs), starch, soluble carbohydrates, nitrogen (N) and phosphorus (P) in buds, expanding shoots and previously formed shoots of two sympatric Nothofagus species with contrasting leaf habit. Species reached similar shoot lengths, though shoot expansion started 35 days earlier and lasted c. 40 days more in the deciduous species. Thus, although the deciduous species had a relatively constant shoot growth rate, the evergreen species experienced a conspicuous growth peak for c. 20 days. In the evergreen species, the greatest decreases in NSC concentrations of previously formed shoots and leaves coincided with the maximum shoot expansion rate and fruit filling, with minimums of 63 and 65% relative to values at bud dormancy, respectively. In contrast, minimum NSC concentrations of the previously formed shoots of the deciduous species were only 73% and occurred prior to the initiation of shoot expansion. Bud N and P concentrations increased during budbreak, whereas previously formed shoots generally did not decrease their nutrient concentrations. Late spring phenology and overlapping of phenophases contributed to the greater dependence on storage of proximal tissues in the studied evergreen compared with deciduous species, suggesting that phenology is a key determinant of the contrasting patterns of storage use in evergreen and deciduous species.
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Affiliation(s)
- Sidonie Löiez
- Agrocampus Ouest, 65, rue de Saint-Brieuc, CS 84215, Rennes Cedex 35042, France
| | - Frida I Piper
- Instituto de Investigación Interdisciplinario (I3), Universidad de Talca, Campus Lircay, Talca 3460000, Chile
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Palacio S, Paterson E, Hester AJ, Nogués S, Lino G, Anadon-Rosell A, Maestro M, Millard P. No preferential carbon-allocation to storage over growth in clipped birch and oak saplings. TREE PHYSIOLOGY 2020; 40:621-636. [PMID: 32050021 PMCID: PMC7201831 DOI: 10.1093/treephys/tpaa011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 01/21/2020] [Accepted: 01/23/2020] [Indexed: 06/10/2023]
Abstract
Herbivory is one of the most globally distributed disturbances affecting carbon (C)-cycling in trees, yet our understanding of how it alters tree C-allocation to different functions such as storage, growth or rhizodeposition is still limited. Prioritized C-allocation to storage replenishment vs growth could explain the fast recovery of C-storage pools frequently observed in growth-reduced defoliated trees. We performed continuous 13C-labeling coupled to clipping to quantify the effects of simulated browsing on the growth, leaf morphology and relative allocation of stored vs recently assimilated C to the growth (bulk biomass) and non-structural carbohydrate (NSC) stores (soluble sugars and starch) of the different organs of two tree species: diffuse-porous (Betula pubescens Ehrh.) and ring-porous (Quercus petraea [Matt.] Liebl.). Carbon-transfers from plants to bulk and rhizosphere soil were also evaluated. Clipped birch and oak trees shifted their C-allocation patterns above-ground as a means to recover from defoliation. However, such increased allocation to current-year stems and leaves did not entail reductions in the allocation to the rhizosphere, which remained unchanged between clipped and control trees of both species. Betula pubescens and Q. petraea showed differences in their vulnerability and recovery strategies to clipping, the ring-porous species being less affected in terms of growth and architecture by clipping than the diffuse-porous. These contrasting patterns could be partly explained by differences in their C cycling after clipping. Defoliated oaks showed a faster recovery of their canopy biomass, which was supported by increased allocation of new C, but associated with large decreases in their fine root biomass. Following clipping, both species recovered NSC pools to a larger extent than growth, but the allocation of 13C-labeled photo-assimilates into storage compounds was not increased as compared with controls. Despite their different response to clipping, our results indicate no preventative allocation into storage occurred during the first year after clipping in either of the species.
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Affiliation(s)
- Sara Palacio
- Instituto Pirenaico de Ecología (IPE-CSIC), Av. Nuestra Señora de la Victoria, 16, Jaca, Huesca 22700, Spain
- James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH, UK
| | - Eric Paterson
- James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH, UK
| | - Alison J Hester
- James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH, UK
| | - Salvador Nogués
- Facultat de Biologia, Universitat de Barcelona, Av. Diagonal 643, Barcelona 08028, Spain
| | - Gladys Lino
- Facultat de Biologia, Universitat de Barcelona, Av. Diagonal 643, Barcelona 08028, Spain
- Facultad de Ciencias Ambientales, Universidad Científica del Sur, Panamericana Sur km 19, Villa El Salvador 15067, Lima, Peru
| | - Alba Anadon-Rosell
- Facultat de Biologia, Universitat de Barcelona, Av. Diagonal 643, Barcelona 08028, Spain
- Institute of Botany and Landscape Ecology, University of Greifswald, Soldmanstraße 15, Greifswald 17487, Germany
| | - Melchor Maestro
- Instituto Pirenaico de Ecología (IPE-CSIC), Av. Montañana, 1005, Zaragoza 50059, Spain
| | - Peter Millard
- Manaaki Whenua Landcare Research, PO Box 69040, Lincoln 7640, New Zealand
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7
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Piper FI. Decoupling between growth rate and storage remobilization in broadleaf temperate tree species. Funct Ecol 2020. [DOI: 10.1111/1365-2435.13552] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Frida I. Piper
- Centro de Investigación en Ecosistemas de la Patagonia (CIEP) Coyhaique Chile
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