1
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Yebra M, Scortechini G, Adeline K, Aktepe N, Almoustafa T, Bar-Massada A, Beget ME, Boer M, Bradstock R, Brown T, Castro FX, Chen R, Chuvieco E, Danson M, Değirmenci CÜ, Delgado-Dávila R, Dennison P, Di Bella C, Domenech O, Féret JB, Forsyth G, Gabriel E, Gagkas Z, Gharbi F, Granda E, Griebel A, He B, Jolly M, Kotzur I, Kraaij T, Kristina A, Kütküt P, Limousin JM, Martín MP, Monteiro AT, Morais M, Moreira B, Mouillot F, Msweli S, Nolan RH, Pellizzaro G, Qi Y, Quan X, Resco de Dios V, Roberts D, Tavşanoğlu Ç, Taylor AFS, Taylor J, Tüfekcioğlu İ, Ventura A, Younes Cardenas N. Globe-LFMC 2.0, an enhanced and updated dataset for live fuel moisture content research. Sci Data 2024; 11:332. [PMID: 38575621 PMCID: PMC10995118 DOI: 10.1038/s41597-024-03159-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 03/18/2024] [Indexed: 04/06/2024] Open
Abstract
Globe-LFMC 2.0, an updated version of Globe-LFMC, is a comprehensive dataset of over 280,000 Live Fuel Moisture Content (LFMC) measurements. These measurements were gathered through field campaigns conducted in 15 countries spanning 47 years. In contrast to its prior version, Globe-LFMC 2.0 incorporates over 120,000 additional data entries, introduces more than 800 new sampling sites, and comprises LFMC values obtained from samples collected until the calendar year 2023. Each entry within the dataset provides essential information, including date, geographical coordinates, plant species, functional type, and, where available, topographical details. Moreover, the dataset encompasses insights into the sampling and weighing procedures, as well as information about land cover type and meteorological conditions at the time and location of each sampling event. Globe-LFMC 2.0 can facilitate advanced LFMC research, supporting studies on wildfire behaviour, physiological traits, ecological dynamics, and land surface modelling, whether remote sensing-based or otherwise. This dataset represents a valuable resource for researchers exploring the diverse LFMC aspects, contributing to the broader field of environmental and ecological research.
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Affiliation(s)
- Marta Yebra
- Fenner School of Environment & Society, Australian National University, Canberra, ACT, Australia.
- School of Engineering, Australian National University, Canberra, ACT, Australia.
| | - Gianluca Scortechini
- Fenner School of Environment & Society, Australian National University, Canberra, ACT, Australia
| | - Karine Adeline
- ONERA / DOTA, Université de Toulouse, F-31055, Toulouse, France
| | - Nursema Aktepe
- Department of Biology, Kastamonu University, Kastamonu, Türkiye
| | - Turkia Almoustafa
- School of Environment and Life Sciences, University of Salford, Salford, UK
- Faculty of Arts and Humanities, Geography Department, Tishreen University, Tishreen, Syria
| | - Avi Bar-Massada
- Department of Biology and Environment, University of Haifa at Oranim, Kiryat Tivon, 36066, Israel
| | | | - Matthias Boer
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | | | - Tegan Brown
- US Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, 5775 Highway 10 West, Missoula, 59803, MT, USA
| | - Francesc Xavier Castro
- Servei de Prevenció d'Incendis Forestals (Generalitat de Catalunya), Santa Perpètua de Mogoda, Barcelona, Spain
| | - Rui Chen
- School of Resources and Environment, University of Electronic Science and Technology of China, Sichuan, China
| | - Emilio Chuvieco
- Department of Geology, Geography and the Environment, University of Alcalá, Colegios 2, 28801, Alcalá de Henares, Spain
| | - Mark Danson
- School of Environment and Life Sciences, University of Salford, Salford, UK
| | - Cihan Ünal Değirmenci
- Division of Ecology, Department of Biology, Hacettepe University, Beytepe, Ankara, Türkiye
| | - Ruth Delgado-Dávila
- Joint Research Unit CTFC - AGROTECNIO, Crta. de St. Llorenç de Morunys, km 2, E, 25280, Solsona, Spain
- Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel
| | - Philip Dennison
- Department of Geography, University of Utah, Salt Lake City, Utah, USA
| | - Carlos Di Bella
- IFEVA-CONICET, Faculty of Agronomy, University of Buenos Aires, Buenos Aires, Argentina
| | - Oriol Domenech
- Centre Forestal de les Illes Balears (CEFOR-Menut), Forest Management Service (Government of the Balearic Islands), Palma de Mallorca, Spain
| | | | | | - Eva Gabriel
- Servei de Prevenció d'Incendis Forestals (Generalitat de Catalunya), Santa Perpètua de Mogoda, Barcelona, Spain
| | - Zisis Gagkas
- Environmental and Biochemical Sciences Department, The James Hutton Institute, Aberdeen, UK
| | - Fatma Gharbi
- Faculty of Sciences of Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Elena Granda
- Departamento de Ciencias de la Vida, Universidad de Alcalá, Alcalá de Henares, Spain
| | - Anne Griebel
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
- School of Life Sciences, University of Technology Sydney, PO Box 123 Broadway, Ultimo, NSW, 2007, Australia
| | - Binbin He
- School of Resources and Environment, University of Electronic Science and Technology of China, Sichuan, China
| | - Matt Jolly
- RMRS, Missoula Fire Sciences Laboratory, USFS, Rocky Mountain Research Station, 5775 Hwy 10 W Missoula, Missoula, MT, 59808, USA
| | - Ivan Kotzur
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Tineke Kraaij
- Nelson Mandela University, School of Natural Resource Management, George, South Africa
| | | | - Pınar Kütküt
- Division of Ecology, Department of Biology, Hacettepe University, Beytepe, Ankara, Türkiye
| | | | - M Pilar Martín
- Environmental Remote Sensing and Spectroscopy Laboratory (SpecLab), IEGD, Spanish National Research Council (CSIC), Madrid, Spain
| | - Antonio T Monteiro
- Centro de Estudos Geográficos (CEG) and Laboratório Associado TERRA, Instituto de Geografia e Ordenamento do Território (IGOT), Universidade de Lisboa, Rua Edmée Marques, 1600-276, Lisboa, Portugal
- Istituto di Geoscienze e Georisorse, Consiglio Nazionale delle Ricerche (CNR-IGG), Via Moruzzi 2, 56124, Pisa, Italy
| | - Marco Morais
- Department of Geography, University of California, Santa Barbara, USA
| | - Bruno Moreira
- Department of Ecology and Global Change. Centro de Investigaciones sobre Desertificación (CIDE-CSIC/UV/GV). Carretera Moncada-Náquera km 4, 5 s/n, E-46113, Moncada, Valencia, Spain
| | - Florent Mouillot
- IRD, CEFE/CNRS, 1919 Route de Mende, 34293, Montpellier, Cedex 5, France
| | - Samukelisiwe Msweli
- Natural Resource Science and Management Cluster, Nelson Mandela University, George, South Africa
| | - Rachael H Nolan
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Grazia Pellizzaro
- Istituto per la Bioeconomia, Consiglio Nazionale delle Ricerche, (CNR-IBE), Traversa La Crucca 3, 07100, Sassari, Italy
| | - Yi Qi
- University of Nebraska-Lincoln, Lincoln, Nebraska, USA
- University of Southern California, Los Angeles, California, USA
| | - Xingwen Quan
- School of Resources and Environment, University of Electronic Science and Technology of China, Sichuan, China
| | | | - Dar Roberts
- Department of Geography, University of California, Santa Barbara, USA
| | - Çağatay Tavşanoğlu
- Division of Ecology, Department of Biology, Hacettepe University, Beytepe, Ankara, Türkiye
| | - Andy F S Taylor
- Ecological Sciences Department. The James Hutton Institute, Aberdeen, UK
| | - Jackson Taylor
- Fenner School of Environment & Society, Australian National University, Canberra, ACT, Australia
| | - İrem Tüfekcioğlu
- Division of Ecology, Department of Biology, Hacettepe University, Beytepe, Ankara, Türkiye
| | - Andrea Ventura
- Istituto per la Bioeconomia, Consiglio Nazionale delle Ricerche, (CNR-IBE), Traversa La Crucca 3, 07100, Sassari, Italy
| | - Nicolas Younes Cardenas
- Fenner School of Environment & Society, Australian National University, Canberra, ACT, Australia
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2
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Cunningham CX, Williamson GJ, Nolan RH, Teckentrup L, Boer MM, Bowman DMJS. Pyrogeography in flux: Reorganization of Australian fire regimes in a hotter world. Glob Chang Biol 2024; 30:e17130. [PMID: 38273509 DOI: 10.1111/gcb.17130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 11/16/2023] [Accepted: 12/12/2023] [Indexed: 01/27/2024]
Abstract
Changes to the spatiotemporal patterns of wildfire are having profound implications for ecosystems and society globally, but we have limited understanding of the extent to which fire regimes will reorganize in a warming world. While predicting regime shifts remains challenging because of complex climate-vegetation-fire feedbacks, understanding the climate niches of fire regimes provides a simple way to identify locations most at risk of regime change. Using globally available satellite datasets, we constructed 14 metrics describing the spatiotemporal dimensions of fire and then delineated Australia's pyroregions-the geographic area encapsulating a broad fire regime. Cluster analysis revealed 18 pyroregions, notably including the (1) high-intensity, infrequent fires of the temperate forests, (2) high-frequency, smaller fires of the tropical savanna, and (3) low-intensity, diurnal, human-engineered fires of the agricultural zones. To inform the risk of regime shifts, we identified locations where the climate under three CMIP6 scenarios is projected to shift (i) beyond each pyroregion's historical climate niche, and (ii) into climate space that is novel to the Australian continent. Under middle-of-the-road climate projections (SSP2-4.5), an average of 65% of the extent of the pyroregions occurred beyond their historical climate niches by 2081-2100. Further, 52% of pyroregion extents, on average, were projected to occur in climate space without present-day analogues on the Australian continent, implying high risk of shifting to states that also lack present-day counterparts. Pyroregions in tropical and hot-arid climates were most at risk of shifting into both locally and continentally novel climate space because (i) their niches are narrower than southern temperate pyroregions, and (ii) their already-hot climates lead to earlier departure from present-day climate space. Such a shift implies widespread risk of regime shifts and the emergence of no-analogue fire regimes. Our approach can be applied to other regions to assess vulnerability to rapid fire regime change.
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Affiliation(s)
- Calum X Cunningham
- Fire Centre, School of Natural Sciences, University of Tasmania, Hobart, Tasmania, Australia
| | - Grant J Williamson
- Fire Centre, School of Natural Sciences, University of Tasmania, Hobart, Tasmania, Australia
| | - Rachael H Nolan
- Hawkesbury Institute for the Environment, Western Sydney University, Sydney, New South Wales, Australia
| | - Lina Teckentrup
- Hawkesbury Institute for the Environment, Western Sydney University, Sydney, New South Wales, Australia
- ARC Centre of Excellence for Climate Extremes, Sydney, New South Wales, Australia
| | - Matthias M Boer
- Hawkesbury Institute for the Environment, Western Sydney University, Sydney, New South Wales, Australia
| | - David M J S Bowman
- Fire Centre, School of Natural Sciences, University of Tasmania, Hobart, Tasmania, Australia
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3
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Collins L, Trouvé R, Baker PJ, Cirulus B, Nitschke CR, Nolan RH, Smith L, Penman TD. Fuel reduction burning reduces wildfire severity during extreme fire events in south-eastern Australia. J Environ Manage 2023; 343:118171. [PMID: 37245307 DOI: 10.1016/j.jenvman.2023.118171] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 05/10/2023] [Accepted: 05/12/2023] [Indexed: 05/30/2023]
Abstract
Extreme fire events have increased across south-eastern Australia owing to warmer and drier conditions driven by anthropogenic climate change. Fuel reduction burning is widely applied to reduce the occurrence and severity of wildfires; however, targeted assessment of the effectiveness of this practice is limited, especially under extreme climatic conditions. Our study utilises fire severity atlases for fuel reduction burns and wildfires to examine: (i) patterns in the extent of fuel treatment within planned burns (i.e., burn coverage) across different fire management zones, and; (ii) the effect of fuel reduction burning on the severity of wildfires under extreme climatic conditions. We assessed the effect of fuel reduction burning on wildfire severity across temporal and spatial scales (i.e., point and local landscape), while accounting for burn coverage and fire weather. Fuel reduction burn coverage was substantially lower (∼20-30%) than desired targets in fuel management zones focused on asset protection, but within the desired range in zones that focus on ecological objectives. At the point scale, wildfire severity was moderated in treated areas for at least 2-3 years after fuel treatment in shrubland and 3-5 years in forests, relative to areas that did not receive fuel reduction treatments (i.e., unburnt patches). Fuel availability strongly limited fire occurrence and severity within the first 18 months of fuel reduction burning, irrespective of fire weather. Fire weather was the dominant driver of high severity canopy defoliating fire by ∼3-5 years after fuel treatment. At the local landscape scale (i.e., 250 ha), the extent of high canopy scorch decreased marginally as the extent of recently (<5 years) treated fuels increased, though there was a high level of uncertainty around the effect of recent fuel treatment. Our findings demonstrate that during extreme fire events, very recent (i.e., <3 years) fuel reduction burning can aid wildfire suppression locally (i.e., near assets) but will have a highly variable effect on the extent and severity of wildfires at larger scales. The patchy coverage of fuel reduction burns in the wildland-urban interface indicates that considerable residual fuel hazard will often be present within the bounds of fuel reduction burns.
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Affiliation(s)
- L Collins
- Pacific Forestry Centre, Canadian Forest Service, Natural Resources Canada, 506 Burnside Road West, Victoria, BC, V8Z 1M5, Canada; Department of Environment and Genetics, La Trobe University, Bundoora, Victoria, 3086, Australia.
| | - R Trouvé
- School of Ecosystem and Forest Sciences, University of Melbourne, Parkville, Victoria, 3010, Australia
| | - P J Baker
- School of Ecosystem and Forest Sciences, University of Melbourne, Parkville, Victoria, 3010, Australia
| | - B Cirulus
- School of Ecosystem and Forest Sciences, University of Melbourne, Creswick, Victoria, 3363, Australia
| | - C R Nitschke
- School of Ecosystem and Forest Sciences, University of Melbourne, Parkville, Victoria, 3010, Australia
| | - R H Nolan
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, 2751, Australia; NSW Bushfire Risk Management Research Hub, Wollongong, New South Wales, Australia
| | - L Smith
- Forest Fire and Regions, Department of Energy, Environment and Climate Action, 1 Licola Rd, Heyfield, Victoria, 3858, Australia
| | - T D Penman
- School of Ecosystem and Forest Sciences, University of Melbourne, Creswick, Victoria, 3363, Australia
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4
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Khanal S, Nolan RH, Medlyn BE, Boer MM. Mapping soil organic carbon stocks in Nepal's forests. Sci Rep 2023; 13:8090. [PMID: 37208346 PMCID: PMC10199042 DOI: 10.1038/s41598-023-34247-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 04/26/2023] [Indexed: 05/21/2023] Open
Abstract
Comprehensive forest carbon accounting requires reliable estimation of soil organic carbon (SOC) stocks. Despite being an important carbon pool, limited information is available on SOC stocks in global forests, particularly for forests in mountainous regions, such as the Central Himalayas. The availability of consistently measured new field data enabled us to accurately estimate forest soil organic carbon (SOC) stocks in Nepal, addressing a previously existing knowledge gap. Our method involved modelling plot-based estimates of forest SOC using covariates related to climate, soil, and topographic position. Our quantile random forest model resulted in the high spatial resolution prediction of Nepal's national forest SOC stock together with prediction uncertainties. Our spatially explicit forest SOC map showed the high SOC levels in high-elevation forests and a significant underrepresentation of these stocks in global-scale assessments. Our results offer an improved baseline on the distribution of total carbon in the forests of the Central Himalayas. The benchmark maps of predicted forest SOC and associated errors, along with our estimate of 494 million tonnes (SE = 16) of total SOC in the topsoil (0-30 cm) of forested areas in Nepal, carry important implications for understanding the spatial variability of forest SOC in mountainous regions with complex terrains.
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Affiliation(s)
- Shiva Khanal
- Forest Research and Training Center, Kathmandu, Nepal.
- Hawkesbury Institute for the Environment, Western Sydney University, Sydney, Australia.
| | - Rachael H Nolan
- Hawkesbury Institute for the Environment, Western Sydney University, Sydney, Australia
| | - Belinda E Medlyn
- Hawkesbury Institute for the Environment, Western Sydney University, Sydney, Australia
| | - Matthias M Boer
- Hawkesbury Institute for the Environment, Western Sydney University, Sydney, Australia
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Dickman LT, Jonko AK, Linn RR, Altintas I, Atchley AL, Bär A, Collins AD, Dupuy J, Gallagher MR, Hiers JK, Hoffman CM, Hood SM, Hurteau MD, Jolly WM, Josephson A, Loudermilk EL, Ma W, Michaletz ST, Nolan RH, O'Brien JJ, Parsons RA, Partelli‐Feltrin R, Pimont F, Resco de Dios V, Restaino J, Robbins ZJ, Sartor KA, Schultz‐Fellenz E, Serbin SP, Sevanto S, Shuman JK, Sieg CH, Skowronski NS, Weise DR, Wright M, Xu C, Yebra M, Younes N. Integrating plant physiology into simulation of fire behavior and effects. New Phytol 2023; 238:952-970. [PMID: 36694296 PMCID: PMC10952334 DOI: 10.1111/nph.18770] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Accepted: 12/20/2022] [Indexed: 06/17/2023]
Abstract
Wildfires are a global crisis, but current fire models fail to capture vegetation response to changing climate. With drought and elevated temperature increasing the importance of vegetation dynamics to fire behavior, and the advent of next generation models capable of capturing increasingly complex physical processes, we provide a renewed focus on representation of woody vegetation in fire models. Currently, the most advanced representations of fire behavior and biophysical fire effects are found in distinct classes of fine-scale models and do not capture variation in live fuel (i.e. living plant) properties. We demonstrate that plant water and carbon dynamics, which influence combustion and heat transfer into the plant and often dictate plant survival, provide the mechanistic linkage between fire behavior and effects. Our conceptual framework linking remotely sensed estimates of plant water and carbon to fine-scale models of fire behavior and effects could be a critical first step toward improving the fidelity of the coarse scale models that are now relied upon for global fire forecasting. This process-based approach will be essential to capturing the influence of physiological responses to drought and warming on live fuel conditions, strengthening the science needed to guide fire managers in an uncertain future.
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Affiliation(s)
- L. Turin Dickman
- Earth & Environmental Sciences DivisionLos Alamos National LaboratoryLos AlamosNM87545USA
| | - Alexandra K. Jonko
- Earth & Environmental Sciences DivisionLos Alamos National LaboratoryLos AlamosNM87545USA
| | - Rodman R. Linn
- Earth & Environmental Sciences DivisionLos Alamos National LaboratoryLos AlamosNM87545USA
| | - Ilkay Altintas
- San Diego Supercomputer Center and Halicioglu Data Science InstituteUniversity of California San DiegoLa JollaCA92093USA
| | - Adam L. Atchley
- Earth & Environmental Sciences DivisionLos Alamos National LaboratoryLos AlamosNM87545USA
| | - Andreas Bär
- Department of BotanyUniversity of Innsbruck6020InnsbruckAustria
| | - Adam D. Collins
- Earth & Environmental Sciences DivisionLos Alamos National LaboratoryLos AlamosNM87545USA
| | - Jean‐Luc Dupuy
- Ecologie des Forêts Méditerranéennes (URFM)INRAe84914AvignonFrance
| | | | | | - Chad M. Hoffman
- Department of Forest and Rangeland StewardshipColorado State UniversityFort CollinsCO80523USA
| | - Sharon M. Hood
- Rocky Mountain Research StationUSDA Forest ServiceMissoulaMT59801USA
| | | | - W. Matt Jolly
- Rocky Mountain Research StationUSDA Forest ServiceMissoulaMT59801USA
| | - Alexander Josephson
- Earth & Environmental Sciences DivisionLos Alamos National LaboratoryLos AlamosNM87545USA
| | | | - Wu Ma
- Earth & Environmental Sciences DivisionLos Alamos National LaboratoryLos AlamosNM87545USA
| | - Sean T. Michaletz
- Department of Botany and Biodiversity Research CentreThe University of British ColumbiaVancouverBCV6T 1Z4Canada
| | - Rachael H. Nolan
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityPenrithNSW2753Australia
- NSW Bushfire Risk Management Research HubWollongongNSW2522Australia
| | | | | | - Raquel Partelli‐Feltrin
- Department of Botany and Biodiversity Research CentreThe University of British ColumbiaVancouverBCV6T 1Z4Canada
| | - François Pimont
- Ecologie des Forêts Méditerranéennes (URFM)INRAe84914AvignonFrance
| | - Víctor Resco de Dios
- School of Life Sciences and EngineeringSouthwest University of Science and TechnologyMianyang621010China
- Department of Crop and Forest Sciences and JRU CTFC‐AGROTECNIOUniversitat de LleidaLleida25198Spain
| | - Joseph Restaino
- Fire and Resource Assessment ProgramCalifornia Department of Forestry and Fire ProtectionSouth Lake TahoeCA96155USA
| | - Zachary J. Robbins
- Earth & Environmental Sciences DivisionLos Alamos National LaboratoryLos AlamosNM87545USA
| | - Karla A. Sartor
- Environmental Protection and Compliance DivisionLos Alamos National LaboratoryLos AlamosNM87545USA
| | - Emily Schultz‐Fellenz
- Earth & Environmental Sciences DivisionLos Alamos National LaboratoryLos AlamosNM87545USA
| | - Shawn P. Serbin
- Environmental and Climate Sciences DepartmentBrookhaven National LaboratoryUptonNY11973USA
| | - Sanna Sevanto
- Earth & Environmental Sciences DivisionLos Alamos National LaboratoryLos AlamosNM87545USA
| | - Jacquelyn K. Shuman
- Climate and Global Dynamics Laboratory, Terrestrial Sciences SectionNational Center for Atmospheric ResearchBoulderCO80305USA
| | - Carolyn H. Sieg
- Rocky Mountain Research StationUSDA Forest ServiceFlagstaffAZ86001USA
| | | | - David R. Weise
- Pacific Southwest Research StationUSDA Forest ServiceRiversideCA92507USA
| | - Molly Wright
- Cibola National ForestUSDA Forest ServiceAlbuquerqueNM87113USA
| | - Chonggang Xu
- Earth & Environmental Sciences DivisionLos Alamos National LaboratoryLos AlamosNM87545USA
| | - Marta Yebra
- Fenner School of Environment and SocietyAustralian National UniversityCanberraACT2601Australia
- School of EngineeringAustralian National UniversityCanberraACT2601Australia
| | - Nicolas Younes
- Fenner School of Environment and SocietyAustralian National UniversityCanberraACT2601Australia
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Westerband AC, Wright IJ, Maire V, Paillassa J, Prentice IC, Atkin OK, Bloomfield KJ, Cernusak LA, Dong N, Gleason SM, Guilherme Pereira C, Lambers H, Leishman MR, Malhi Y, Nolan RH. Coordination of photosynthetic traits across soil and climate gradients. Glob Chang Biol 2023; 29:856-873. [PMID: 36278893 PMCID: PMC10098586 DOI: 10.1111/gcb.16501] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Accepted: 09/23/2022] [Indexed: 06/16/2023]
Abstract
"Least-cost theory" posits that C3 plants should balance rates of photosynthetic water loss and carboxylation in relation to the relative acquisition and maintenance costs of resources required for these activities. Here we investigated the dependency of photosynthetic traits on climate and soil properties using a new Australia-wide trait dataset spanning 528 species from 67 sites. We tested the hypotheses that plants on relatively cold or dry sites, or on relatively more fertile sites, would typically operate at greater CO2 drawdown (lower ratio of leaf internal to ambient CO2 , Ci :Ca ) during light-saturated photosynthesis, and at higher leaf N per area (Narea ) and higher carboxylation capacity (Vcmax 25 ) for a given rate of stomatal conductance to water vapour, gsw . These results would be indicative of plants having relatively higher water costs than nutrient costs. In general, our hypotheses were supported. Soil total phosphorus (P) concentration and (more weakly) soil pH exerted positive effects on the Narea -gsw and Vcmax 25 -gsw slopes, and negative effects on Ci :Ca . The P effect strengthened when the effect of climate was removed via partial regression. We observed similar trends with increasing soil cation exchange capacity and clay content, which affect soil nutrient availability, and found that soil properties explained similar amounts of variation in the focal traits as climate did. Although climate typically explained more trait variation than soil did, together they explained up to 52% of variation in the slope relationships and soil properties explained up to 30% of the variation in individual traits. Soils influenced photosynthetic traits as well as their coordination. In particular, the influence of soil P likely reflects the Australia's geologically ancient low-relief landscapes with highly leached soils. Least-cost theory provides a valuable framework for understanding trade-offs between resource costs and use in plants, including limiting soil nutrients.
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Affiliation(s)
- Andrea C. Westerband
- Faculty of Science and EngineeringSchool of Natural SciencesMacquarie UniversityNorth RydeNew South WalesAustralia
| | - Ian J. Wright
- Faculty of Science and EngineeringSchool of Natural SciencesMacquarie UniversityNorth RydeNew South WalesAustralia
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityPenrithNew South WalesAustralia
| | - Vincent Maire
- Département des Sciences de l'environnementUniversité du Québec à Trois‐RivièresTrois‐RivièresQuébecCanada
| | - Jennifer Paillassa
- Département des Sciences de l'environnementUniversité du Québec à Trois‐RivièresTrois‐RivièresQuébecCanada
| | - Iain Colin Prentice
- Faculty of Science and EngineeringSchool of Natural SciencesMacquarie UniversityNorth RydeNew South WalesAustralia
- Georgina Mace Centre for the Living PlanetImperial College LondonAscotUK
- Department of Earth System ScienceTsinghua UniversityBeijingChina
| | - Owen K. Atkin
- Australian Research Council Centre of Excellence in Plant Energy BiologyResearch School of BiologyThe Australian National UniversityCanberraAustralian Capital TerritoryAustralia
| | | | - Lucas A. Cernusak
- College of Science and EngineeringJames Cook UniversityCairnsQueenslandAustralia
| | - Ning Dong
- Faculty of Science and EngineeringSchool of Natural SciencesMacquarie UniversityNorth RydeNew South WalesAustralia
- Georgina Mace Centre for the Living PlanetImperial College LondonAscotUK
| | - Sean M. Gleason
- USDA‐ARS Water Management and Systems Research UnitFort CollinsColoradoUSA
| | - Caio Guilherme Pereira
- Department of Civil and Environmental EngineeringMassachusetts Institute of TechnologyCambridgeMassachusettsUSA
| | - Hans Lambers
- School of Biological SciencesUniversity of Western AustraliaPerthWestern AustraliaAustralia
| | - Michelle R. Leishman
- Faculty of Science and EngineeringSchool of Natural SciencesMacquarie UniversityNorth RydeNew South WalesAustralia
| | - Yadvinder Malhi
- School of Geography and the EnvironmentEnvironmental Change InstituteUniversity of OxfordOxfordUK
| | - Rachael H. Nolan
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityPenrithNew South WalesAustralia
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7
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Griebel A, Boer MM, Blackman C, Choat B, Ellsworth DS, Madden P, Medlyn B, Resco de Dios V, Wujeska‐Klause A, Yebra M, Younes Cardenas N, Nolan RH. Specific leaf area and vapour pressure deficit control live fuel moisture content. Funct Ecol 2023. [DOI: 10.1111/1365-2435.14271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Anne Griebel
- Hawkesbury Institute for the Environment Western Sydney University Penrith Australia
- NSW Bushfire Risk Management Research Hub Wollongong Australia
| | - Matthias M. Boer
- Hawkesbury Institute for the Environment Western Sydney University Penrith Australia
- NSW Bushfire Risk Management Research Hub Wollongong Australia
| | - Chris Blackman
- School of Biological Science University of Tasmania Hobart Australia
| | - Brendan Choat
- Hawkesbury Institute for the Environment Western Sydney University Penrith Australia
| | - David S. Ellsworth
- Hawkesbury Institute for the Environment Western Sydney University Penrith Australia
| | - Paul Madden
- Hawkesbury Institute for the Environment Western Sydney University Penrith Australia
| | - Belinda Medlyn
- Hawkesbury Institute for the Environment Western Sydney University Penrith Australia
| | - Víctor Resco de Dios
- Joint Research Unit CTFC - AGROTECNIO - CERCA Center Lleida Spain
- Department of Crop and Forest Sciences, Universitat de Lleida Lleida Spain
| | | | - Marta Yebra
- Fenner School of Environment & Society Australian National University Canberra Australia
- School of Engineering Australian National University Canberra Australia
| | | | - Rachael H. Nolan
- Hawkesbury Institute for the Environment Western Sydney University Penrith Australia
- NSW Bushfire Risk Management Research Hub Wollongong Australia
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8
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Losso A, Challis A, Gauthey A, Nolan RH, Hislop S, Roff A, Boer MM, Jiang M, Medlyn BE, Choat B. Canopy dieback and recovery in Australian native forests following extreme drought. Sci Rep 2022; 12:21608. [PMID: 36517498 PMCID: PMC9751299 DOI: 10.1038/s41598-022-24833-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 11/21/2022] [Indexed: 12/15/2022] Open
Abstract
In 2019, south-eastern Australia experienced its driest and hottest year on record, resulting in massive canopy dieback events in eucalypt dominated forests. A subsequent period of high precipitation in 2020 provided a rare opportunity to quantify the impacts of extreme drought and consequent recovery. We quantified canopy health and hydraulic impairment (native percent loss of hydraulic conductivity, PLC) of 18 native tree species growing at 15 sites that were heavily impacted by the drought both during and 8-10 months after the drought. Most species exhibited high PLC during drought (PLC:65.1 ± 3.3%), with no clear patterns across sites or species. Heavily impaired trees (PLC > 70%) showed extensive canopy browning. In the post-drought period, most surviving trees exhibited hydraulic recovery (PLC:26.1 ± 5.1%), although PLC remained high in some trees (50-70%). Regained hydraulic function (PLC < 50%) corresponded to decreased canopy browning indicating improved tree health. Similar drought (37.1 ± 4.2%) and post-drought (35.1 ± 4.4%) percentages of basal area with dead canopy suggested that trees with severely compromised canopies immediately after drought were not able to recover. This dataset provides insights into the impacts of severe natural drought on the health of mature trees, where hydraulic failure is a major contributor in canopy dieback and tree mortality during extreme drought events.
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Affiliation(s)
- Adriano Losso
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia.
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020, Innsbruck, Austria.
| | - Anthea Challis
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Alice Gauthey
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
- Plant Ecology Research Laboratory PERL, Ecole Polytechnique Fédérale de Lausanne EPFL, 1015, Lausanne, Switzerland
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903, Birmensdorf, Switzerland
| | - Rachael H Nolan
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
- NSW Bushfire Risk Management Research Hub, Wollongong, NSW, Australia
| | - Samuel Hislop
- Forest Science, NSW Department of Primary Industries, Parramatta, NSW, 2150, Australia
| | - Adam Roff
- Department of Planning, Industry and Environment, Remote Sensing and Landscape Science, 26 Honeysuckle Drive, Newcastle, NSW, 2302, Australia
| | - Matthias M Boer
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
- NSW Bushfire Risk Management Research Hub, Wollongong, NSW, Australia
| | - Mingkai Jiang
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
- College of Life Sciences, Zhejiang University, 866 Yuhangtang Rd, Hangzhou, Zhejiang, China
| | - Belinda E Medlyn
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Brendan Choat
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia.
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9
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Clarke H, Nolan RH, De Dios VR, Bradstock R, Griebel A, Khanal S, Boer MM. Forest fire threatens global carbon sinks and population centres under rising atmospheric water demand. Nat Commun 2022; 13:7161. [PMID: 36418312 PMCID: PMC9684135 DOI: 10.1038/s41467-022-34966-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 11/14/2022] [Indexed: 11/25/2022] Open
Abstract
Levels of fire activity and severity that are unprecedented in the instrumental record have recently been observed in forested regions around the world. Using a large sample of daily fire events and hourly climate data, here we show that fire activity in all global forest biomes responds strongly and predictably to exceedance of thresholds in atmospheric water demand, as measured by maximum daily vapour pressure deficit. The climatology of vapour pressure deficit can therefore be reliably used to predict forest fire risk under projected future climates. We find that climate change is projected to lead to widespread increases in risk, with at least 30 additional days above critical thresholds for fire activity in forest biomes on every continent by 2100 under rising emissions scenarios. Escalating forest fire risk threatens catastrophic carbon losses in the Amazon and major population health impacts from wildfire smoke in south Asia and east Africa.
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Affiliation(s)
- Hamish Clarke
- grid.1007.60000 0004 0486 528XCentre for Environmental Risk Management of Bushfire, Centre for Sustainable Ecosystem Solutions, University of Wollongong, Wollongong, Australia ,NSW Bushfire Risk Management Research Hub, Wollongong, Australia ,grid.1029.a0000 0000 9939 5719Hawkesbury Institute for the Environment, Western Sydney University, Richmond, Australia ,grid.1008.90000 0001 2179 088XSchool of Ecosystem and Forest Sciences, University of Melbourne, Parkville, Australia
| | - Rachael H. Nolan
- NSW Bushfire Risk Management Research Hub, Wollongong, Australia ,grid.1029.a0000 0000 9939 5719Hawkesbury Institute for the Environment, Western Sydney University, Richmond, Australia
| | - Victor Resco De Dios
- grid.15043.330000 0001 2163 1432Department of Crop and Forest Sciences, Universitat de Lleida, Lérida, Spain ,JRU CTFC-AGROTECNIO-Cerca Center, Lérida, Spain ,grid.440649.b0000 0004 1808 3334School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, China
| | - Ross Bradstock
- grid.1007.60000 0004 0486 528XCentre for Environmental Risk Management of Bushfire, Centre for Sustainable Ecosystem Solutions, University of Wollongong, Wollongong, Australia ,NSW Bushfire Risk Management Research Hub, Wollongong, Australia ,grid.502060.1Applied Bushfire Science Program, NSW Department of Planning, Industry and Environment, Parramatta, Australia
| | - Anne Griebel
- NSW Bushfire Risk Management Research Hub, Wollongong, Australia ,grid.1029.a0000 0000 9939 5719Hawkesbury Institute for the Environment, Western Sydney University, Richmond, Australia
| | - Shiva Khanal
- grid.1029.a0000 0000 9939 5719Hawkesbury Institute for the Environment, Western Sydney University, Richmond, Australia
| | - Matthias M. Boer
- grid.1029.a0000 0000 9939 5719Hawkesbury Institute for the Environment, Western Sydney University, Richmond, Australia
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10
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Wang B, Spessa AC, Feng P, Hou X, Yue C, Luo JJ, Ciais P, Waters C, Cowie A, Nolan RH, Nikonovas T, Jin H, Walshaw H, Wei J, Guo X, Liu DL, Yu Q. Extreme fire weather is the major driver of severe bushfires in southeast Australia. Sci Bull (Beijing) 2022; 67:655-664. [PMID: 36546127 DOI: 10.1016/j.scib.2021.10.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 09/07/2021] [Accepted: 09/08/2021] [Indexed: 01/06/2023]
Abstract
In Australia, the proportion of forest area that burns in a typical fire season is less than for other vegetation types. However, the 2019-2020 austral spring-summer was an exception, with over four times the previous maximum area burnt in southeast Australian temperate forests. Temperate forest fires have extensive socio-economic, human health, greenhouse gas emissions, and biodiversity impacts due to high fire intensities. A robust model that identifies driving factors of forest fires and relates impact thresholds to fire activity at regional scales would help land managers and fire-fighting agencies prepare for potentially hazardous fire in Australia. Here, we developed a machine-learning diagnostic model to quantify nonlinear relationships between monthly burnt area and biophysical factors in southeast Australian forests for 2001-2020 on a 0.25° grid based on several biophysical parameters, notably fire weather and vegetation productivity. Our model explained over 80% of the variation in the burnt area. We identified that burnt area dynamics in southeast Australian forest were primarily controlled by extreme fire weather, which mainly linked to fluctuations in the Southern Annular Mode (SAM) and Indian Ocean Dipole (IOD), with a relatively smaller contribution from the central Pacific El Niño Southern Oscillation (ENSO). Our fire diagnostic model and the non-linear relationships between burnt area and environmental covariates can provide useful guidance to decision-makers who manage preparations for an upcoming fire season, and model developers working on improved early warning systems for forest fires.
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Affiliation(s)
- Bin Wang
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling 712100, China; New South Wales Department of Primary Industries, Wagga Wagga Agricultural Institute, Wagga Wagga 2650, Australia.
| | - Allan C Spessa
- Department of Geography, College of Science, Swansea University, Singleton Park, Swansea SA2 8PP, UK
| | - Puyu Feng
- College of Land Science and Technology, China Agricultural University, Beijing 100193, China
| | - Xin Hou
- College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, China
| | - Chao Yue
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling 712100, China
| | - Jing-Jia Luo
- Institute for Climate and Application Research (ICAR)/Key Laboratory of Meteorological Disaster of Ministry of Education (KLME), Nanjing University of Information Science and Technology, Nanjing 210044, China.
| | - Philippe Ciais
- Laboratoire des Sciences du Climat et de l'Environnement, CEA-CNRS-UVSQ, Gif sur Yvette F-91191, France
| | - Cathy Waters
- New South Wales Department of Primary Industries, Dubbo 2830, Australia
| | - Annette Cowie
- New South Wales Department of Primary Industries, Armidale 2351, Australia; School of Environmental and Rural Science, University of New England, Armidale 2351, Australia
| | - Rachael H Nolan
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith 2751, Australia
| | - Tadas Nikonovas
- Department of Geography, College of Science, Swansea University, Singleton Park, Swansea SA2 8PP, UK
| | | | | | - Jinghua Wei
- Institute for Climate and Application Research (ICAR)/Key Laboratory of Meteorological Disaster of Ministry of Education (KLME), Nanjing University of Information Science and Technology, Nanjing 210044, China
| | - Xiaowei Guo
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810008, China
| | - De Li Liu
- New South Wales Department of Primary Industries, Wagga Wagga Agricultural Institute, Wagga Wagga 2650, Australia; Climate Change Research Centre, University of New South Wales, Sydney 2052, Australia
| | - Qiang Yu
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling 712100, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
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11
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Griebel A, Peters JMR, Metzen D, Maier C, Barton CVM, Speckman HN, Boer MM, Nolan RH, Choat B, Pendall E. Tapping into the physiological responses to mistletoe infection during heat and drought stress. Tree Physiol 2022; 42:523-536. [PMID: 34612494 DOI: 10.1093/treephys/tpab113] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 08/09/2021] [Indexed: 06/13/2023]
Abstract
Mistletoes are important co-contributors to tree mortality globally, particularly during droughts. In Australia, mistletoe distributions are expanding in temperate woodlands, while their hosts have experienced unprecedented heat and drought stress in recent years. We investigated whether the excessive water use of mistletoes increased the probability of xylem emboli in a mature woodland during the recent record drought that was compounded by multiple heatwaves. We continuously recorded transpiration ($T_{SLA}$) of infected and uninfected branches from two eucalypt species over two summers, monitored stem and leaf water potentials ($\Psi $) and used hydraulic vulnerability curves to estimate percent loss in conductivity (PLC) for each species. Variations in weather (vapor pressure deficit, photosynthetically active radiation, soil water content), host species and % mistletoe foliage explained 78% of hourly $T_{SLA}$. While mistletoe acted as an uncontrollable sink for water in the host even during typical summer days, daily $T_{SLA}$ increased up to 4-fold in infected branches on hot days, highlighting the previously overlooked importance of temperature stress in amplifying water loss in mistletoes. The increased water use of mistletoes resulted in significantly decreased host $\Psi _{\rm{leaf}}$ and $\Psi _{\rm{trunk}}$. It further translated to an estimated increase of up to 11% PLC for infected hosts, confirming greater hydraulic dysfunction of infected trees that place them at higher risk of hydraulic failure. However, uninfected branches of Eucalyptus fibrosa F.Muell. had much tighter controls on water loss than uninfected branches of Eucalyptus moluccana Roxb., which shifted the risk of hydraulic failure towards an increased risk of carbon starvation for E. fibrosa. The contrasting mechanistic responses to heat and drought stress between both co-occurring species demonstrates the complexity of host-parasite interactions and highlights the challenge in predicting species-specific responses to biotic agents in a warmer and drier climate.
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Affiliation(s)
- Anne Griebel
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2571, Australia
| | - Jennifer M R Peters
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2571, Australia
- Climate Change Science Institute & Environmental Science Division, Oak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, TN 37831, USA
| | - Daniel Metzen
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2571, Australia
| | - Chelsea Maier
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2571, Australia
| | - Craig V M Barton
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2571, Australia
| | - Heather N Speckman
- Department of Botany, University of Wyoming, 1000 E. Univ. Ave, Laramie, WY 82071, USA
| | - Matthias M Boer
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2571, Australia
| | - Rachael H Nolan
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2571, Australia
| | - Brendan Choat
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2571, Australia
| | - Elise Pendall
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2571, Australia
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12
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Nolan RH, Collins L, Leigh A, Ooi MKJ, Curran TJ, Fairman TA, Resco de Dios V, Bradstock R. Limits to post-fire vegetation recovery under climate change. Plant Cell Environ 2021; 44:3471-3489. [PMID: 34453442 DOI: 10.1111/pce.14176] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 08/09/2021] [Accepted: 08/13/2021] [Indexed: 06/13/2023]
Abstract
Record-breaking fire seasons in many regions across the globe raise important questions about plant community responses to shifting fire regimes (i.e., changing fire frequency, severity and seasonality). Here, we examine the impacts of climate-driven shifts in fire regimes on vegetation communities, and likely responses to fire coinciding with severe drought, heatwaves and/or insect outbreaks. We present scenario-based conceptual models on how overlapping disturbance events and shifting fire regimes interact differently to limit post-fire resprouting and recruitment capacity. We demonstrate that, although many communities will remain resilient to changing fire regimes in the short-term, longer-term changes to vegetation structure, demography and species composition are likely, with a range of subsequent effects on ecosystem function. Resprouting species are likely to be most resilient to changing fire regimes. However, even these species are susceptible if exposed to repeated short-interval fire in combination with other stressors. Post-fire recruitment is highly vulnerable to increased fire frequency, particularly as climatic limitations on propagule availability intensify. Prediction of community responses to fire under climate change will be greatly improved by addressing knowledge gaps on how overlapping disturbances and climate change-induced shifts in fire regime affect post-fire resprouting, recruitment, growth rates, and species-level adaptation capacity.
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Affiliation(s)
- Rachael H Nolan
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
- NSW Bushfire Risk Management Research Hub, Wollongong, New South Wales, Australia
| | - Luke Collins
- School of Ecosystem and Forest Sciences, University of Melbourne, Creswick, Victoria, Australia
- Department of Ecology, Environment & Evolution, La Trobe University, Bundoora, Victoria, Australia
- Pacific Forestry Centre, Canadian Forest Service, Natural Resources Canada, Canada
| | - Andy Leigh
- School of Life Sciences, University of Technology Sydney, Broadway, New South Wales, Australia
| | - Mark K J Ooi
- NSW Bushfire Risk Management Research Hub, Wollongong, New South Wales, Australia
- School of Biological, Earth and Environmental Sciences, University of New South Wales UNSW, Sydney, New South Wales, Australia
| | - Timothy J Curran
- Department of Pest-management and Conservation, Lincoln University, Lincoln, New Zealand
| | - Thomas A Fairman
- School of Ecosystem and Forest Sciences, University of Melbourne, Creswick, Victoria, Australia
| | - Víctor Resco de Dios
- School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, China
- Joint Research Unit CTFC-AGROTECNIO, University of Lleida, Lleida, Spain
- Department of Crop and Forest Sciences, University of Lleida, Lleida, Spain
| | - Ross Bradstock
- NSW Bushfire Risk Management Research Hub, Wollongong, New South Wales, Australia
- Centre for Environmental Risk Management of Bushfires, University of Wollongong, Wollongong, New South Wales, Australia
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13
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Griebel A, Metzen D, Pendall E, Nolan RH, Clarke H, Renchon AA, Boer MM. Recovery from Severe Mistletoe Infection After Heat- and Drought-Induced Mistletoe Death. Ecosystems 2021. [DOI: 10.1007/s10021-021-00635-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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14
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Nolan RH, Gauthey A, Losso A, Medlyn BE, Smith R, Chhajed SS, Fuller K, Song M, Li X, Beaumont LJ, Boer MM, Wright IJ, Choat B. Hydraulic failure and tree size linked with canopy die-back in eucalypt forest during extreme drought. New Phytol 2021; 230:1354-1365. [PMID: 33629360 DOI: 10.1111/nph.17298] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 02/17/2021] [Indexed: 06/12/2023]
Abstract
Eastern Australia was subject to its hottest and driest year on record in 2019. This extreme drought resulted in massive canopy die-back in eucalypt forests. The role of hydraulic failure and tree size on canopy die-back in three eucalypt tree species during this drought was examined. We measured pre-dawn and midday leaf water potential (Ψleaf ), per cent loss of stem hydraulic conductivity and quantified hydraulic vulnerability to drought-induced xylem embolism. Tree size and tree health was also surveyed. Trees with most, or all, of their foliage dead exhibited high rates of native embolism (78-100%). This is in contrast to trees with partial canopy die-back (30-70% canopy die-back: 72-78% native embolism), or relatively healthy trees (little evidence of canopy die-back: 25-31% native embolism). Midday Ψleaf was significantly more negative in trees exhibiting partial canopy die-back (-2.7 to -6.3 MPa), compared with relatively healthy trees (-2.1 to -4.5 MPa). In two of the species the majority of individuals showing complete canopy die-back were in the small size classes. Our results indicate that hydraulic failure is strongly associated with canopy die-back during drought in eucalypt forests. Our study provides valuable field data to help constrain models predicting mortality risk.
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Affiliation(s)
- Rachael H Nolan
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
- Bushfire Risk Management Research Hub, Wollongong, NSW, 2522, Australia
| | - Alice Gauthey
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Adriano Losso
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
- Department of Botany, University of Innsbruck, Sternwartestraße 15, Innsbruck, 6020, Austria
| | - Belinda E Medlyn
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Rhiannon Smith
- Ecosystem Management, University of New England, Armidale, NSW, 2351, Australia
| | - Shubham S Chhajed
- Department of Biological Sciences, Macquarie University, Macquarie Park, NSW, 2109, Australia
| | - Kathryn Fuller
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
- Bushfire Risk Management Research Hub, Wollongong, NSW, 2522, Australia
| | - Magnolia Song
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Xine Li
- Department of Biological Sciences, Macquarie University, Macquarie Park, NSW, 2109, Australia
- Department of Animal Science and Technology, Yangzhou University, Yangzhou, Jiangsu, 225009, China
| | - Linda J Beaumont
- Department of Biological Sciences, Macquarie University, Macquarie Park, NSW, 2109, Australia
| | - Matthias M Boer
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
- Bushfire Risk Management Research Hub, Wollongong, NSW, 2522, Australia
| | - Ian J Wright
- Department of Biological Sciences, Macquarie University, Macquarie Park, NSW, 2109, Australia
| | - Brendan Choat
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
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15
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Resco de Dios V, Anderegg WR, Li X, Tissue DT, Bahn M, Landais D, Milcu A, Yao Y, Nolan RH, Roy J, Gessler A. Circadian Regulation Does Not Optimize Stomatal Behaviour. Plants (Basel) 2020; 9:E1091. [PMID: 32854373 PMCID: PMC7570086 DOI: 10.3390/plants9091091] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/13/2020] [Accepted: 08/21/2020] [Indexed: 02/05/2023]
Abstract
The circadian clock is a molecular timer of metabolism that affects the diurnal pattern of stomatal conductance (gs), amongst other processes, in a broad array of plant species. The function of circadian gs regulation remains unknown and here, we test whether circadian regulation helps to optimize diurnal variations in stomatal conductance. We subjected bean (Phaseolus vulgaris) and cotton (Gossypium hirsutum) canopies to fixed, continuous environmental conditions of photosynthetically active radiation, temperature, and vapour pressure deficit (free-running conditions) over 48 h. We modelled gs variations in free-running conditions to test for two possible optimizations of stomatal behaviour under circadian regulation: (i) that stomata operate to maintain constant marginal water use efficiency; or (ii) that stomata maximize C net gain minus the costs or risks of hydraulic damage. We observed that both optimization models predicted gs poorly under free-running conditions, indicating that circadian regulation does not directly lead to stomatal optimization. We also demonstrate that failure to account for circadian variation in gs could potentially lead to biased parameter estimates during calibrations of stomatal models. More broadly, our results add to the emerging field of plant circadian ecology, where circadian controls may partially explain leaf-level patterns observed in the field.
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Affiliation(s)
- Víctor Resco de Dios
- School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, China;
- Department of Crop and Forest Sciences-AGROTECNIO Center, University of Lleida, 25198 Lleida, Spain
| | | | - Ximeng Li
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW 2751, Australia; (X.L.); (D.T.T.); (R.H.N.)
| | - David T. Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW 2751, Australia; (X.L.); (D.T.T.); (R.H.N.)
| | - Michael Bahn
- Department of Ecology, University of Innsbruck, 6020 Innsbruck, Austria;
| | - Damien Landais
- Ecotron Européen de Montpellier, CNRS, 34980 Montferrier-sur-Lez, France; (D.L.); (A.M.); (J.R.)
| | - Alexandru Milcu
- Ecotron Européen de Montpellier, CNRS, 34980 Montferrier-sur-Lez, France; (D.L.); (A.M.); (J.R.)
- Centre d’Ecologie Fonctionnelle et Evolutive (CEFE), CNRS, UMR 5175, Université de Montpellier, Université Paul Valéry, EPHE, IRD, 34293 Montpellier, France
| | - Yinan Yao
- School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, China;
| | - Rachael H. Nolan
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW 2751, Australia; (X.L.); (D.T.T.); (R.H.N.)
| | - Jacques Roy
- Ecotron Européen de Montpellier, CNRS, 34980 Montferrier-sur-Lez, France; (D.L.); (A.M.); (J.R.)
| | - Arthur Gessler
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, 8903 Birmensdorf, Switzerland;
- Institute of Terrestrial Ecosystems, ETH Zurich, 8092 Zurich, Switzerland
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16
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Bradstock RA, Nolan RH, Collins L, Resco de Dios V, Clarke H, Jenkins M, Kenny B, Boer MM. A broader perspective on the causes and consequences of eastern Australia's 2019-20 season of mega-fires: A response to Adams et al. Glob Chang Biol 2020; 26:e8-e9. [PMID: 32255228 DOI: 10.1111/gcb.15111] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 03/26/2020] [Indexed: 06/11/2023]
Affiliation(s)
- Ross A Bradstock
- Centre for Environmental Risk Management of Bushfires, University of Wollongong, Wollongong, NSW, Australia
- Bushfire Risk Management Research Hub, Wollongong, NSW, Australia
| | - Rachael H Nolan
- Bushfire Risk Management Research Hub, Wollongong, NSW, Australia
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Luke Collins
- Department of Ecology, Environment & Evolution, La Trobe University, Bundoora, Vic., Australia
- Arthur Rylah Institute for Environmental Research, Department of Environment, Land, Water and Planning, Heidelberg, Vic., Australia
| | - Víctor Resco de Dios
- School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, China
- AGROTECNIO Centre, Universitat de Lleida, Lleida, Spain
| | - Hamish Clarke
- Centre for Environmental Risk Management of Bushfires, University of Wollongong, Wollongong, NSW, Australia
- Bushfire Risk Management Research Hub, Wollongong, NSW, Australia
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Meaghan Jenkins
- Centre for Environmental Risk Management of Bushfires, University of Wollongong, Wollongong, NSW, Australia
- NSW Rural Fire Service, Sydney Olympic Park, NSW, Australia
| | - Belinda Kenny
- NSW Rural Fire Service, Sydney Olympic Park, NSW, Australia
| | - Matthias M Boer
- Bushfire Risk Management Research Hub, Wollongong, NSW, Australia
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
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Nolan RH, Boer MM, Collins L, Resco de Dios V, Clarke H, Jenkins M, Kenny B, Bradstock RA. Causes and consequences of eastern Australia's 2019-20 season of mega-fires. Glob Chang Biol 2020; 26:1039-1041. [PMID: 31916352 DOI: 10.1111/gcb.14987] [Citation(s) in RCA: 126] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 12/31/2019] [Accepted: 01/02/2020] [Indexed: 05/23/2023]
Affiliation(s)
- Rachael H Nolan
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
- New South Wales Bushfire Risk Management Research Hub, Parramatta, NSW, Australia
| | - Matthias M Boer
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
- New South Wales Bushfire Risk Management Research Hub, Parramatta, NSW, Australia
| | - Luke Collins
- Department of Ecology, Environment & Evolution, La Trobe University, Bundoora, Vic., Australia
- Arthur Rylah Institute for Environmental Research, Department of Environment, Land, Water and Planning, Heidelberg, Vic., Australia
| | - Víctor Resco de Dios
- School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, China
- AGROTECNIO Centre, Universitat de Lleida, Lleida, Spain
| | - Hamish Clarke
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
- New South Wales Bushfire Risk Management Research Hub, Parramatta, NSW, Australia
- Centre for Environmental Risk Management of Bushfires, University of Wollongong, Wollongong, NSW, Australia
| | - Meaghan Jenkins
- Centre for Environmental Risk Management of Bushfires, University of Wollongong, Wollongong, NSW, Australia
| | - Belinda Kenny
- NSW Rural Fire Service, Sydney Olympic Park, NSW, Australia
| | - Ross A Bradstock
- New South Wales Bushfire Risk Management Research Hub, Parramatta, NSW, Australia
- Centre for Environmental Risk Management of Bushfires, University of Wollongong, Wollongong, NSW, Australia
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18
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Tarin T, Nolan RH, Medlyn BE, Cleverly J, Eamus D. Water-use efficiency in a semi-arid woodland with high rainfall variability. Glob Chang Biol 2020; 26:496-508. [PMID: 31597216 DOI: 10.1111/gcb.14866] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 08/30/2019] [Accepted: 10/03/2019] [Indexed: 06/10/2023]
Abstract
As the ratio of carbon uptake to water use by vegetation, water-use efficiency (WUE) is a key ecosystem property linking global carbon and water cycles. It can be estimated in several ways, but it is currently unclear how different measures of WUE relate, and how well they each capture variation in WUE with soil moisture availability. We evaluated WUE in an Acacia-dominated woodland ecosystem of central Australia at various spatial and temporal scales using stable carbon isotope analysis, leaf gas exchange and eddy covariance (EC) fluxes. Semi-arid Australia has a highly variable rainfall pattern, making it an ideal system to study how WUE varies with water availability. We normalized our measures of WUE across a range of vapour pressure deficits using g1 , which is a parameter derived from an optimal stomatal conductance model and which is inversely related to WUE. Continuous measures of whole-ecosystem g1 obtained from EC data were elevated in the 3 days following rain, indicating a strong effect of soil evaporation. Once these values were removed, a close relationship of g1 with soil moisture content was observed. Leaf-scale values of g1 derived from gas exchange were in close agreement with ecosystem-scale values. In contrast, values of g1 obtained from stable isotopes did not vary with soil moisture availability, potentially indicating remobilization of stored carbon during dry periods. Our comprehensive comparison of alternative measures of WUE shows the importance of stomatal control of fluxes in this highly variable rainfall climate and demonstrates the ability of these different measures to quantify this effect. Our study provides the empirical evidence required to better predict the dynamic carbon-water relations in semi-arid Australian ecosystems.
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Affiliation(s)
- Tonantzin Tarin
- Terrestrial Ecohydrology Research Group, School of Life Sciences, University of Technology Sydney, Sydney, NSW, Australia
- Department of Soil and Plant Sciences, University of Delaware, Newark, DE, USA
| | - Rachael H Nolan
- Terrestrial Ecohydrology Research Group, School of Life Sciences, University of Technology Sydney, Sydney, NSW, Australia
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Belinda E Medlyn
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - James Cleverly
- Terrestrial Ecohydrology Research Group, School of Life Sciences, University of Technology Sydney, Sydney, NSW, Australia
- Terrestrial Ecosystem Research Network (TERN), University of Technology, Sydney, NSW, Australia
| | - Derek Eamus
- Terrestrial Ecohydrology Research Group, School of Life Sciences, University of Technology Sydney, Sydney, NSW, Australia
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19
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Yebra M, Scortechini G, Badi A, Beget ME, Boer MM, Bradstock R, Chuvieco E, Danson FM, Dennison P, Resco de Dios V, Di Bella CM, Forsyth G, Frost P, Garcia M, Hamdi A, He B, Jolly M, Kraaij T, Martín MP, Mouillot F, Newnham G, Nolan RH, Pellizzaro G, Qi Y, Quan X, Riaño D, Roberts D, Sow M, Ustin S. Globe-LFMC, a global plant water status database for vegetation ecophysiology and wildfire applications. Sci Data 2019; 6:155. [PMID: 31434899 PMCID: PMC6704185 DOI: 10.1038/s41597-019-0164-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 07/26/2019] [Indexed: 11/09/2022] Open
Abstract
Globe-LFMC is an extensive global database of live fuel moisture content (LFMC) measured from 1,383 sampling sites in 11 countries: Argentina, Australia, China, France, Italy, Senegal, Spain, South Africa, Tunisia, United Kingdom and the United States of America. The database contains 161,717 individual records based on in situ destructive samples used to measure LFMC, representing the amount of water in plant leaves per unit of dry matter. The primary goal of the database is to calibrate and validate remote sensing algorithms used to predict LFMC. However, this database is also relevant for the calibration and validation of dynamic global vegetation models, eco-physiological models of plant water stress as well as understanding the physiological drivers of spatiotemporal variation in LFMC at local, regional and global scales. Globe-LFMC should be useful for studying LFMC trends in response to environmental change and LFMC influence on wildfire occurrence, wildfire behavior, and overall vegetation health. Design Type(s) | database creation objective • cross validation objective • physiological process monitoring objective | Measurement Type(s) | moisture content trait | Technology Type(s) | digital curation | Factor Type(s) | geographic location • environmental feature | Sample Characteristic(s) | Earth (Planet) • United States of America • French Republic |
Machine-accessible metadata file describing the reported data (ISA-Tab format)
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Affiliation(s)
- Marta Yebra
- Fenner School of Environment & Society, Australian National University, Canberra, ACT, Australia. .,Bushfire & Natural Hazards Cooperative Research Centre, Melbourne, Victoria, Australia.
| | - Gianluca Scortechini
- Fenner School of Environment & Society, Australian National University, Canberra, ACT, Australia
| | - Abdulbaset Badi
- School of Environment and Life Sciences, University of Salford, Salford, UK
| | | | - Matthias M Boer
- Hawkesbury Institute for the Environment, Western Sydney University, Sydney, NSW, Australia
| | | | - Emilio Chuvieco
- Department of Geology, Geography and the Environment, University of Alcala, Alcala de Henares, Madrid, Spain
| | - F Mark Danson
- School of Environment and Life Sciences, University of Salford, Salford, UK
| | - Philip Dennison
- Department of Geography, University of Utah, Salt Lake City, USA
| | | | - Carlos M Di Bella
- Instituto de Clima y Agua, INTA. Hurlingham, Buenos Aires, Argentina
| | | | | | - Mariano Garcia
- Department of Geology, Geography and the Environment, University of Alcala, Alcala de Henares, Madrid, Spain
| | - Abdelaziz Hamdi
- Laboratoire des Ressources Sylvo-Pastorales, Institut Sylvo Pastoral de Tabarka, 8110, Jendouba, Tunisia
| | - Binbin He
- School of Resources and Environment, University of Electronic Science and Technology of China, Sichuan, China
| | - Matt Jolly
- Rocky Mountain Research Station, Fire Sciences Laboratory, USFS, Montana, USA
| | - Tineke Kraaij
- Nelson Mandela University, School of Natural Resource Management, George, South Africa
| | - M Pilar Martín
- Environmental Remote Sensing and Spectroscopy Laboratory (SpecLab), Spanish National Research Council (CSIC), Madrid, Spain
| | - Florent Mouillot
- UMR CEFE, CNRS, université de Montpellier, Université Paul Valery Montpellier, EPHE, IRD, 1919 route de mende, 34293, Montpellier Cedex 5, France
| | | | - Rachael H Nolan
- Hawkesbury Institute for the Environment, Western Sydney University, Sydney, NSW, Australia
| | - Grazia Pellizzaro
- Istituto di Biometeorologia (Sassari) Consiglio Nazionale delle Ricerche (CNR-IBIMET), Sassari, Italy
| | - Yi Qi
- University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - Xingwen Quan
- School of Resources and Environment, University of Electronic Science and Technology of China, Sichuan, China
| | - David Riaño
- Environmental Remote Sensing and Spectroscopy Laboratory (SpecLab), Spanish National Research Council (CSIC), Madrid, Spain.,Center for Spatial Technologies and Remote Sensing, UC-Davis, Davis, USA
| | - Dar Roberts
- Department of Geography, University of California, Santa Barbara, USA
| | - Momadou Sow
- Institut des Sciences de l'Environnement (ISE), Faculté des Sciences et Techniques, Université Cheikh Anta Diop de Dakar, Dakar, Senegal
| | - Susan Ustin
- Center for Spatial Technologies and Remote Sensing, UC-Davis, Davis, USA
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Nolan RH, Sinclair J, Waters CM, Mitchell PJ, Eldridge DJ, Paul KI, Roxburgh S, Butler DW, Ramp D. Risks to carbon dynamics in semi-arid woodlands of eastern Australia under current and future climates. J Environ Manage 2019; 235:500-510. [PMID: 30711835 DOI: 10.1016/j.jenvman.2019.01.076] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 08/17/2018] [Accepted: 01/21/2019] [Indexed: 06/09/2023]
Abstract
Extreme disturbance events, such as wildfire and drought, have large impacts on carbon storage and sequestration of forests and woodlands globally. Here, we present a modelling approach that assesses the relative impact of disturbances on carbon storage and sequestration, and how this will alter under climate change. Our case study is semi-arid Australia where large areas of land are managed to offset over 122 million tonnes of anthropogenic carbon emissions over a 100-year period. These carbon offsets include mature vegetation that has been protected from clearing and regenerating vegetation on degraded agricultural land. We use a Bayesian Network model to combine multiple probabilistic models of the risk posed by fire, drought, grazing and recruitment failure to carbon dynamics. The model is parameterised from a review of relevant literature and additional quantitative analyses presented here. We found that the risk of vegetation becoming a net source of carbon due to a mortality event, or failing to realise maximum sequestration potential, through recruitment failure in regenerating vegetation, was primarily a function of rainfall in this semi-arid environment. However, the relative size of an emissions event varied across vegetation communities depending on plant attributes, specifically resprouting capacity. Modelled climate change effects were variable, depending on the climate change projection used. Under 'best-case' or 'most-likely' climate scenarios for 2050, similar or increased projections of mean annual precipitation, associated with a build-up of fuel, were expected to drive an increase in fire activity (a 40-160% increase), but a decrease in drought (a 20-35% decrease). Under a 'worst-case' climate scenario, fire activity was expected to decline (a 37% decrease), but drought conditions remain similar (a 5% decrease). These projected changes to the frequency of drought and fire increase the risk that vegetation used for carbon offsetting will fail to provide anticipated amounts of carbon abatement over their lifetime.
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Affiliation(s)
- Rachael H Nolan
- School of Life Sciences, University of Technology Sydney, PO Box 123, Broadway, NSW 2007, Australia; Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia.
| | - Jennifer Sinclair
- School of Life Sciences, University of Technology Sydney, PO Box 123, Broadway, NSW 2007, Australia; GreenCollar, The Rocks, Sydney, NSW, 2000, Australia
| | - Cathleen M Waters
- New South Wales Department of Primary Industries, Climate Research, Orange, New South Wales, 2800, Australia
| | | | - David J Eldridge
- Centre for Ecosystem Science, School of Biological, Earth and Environmental Sciences, University of New South Wales, NSW, 2052, Australia
| | - Keryn I Paul
- CSIRO Land and Water Flagship, Canberra, Australian Capital Territory, 2601, Australia
| | - Stephen Roxburgh
- CSIRO Land and Water Flagship, Canberra, Australian Capital Territory, 2601, Australia
| | - Don W Butler
- Queensland Herbarium, Toowong, Queensland, 4066, Australia
| | - Daniel Ramp
- School of Life Sciences, University of Technology Sydney, PO Box 123, Broadway, NSW 2007, Australia
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Nolan RH, Sinclair J, Eldridge DJ, Ramp D. Biophysical risks to carbon sequestration and storage in Australian drylands. J Environ Manage 2018; 208:102-111. [PMID: 29248786 DOI: 10.1016/j.jenvman.2017.12.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 11/29/2017] [Accepted: 12/02/2017] [Indexed: 06/07/2023]
Abstract
Carbon abatement schemes that reduce land clearing and promote revegetation are now an important component of climate change policy globally. There is considerable potential for these schemes to operate in drylands which are spatially extensive. However, projects in these environments risk failure through unplanned release of stored carbon to the atmosphere. In this review, we identify factors that may adversely affect the success of vegetation-based carbon abatement projects in dryland ecosystems, evaluate their likelihood of occurrence, and estimate the potential consequences for carbon storage and sequestration. We also evaluate management strategies to reduce risks posed to these carbon abatement projects. Identified risks were primarily disturbances, including unplanned fire, drought, and grazing. Revegetation projects also risk recruitment failure, thereby failing to reach projected rates of sequestration. Many of these risks are dependent on rainfall, which is highly variable in drylands and susceptible to further variation under climate change. Resprouting vegetation is likely to be less vulnerable to disturbance and have faster recovery rates upon release from disturbance. We conclude that there is a strong impetus for identifying management strategies and risk reduction mechanisms for carbon abatement projects. Risk mitigation would be enhanced by effective co-ordination of mitigation strategies at scales larger than individual abatement project boundaries, and by implementing risk assessment throughout project planning and implementation stages. Reduction of risk is vital for maximising carbon sequestration of individual projects and for reducing barriers to the establishment of new projects entering the market.
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Affiliation(s)
- Rachael H Nolan
- Centre for Compassionate Conservation, University of Technology Sydney, PO Box 123, Broadway, NSW 2007, Australia.
| | - Jennifer Sinclair
- Centre for Compassionate Conservation, University of Technology Sydney, PO Box 123, Broadway, NSW 2007, Australia; GreenCollar, The Rocks, Sydney, NSW 2000, Australia
| | - David J Eldridge
- School of Biological, Earth and Environmental Sciences, University of New South Wales, NSW 2052, Australia
| | - Daniel Ramp
- Centre for Compassionate Conservation, University of Technology Sydney, PO Box 123, Broadway, NSW 2007, Australia
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Affiliation(s)
- Rachael H. Nolan
- School of Life Sciences; University of Technology Sydney; Broadway NSW Australia
- School of Biological Sciences; Monash University; Clayton Vic. 3800 Australia
| | - Peter A. Vesk
- School of BioSciences; The University of Melbourne; Parkville Vic. Australia
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Nolan RH, Tarin T, Santini NS, McAdam SAM, Ruman R, Eamus D. Differences in osmotic adjustment, foliar abscisic acid dynamics, and stomatal regulation between an isohydric and anisohydric woody angiosperm during drought. Plant Cell Environ 2017; 40:3122-3134. [PMID: 28982212 DOI: 10.1111/pce.13077] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 09/18/2017] [Accepted: 09/20/2017] [Indexed: 06/07/2023]
Abstract
Species are often classified along a continuum from isohydric to anisohydric, with isohydric species exhibiting tighter regulation of leaf water potential through stomatal closure in response to drought. We investigated plasticity in stomatal regulation in an isohydric (Eucalyptus camaldulensis) and an anisohydric (Acacia aptaneura) angiosperm species subject to repeated drying cycles. We also assessed foliar abscisic acid (ABA) content dynamics, aboveground/belowground biomass allocation and nonstructural carbohydrates. The anisohydric species exhibited large plasticity in the turgor loss point (ΨTLP ), with plants subject to repeated drying exhibiting lower ΨTLP and correspondingly larger stomatal conductance at low water potential, compared to plants not previously exposed to drought. The anisohydric species exhibited a switch from ABA to water potential-driven stomatal closure during drought, a response previously only reported for anisohydric gymnosperms. The isohydric species showed little osmotic adjustment, with no evidence of switching to water potential-driven stomatal closure, but did exhibit increased root:shoot ratios. There were no differences in carbohydrate depletion between species. We conclude that a large range in ΨTLP and biphasic ABA dynamics are indicative of anisohydric species, and these traits are associated with exposure to low minimum foliar water potential, dense sapwood and large resistance to xylem embolism.
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Affiliation(s)
- Rachael H Nolan
- School of Life Sciences, University of Technology Sydney, PO Box 123, Broadway, Ultimo, New South Wales, 2007, Australia
| | - Tonantzin Tarin
- School of Life Sciences, University of Technology Sydney, PO Box 123, Broadway, Ultimo, New South Wales, 2007, Australia
| | - Nadia S Santini
- School of Life Sciences, University of Technology Sydney, PO Box 123, Broadway, Ultimo, New South Wales, 2007, Australia
- Institute of Ecology, National Autonomous University of Mexico, External Circuit S/N annex Botanical Garden exterior, University City, Mexico City, 04500, Mexico
| | - Scott A M McAdam
- School of Biological Sciences, University of Tasmania, Hobart, Tasmania, 7001, Australia
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA
| | - Rizwana Ruman
- School of Life Sciences, University of Technology Sydney, PO Box 123, Broadway, Ultimo, New South Wales, 2007, Australia
| | - Derek Eamus
- School of Life Sciences, University of Technology Sydney, PO Box 123, Broadway, Ultimo, New South Wales, 2007, Australia
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Nolan RH, Fairweather KA, Tarin T, Santini NS, Cleverly J, Faux R, Eamus D. Divergence in plant water-use strategies in semiarid woody species. Funct Plant Biol 2017; 44:1134-1146. [PMID: 32480639 DOI: 10.1071/fp17079] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 07/16/2017] [Indexed: 06/11/2023]
Abstract
Partitioning of water resources amongst plant species within a single climate envelope is possible if the species differ in key hydraulic traits. We examined 11 bivariate trait relationships across nine woody species found in the Ti-Tree basin of central Australia. We found that species with limited access to soil moisture, evidenced by low pre-dawn leaf water potential, displayed anisohydric behaviour (e.g. large seasonal fluctuations in minimum leaf water potential), had greater sapwood density and lower osmotic potential at full turgor. Osmotic potential at full turgor was positively correlated with the leaf water potential at turgor loss, which was, in turn, positively correlated with the water potential at incipient stomatal closure. We also observed divergent behaviour in two species of Mulga, a complex of closely related Acacia species which range from tall shrubs to low trees and dominate large areas of arid and semiarid Australia. These Mulga species had much lower minimum leaf water potentials and lower specific leaf area compared with the other seven species. Finally, one species, Hakea macrocarpa A.Cunn ex.R.Br., had traits that may allow it to tolerate seasonal dryness (through possession of small specific leaf area and cavitation resistant xylem) despite exhibiting cellular water relations that were similar to groundwater-dependent species. We conclude that traits related to water transport and leaf water status differ across species that experience differences in soil water availability and that this enables a diversity of species to exist in this low rainfall environment.
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Affiliation(s)
- Rachael H Nolan
- Terrestrial Ecohydrology Research Group, School of Life Sciences, University of Technology Sydney, PO Box 123, Broadway, NSW 2007, Australia
| | - Kendal A Fairweather
- Terrestrial Ecohydrology Research Group, School of Life Sciences, University of Technology Sydney, PO Box 123, Broadway, NSW 2007, Australia
| | - Tonantzin Tarin
- Terrestrial Ecohydrology Research Group, School of Life Sciences, University of Technology Sydney, PO Box 123, Broadway, NSW 2007, Australia
| | - Nadia S Santini
- Centre for Marine Bio-Innovation, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - James Cleverly
- Terrestrial Ecohydrology Research Group, School of Life Sciences, University of Technology Sydney, PO Box 123, Broadway, NSW 2007, Australia
| | - Ralph Faux
- Terrestrial Ecohydrology Research Group, School of Life Sciences, University of Technology Sydney, PO Box 123, Broadway, NSW 2007, Australia
| | - Derek Eamus
- Terrestrial Ecohydrology Research Group, School of Life Sciences, University of Technology Sydney, PO Box 123, Broadway, NSW 2007, Australia
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Nolan RH, Tarin T, Fairweather KA, Cleverly J, Eamus D. Variation in photosynthetic traits related to access to water in semiarid Australian woody species. Funct Plant Biol 2017; 44:1087-1097. [PMID: 32480635 DOI: 10.1071/fp17096] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 07/11/2017] [Indexed: 06/11/2023]
Abstract
Low soil water content can limit photosynthesis by reducing stomatal conductance. Here, we explore relationships among traits pertaining to carbon uptake and pre-dawn leaf water potential (as an index of soil water availability) across eight species found in semiarid central Australia. We found that as pre-dawn leaf water potential declined, stomatal limitations to photosynthesis increased, as did foliar nitrogen, which enhanced photosynthesis. Nitrogen-fixing Acacia species had higher foliar nitrogen concentrations compared with non-nitrogen fixing species, although there was considerable variability of traits within the Acacia genus. From principal component analysis we found that the most dissimilar species was Acacia aptaneura Maslin&J.E.Reid compared with both Eucalyptus camaldulensis Dehnh. and Corymbia opaca. (D.J.Carr & S.G.M.Carr)K.D.Hill&L.A.S.Johnson, having both the largest foliar N content, equal largest leaf mass per area and experiencing the lowest pre-dawn water potential of all species. A. aptaneura has shallow roots and grows above a hardpan that excludes access to groundwater, in contrast to E. camaldulensis and C. opaca, which are known to access groundwater. We conclude that ecohydrological niche separation is an important factor driving the variability of within-biome traits related to carbon gain. These observations have important implications for global vegetation models, which are parameterised with many of the traits measured here, but are often limited by data availability.
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Affiliation(s)
- Rachael H Nolan
- School of Life Sciences, University of Technology Sydney, PO Box 123, Broadway, NSW 2007, Australia
| | - Tonantzin Tarin
- School of Life Sciences, University of Technology Sydney, PO Box 123, Broadway, NSW 2007, Australia
| | - Kendal A Fairweather
- School of Life Sciences, University of Technology Sydney, PO Box 123, Broadway, NSW 2007, Australia
| | - James Cleverly
- School of Life Sciences, University of Technology Sydney, PO Box 123, Broadway, NSW 2007, Australia
| | - Derek Eamus
- School of Life Sciences, University of Technology Sydney, PO Box 123, Broadway, NSW 2007, Australia
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Nolan RH, Mitchell PJ, Bradstock RA, Lane PNJ. Structural adjustments in resprouting trees drive differences in post-fire transpiration. Tree Physiol 2014; 34:123-136. [PMID: 24536069 DOI: 10.1093/treephys/tpt125] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Following disturbance many woody species are capable of resprouting new foliage, resulting in a reduced leaf-to-sapwood area ratio and altered canopy structure. We hypothesized that such changes would promote adjustments in leaf physiology, resulting in higher rates of transpiration per unit leaf area, consistent with the mechanistic framework proposed by Whitehead et al. (Whitehead D, Jarvis PG, Waring RH (1984) Stomatal conductance, transpiration and resistance to water uptake in a Pinus sylvestris spacing experiment. Can J For Res 14:692-700). We tested this in Eucalyptus obliqua L'Hér following a wildfire by comparing trees with unburnt canopies with trees that had been subject to 100% canopy scorch and were recovering their leaf area via resprouting. In resprouting trees, foliage was distributed along the trunk and on lateral branches, resulting in shorter hydraulic path lengths. We evaluated measurements of whole-tree transpiration and structural and physiological traits expected to drive any changes in transpiration. We used these structural and physiological measurements to parameterize the Whitehead et al. equation, and found that the expected ratio of transpiration per unit leaf area between resprouting and unburnt trees was 3.41. This is similar to the observed ratio of transpiration per unit leaf area, measured from sapflow observations, which was 2.89 (i.e., resprouting trees had 188% higher transpiration per unit leaf area). Foliage at low heights (<2 m) was found to be significantly different to foliage in the tree crown (14-18 m) in a number of traits, including higher specific leaf area, midday leaf water potential and higher rates of stomatal conductance and photosynthesis. We conclude that these post-fire adjustments in resprouting trees help to drive increased stomatal conductance and hydraulic efficiency, promoting the rapid return of tree-scale transpiration towards pre-disturbance levels. These transient patterns in canopy transpiration have important implications for modelling stand-level water fluxes in forests capable of resprouting, which is frequently done on the basis of the leaf area index.
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Affiliation(s)
- Rachael H Nolan
- Department of Forest and Ecosystem Science, The University of Melbourne, 221 Bouverie St, Parkville, VIC 3010, Australia
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