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Harford AJ, Bartolo RE, Humphrey CL, Nicholson JD, Richardson DL, Rissik D, Iles M, Dambacher JM. Resolving ecosystem complexity in ecological risk assessment for mine site rehabilitation. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 319:115488. [PMID: 35982549 DOI: 10.1016/j.jenvman.2022.115488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 03/24/2022] [Accepted: 06/03/2022] [Indexed: 06/15/2023]
Abstract
CONTEXT Ecological Risk Assessments (ERAs) are important tools for supporting evidence-based decision making. However, most ERA frameworks rarely consider complex ecological feedbacks, which limit their capacity to evaluate risks at community and ecosystem levels of organisation. METHOD We used qualitative mathematical modelling to add additional perspectives to previously conducted ERAs for the rehabilitation of the Ranger uranium mine (Northern Territory, Australia) and support an assessment of the cumulative risks from the mine site. Using expert elicitation workshops, separate qualitative models and scenarios were developed for aquatic and terrestrial systems. The models developed in the workshops were used to construct Bayes Nets that predicted whole-of-ecosystem outcomes after components were perturbed. RESULTS The terrestrial model considered the effect of fire and weeds on established native vegetation that will be important for the successful rehabilitation of Ranger. It predicted that a combined intervention that suppresses both weeds and fire intensity gave similar response predictions as for weed control alone, except for lower levels of certainty to tall grasses and fire intensity in models with immature trees or tall grasses. However, this had ambiguous predictions for short grasses and forbs, and tall grasses in models representing mature vegetation. The aquatic model considered the effects of magnesium (Mg), a key solute in current and predicted mine runoff and groundwater egress, which is known to adversely affect many aquatic species. The aquatic models provided support that attached algae and phytoplankton assemblages are the key trophic base for food webs. It predicted that shifts in phytoplankton abundance arising from increase in Mg to receiving waters, may result in cascading effects through the food-chain. CONCLUSION The qualitative modelling approach was flexible and capable of modelling both gradual (i.e. decadal) processes in the mine-site restoration and the comparatively more rapid (seasonal) processes of the aquatic ecosystem. The modelling also provides a useful decision tool for identifying important ecosystem sub-systems for further research efforts.
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Affiliation(s)
- Andrew J Harford
- Department of Agriculture, Water and the Environment, Supervising Scientist Branch, Darwin, Northern Territory, 0801, Australia.
| | - Renee E Bartolo
- Department of Agriculture, Water and the Environment, Supervising Scientist Branch, Darwin, Northern Territory, 0801, Australia
| | - Chris L Humphrey
- Department of Agriculture, Water and the Environment, Supervising Scientist Branch, Darwin, Northern Territory, 0801, Australia
| | - Jaylen D Nicholson
- Department of Agriculture, Water and the Environment, Supervising Scientist Branch, Darwin, Northern Territory, 0801, Australia
| | | | - David Rissik
- BMT Australia, PO Box 203, Spring Hill, QLD, 4004, Australia
| | - Michelle Iles
- Energy Resources Australia, Darwin, Northern Territory, 0801, Australia
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Beringer J, Moore CE, Cleverly J, Campbell DI, Cleugh H, De Kauwe MG, Kirschbaum MUF, Griebel A, Grover S, Huete A, Hutley LB, Laubach J, Van Niel T, Arndt SK, Bennett AC, Cernusak LA, Eamus D, Ewenz CM, Goodrich JP, Jiang M, Hinko‐Najera N, Isaac P, Hobeichi S, Knauer J, Koerber GR, Liddell M, Ma X, Macfarlane C, McHugh ID, Medlyn BE, Meyer WS, Norton AJ, Owens J, Pitman A, Pendall E, Prober SM, Ray RL, Restrepo‐Coupe N, Rifai SW, Rowlings D, Schipper L, Silberstein RP, Teckentrup L, Thompson SE, Ukkola AM, Wall A, Wang Y, Wardlaw TJ, Woodgate W. Bridge to the future: Important lessons from 20 years of ecosystem observations made by the OzFlux network. GLOBAL CHANGE BIOLOGY 2022; 28:3489-3514. [PMID: 35315565 PMCID: PMC9314624 DOI: 10.1111/gcb.16141] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 01/30/2022] [Accepted: 02/08/2022] [Indexed: 06/14/2023]
Abstract
In 2020, the Australian and New Zealand flux research and monitoring network, OzFlux, celebrated its 20th anniversary by reflecting on the lessons learned through two decades of ecosystem studies on global change biology. OzFlux is a network not only for ecosystem researchers, but also for those 'next users' of the knowledge, information and data that such networks provide. Here, we focus on eight lessons across topics of climate change and variability, disturbance and resilience, drought and heat stress and synergies with remote sensing and modelling. In distilling the key lessons learned, we also identify where further research is needed to fill knowledge gaps and improve the utility and relevance of the outputs from OzFlux. Extreme climate variability across Australia and New Zealand (droughts and flooding rains) provides a natural laboratory for a global understanding of ecosystems in this time of accelerating climate change. As evidence of worsening global fire risk emerges, the natural ability of these ecosystems to recover from disturbances, such as fire and cyclones, provides lessons on adaptation and resilience to disturbance. Drought and heatwaves are common occurrences across large parts of the region and can tip an ecosystem's carbon budget from a net CO2 sink to a net CO2 source. Despite such responses to stress, ecosystems at OzFlux sites show their resilience to climate variability by rapidly pivoting back to a strong carbon sink upon the return of favourable conditions. Located in under-represented areas, OzFlux data have the potential for reducing uncertainties in global remote sensing products, and these data provide several opportunities to develop new theories and improve our ecosystem models. The accumulated impacts of these lessons over the last 20 years highlights the value of long-term flux observations for natural and managed systems. A future vision for OzFlux includes ongoing and newly developed synergies with ecophysiologists, ecologists, geologists, remote sensors and modellers.
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Three-Dimensional Distribution of Biomass Burning Aerosols from Australian Wildfires Observed by TROPOMI Satellite Observations. REMOTE SENSING 2022. [DOI: 10.3390/rs14112582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We present a novel passive satellite remote sensing approach for observing the three-dimensional distribution of aerosols emitted from wildfires. This method, called AEROS5P, retrieves vertical profiles of aerosol extinction from cloud-free measurements of the TROPOMI satellite sensor onboard the Sentinel 5 Precursor mission. It uses a Tikhonov–Phillips regularization, which iteratively fits near-infrared and visible selected reflectances to simultaneously adjust the vertical distribution and abundance of aerosols. The information on the altitude of the aerosol layers is provided by TROPOMI measurements of the reflectance spectra at the oxygen A-band near 760 nm. In the present paper, we use this new approach for observing the daily evolution of the three-dimensional distribution of biomass burning aerosols emitted by Australian wildfires on 20–24 December 2019. Aerosol optical depths (AOD) derived by vertical integration of the aerosol extinction profiles retrieved by AEROS5P are compared with MODIS, VIIRS and AERONET coincident observations. They show a good agreement in the horizontal distribution of biomass burning aerosols, with a correlation coefficient of 0.87 and a mean absolute error of 0.2 with respect to VIIRS. Moderately lower correlations (0.63) were found between AODs from AEROS5P and MODIS, while the range of values for this comparison was less than half of that with respect to VIIRS. A fair agreement was found between coincident transects of vertical profiles of biomass burning aerosols derived from AEROS5P and from the CALIOP spaceborne lidar. The mean altitudes of these aerosols derived from these two measurements showed a good agreement, with a small mean bias (185 m) and a correlation coefficient of 0.83. Moreover, AEROS5P observations reveal the height of injection of the biomass burning aerosols in 3D. The highest injection heights during the period of analysis were coincident with the largest fire radiative power derived from MODIS. Consistency was also found with respect to the vertical stability of the atmosphere. The AEROS5P approach provides retrievals for cloud-free scenes over several regions, although currently limited to situations with a dominating presence of smoke particles. Future developments will also aim at observing other aerosol species.
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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] [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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Teixeira J, Souza L, Le Stradic S, Fidelis A. Fire promotes functional plant diversity and modifies soil carbon dynamics in tropical savanna. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 812:152317. [PMID: 34914993 DOI: 10.1016/j.scitotenv.2021.152317] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 12/07/2021] [Accepted: 12/07/2021] [Indexed: 06/14/2023]
Abstract
Fire is an evolutionary environmental filter in tropical savanna ecosystems altering functional diversity and associated C pools in the biosphere and fluxes between the atmosphere and biosphere. Therefore, alterations in fire regimes (e.g. fire exclusion) will strongly influence ecosystem processes and associated dynamics. In those ecosystems C dynamics and functions are underestimated by the fire-induced offset between C output and input. To determine how fire shapes ecosystem C pools and fluxes in an open savanna across recently burned and fire excluded areas, we measured the following metrics: (I) plant diversity including taxonomic (i.e. richness, evenness) and plant functional diversity (i.e. functional diversity, functional richness, functional dispersion and community weighted means); (II) structure (i.e. above- and below-ground biomass, litter accumulation); and (III) functions related to C balance (i.e. net ecosystem carbon dioxide (CO2) exchange (NEE), ecosystem transpiration (ET), soil respiration (soil CO2 efflux), ecosystem water use efficiency (eWUE) and total soil organic C (SOC). We found that fire promoted aboveground live and belowground biomass, including belowground organs, coarse and fine root biomass and contributed to higher biomass allocation belowground. Fire also increased both functional diversity and dispersion. NEE and total SOC were higher in burned plots compared to fire-excluded plots whereas soil respiration recorded lower values in burned areas. Both ET and eWUE were not affected by fire. Fire strongly favored functional diversity, fine root and belowground organ biomass in piecewise SEM models but the role of both functional diversity and ecosystem structure to mediate the effect of fire on ecosystem functions remain unclear. Fire regime will impact C balance, and fire exclusion may lead to lower C input in open savanna ecosystems.
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Affiliation(s)
- Juliana Teixeira
- Laboratory of Vegetation Ecology, Department of Biodiversity, Bioscience Institute, São Paulo State University (Unesp), Av. 24 A 1515, 13506-900 Rio Claro, SP, Brazil; Oklahoma Biological Survey & Department of Microbiology and Plant Biology, the University of Oklahoma, 111 E. Chesapeake Street, Norman, OK 73019-0390, USA.
| | - Lara Souza
- Oklahoma Biological Survey & Department of Microbiology and Plant Biology, the University of Oklahoma, 111 E. Chesapeake Street, Norman, OK 73019-0390, USA
| | - Soizig Le Stradic
- Chair of Restoration Ecology, Department of Life Science Systems, Technical University of Munich, Emil-Ramann-Str. 6, 85354 Freising, Germany
| | - Alessandra Fidelis
- Laboratory of Vegetation Ecology, Department of Biodiversity, Bioscience Institute, São Paulo State University (Unesp), Av. 24 A 1515, 13506-900 Rio Claro, SP, Brazil
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Rehn E, Rowe C, Ulm S, Gadd P, Zawadzki A, Jacobsen G, Woodward C, Bird M. Multiproxy Holocene Fire Records From the Tropical Savannas of Northern Cape York Peninsula, Queensland, Australia. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.771700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Paleoecology has demonstrated potential to inform current and future land management by providing long-term baselines for fire regimes, over thousands of years covering past periods of lower/higher rainfall and temperatures. To extend this potential, more work is required for methodological innovation able to generate nuanced, relevant and clearly interpretable results. This paper presents records from Cape York Peninsula, Queensland, Australia, as a case study where fire management is an important but socially complex modern management issue, and where palaeofire records are limited. Two new multiproxy palaeofire records are presented from Sanamere Lagoon (8,150–6,600 cal BP) and Big Willum Swamp (3,900 cal BP to present). These records combine existing methods to investigate fire occurrence, vegetation types, and relative fire intensity. Results presented here demonstrate a diversity of fire histories at different sites across Cape York Peninsula, highlighting the need for finer scale palaeofire research. Future fire management planning on Cape York Peninsula must take into account the thousands of years of active Indigenous management and this understanding can be further informed by paleoecological research.
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Bennett AC, Arndt SK, Bennett LT, Knauer J, Beringer J, Griebel A, Hinko-Najera N, Liddell MJ, Metzen D, Pendall E, Silberstein RP, Wardlaw TJ, Woodgate W, Haverd V. Thermal optima of gross primary productivity are closely aligned with mean air temperatures across Australian wooded ecosystems. GLOBAL CHANGE BIOLOGY 2021; 27:4727-4744. [PMID: 34165839 DOI: 10.1111/gcb.15760] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 06/15/2021] [Accepted: 06/19/2021] [Indexed: 06/13/2023]
Abstract
Gross primary productivity (GPP) of wooded ecosystems (forests and savannas) is central to the global carbon cycle, comprising 67%-75% of total global terrestrial GPP. Climate change may alter this flux by increasing the frequency of temperatures beyond the thermal optimum of GPP (Topt ). We examined the relationship between GPP and air temperature (Ta) in 17 wooded ecosystems dominated by a single plant functional type (broadleaf evergreen trees) occurring over a broad climatic gradient encompassing five ecoregions across Australia ranging from tropical in the north to Mediterranean and temperate in the south. We applied a novel boundary-line analysis to eddy covariance flux observations to (a) derive ecosystem GPP-Ta relationships and Topt (including seasonal analyses for five tropical savannas); (b) quantitatively and qualitatively assess GPP-Ta relationships within and among ecoregions; (c) examine the relationship between Topt and mean daytime air temperature (MDTa) across all ecosystems; and (d) examine how down-welling short-wave radiation (Fsd) and vapour pressure deficit (VPD) influence the GPP-Ta relationship. GPP-Ta relationships were convex parabolas with narrow curves in tropical forests, tropical savannas (wet season), and temperate forests, and wider curves in temperate woodlands, Mediterranean woodlands, and tropical savannas (dry season). Ecosystem Topt ranged from 15℃ (temperate forest) to 32℃ (tropical savanna-wet and dry seasons). The shape of GPP-Ta curves was largely determined by daytime Ta range, MDTa, and maximum GPP with the upslope influenced by Fsd and the downslope influenced by VPD. Across all ecosystems, there was a strong positive linear relationship between Topt and MDTa (Adjusted R2 : 0.81; Slope: 1.08) with Topt exceeding MDTa by >1℃ at all but two sites. We conclude that ecosystem GPP has adjusted to local MDTa within Australian broadleaf evergreen forests and that GPP is buffered against small Ta increases in the majority of these ecosystems.
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Affiliation(s)
- Alison C Bennett
- School of Ecosystem and Forest Science, University of Melbourne, Richmond, Vic., Australia
| | - Stefan K Arndt
- School of Ecosystem and Forest Science, University of Melbourne, Richmond, Vic., Australia
| | - Lauren T Bennett
- School of Ecosystem and Forest Science, University of Melbourne, Creswick, Vic., Australia
| | - Jürgen Knauer
- CSIRO, Oceans and Atmosphere, Canberra, ACT, Australia
| | - Jason Beringer
- School of Agriculture and Environment, The University of Western Australia, Crawley, WA, Australia
| | - Anne Griebel
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Nina Hinko-Najera
- School of Ecosystem and Forest Science, University of Melbourne, Creswick, Vic., Australia
| | - Michael J Liddell
- Centre for Tropical Environmental and Sustainability Science and College of Science and Engineering, James Cook University, Cairns, Qld, Australia
| | - Daniel Metzen
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Elise Pendall
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Richard P Silberstein
- School of Agriculture and Environment, The University of Western Australia, Crawley, WA, Australia
- Centre for Ecosystem Management, School of Science, Edith Cowan University, Joondalup, WA, Australia
| | - Timothy J Wardlaw
- ARC Centre for Forest Value, University of Tasmania, Hobart, TAS, Australia
| | - William Woodgate
- CSIRO, Land and Water, Canberra, ACT, Australia
- School of Earth and Environmental Sciences, The University of Queensland, St Lucia, Qld, Australia
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Edwards A, Archer R, De Bruyn P, Evans J, Lewis B, Vigilante T, Whyte S, Russell-Smith J. Transforming fire management in northern Australia through successful implementation of savanna burning emissions reductions projects. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 290:112568. [PMID: 33887642 DOI: 10.1016/j.jenvman.2021.112568] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 04/05/2021] [Accepted: 04/05/2021] [Indexed: 06/12/2023]
Abstract
Savannas are the most fire-prone of Earth's biomes and currently account for most global burned area and associated carbon emissions. In Australia, over recent decades substantial development of savanna burning emissions accounting methods has been undertaken to incentivise more conservative savanna fire management and reduce the extent and severity of late dry season wildfires. Since inception of Australia's formal regulated savanna burning market in 2012, today 25% of the 1.2M km2 fire-prone northern savanna region is managed under such arrangements. Although savanna burning projects generate significant emissions reductions and associated financial benefits especially for Indigenous landowners, various biodiversity conservation considerations, including fine-scale management requirements for conservation of fire-vulnerable taxa, remain contentious. For the entire savanna burning region, here we compare outcomes achieved at 'with-project' vs 'non-project' sites over the period 2000-19, with respect to explicit ecologically defined fire regime metrics, and assembled fire history and spatial mapping coverages. We find that there has been little significant fire regime change at non-project sites, whereas, at with-project sites under all land uses, from 2013 there has been significant reduction in late season wildfire, increase in prescribed early season mitigation burning and patchiness metrics, and seasonally variable changes in extent of unburnt (>2, >5 years) habitat. Despite these achievements, it is acknowledged that savanna burning projects do not provide a fire management panacea for a variety of key regional conservation, production, and cultural management issues. Rather, savanna burning projects can provide an effective operational funded framework to assist with delivering various landscape-scale management objectives. With these caveats in mind, significant potential exists for implementing incentivised fire management approaches in other fire-prone international savanna settings.
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Affiliation(s)
- Andrew Edwards
- Darwin Centre for Bushfire Research, Charles Darwin University, Darwin NT, 0909, Australia; Bushfire & Natural Hazards Cooperative Research Centre, East Melbourne Vic, 3002, Australia
| | - Ricky Archer
- North Australian Land and Sea Management Alliance, PO Box 486 CDU NT 0815, Australia
| | - Phillip De Bruyn
- Western Australia Department of Biodiversity, Conservation and Attractions, PO Box 65 Broome, WA, 6725, Australia
| | - Jay Evans
- Darwin Centre for Bushfire Research, Charles Darwin University, Darwin NT, 0909, Australia; Bushfire & Natural Hazards Cooperative Research Centre, East Melbourne Vic, 3002, Australia
| | - Ben Lewis
- Fire Stick & Associates, PO Box 18 Pine Creek NT 0847, Australia
| | - Tom Vigilante
- Wunambal Gaambera Aboriginal Corporation, PMB 16 Kalumburu, WA, 6740, Australia
| | - Sandy Whyte
- APN (Aaak Puul Ngantam) Cape York, Level 1 18-20 Donaldson street, Cairns Qld, 4870, Australia
| | - Jeremy Russell-Smith
- Darwin Centre for Bushfire Research, Charles Darwin University, Darwin NT, 0909, Australia; Bushfire & Natural Hazards Cooperative Research Centre, East Melbourne Vic, 3002, Australia; North Australian Land and Sea Management Alliance, PO Box 486 CDU NT 0815, Australia
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Veenendaal EM, Torello‐Raventos M, Miranda HS, Sato NM, Janssen TAJ, van Langevelde F, Lloyd J. Fire regimes, fire experiments and alternative stable states in mesic savannas: A response to Laris & Jacobs (2021) 'On the problem of natural savanna fires'. THE NEW PHYTOLOGIST 2021; 231:14-18. [PMID: 33759454 PMCID: PMC9292302 DOI: 10.1111/nph.17331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 08/19/2018] [Indexed: 06/12/2023]
Affiliation(s)
- Elmar M. Veenendaal
- Plant Ecology and Nature Conservation GroupWageningen UniversityWageningen6700 AAthe Netherlands
| | | | - Heloisa S. Miranda
- Departmento de EcologiaUniversidade de BrasiliaBrasiliaDF70910‐900Brazil
| | - Naomi M. Sato
- Departmento de EcologiaUniversidade de BrasiliaBrasiliaDF70910‐900Brazil
| | - Thomas A. J. Janssen
- Department of Earth Sciences, Cluster Earth and ClimateVrije Universiteit AmsterdamAmsterdamthe Netherlands
| | - Frank van Langevelde
- Wildlife Ecology and Conservation GroupWageningen UniversityWageningen6700 AAthe Netherlands
- School of Life SciencesUniversity of KwaZulu‐NatalWestville CampusDurban4000South Africa
| | - Jon Lloyd
- School of Marine and Environmental SciencesJames Cook UniversityCairnsQld4870Australia
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Santos ACD, Montenegro SDR, Ferreira MC, Barradas ACS, Schmidt IB. Managing fires in a changing world: Fuel and weather determine fire behavior and safety in the neotropical savannas. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 289:112508. [PMID: 33831763 DOI: 10.1016/j.jenvman.2021.112508] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Revised: 03/23/2021] [Accepted: 03/25/2021] [Indexed: 06/12/2023]
Abstract
Fire is an important ecological disturbance, but anthropogenic wildfires increasingly threaten native ecosystems and human lives. In fire-prone ecosystems, zero-fire policies have been replaced by active fire management to reduce the risk of wildfires and improve ecological outcomes. The environmental drivers of fire behavior are widely known, but climate change and deforestation are changing their roles, making fires less predictable. Thus, reassessing the main determinants of fire behavior is preeminent to allow for safe and adaptive uses of fire in protected areas (PA). We did this research in collaboration with PA managers during the initial implementation of a pilot Integrated Fire Management (IFM) program in the Brazilian savanna. The program mainly aimed to prevent large wildfires in the late-dry season and included prescribed burns during the rainy, early- and mid-dry seasons to create vegetation patch mosaics with different fire histories. We assessed fire behavior and its environmental drivers during prescribed fires in the mid-dry season (MF) and experimental late-dry season fires (LF) (emulating wildfires). We applied Linear Models to test for differences in fire intensity, heat released, combustion factor and flame height between fire seasons and to check the influence of meteorological and fuel conditions in these parameters. LF had a significantly higher fire intensity (3508 vs. 895 kW m-1), heat released (5537 vs. 3329 kW m-2), combustion factor (90 vs. 51%) and flame height (2.5 vs. 1.9 m) than MF. Relative humidity, air temperature, wind speed and fuel load were the best predictors of fire behavior, corroborating previous research. Air temperature and relative humidity pushed the seasonal differences in fire behavior while wind speed and fuel load showed similar effects across seasons. Our results emphasize the importance of considering primarily environmental variables during fire management planning, especially in the current climate changing world where extreme events and seasonal weather fluctuations are constantly defying our knowledge about fire behavior.
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Affiliation(s)
- Ana Carla Dos Santos
- Departamento de Ecologia, Universidade de Brasília, Campus Universitário Darcy Ribeiro, Brasília, DF, CEP 70910-900, Brazil; PEQUI - Pesquisa e Conservação do Cerrado. SRTVN Qd. 701, Ed. Brasília Rádio Center, Sala 3030, Brasília, DF, CEP: 70719-900, Brazil.
| | - Samuel da Rocha Montenegro
- Departamento de Ecologia, Universidade de Brasília, Campus Universitário Darcy Ribeiro, Brasília, DF, CEP 70910-900, Brazil.
| | - Maxmiller Cardoso Ferreira
- Departamento de Ecologia, Universidade de Brasília, Campus Universitário Darcy Ribeiro, Brasília, DF, CEP 70910-900, Brazil.
| | - Ana Carolina Sena Barradas
- Estação Ecológica Serra Geral do Tocantins, Avenida Beira Rio. Quadra 02. Lote 06, Bairro Centro, Rio da Conceição, TO, CEP 77303-000, Brazil.
| | - Isabel Belloni Schmidt
- Departamento de Ecologia, Universidade de Brasília, Campus Universitário Darcy Ribeiro, Brasília, DF, CEP 70910-900, Brazil; PEQUI - Pesquisa e Conservação do Cerrado. SRTVN Qd. 701, Ed. Brasília Rádio Center, Sala 3030, Brasília, DF, CEP: 70719-900, Brazil.
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11
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Leveraging TLS as a Calibration and Validation Tool for MLS and ULS Mapping of Savanna Structure and Biomass at Landscape-Scales. REMOTE SENSING 2021. [DOI: 10.3390/rs13020257] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Savanna ecosystems are challenging to map and monitor as their vegetation is highly dynamic in space and time. Understanding the structural diversity and biomass distribution of savanna vegetation requires high-resolution measurements over large areas and at regular time intervals. These requirements cannot currently be met through field-based inventories nor spaceborne satellite remote sensing alone. UAV-based remote sensing offers potential as an intermediate scaling tool, providing acquisition flexibility and cost-effectiveness. Yet despite the increased availability of lightweight LiDAR payloads, the suitability of UAV-based LiDAR for mapping and monitoring savanna 3D vegetation structure is not well established. We mapped a 1 ha savanna plot with terrestrial-, mobile- and UAV-based laser scanning (TLS, MLS, and ULS), in conjunction with a traditional field-based inventory (n = 572 stems > 0.03 m). We treated the TLS dataset as the gold standard against which we evaluated the degree of complementarity and divergence of structural metrics from MLS and ULS. Sensitivity analysis showed that MLS and ULS canopy height models (CHMs) did not differ significantly from TLS-derived models at spatial resolutions greater than 2 m and 4 m respectively. Statistical comparison of the resulting point clouds showed minor over- and under-estimation of woody canopy cover by MLS and ULS, respectively. Individual stem locations and DBH measurements from the field inventory were well replicated by the TLS survey (R2 = 0.89, RMSE = 0.024 m), which estimated above-ground woody biomass to be 7% greater than field-inventory estimates (44.21 Mg ha−1 vs 41.08 Mg ha−1). Stem DBH could not be reliably estimated directly from the MLS or ULS, nor indirectly through allometric scaling with crown attributes (R2 = 0.36, RMSE = 0.075 m). MLS and ULS show strong potential for providing rapid and larger area capture of savanna vegetation structure at resolutions suitable for many ecological investigations; however, our results underscore the necessity of nesting TLS sampling within these surveys to quantify uncertainty. Complementing large area MLS and ULS surveys with TLS sampling will expand our options for the calibration and validation of multiple spaceborne LiDAR, SAR, and optical missions.
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12
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Vogado NO, Winter K, Ubierna N, Farquhar GD, Cernusak LA. Directional change in leaf dry matter δ 13C during leaf development is widespread in C3 plants. ANNALS OF BOTANY 2020; 126:981-990. [PMID: 32577724 PMCID: PMC7596372 DOI: 10.1093/aob/mcaa114] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 06/17/2020] [Indexed: 05/23/2023]
Abstract
BACKGROUND AND AIMS The stable carbon isotope ratio of leaf dry matter (δ 13Cp) is generally a reliable recorder of intrinsic water-use efficiency in C3 plants. Here, we investigated a previously reported pattern of developmental change in leaf δ 13Cp during leaf expansion, whereby emerging leaves are initially 13C-enriched compared to mature leaves on the same plant, with their δ 13Cp decreasing during leaf expansion until they eventually take on the δ 13Cp of other mature leaves. METHODS We compiled data to test whether the difference between mature and young leaf δ 13Cp differs between temperate and tropical species, or between deciduous and evergreen species. We also tested whether the developmental change in δ 13Cp is indicative of a concomitant change in intrinsic water-use efficiency. To gain further insight, we made online measurements of 13C discrimination (∆ 13C) in young and mature leaves. KEY RESULTS We found that the δ 13Cp difference between mature and young leaves was significantly larger for deciduous than for evergreen species (-2.1 ‰ vs. -1.4 ‰, respectively). Counter to expectation based on the change in δ 13Cp, intrinsic water-use efficiency did not decrease between young and mature leaves; rather, it did the opposite. The ratio of intercellular to ambient CO2 concentrations (ci/ca) was significantly higher in young than in mature leaves (0.86 vs. 0.72, respectively), corresponding to lower intrinsic water-use efficiency. Accordingly, instantaneous ∆ 13C was also higher in young than in mature leaves. Elevated ci/ca and ∆ 13C in young leaves resulted from a combination of low photosynthetic capacity and high day respiration rates. CONCLUSION The decline in leaf δ 13Cp during leaf expansion appears to reflect the addition of the expanding leaf's own 13C-depleted photosynthetic carbon to that imported from outside the leaf as the leaf develops. This mixing of carbon sources results in an unusual case of isotopic deception: less negative δ 13Cp in young leaves belies their low intrinsic water-use efficiency.
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Affiliation(s)
- Nara O Vogado
- Centre for Tropical Environmental and Sustainability Science, College of Science and Engineering, James Cook University, Cairns, Australia
| | - Klaus Winter
- Smithsonian Tropical Research Institute, Balboa, Ancon, Republic of Panama
| | - Nerea Ubierna
- Research School of Biology, The Australian National University, Canberra, Australia
| | - Graham D Farquhar
- Research School of Biology, The Australian National University, Canberra, Australia
| | - Lucas A Cernusak
- Centre for Tropical Environmental and Sustainability Science, College of Science and Engineering, James Cook University, Cairns, Australia
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13
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Duvert C, Hutley LB, Beringer J, Bird MI, Birkel C, Maher DT, Northwood M, Rudge M, Setterfield SA, Wynn JG. Net landscape carbon balance of a tropical savanna: Relative importance of fire and aquatic export in offsetting terrestrial production. GLOBAL CHANGE BIOLOGY 2020; 26:5899-5913. [PMID: 32686242 DOI: 10.1111/gcb.15287] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 07/07/2020] [Accepted: 07/14/2020] [Indexed: 06/11/2023]
Abstract
The magnitude of the terrestrial carbon (C) sink may be overestimated globally due to the difficulty of accounting for all C losses across heterogeneous landscapes. More complete assessments of net landscape C balances (NLCB) are needed that integrate both emissions by fire and transfer to aquatic systems, two key loss pathways of terrestrial C. These pathways can be particularly significant in the wet-dry tropics, where fire plays a fundamental part in ecosystems and where intense rainfall and seasonal flooding can result in considerable aquatic C export (ΣFaq ). Here, we determined the NLCB of a lowland catchment (~140 km2 ) in tropical Australia over 2 years by evaluating net terrestrial productivity (NEP), fire-related C emissions and ΣFaq (comprising both downstream transport and gaseous evasion) for the two main landscape components, that is, savanna woodland and seasonal wetlands. We found that the catchment was a large C sink (NLCB 334 Mg C km-2 year-1 ), and that savanna and wetland areas contributed 84% and 16% to this sink, respectively. Annually, fire emissions (-56 Mg C km-2 year-1 ) and ΣFaq (-28 Mg C km-2 year-1 ) reduced NEP by 13% and 7%, respectively. Savanna burning shifted the catchment to a net C source for several months during the dry season, while ΣFaq significantly offset NEP during the wet season, with a disproportionate contribution by single major monsoonal events-up to 39% of annual ΣFaq was exported in one event. We hypothesize that wetter and hotter conditions in the wet-dry tropics in the future will increase ΣFaq and fire emissions, potentially further reducing the current C sink in the region. More long-term studies are needed to upscale this first NLCB estimate to less productive, yet hydrologically dynamic regions of the wet-dry tropics where our result indicating a significant C sink may not hold.
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Affiliation(s)
- Clément Duvert
- Research Institute for the Environment & Livelihoods, Charles Darwin University, Darwin, NT, Australia
| | - Lindsay B Hutley
- Research Institute for the Environment & Livelihoods, Charles Darwin University, Darwin, NT, Australia
| | - Jason Beringer
- School of Agriculture & Environment, The University of Western Australia, Perth, WA, Australia
| | - Michael I Bird
- College of Science & Engineering, James Cook University, Cairns, Qld, Australia
| | - Christian Birkel
- Department of Geography, Water & Global Change Observatory, University of Costa Rica, San José, Costa Rica
- Northern Rivers Institute, University of Aberdeen, Aberdeen, UK
| | - Damien T Maher
- Southern Cross Geoscience, Southern Cross University, Lismore, NSW, Australia
| | - Matthew Northwood
- Research Institute for the Environment & Livelihoods, Charles Darwin University, Darwin, NT, Australia
| | - Mitchel Rudge
- Sustainable Minerals Institute, The University of Queensland, Brisbane, Qld, Australia
| | - Samantha A Setterfield
- School of Biological Sciences, The University of Western Australia, Perth, WA, Australia
| | - Jonathan G Wynn
- Division of Earth Sciences, National Science Foundation, Alexandria, VA, USA
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14
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Liu N, Kala J, Liu S, Haverd V, Dell B, Smettem KRJ, Harper RJ. Drought can offset potential water use efficiency of forest ecosystems from rising atmospheric CO 2. J Environ Sci (China) 2020; 90:262-274. [PMID: 32081322 DOI: 10.1016/j.jes.2019.11.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Revised: 03/06/2019] [Accepted: 12/05/2019] [Indexed: 06/10/2023]
Abstract
Increasing atmospheric CO2 is both leading to climate change and providing a potential fertilisation effect on plant growth. However, southern Australia has also experienced a significant decline in rainfall over the last 30 years, resulting in increased vegetative water stress. To better understand the dynamics and responses of Australian forest ecosystems to drought and elevated CO2, the magnitude and trend in water use efficiency (WUE) of forests, and their response to drought and elevated CO2 from 1982 to 2014 were analysed, using the best available model estimates constrained by observed fluxes from simulations with fixed and time-varying CO2. The ratio of gross primary productivity (GPP) to evapotranspiration (ET) (WUEe) was used to identify the ecosystem scale WUE, while the ratio of GPP to transpiration (Tr) (WUEc) was used as a measure of canopy scale WUE. WUE increased significantly in northern Australia (p < 0.001) for woody savannas (WSA), whereas there was a slight decline in the WUE of evergreen broadleaf forests (EBF) in the southeast and southwest of Australia. The lag of WUEc to drought was consistent and relatively short and stable between biomes (≤3 months), but notably varied for WUEe, with a long time-lag (mean of 10 months). The dissimilar responses of WUEe and WUEc to climate change for different geographical areas result from the different proportion of Tr in ET. CO2 fertilization and a wetter climate enhanced WUE in northern Australia, whereas drought offset the CO2 fertilization effect in southern Australia.
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Affiliation(s)
- Ning Liu
- Environmental and Conservation Sciences, Murdoch University, Murdoch, WA 6150 Australia; Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 10091 China.
| | - Jatin Kala
- Environmental and Conservation Sciences, Murdoch University, Murdoch, WA 6150 Australia
| | - Shirong Liu
- Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 10091 China
| | | | - Bernard Dell
- Environmental and Conservation Sciences, Murdoch University, Murdoch, WA 6150 Australia; Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 10091 China
| | - Keith R J Smettem
- Environmental and Conservation Sciences, Murdoch University, Murdoch, WA 6150 Australia
| | - Richard J Harper
- Environmental and Conservation Sciences, Murdoch University, Murdoch, WA 6150 Australia; Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 10091 China.
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15
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Indigenous Knowledge and Seasonal Calendar Inform Adaptive Savanna Burning in Northern Australia. SUSTAINABILITY 2020. [DOI: 10.3390/su12030995] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Indigenous fire management is experiencing a resurgence worldwide. Northern Australia is the world leader in Indigenous savanna burning, delivering social, cultural, environmental and economic benefits. In 2016, a greenhouse gas abatement fire program commenced in the savannas of south-eastern Arnhem Land in the Northern Territory, managed by the Indigenous Yugul Mangi rangers. We undertook participatory action research and semi-structured interviews with rangers and Elders during 2016 and 2019 to investigate Indigenous knowledge and obtain local feedback about fire management. Results indicated that Indigenous rangers effectively use cross-cultural science (including local and Traditional Ecological Knowledge alongside western science) to manage fire. Fire management is a key driver in the production of bush tucker (wild food) resources and impacts other cultural and ecological values. A need for increased education and awareness about Indigenous burning was consistently emphasized. To address this, the project participants developed the Yugul Mangi Faiya En Sisen Kelenda (Yugul Mangi Fire and Seasons Calendar) that drew on Indigenous knowledge of seasonal biocultural indicators to guide the rangers’ fire management planning. The calendar has potential for application in fire management planning, intergenerational transfer of Indigenous knowledge and locally driven adaptive fire management.
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16
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Cernusak LA. Gas exchange and water-use efficiency in plant canopies. PLANT BIOLOGY (STUTTGART, GERMANY) 2020; 22 Suppl 1:52-67. [PMID: 30428160 DOI: 10.1111/plb.12939] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 11/08/2018] [Indexed: 06/09/2023]
Abstract
In this review, I first address the basics of gas exchange, water-use efficiency and carbon isotope discrimination in C3 plant canopies. I then present a case study of water-use efficiency in northern Australian tree species. In general, C3 plants face a trade-off whereby increasing stomatal conductance for a given set of conditions will result in a higher CO2 assimilation rate, but a lower photosynthetic water-use efficiency. A common garden experiment suggested that tree species which are able to establish and grow in drier parts of northern Australia have a capacity to use water rapidly when it is available through high stomatal conductance, but that they do so at the expense of low water-use efficiency. This may explain why community-level carbon isotope discrimination does not decrease as steeply with decreasing rainfall on the North Australian Tropical Transect as has been observed on some other precipitation gradients. Next, I discuss changes in water-use efficiency that take place during leaf expansion in C3 plant leaves. Leaf phenology has recently been recognised as a significant driver of canopy gas exchange in evergreen forest canopies, and leaf expansion involves changes in both photosynthetic capacity and water-use efficiency. Following this, I discuss the role of woody tissue respiration in canopy gas exchange and how photosynthetic refixation of respired CO2 can increase whole-plant water-use efficiency. Finally, I discuss the role of water-use efficiency in driving terrestrial plant responses to global change, especially the rising concentration of atmospheric CO2 . In coming decades, increases in plant water-use efficiency caused by rising CO2 are likely to partially mitigate impacts on plants of drought stress caused by global warming.
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Affiliation(s)
- L A Cernusak
- College of Science and Engineering, James Cook University, Cairns, Australia
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17
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Exploring the Potential of C-Band SAR in Contributing to Burn Severity Mapping in Tropical Savanna. REMOTE SENSING 2019. [DOI: 10.3390/rs12010049] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The ability to map burn severity and to understand how it varies as a function of time of year and return frequency is an important tool for landscape management and carbon accounting in tropical savannas. Different indices based on optical satellite imagery are typically used for mapping fire scars and for estimating burn severity. However, cloud cover is a major limitation for analyses using optical data over tropical landscapes. To address this pitfall, we explored the suitability of C-band Synthetic Aperture Radar (SAR) data for detecting vegetation response to fire, using experimental fires in northern Australia. Pre- and post-fire results from Sentinel-1 C-band backscatter intensity data were compared to those of optical satellite imagery and were corroborated against structural changes on the ground that we documented through terrestrial laser scanning (TLS). Sentinel-1 C-band backscatter (VH) proved sensitive to the structural changes imparted by fire and was correlated with the Normalised Burn Ratio (NBR) derived from Sentinel-2 optical data. Our results suggest that C-band SAR holds potential to inform the mapping of burn severity in savannas, but further research is required over larger spatial scales and across a broader spectrum of fire regime conditions before automated products can be developed. Combining both Sentinel-1 SAR and Sentinel-2 multi-spectral data will likely yield the best results for mapping burn severity under a range of weather conditions.
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18
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Corey B, Andersen AN, Legge S, Woinarski JCZ, Radford IJ, Perry JJ. Better biodiversity accounting is needed to prevent bioperversity and maximize co‐benefits from savanna burning. Conserv Lett 2019. [DOI: 10.1111/conl.12685] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Affiliation(s)
- Ben Corey
- Department of Biodiversity, Conservation and Attractions Kununurra Western Australia Australia
| | - Alan N. Andersen
- Research Institute for the Environment and LivelihoodsCharles Darwin University Darwin Northern Territory Australia
| | - Sarah Legge
- School of Conservation and Biodiversity ScienceUniversity of Queensland St. Lucia Queensland Australia
- Fenner School of Environment and SocietyThe Australian National University Canberra Australian Capital Territory Australia
| | - John C. Z. Woinarski
- Research Institute for the Environment and LivelihoodsCharles Darwin University Darwin Northern Territory Australia
| | - Ian J. Radford
- Department of Biodiversity, Conservation and Attractions Kununurra Western Australia Australia
| | - Justin J. Perry
- Department of Land and WaterCSIRO Townsville Queensland Australia
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19
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Martin DA. Linking fire and the United Nations Sustainable Development Goals. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 662:547-558. [PMID: 30699375 DOI: 10.1016/j.scitotenv.2018.12.393] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Revised: 10/15/2018] [Accepted: 12/25/2018] [Indexed: 06/09/2023]
Abstract
Fire is a ubiquitous natural disturbance that affects 3-4% of the Earth's surface each year. It is a tool used by humans for land clearing and burning of agricultural wastes. The United Nations Sustainable Development Goals (SDGs) do not explicitly mention fire, though many of the Goals are affected by the beneficial and adverse consequences of fires on ecosystem services. There are at least three compelling reasons to include a fire perspective in the implementation of the United Nations Sustainable Development Goals. The first reason relates to the stated vision of the United Nations 2030 Agenda to protect the environment. In order to achieve environmental protection during sustainable development activities, it is necessary to understand and plan for the effects of disturbances, in this case fire, on ecosystem services. The second reason is that fires produce emissions with regional and global impacts on air quality and rainfall patterns. Fires contribute to global warming though the release greenhouse gases, primarily CO2, and black carbon, identified as a SLCP (short-lived climate pollutant). The third reason is that fire is one of several complex processes that lead to land degradation across the globe. Opportunities exist to incorporate a fire perspective into sustainable development projects or approaches. Two examples are highlighted here. Transdisciplinary communication and collaboration are needed to address the complex issues related to fire, and to climate and land use change.
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Affiliation(s)
- Deborah A Martin
- Research Hydrologist, Emerita, U.S. Geological Survey, 3215 Marine Street, Boulder, CO, USA.
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20
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Using Near-Infrared-Enabled Digital Repeat Photography to Track Structural and Physiological Phenology in Mediterranean Tree–Grass Ecosystems. REMOTE SENSING 2018. [DOI: 10.3390/rs10081293] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Tree–grass ecosystems are widely distributed. However, their phenology has not yet been fully characterized. The technique of repeated digital photographs for plant phenology monitoring (hereafter referred as PhenoCam) provide opportunities for long-term monitoring of plant phenology, and extracting phenological transition dates (PTDs, e.g., start of the growing season). Here, we aim to evaluate the utility of near-infrared-enabled PhenoCam for monitoring the phenology of structure (i.e., greenness) and physiology (i.e., gross primary productivity—GPP) at four tree–grass Mediterranean sites. We computed four vegetation indexes (VIs) from PhenoCams: (1) green chromatic coordinates (GCC), (2) normalized difference vegetation index (CamNDVI), (3) near-infrared reflectance of vegetation index (CamNIRv), and (4) ratio vegetation index (CamRVI). GPP is derived from eddy covariance flux tower measurement. Then, we extracted PTDs and their uncertainty from different VIs and GPP. The consistency between structural (VIs) and physiological (GPP) phenology was then evaluated. CamNIRv is best at representing the PTDs of GPP during the Green-up period, while CamNDVI is best during the Dry-down period. Moreover, CamNIRv outperforms the other VIs in tracking growing season length of GPP. In summary, the results show it is promising to track structural and physiology phenology of seasonally dry Mediterranean ecosystem using near-infrared-enabled PhenoCam. We suggest using multiple VIs to better represent the variation of GPP.
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21
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Moore CE, Beringer J, Donohue RJ, Evans B, Exbrayat JF, Hutley LB, Tapper NJ. Seasonal, interannual and decadal drivers of tree and grass productivity in an Australian tropical savanna. GLOBAL CHANGE BIOLOGY 2018; 24:2530-2544. [PMID: 29488666 DOI: 10.1111/gcb.14072] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2017] [Revised: 01/02/2018] [Accepted: 01/06/2018] [Indexed: 06/08/2023]
Abstract
Tree-grass savannas are a widespread biome and are highly valued for their ecosystem services. There is a need to understand the long-term dynamics and meteorological drivers of both tree and grass productivity separately in order to successfully manage savannas in the future. This study investigated the interannual variability (IAV) of tree and grass gross primary productivity (GPP) by combining a long-term (15 year) eddy covariance flux record and model estimates of tree and grass GPP inferred from satellite remote sensing. On a seasonal basis, the primary drivers of tree and grass GPP were solar radiation in the wet season and soil moisture in the dry season. On an interannual basis, soil water availability had a positive effect on tree GPP and a negative effect on grass GPP. No linear trend in the tree-grass GPP ratio was observed over the 15-year study period. However, the tree-grass GPP ratio was correlated with the modes of climate variability, namely the Southern Oscillation Index. This study has provided insight into the long-term contributions of trees and grasses to savanna productivity, along with their respective meteorological determinants of IAV.
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Affiliation(s)
- Caitlin E Moore
- School of Earth, Atmosphere and Environment, Monash University, Clayton, Vic., Australia
- Genomic Ecology of Global Change, Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, IL, USA
| | - Jason Beringer
- School of Earth, Atmosphere and Environment, Monash University, Clayton, Vic., Australia
- The UWA school of Agriculture and Environment, University of Western Australia, Crawley, WA, Australia
| | - Randall J Donohue
- CSIRO Land and Water, Canberra, ACT, Australia
- Australian Research Council Centre of Excellence for Climate System Science, Sydney, NSW, Australia
| | - Bradley Evans
- Department of Environmental Sciences, The University of Sydney, Eveleigh, NSW, Australia
- Terrestrial Ecosystem Research Network Ecosystem Modelling and Scaling Infrastructure, The University of Sydney, Eveleigh, NSW, Australia
| | - Jean-François Exbrayat
- School of GeoSciences and National Centre for Earth Observation, University of Edinburgh, Edinburgh, UK
| | - Lindsay B Hutley
- School of Environment, Research Institute for the Environment and Livelihoods, Charles Darwin University, Casuarina, NT, Australia
| | - Nigel J Tapper
- School of Earth, Atmosphere and Environment, Monash University, Clayton, Vic., Australia
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22
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Veenendaal EM, Torello-Raventos M, Miranda HS, Sato NM, Oliveras I, van Langevelde F, Asner GP, Lloyd J. On the relationship between fire regime and vegetation structure in the tropics. THE NEW PHYTOLOGIST 2018; 218:153-166. [PMID: 29315603 DOI: 10.1111/nph.14940] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Accepted: 10/28/2017] [Indexed: 06/07/2023]
Abstract
We assessed data from 11 experiments examining the effects of the timing and/or frequency of fire on tropical forest and/or savanna vegetation structure over one decade or more. The initial 'control treatment' in many such cases consisted of previously cleared land. This is as opposed to natural vegetation subject to some sort of endogenous fire regime before the imposition of fire treatments. Effects of fire on fractional foliar cover are up to 10-fold greater when clearing pre-treatments are imposed. Moreover, because many of the 'classic' fire trials were initialised with applied management questions in mind, most have also used burning regimes much more frequent and/or severe than those occurring in the absence of human activity. Once these factors are taken into account, our modelling analysis shows that nonanthropogenic fire regimes serve to reduce canopy vegetative cover to a much lower extent than has previously been argued to be the case. These results call into question the notion that fire effects on tropical vegetation can be of a sufficient magnitude to maintain open-type savanna ecosystems under climatic/soil regimes otherwise sufficient to give rise to a more luxurious forest-type vegetation cover.
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Affiliation(s)
- Elmar M Veenendaal
- Plant Ecology and Nature Conservation Group, Wageningen University, 6700 AA, Wageningen, the Netherlands
| | - Mireia Torello-Raventos
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot, SL5 7PY, UK
| | - Heloisa S Miranda
- Departmento de Ecologia, Universidade de Brasilia, 70910-900, Brasilia, DF, Brazil
| | - Naomi Margarete Sato
- Departmento de Ecologia, Universidade de Brasilia, 70910-900, Brasilia, DF, Brazil
| | - Imma Oliveras
- Plant Ecology and Nature Conservation Group, Wageningen University, 6700 AA, Wageningen, the Netherlands
- Environmental Change Institute, School of Geography and the Environment, University of Oxford, South Park Road, Oxford, OX1 3QY, UK
| | - Frank van Langevelde
- Resource Ecology Group, Wageningen University, 6700 AA, Wageningen, the Netherlands
| | - Gregory P Asner
- Department of Global Ecology, Carnegie Institution for Science, Stanford, CA, 94305, USA
| | - Jon Lloyd
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot, SL5 7PY, UK
- School of Marine and Environmental Sciences, James Cook University, Cairns, 4870, Qld, Australia
- Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, 14040-900, Ribeirão Preto, Brazil
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23
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Efficiency of Individual Tree Detection Approaches Based on Light-Weight and Low-Cost UAS Imagery in Australian Savannas. REMOTE SENSING 2018. [DOI: 10.3390/rs10020161] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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24
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Fire-Driven Decline of Endemic Allosyncarpia Monsoon Rainforests in Northern Australia. FORESTS 2017. [DOI: 10.3390/f8120481] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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25
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Li L, Wang YP, Beringer J, Shi H, Cleverly J, Cheng L, Eamus D, Huete A, Hutley L, Lu X, Piao S, Zhang L, Zhang Y, Yu Q. Responses of LAI to rainfall explain contrasting sensitivities to carbon uptake between forest and non-forest ecosystems in Australia. Sci Rep 2017; 7:11720. [PMID: 28916760 PMCID: PMC5601939 DOI: 10.1038/s41598-017-11063-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 08/11/2017] [Indexed: 11/17/2022] Open
Abstract
Non-forest ecosystems (predominant in semi-arid and arid regions) contribute significantly to the increasing trend and interannual variation of land carbon uptake over the last three decades, yet the mechanisms are poorly understood. By analysing the flux measurements from 23 ecosystems in Australia, we found the the correlation between gross primary production (GPP) and ecosystem respiration (Re) was significant for non-forest ecosystems, but was not for forests. In non-forest ecosystems, both GPP and Re increased with rainfall, and, consequently net ecosystem production (NEP) increased with rainfall. In forest ecosystems, GPP and Re were insensitive to rainfall. Furthermore sensitivity of GPP to rainfall was dominated by the rainfall-driven variation of LAI rather GPP per unit LAI in non-forest ecosystems, which was not correctly reproduced by current land models, indicating that the mechanisms underlying the response of LAI to rainfall should be targeted for future model development.
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Affiliation(s)
- Longhui Li
- School of Life Sciences, University of Technology Sydney, Sydney, Australia.
| | - Ying-Ping Wang
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China
- China and CSIRO Oceans and Atmosphere, PMB 1, Aspendale, Victoria, 3195, Australia
| | - Jason Beringer
- School of Earth and Environment, the University of Western Australia, Crawley, Australia
| | - Hao Shi
- School of Life Sciences, University of Technology Sydney, Sydney, Australia
| | - James Cleverly
- School of Life Sciences, University of Technology Sydney, Sydney, Australia
| | - Lei Cheng
- CSIRO, Land and Water, Canberra, Australia
| | - Derek Eamus
- School of Life Sciences, University of Technology Sydney, Sydney, Australia
| | - Alfredo Huete
- School of Life Sciences, University of Technology Sydney, Sydney, Australia
| | - Lindsay Hutley
- Research Institute for the Environment and Livelihoods, Charles Darwin University, Casuarina, Australia
| | - Xingjie Lu
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China
- China and CSIRO Oceans and Atmosphere, PMB 1, Aspendale, Victoria, 3195, Australia
| | | | - Lu Zhang
- CSIRO, Land and Water, Canberra, Australia
| | | | - Qiang Yu
- School of Life Sciences, University of Technology Sydney, Sydney, Australia
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A & F University, Yangling, 712100, China
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Maraseni TN, Reardon-Smith K, Griffiths G, Apan A. Savanna burning methodology for fire management and emissions reduction: a critical review of influencing factors. CARBON BALANCE AND MANAGEMENT 2016; 11:25. [PMID: 27909461 PMCID: PMC5112293 DOI: 10.1186/s13021-016-0067-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 11/07/2016] [Indexed: 06/06/2023]
Abstract
Savanna fire is a major source of global greenhouse gas (GHG) emissions. In Australia, savanna fire contributes about 3% of annual GHG emissions reportable to the Kyoto Protocol. In order to reduce GHG emissions from savanna burning, the Australian government has developed and approved a Kyoto compliant savanna controlled burning methodology-the first legal instrument of this kind at a global level-under its Emission Reduction Fund. However, this approved methodology is currently only applicable to nine vegetation fuel types across northern parts of Australia in areas which receive on average over 600 mm rainfall annually, covering only 15.4% of the total land area in Australia. Savanna ecosystems extend across a large proportion of mainland Australia. This paper provides a critical review of ten key factors that need to be considered in developing a savanna burning methodology applicable to the other parts of Australia. It will also inform discussion in other countries intent on developing similar emissions reduction strategies.
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Affiliation(s)
- Tek Narayan Maraseni
- Institute for Agriculture and the Environment, University of Southern Queensland, Toowoomba, 4350 Australia
| | - Kathryn Reardon-Smith
- Institute for Agriculture and the Environment, University of Southern Queensland, Toowoomba, 4350 Australia
| | - Greg Griffiths
- Natural Resources Management and Parks, South Burnett Regional Council, Queensland, 4610 Australia
| | - Armando Apan
- Institute for Agriculture and the Environment, University of Southern Queensland, Toowoomba, 4350 Australia
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Russell-Smith J, Yates CP, Edwards AC, Whitehead PJ, Murphy BP, Lawes MJ. Deriving Multiple Benefits from Carbon Market-Based Savanna Fire Management: An Australian Example. PLoS One 2015; 10:e0143426. [PMID: 26630453 PMCID: PMC4668068 DOI: 10.1371/journal.pone.0143426] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 11/04/2015] [Indexed: 11/30/2022] Open
Abstract
Carbon markets afford potentially useful opportunities for supporting socially and environmentally sustainable land management programs but, to date, have been little applied in globally significant fire-prone savanna settings. While fire is intrinsic to regulating the composition, structure and dynamics of savanna systems, in north Australian savannas frequent and extensive late dry season wildfires incur significant environmental, production and social impacts. Here we assess the potential of market-based savanna burning greenhouse gas emissions abatement and allied carbon biosequestration projects to deliver compatible environmental and broader socio-economic benefits in a highly biodiverse north Australian setting. Drawing on extensive regional ecological knowledge of fire regime effects on fire-vulnerable taxa and communities, we compare three fire regime metrics (seasonal fire frequency, proportion of long-unburnt vegetation, fire patch-size distribution) over a 15-year period for three national parks with an indigenously (Aboriginal) owned and managed market-based emissions abatement enterprise. Our assessment indicates improved fire management outcomes under the emissions abatement program, and mostly little change or declining outcomes on the parks. We attribute improved outcomes and putative biodiversity benefits under the abatement program to enhanced strategic management made possible by the market-based mitigation arrangement. For these same sites we estimate quanta of carbon credits that could be delivered under realistic enhanced fire management practice, using currently available and developing accredited Australian savanna burning accounting methods. We conclude that, in appropriate situations, market-based savanna burning activities can provide transformative climate change mitigation, ecosystem health, and community benefits in northern Australia, and, despite significant challenges, potentially in other fire-prone savanna settings.
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Affiliation(s)
- Jeremy Russell-Smith
- Darwin Centre for Bushfires Research, Charles Darwin University, Darwin, Northern Territory, Australia
- North Australian Indigenous Land & Sea Management Alliance, Darwin, Northern Territory, Australia
- Long Term Ecological Research Network, Australian National University, Canberra, Australia
| | - Cameron P. Yates
- Darwin Centre for Bushfires Research, Charles Darwin University, Darwin, Northern Territory, Australia
- Long Term Ecological Research Network, Australian National University, Canberra, Australia
| | - Andrew C. Edwards
- Darwin Centre for Bushfires Research, Charles Darwin University, Darwin, Northern Territory, Australia
- Long Term Ecological Research Network, Australian National University, Canberra, Australia
| | - Peter J. Whitehead
- Darwin Centre for Bushfires Research, Charles Darwin University, Darwin, Northern Territory, Australia
- North Australian Indigenous Land & Sea Management Alliance, Darwin, Northern Territory, Australia
| | - Brett P. Murphy
- Research Institute for the Environment and Livelihoods, Charles Darwin University, Darwin, Northern Territory, Australia
| | - Michael J. Lawes
- Research Institute for the Environment and Livelihoods, Charles Darwin University, Darwin, Northern Territory, Australia
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28
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Scheiter S, Higgins SI, Beringer J, Hutley LB. Climate change and long-term fire management impacts on Australian savannas. THE NEW PHYTOLOGIST 2015; 205:1211-1226. [PMID: 25388673 DOI: 10.1111/nph.13130] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 09/18/2014] [Indexed: 06/04/2023]
Abstract
Tropical savannas cover a large proportion of the Earth's land surface and many people are dependent on the ecosystem services that savannas supply. Their sustainable management is crucial. Owing to the complexity of savanna vegetation dynamics, climate change and land use impacts on savannas are highly uncertain. We used a dynamic vegetation model, the adaptive dynamic global vegetation model (aDGVM), to project how climate change and fire management might influence future vegetation in northern Australian savannas. Under future climate conditions, vegetation can store more carbon than under ambient conditions. Changes in rainfall seasonality influence future carbon storage but do not turn vegetation into a carbon source, suggesting that CO₂ fertilization is the main driver of vegetation change. The application of prescribed fires with varying return intervals and burning season influences vegetation and fire impacts. Carbon sequestration is maximized with early dry season fires and long fire return intervals, while grass productivity is maximized with late dry season fires and intermediate fire return intervals. The study has implications for management policy across Australian savannas because it identifies how fire management strategies may influence grazing yield, carbon sequestration and greenhouse gas emissions. This knowledge is crucial to maintaining important ecosystem services of Australian savannas.
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Affiliation(s)
- Simon Scheiter
- Biodiversity and Climate Research Centre (LOEWE BiK-F), Senckenberg Gesellschaft für Naturforschung, Senckenberganlage 25, 60325, Frankfurt am Main, Germany
| | - Steven I Higgins
- Department of Botany, University of Otago, Dunedin, 9054, New Zealand
| | - Jason Beringer
- School of Geography and Environmental Science, Monash University, Melbourne, Vic., Australia
- School of Earth and Environment, University of Western Australia, Crawley, WA, Australia
| | - Lindsay B Hutley
- Research Institute for the Environment and Livelihoods, Charles Darwin University, Darwin, NT, Australia
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