Fire, Rain and CO<sub>2</sub>: Potential Drivers of Tropical Savanna Vegetation Change, with Implications for Carbon Crediting
A global trend of increasing tree cover in savannas has been observed and ascribed to a range of possible causes, including CO<sub>2</sub> levels, changing rainfall and fire frequency. We tested these explanations in the Australian tropical savanna, taking 96 savanna ‘cool burning’ proje...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-12-01
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| Series: | Fire |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2571-6255/6/12/465 |
| _version_ | 1797381102442119168 |
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| author | Greg Barber Andrew Edwards Kerstin Zander |
| author_facet | Greg Barber Andrew Edwards Kerstin Zander |
| author_sort | Greg Barber |
| collection | DOAJ |
| description | A global trend of increasing tree cover in savannas has been observed and ascribed to a range of possible causes, including CO<sub>2</sub> levels, changing rainfall and fire frequency. We tested these explanations in the Australian tropical savanna, taking 96 savanna ‘cool burning’ projects from Australia’s emissions offset scheme as case studies. We obtained readings of tree cover and explanatory variables from published remote sensing or spatial data sources. These were analysed using time-series linear regression to obtain coefficients for the influence of severe fire occurrence, annual rainfall and prior percentage tree cover. Although statistically significant coefficients for the key variables were found in only half (severe fire) or one quarter (rainfall) of the individual project models, when comparing all the model coefficients across the rainfall gradient, ecologically coherent explanations emerge. No residual trend was observed, suggesting rising CO<sub>2</sub> levels have not influenced tree cover over the study period. Our approach models tree cover change by separating ecological drivers from human-controlled factors such as fire management. This is an essential design feature of national emissions inventories and emissions offsets programs, where crediting must be additional to the expected baseline, and arise from human activity. |
| first_indexed | 2024-03-08T20:46:33Z |
| format | Article |
| id | doaj.art-338a4e33330e48a0a4fa9a5fd801252c |
| institution | Directory Open Access Journal |
| issn | 2571-6255 |
| language | English |
| last_indexed | 2024-03-08T20:46:33Z |
| publishDate | 2023-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Fire |
| spelling | doaj.art-338a4e33330e48a0a4fa9a5fd801252c2023-12-22T14:08:05ZengMDPI AGFire2571-62552023-12-0161246510.3390/fire6120465Fire, Rain and CO<sub>2</sub>: Potential Drivers of Tropical Savanna Vegetation Change, with Implications for Carbon CreditingGreg Barber0Andrew Edwards1Kerstin Zander2Northern Institute, Charles Darwin University, Darwin, NT 0909, AustraliaDarwin Centre for Bushfire Research, Research Institute for the Environment and Livelihoods, Charles Darwin University, Darwin, NT 0909, AustraliaNorthern Institute, Charles Darwin University, Darwin, NT 0909, AustraliaA global trend of increasing tree cover in savannas has been observed and ascribed to a range of possible causes, including CO<sub>2</sub> levels, changing rainfall and fire frequency. We tested these explanations in the Australian tropical savanna, taking 96 savanna ‘cool burning’ projects from Australia’s emissions offset scheme as case studies. We obtained readings of tree cover and explanatory variables from published remote sensing or spatial data sources. These were analysed using time-series linear regression to obtain coefficients for the influence of severe fire occurrence, annual rainfall and prior percentage tree cover. Although statistically significant coefficients for the key variables were found in only half (severe fire) or one quarter (rainfall) of the individual project models, when comparing all the model coefficients across the rainfall gradient, ecologically coherent explanations emerge. No residual trend was observed, suggesting rising CO<sub>2</sub> levels have not influenced tree cover over the study period. Our approach models tree cover change by separating ecological drivers from human-controlled factors such as fire management. This is an essential design feature of national emissions inventories and emissions offsets programs, where crediting must be additional to the expected baseline, and arise from human activity.https://www.mdpi.com/2571-6255/6/12/465tropical savannawoody thickeningCO<sub>2</sub> fertilisationfire severityoffsetsemissions credits |
| spellingShingle | Greg Barber Andrew Edwards Kerstin Zander Fire, Rain and CO<sub>2</sub>: Potential Drivers of Tropical Savanna Vegetation Change, with Implications for Carbon Crediting Fire tropical savanna woody thickening CO<sub>2</sub> fertilisation fire severity offsets emissions credits |
| title | Fire, Rain and CO<sub>2</sub>: Potential Drivers of Tropical Savanna Vegetation Change, with Implications for Carbon Crediting |
| title_full | Fire, Rain and CO<sub>2</sub>: Potential Drivers of Tropical Savanna Vegetation Change, with Implications for Carbon Crediting |
| title_fullStr | Fire, Rain and CO<sub>2</sub>: Potential Drivers of Tropical Savanna Vegetation Change, with Implications for Carbon Crediting |
| title_full_unstemmed | Fire, Rain and CO<sub>2</sub>: Potential Drivers of Tropical Savanna Vegetation Change, with Implications for Carbon Crediting |
| title_short | Fire, Rain and CO<sub>2</sub>: Potential Drivers of Tropical Savanna Vegetation Change, with Implications for Carbon Crediting |
| title_sort | fire rain and co sub 2 sub potential drivers of tropical savanna vegetation change with implications for carbon crediting |
| topic | tropical savanna woody thickening CO<sub>2</sub> fertilisation fire severity offsets emissions credits |
| url | https://www.mdpi.com/2571-6255/6/12/465 |
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