Disturbance associated with severe wildfires and wildfire simulating harvest operations can poten... more Disturbance associated with severe wildfires and wildfire simulating harvest operations can potentially alter soil methane (CH4 ) oxidation in well aerated forest soils due to the effect on soil properties linked to diffusivity, methanotrophic activity or changes in methanotrophic bacterial community structure. However, changes in soil CH4 flux related to such disturbances are still rarely studied even though wildfire frequency is predicted to increase as a consequence of global climate change. We measured in situ soil atmosphere CH4 exchange along a wet sclerophyll eucalypt forest regeneration chronosequence in Tasmania, Australia, where the time since the last severe fire or harvesting disturbance ranged from 9 to >200 years. On all sampling occasions mean CH4 uptake increased from most recently disturbed sites (9 year) to sites at stand 'maturity' (44 and 76 years). In stands >76 years since disturbance we observed a decrease in soil CH4 uptake. A similar age depend...
ABSTRACT QuestionPlant communities are not necessarily spatially exclusive; a point in space can ... more ABSTRACT QuestionPlant communities are not necessarily spatially exclusive; a point in space can exhibit properties of multiple communities. Such variation can be described using floristically defined ‘fuzzy’ units, however these may not be easily delineated using standard remote sensing methods. Is there value in considering communities as fuzzy? Can species distribution modelling methods be used to represent fuzzy communities spatially? LocationWestern Victoria, Australia. Methods Fuzzy communities were objectively identified from vegetation census quadrats with a cluster analysis of ordinated species data. Boosted regression trees were used to create models that defined relationships between the sampled communities and environmental predictor variables. These were applied to the mapped predictors to create maps of estimated fuzzy community membership for the entire study area. ResultsFour separate fuzzy communities were identified from the sampled vegetation data. Models were created for each community and these were effectively used to generate maps of fuzzy community membership. Individual fuzzy community maps illustrated vegetation variation that could not be discerned on a discretely classified map. Conclusions Fuzzy communities were found to represent a greater proportion of species variation than discretely classified units. Species distribution modelling methods were effective in creating independent spatial maps of each floristically defined fuzzy community; however the interpretation of these maps is more complex than with a single discrete community map.
The organisations that manage wildfires are expected to deliver scientifically defensible decisio... more The organisations that manage wildfires are expected to deliver scientifically defensible decisions. However, the limited availability of high quality data restricts the rate at which research can advance. The nature of wildfires contributes to this; they are infrequent, complex events and occur rapidly. While some information about wildfires is usually collected, it is often not of an appropriate standard for research. Valuable information may be discarded or not collected as it is not seen as operationally useful. The harmonisation of fire data management worldwide could increase the availability and quality of information for research. We propose a three tiered approach where agreements are created to standardise data quality, define the scope of information to be collected and establish access protocols for sharing. Standardisation of data collection would facilitate the aggregation of data throughout the world, providing leverage on data collected and reduce unnecessary duplication. If the scope of collection can be expanded, there are a wide range of research fields that stand to benefit. Appropriate data sharing between agencies would increase the value of the data and enable robust conclusions to be reached. It is imperative that the losses caused by severe fires are not in vain; losses should be offset by efforts to maximise the information obtained, helping to prevent a repeat of such events in the future.
Forest fires are periodic occurrences in many parts of the world. Where they coincide with human ... more Forest fires are periodic occurrences in many parts of the world. Where they coincide with human populations, they have the potential to have substantial impacts on human values. Consequently, strategies are adopted by land managers to reduce the probability of fire occurrence and, in the event of a fire, reduce subsequent impacts.
One such strategy has involved the adoption of fire danger ratings. These are levels of alertness that are applied at a regional level on a daily basis. They are based on preceding and forecast weather and provide an indication of the potential severity of fire behaviour. Danger ratings are generally based on weather derived indices and have limited ability to represent the contribution of landscape attributes to potential impacts, including the properties of vegetation (fuels) and the amount and spatial configuration of vulnerable assets. We propose an alternative method for representing fire danger using fire simulation. An ensemble approach is demonstrated whereby thousands of virtual fires are ignited on a regular grid and simulated on a daily basis using forecast weather with the model PHOENIX RapidFire. Each fire is simulated in succession and burns for a specified period. Fire simulations integrate the contributions of local fuel, topography and weather to fire behaviour. The resultant fires can be aggregated to provide spatially explicit representations of potential spread patterns. These maps can be combined with asset registers to quantify potential impacts and assist with the prioritisation of response and protection measures.
Disturbance associated with severe wildfires and wildfire simulating harvest operations can poten... more Disturbance associated with severe wildfires and wildfire simulating harvest operations can potentially alter soil methane (CH4 ) oxidation in well aerated forest soils due to the effect on soil properties linked to diffusivity, methanotrophic activity or changes in methanotrophic bacterial community structure. However, changes in soil CH4 flux related to such disturbances are still rarely studied even though wildfire frequency is predicted to increase as a consequence of global climate change. We measured in situ soil atmosphere CH4 exchange along a wet sclerophyll eucalypt forest regeneration chronosequence in Tasmania, Australia, where the time since the last severe fire or harvesting disturbance ranged from 9 to >200 years. On all sampling occasions mean CH4 uptake increased from most recently disturbed sites (9 year) to sites at stand 'maturity' (44 and 76 years). In stands >76 years since disturbance we observed a decrease in soil CH4 uptake. A similar age depend...
ABSTRACT QuestionPlant communities are not necessarily spatially exclusive; a point in space can ... more ABSTRACT QuestionPlant communities are not necessarily spatially exclusive; a point in space can exhibit properties of multiple communities. Such variation can be described using floristically defined ‘fuzzy’ units, however these may not be easily delineated using standard remote sensing methods. Is there value in considering communities as fuzzy? Can species distribution modelling methods be used to represent fuzzy communities spatially? LocationWestern Victoria, Australia. Methods Fuzzy communities were objectively identified from vegetation census quadrats with a cluster analysis of ordinated species data. Boosted regression trees were used to create models that defined relationships between the sampled communities and environmental predictor variables. These were applied to the mapped predictors to create maps of estimated fuzzy community membership for the entire study area. ResultsFour separate fuzzy communities were identified from the sampled vegetation data. Models were created for each community and these were effectively used to generate maps of fuzzy community membership. Individual fuzzy community maps illustrated vegetation variation that could not be discerned on a discretely classified map. Conclusions Fuzzy communities were found to represent a greater proportion of species variation than discretely classified units. Species distribution modelling methods were effective in creating independent spatial maps of each floristically defined fuzzy community; however the interpretation of these maps is more complex than with a single discrete community map.
The organisations that manage wildfires are expected to deliver scientifically defensible decisio... more The organisations that manage wildfires are expected to deliver scientifically defensible decisions. However, the limited availability of high quality data restricts the rate at which research can advance. The nature of wildfires contributes to this; they are infrequent, complex events and occur rapidly. While some information about wildfires is usually collected, it is often not of an appropriate standard for research. Valuable information may be discarded or not collected as it is not seen as operationally useful. The harmonisation of fire data management worldwide could increase the availability and quality of information for research. We propose a three tiered approach where agreements are created to standardise data quality, define the scope of information to be collected and establish access protocols for sharing. Standardisation of data collection would facilitate the aggregation of data throughout the world, providing leverage on data collected and reduce unnecessary duplication. If the scope of collection can be expanded, there are a wide range of research fields that stand to benefit. Appropriate data sharing between agencies would increase the value of the data and enable robust conclusions to be reached. It is imperative that the losses caused by severe fires are not in vain; losses should be offset by efforts to maximise the information obtained, helping to prevent a repeat of such events in the future.
Forest fires are periodic occurrences in many parts of the world. Where they coincide with human ... more Forest fires are periodic occurrences in many parts of the world. Where they coincide with human populations, they have the potential to have substantial impacts on human values. Consequently, strategies are adopted by land managers to reduce the probability of fire occurrence and, in the event of a fire, reduce subsequent impacts.
One such strategy has involved the adoption of fire danger ratings. These are levels of alertness that are applied at a regional level on a daily basis. They are based on preceding and forecast weather and provide an indication of the potential severity of fire behaviour. Danger ratings are generally based on weather derived indices and have limited ability to represent the contribution of landscape attributes to potential impacts, including the properties of vegetation (fuels) and the amount and spatial configuration of vulnerable assets. We propose an alternative method for representing fire danger using fire simulation. An ensemble approach is demonstrated whereby thousands of virtual fires are ignited on a regular grid and simulated on a daily basis using forecast weather with the model PHOENIX RapidFire. Each fire is simulated in succession and burns for a specified period. Fire simulations integrate the contributions of local fuel, topography and weather to fire behaviour. The resultant fires can be aggregated to provide spatially explicit representations of potential spread patterns. These maps can be combined with asset registers to quantify potential impacts and assist with the prioritisation of response and protection measures.
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management worldwide could increase the availability and quality of information for research. We propose a three tiered approach where agreements are created to standardise data quality, define the scope of information to be collected and establish access protocols for sharing. Standardisation of data collection would facilitate the aggregation of data throughout the world, providing leverage on data collected and reduce unnecessary duplication. If the scope of collection can be expanded, there are a wide range of research fields that stand to benefit. Appropriate data sharing between agencies would increase the value of the data and enable robust conclusions to be reached. It is imperative that the losses caused by severe fires are not in vain; losses should be offset by efforts to maximise the information obtained, helping to prevent a repeat of such events in the future.
they have the potential to have substantial impacts on human values. Consequently, strategies are adopted by land managers to reduce the probability of fire occurrence and, in the event of a fire, reduce subsequent impacts.
One such strategy has involved the adoption of fire danger ratings. These are levels of alertness that are applied at a regional level on a daily basis. They are based on preceding and forecast weather and provide an indication of the potential severity of fire behaviour. Danger ratings are generally based on weather derived indices and have limited ability to represent the contribution of landscape attributes to potential impacts, including the properties of vegetation (fuels) and the amount and spatial configuration of vulnerable assets. We propose an
alternative method for representing fire danger using fire simulation. An ensemble approach is demonstrated
whereby thousands of virtual fires are ignited on a regular grid and simulated on a daily basis using forecast weather with the model PHOENIX RapidFire. Each fire is simulated in succession and burns for a specified period. Fire simulations integrate the contributions of local fuel, topography and weather to fire behaviour. The resultant fires can be aggregated to provide spatially explicit representations of potential spread patterns. These maps can be combined with asset registers to quantify potential impacts and assist with the prioritisation of
response and protection measures.
management worldwide could increase the availability and quality of information for research. We propose a three tiered approach where agreements are created to standardise data quality, define the scope of information to be collected and establish access protocols for sharing. Standardisation of data collection would facilitate the aggregation of data throughout the world, providing leverage on data collected and reduce unnecessary duplication. If the scope of collection can be expanded, there are a wide range of research fields that stand to benefit. Appropriate data sharing between agencies would increase the value of the data and enable robust conclusions to be reached. It is imperative that the losses caused by severe fires are not in vain; losses should be offset by efforts to maximise the information obtained, helping to prevent a repeat of such events in the future.
they have the potential to have substantial impacts on human values. Consequently, strategies are adopted by land managers to reduce the probability of fire occurrence and, in the event of a fire, reduce subsequent impacts.
One such strategy has involved the adoption of fire danger ratings. These are levels of alertness that are applied at a regional level on a daily basis. They are based on preceding and forecast weather and provide an indication of the potential severity of fire behaviour. Danger ratings are generally based on weather derived indices and have limited ability to represent the contribution of landscape attributes to potential impacts, including the properties of vegetation (fuels) and the amount and spatial configuration of vulnerable assets. We propose an
alternative method for representing fire danger using fire simulation. An ensemble approach is demonstrated
whereby thousands of virtual fires are ignited on a regular grid and simulated on a daily basis using forecast weather with the model PHOENIX RapidFire. Each fire is simulated in succession and burns for a specified period. Fire simulations integrate the contributions of local fuel, topography and weather to fire behaviour. The resultant fires can be aggregated to provide spatially explicit representations of potential spread patterns. These maps can be combined with asset registers to quantify potential impacts and assist with the prioritisation of
response and protection measures.