Limits...
Modelling Carbon Emissions in Calluna vulgaris – Dominated Ecosystems when Prescribed Burning and Wildfires Interact

View Article: PubMed Central - PubMed

ABSTRACT

A present challenge in fire ecology is to optimize management techniques so that ecological services are maximized and C emissions minimized. Here, we modeled the effects of different prescribed-burning rotation intervals and wildfires on carbon emissions (present and future) in British moorlands. Biomass-accumulation curves from four Calluna-dominated ecosystems along a north-south gradient in Great Britain were calculated and used within a matrix-model based on Markov Chains to calculate above-ground biomass-loads and annual C emissions under different prescribed-burning rotation intervals. Additionally, we assessed the interaction of these parameters with a decreasing wildfire return intervals. We observed that litter accumulation patterns varied between sites. Northern sites (colder and wetter) accumulated lower amounts of litter with time than southern sites (hotter and drier). The accumulation patterns of the living vegetation dominated by Calluna were determined by site-specific conditions. The optimal prescribed-burning rotation interval for minimizing annual carbon emissions also differed between sites: the optimal rotation interval for northern sites was between 30 and 50 years, whereas for southern sites a hump-backed relationship was found with the optimal interval either between 8 to 10 years or between 30 to 50 years. Increasing wildfire frequency interacted with prescribed-burning rotation intervals by both increasing C emissions and modifying the optimum prescribed-burning interval for minimum C emission. This highlights the importance of studying site-specific biomass accumulation patterns with respect to environmental conditions for identifying suitable fire-rotation intervals to minimize C emissions.

No MeSH data available.


Related in: MedlinePlus

Modelled annual carbon loss at different prescribed burns rotation intervals for four different sites across Great Britain under varying combustion completeness (CC) scenarios.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5120849&req=5

pone.0167137.g005: Modelled annual carbon loss at different prescribed burns rotation intervals for four different sites across Great Britain under varying combustion completeness (CC) scenarios.

Mentions: The annual carbon lost through prescribed burning (ClossPBA) was highly variable depending on the site studied (ranging from 0.1 to 0.55 t ha-1, Fig 4). Two clear patterns were also detected depending on the climatic conditions of sites. At the sites with the lowest temperatures and highest precipitation (Kerloch and Moor House), short rotation intervals of ca. 8–10 years maximized carbon emissions. In contrast, the warmer and drier sites (Dorset and Howden) demonstrated a hump-shaped response with the highest C emissions at intermediate rotation intervals. Emissions were maximized in Dorset at ca. 15 year intervals, whereas Howden showed a less pronounced hump-shaped curve with a maximum loss at 15–25 year intervals. Carbon lost was therefore minimized at long rotation intervals (30–50 years) for all sites, but for Howden and Dorset short prescribed-burning rotation intervals (8–10) can also minimize C emissions. As expected, higher combustion completeness (CC) increased the carbon annual loss (ClossPBA), especially for sites with faster regeneration after fire (Kerloch and Dorset; Fig 5).


Modelling Carbon Emissions in Calluna vulgaris – Dominated Ecosystems when Prescribed Burning and Wildfires Interact
Modelled annual carbon loss at different prescribed burns rotation intervals for four different sites across Great Britain under varying combustion completeness (CC) scenarios.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5120849&req=5

pone.0167137.g005: Modelled annual carbon loss at different prescribed burns rotation intervals for four different sites across Great Britain under varying combustion completeness (CC) scenarios.
Mentions: The annual carbon lost through prescribed burning (ClossPBA) was highly variable depending on the site studied (ranging from 0.1 to 0.55 t ha-1, Fig 4). Two clear patterns were also detected depending on the climatic conditions of sites. At the sites with the lowest temperatures and highest precipitation (Kerloch and Moor House), short rotation intervals of ca. 8–10 years maximized carbon emissions. In contrast, the warmer and drier sites (Dorset and Howden) demonstrated a hump-shaped response with the highest C emissions at intermediate rotation intervals. Emissions were maximized in Dorset at ca. 15 year intervals, whereas Howden showed a less pronounced hump-shaped curve with a maximum loss at 15–25 year intervals. Carbon lost was therefore minimized at long rotation intervals (30–50 years) for all sites, but for Howden and Dorset short prescribed-burning rotation intervals (8–10) can also minimize C emissions. As expected, higher combustion completeness (CC) increased the carbon annual loss (ClossPBA), especially for sites with faster regeneration after fire (Kerloch and Dorset; Fig 5).

View Article: PubMed Central - PubMed

ABSTRACT

A present challenge in fire ecology is to optimize management techniques so that ecological services are maximized and C emissions minimized. Here, we modeled the effects of different prescribed-burning rotation intervals and wildfires on carbon emissions (present and future) in British moorlands. Biomass-accumulation curves from four Calluna-dominated ecosystems along a north-south gradient in Great Britain were calculated and used within a matrix-model based on Markov Chains to calculate above-ground biomass-loads and annual C emissions under different prescribed-burning rotation intervals. Additionally, we assessed the interaction of these parameters with a decreasing wildfire return intervals. We observed that litter accumulation patterns varied between sites. Northern sites (colder and wetter) accumulated lower amounts of litter with time than southern sites (hotter and drier). The accumulation patterns of the living vegetation dominated by Calluna were determined by site-specific conditions. The optimal prescribed-burning rotation interval for minimizing annual carbon emissions also differed between sites: the optimal rotation interval for northern sites was between 30 and 50 years, whereas for southern sites a hump-backed relationship was found with the optimal interval either between 8 to 10 years or between 30 to 50 years. Increasing wildfire frequency interacted with prescribed-burning rotation intervals by both increasing C emissions and modifying the optimum prescribed-burning interval for minimum C emission. This highlights the importance of studying site-specific biomass accumulation patterns with respect to environmental conditions for identifying suitable fire-rotation intervals to minimize C emissions.

No MeSH data available.


Related in: MedlinePlus