In this areas: Some plants are completely burned and unburned others, In critical condition Some plants are affected by livestock grazing, Soil conditions and plant cover has changed, Life cycles have changed, and ...
With this condition, how determine the fire damage from Loss of grazing?
Savadogo et al. (Agriculture, Ecosystems and Environment 118 (2007) 80–92) will assist you in this area of work. I think you will also need to estimate the effective area available for grazing (discounting the burned areas until they have got to a herbage regrowth that would be available for grazing) and the biomass + quality of biomass available. These are not easy as teh free-ranging animal may spend sometime in burned vs. non burned areas.
To Julian's answer, which is good, I'd add that any calculation you make is likely to be accurate for only a short while before changing conditions make re-calculation advisable. This because, depending on where the land is located, you may have seasonal weather effects that will impact on herbage regrowth. You will also probably have variable recovery depending on micro-climates (if your area is extensive and/or hilly), soil type, fertiliser history (if any), viable seed in the ground and similar factors. Depending on what plant material was burned you may also see an impact from the addition of carbon to the soil (C/N ratio) and how fast that high-carbon material is incorporated into soil organic matter, if at all - this will be site and soil micro-organism and climate specific.
In the above I'm assuming, like Julian, that you want to elucidate the impact of burning from a forage production / new growth / plant digestibility etc. perspective. A somewhat different approach might be advisable if, instead, you are wanting to assess the situation from an economic perspective to enable damages to be sought from whoever caused the fire.
To add to what other colleagues mentioned, the effect on the grazing land comes both from the fire and the grazing pressure. To clearly see the two sources of effects, I suggest you also consider collecting data from a control adjacent grazing land, which has been managed without fire.
On a purely nutritional aspect, be cautious when exposing grazing animals to early stage rapid regrowth areas as there is a high possibility of exposing the animals to high levels of nitrogen. This offers the potential for ammonia poisoning due to excessive N in the diet. This is often a condition associated with immediate post-drought grazing but post-fire grazing will have the same impact. Just keep in mind!
Is your question, how much forage has been lost due to the fire? If it is you need to know how much forage the area normally produces and then determine how much was left after the fire.
Dear Bob
Thank you for your answer. But, It is not enough for an accurate estimate.
Dear Mark
Thank you for your answer, I mean, Fire in the normal conditions area.
- Badges
- Science topic