Effects of post Burn

The skin has an important role to play in the fluid and temperature regulation of the body. If enough skin area is injured, the ability to maintain that control can be lost. The skin also acts as a protective barrier against the bacteria and viruses that inhabit the world outside the body. Burns are classified based upon their depth. A first degree burn is superficial and causes local inflammation of the skin. Sunburns often are categorized as first degree burns. The inflammation is characterized by pain, redness, and a mild amount of swelling. The skin may be very tender to touch.rnSecond degree burns are deeper and in addition to the pain, redness and inflammation, there is also blistering of the skinrnThird degree burns are deeper still, involving all layers of the skin, in effect killing that area of skin. Because the nerves and blood vessels are damaged, third degree burns appear white and leathery and tend to be relatively painless. Burns are not static and may mature. Over a few hours a first degree burn may involve deeper structures and become second degree. Think of sunburn that blisters the next day. Similarly, second degree burns may evolve into third degree burns. We used pre- and post-burn fire effects data from six prescribed burns to examine post-burn threshold effects of stand structure (understory density, over story density, shrub cover, duff depth, and total fuel load) on the regeneration of yellow pine (Pinups subgenus Diploxylon) seedlings and cover of herbaceous vegetation in six prescribed-fire management units located within western Great Smoky Mountains National Park (GSMNP) in east Tennessee, USA. We also evaluated the utility of the Keetch–Byram Drought Index (KBDI) as a predictor of post-burn stand and fuel conditions by comparing post-burn stand variables for different ranges of KBDI (23–78; more wet, and 328–368; more dry). We found that yellow pine seedlings were effectively absent in post-burn forests until over story density was reduced over 40%, understory density was reduced over 80%, and post-burn shrub cover was 10% or less. We also observed that a reduction in total fuels of 60% and a post-burn duff layer depth of less than four cm were required for successful regeneration of yellow pine. Total herbaceous species cover exhibited near identical responses with increased cover following an 80% reduction in understory density and a post-burn duff depth of less than 4 cm. We observed strong positive relationships between high KBDI values and burn severity, changes in forest structure, reductions in fuels, and post-burn yellow pine reproduction. We observed continuous recruitment of yellow pine seedlings 5 years after fire in high KBDI burns while low KBDI burns showed little change in yellow pine density through time.