why must controlled fires be set in some ecosystem?What are the disadvantages?What are the advantages?

Answer 1

The biggest disadvantage is erosion caused by early rains before new growth can help anchor the soil in more arid climates sandier soils. The better advantages are enriched soil nutrients as a by product of the burn and removing high concentration of damaging plants in the Eco system.

Answer 2

The advantages are that dead fall does not accumulate, it kills the likes of poison ivy, poison oak and other nuisances plant. Dead fall more often then not is what really starts forest fires. If one had a home in the woods you would do a clearing of under brush every few years by burning it back and not having any trees around the home. after the burn off most state forestry service will plant quick growing plants and or flowers to stabilize the soil (remember good or bad under growth gets destroyed). If the burn off is controlled the taller healthier trees survive.

The bad part is if there should be a high wind and it blows embers into areas you do not want to burn off and the burn off gets out of control. But that is always the risk on any burn off.

Answer 3

Dead vegetation builds up.

Normally (without us interfering), fires would happen every few years, mostly started by lightening strikes.

These burn away the dry stuff (which enriches the soil), and keeps it from building up so much fires go berserk and destroy the trees.

Be doing the controlled burns, the dry stuff is kept down and the trees survive the smaller fires.

In effect, we're replicating what would happen if we didn't keep putting fires out.

The dangers are the fire getting out of control, and, as mentioned, the soil and ashes being washed away.

At least, that's always been my understanding. I'm no expert, though.