nasa scientists are using an instrument on the terra satellite to detect these signs of damage , which include slight alterations in the amount and condition of foliage present .
unlike fires in the amazon 's grassy areas , which can spread rapidly and are known to have towering flames , understory fires burn nearly undetected .
 
 
in contrast , understory fires in the amazon rain forest are having a huge impact .
amazon forests are quite vulnerable to fire , given the frequency of ignitions for deforestation in regards to recent years .
a new study 's lead author , said in the statement .
moreover , the study goes further , pointing to climate conditions - not deforestation - as the most important factor in determining fire risk in the amazon at a regional scale .