Why are Fires Important?

Fires play an important role in the natural changes that occur in Earth's ecosystems. The diversity of plant and animal life in the world's forests, prairies, and wetlands is (partly) dependent on the effects of fire; in fact, some plants cannot reproduce without fire (fire breaks open the outside coating of some seeds and stimulates germination). What may at first look like total devastation soon becomes a panorama of new life. Fire initiates critical natural processes by breaking down organic matter into soil nutrients. Rain then moves these nutrients back into the soil providing a rejuvenated fertile seedbed for plants. With less competition and more sunlight, seedlings grow more quickly.

Wild animals deal with fire remarkably well. Birds fly out of the fire area, large animals leave the danger zone by escaping to ponds and streams, while others return to their burrows. Usually few animals are killed by fire.

Prescribed fire is one of the most important tools used today to manage Earth's diverse ecosystems. A scientific prescription, prescribed fires help create a mosaic of diverse habitats for plants and animals. If all fire is suppressed, fuel (grasses, needles, leaves, brush, and fallen trees) can build up and allow larger, and sometimes uncontrollable, fires to occur. If enough fuel builds up, the fires could be so intense that they may destroy the seeds in the soil and hinder new tree and plant growth. By burning away accumulated fuels, planned fires make landscapes safer for future natural fires.

State of the Science
By 1990, global tropical deforestation was occurring at a rate of about 1.8 percent of the world's total forest lands per year. Approximately 142,000 square kilometers of rainforest are eliminated annually—an area slightly larger than the state of Arkansas (more information on this topic can be found in the Tropical Deforestation Fact Sheet). Using data from satellite sensors, aircraft, and ground-based initiatives, scientists are working to develop a new global fire monitoring program that will enable them to better understand the myriad implications of this growing problem. Specifically, efforts are underway to quantify the total area of forests and grass land burned each year and to more precisely estimate the amount of resulting emission products. These newer and better data will facilitate development of more robust computer models that will enhance scientists' abilities to predict how biomass burning will impact climate, the environment, and air quality.

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Global Fire Monitoring
Introduction
Why are Fire Important?
Trace Gases Emissions
Aerosol Emissions
NASA and NOAA Missions for Monitoring Global Fires

Related Case Studies
Evolving in the Presence of Fire
A Burning Question
Fire!

Related Data Sets
1km² AVHRR Fires
4km² TRMM Fires

Top Left: Burned vegetation quickly releases nutrients back into the soil, nurturing the rapid growth of new vegetation. These jack pine seedlings germinated after a fire softened pinecones littering the forest floor, releasing the seeds they held. (Photograph courtesy Forrest Hall, NASA GSFC/University of Maryland)