In the savannas of Australias Northern Territory, the wetseason draws to a close around April. In the early months of the dry season,while conditions are still relatively cool, and the vegetation is still moistfrom the recent rains, land managers set strategic fires in a patchwork oflandscapes to prevent larger, more devastating fires later in the dry season.This image of the Northern Territory on 10 June 2007, was captured by theModerate Resolution Imaging Spectroradiometer (MODIS) on NASAs Aqua satellite. Places whereMODIS detected active fires, probably planned strategic burns, are marked inred. Southeasterly winds are pushing the smoke out toward the Timor Sea.
Traditional Aboriginal landholders (Arnhem Land is an Aboriginal land holding)have been strategically using fire in this way for thousands of years, but inthe century following European settlement of Australia, settlement and landownership patterns have dramatically changed. A decline in strategic,early-season burning across much of the area has lead to an increase in huge,intense, late dry-season fires.
10 June 2007
This shift in the regional fire patterns has important implications not onlyfor the ecosystem’s ability to recover from fire, but also for greenhouse gasemissions. When fires occur early in the season, when the vegetation is stillmoist, they are less intense and they produce fewer greenhouse gas emissions.The carbon dioxide released by the burning grass and smaller shrubs is roughlyin balance with the amount taken in when vegetation re-grows in the burned areaduring the following wet season.
However, the same cannot be said for the larger, more intense fires of thelate dry season; these fires consume not only grasses and leaves, but also trees.Too frequent, intense burns do not allow the ecosystem to recover an equalamount of carbon in the next growing season. The carbon dioxide equilibriumbetween burning and re-growth is tipped in favor of emissions. Over time, latedry-season fires have become a major source of greenhouse gas emissions in theNorthern Territory.
Awareness of these ecological and atmospheric connections is at the heart ofa partnership between energy producers, territory government, and Aboriginalland holders in the area. Through the partnership, a re-establishment ofstrategic early-season burning across larger areas of Arnhem Land will reducegreenhouse gas emissions from late-season fires, offsetting some of thegreenhouse gas emissions produced by the operation of a liquefied natural gasplant in Darwin. To read more about fire in the tropical savannas of NorthernTerritory, please visit the Website of the Tropical Savannas Cooperative Research Centre.
The large image provided above has a spatial resolution (level of detail) of250 meters per pixel.