Uncontrolled wildfires and prescribed fires occur in all vegetation zones of the world. It is estimated that fires annually affect 1015 million hectares of boreal and temperate forest and other lands, 2040 million hectares of tropical rain forests due to forest conversion activities and escaped agricultural fires, and up to 500 million hectares of tropical and subtropical savannas, woodlands, and open forests
Only a minor part of these fires is caused by nature (lightening). Most of today's fires are caused by human activities. Some burning practices still follow the traditional rules of rural populations, and many ecosystems are well adapted to fire.
This paper presents a review of the environmental aspects of plant biomass burning, particularly on the global carbon cycle and other atmospheric chemical effects. The use and extent of biomass burning in forestry, agriculture and economy, and its geographical distribution are outlined. The emissions of gases and aerosols to the atmosphere are estimated based on field and laboratory measurements. The chemical processes in the emission plumes and their atmospheric transport on the regional to global scale are evaluated.
A series of regional and global interdisciplinary research programs on the ecological, atmospheric chemical, and climatic role of vegetation fires and other plant biomass burning has been initiated in the past years. The lead of coordinating this research is taken by the International Geosphere-Biosphere Programme (IGBP) through its Core Project International Global Atmospheric Chemistry (IGAC). Three ongoing and planned research campaigns are described in brief, the Southern Africa Fire-Atmosphere Research Initiative (SAFARI), the Fire Research Campaign Asia-North (FIRESCAN), an effort of institutions and individual scientists jointly working under the umbrella of IGAC-BIBEX and the International Boreal Forest Research Association (IBFRA), and the South East Asia Fire Experiment (SEAFIRE) which is in the preparatory stage.
Key words: vegetation fires, forest fires, biomass burning, atmospheric chemistry, global carbon cycle.
Correspondence: Johann Georg Goldammer, Fire Ecology Research Group (MPIC), c/o Freiburg University, D-79100 Freiburg
Telefax: +49-761-808011
E-mail: jggold@sun1.ruf.uni-freiburg. de