Departamento de Ecologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, Travessa 14, São Paulo, S.P., Brazil 05508-900, BR.
Environ Manage. 2000 Dec;26(6):675-84. doi: 10.1007/s002670010124.
Fire occurrences and their sources were monitored in Emas National Park, Brazil (17°49'-18°28'S; 52°39'-53°10'W) from June 1995 to May 1999. The extent of burned area and weather conditions were registered. Forty-five fires were recorded and mapped on a GIS during this study. Four fires occurred in the dry winter season (June-August; 7,942 ha burned), all caused by humans; 10 fires occurred in the seasonally transitional months (May and September) (33,386 ha burned); 31 fires occurred in the wet season, of which 30 were caused by lightning inside the park (29,326 ha burned), and one started outside the park (866 ha burned). Wet season lightning fires started in the open vegetation (wet field or grassy savanna) at a flat plateau, an area that showed significantly higher fire incidence. On average, winter fires burned larger areas and spread more quickly, compared to lightning fires, and fire suppression was necessary to extinguish them. Most lightning fires were patchy and extinguished primarily by rain. Lightning fires in the wet season, previously considered unimportant episodes, were shown to be very frequent and probably represent the natural fire pattern in the region. Lightning fires should be regarded as ecologically beneficial, as they create natural barriers to the spread of winter fires. The present fire management in the park is based on the burning of preventive firebreaks in the dry season and exclusion of any other fire. This policy does not take advantage of the beneficial effects of the natural fire regime and may in fact reduce biodiversity. The results presented here stress the need for reevaluating present policies and management procedures concerning fire in cerrado conservation areas.
1995 年 6 月至 1999 年 5 月期间，在巴西伊马司国家公园（南纬 17°49′-18°28′，西经 52°39′-53°10′）对火灾发生情况及其火源进行了监测。记录并在 GIS 上绘制了过火面积和天气条件图。在此研究期间，共记录了 45 起火灾并进行了定位。其中 4 起火灾发生在旱季（6-8 月，7942 公顷被烧毁），均由人为引起；10 起火灾发生在季节性过渡月份（5 月和 9 月）（33386 公顷被烧毁）；31 起火灾发生在雨季，其中 30 起是公园内闪电引起的（29326 公顷被烧毁），一起是公园外引起的（866 公顷被烧毁）。雨季闪电火灾发生在一个平坦高原上的开阔植被（湿地或草地稀树草原），该地区火灾发生率显著较高。与闪电火灾相比，冬季火灾的过火面积更大，蔓延速度更快，需要进行灭火才能扑灭。大多数闪电火灾呈斑片状，主要因降雨而熄灭。雨季闪电火灾以前被认为是不重要的事件，但现在发现它们非常频繁，可能代表了该地区的自然火灾模式。闪电火灾应被视为生态有益的，因为它们为冬季火灾的蔓延创造了天然屏障。目前公园里的火灾管理是基于旱季预防性燃烧防火带和排除任何其他火源。这一政策没有利用自然火灾机制的有益影响，实际上可能会降低生物多样性。这里呈现的结果强调了需要重新评估有关塞拉多保护区火灾的现有政策和管理程序。
