滇中地区入侵紫茎泽兰的潜在火行为

Potential Fire Behaviors of Invasive Eupatorium adenophorum in Middle-Yunnan Province

在滇中昆明西山国家森林公园内紫茎泽兰连续、致密分布区设置样地,进行外业调查、采集样品,在燃烧床内测定和计算枯死紫茎泽兰、凋落物的潜在火行为:点着时间、熄灭时间,辐射热,火焰高度和火强度等。结果表明:枯死紫茎泽兰、凋落物的点燃时间都很短,仅为2 s、3 s,非常易燃;着火后维持燃烧都超过7 min;最大火焰高度都不到1 m;消耗率分别为86.5%、77.0%;火强度分别为2351.2 k W·m-1、2303.9 k W·m-1,均为中强度火。

After selecting field samples of fire sites from Xishan national park, Kunming, where Eupatorium adenophorum is the domi- nant species and its degree of dominance is a key element in behavior of fire, and by field investigating and lab experiments of fire behaviors, including ignite time, extinguishing time, heat values of radiation, flame height, and fire intensity of dead fuel and litter, the index of fire behaviors can be gained. The results are shown as the following： the ignite time of dead Eupatorium adenophorum and lit- ter are 2s and 3s, respectively, which means they are easily-ignited;the endurance of both flames exceeds 7 minutes, and the maximal flame heights of both are less than 1 meter,and their consuming rates are 86. 5% and 77.0% ,respectively. While their maximal fire intensity are 2351.2 kW/m and 2303.9 kW/m, which shows they are medium intensity fires. Their easily-ignited characteristic is due to the low ignite temperature which is below 300 degrees Celsius and their dead leaves are still on their stems. Once on fire ,.they will release massive amount of heat energy and bring about extinguishing difficulties.