摘要
大兴安岭50年来严格的火控制政策已经极大地改变了自然火格局,同时也改变了森林的物种组成和年龄结构。理解大兴安岭森林对长期火控制的响应是制定森林可持续发展的依据之一。本文应用LANDIS模型模拟了大兴安岭森林景观对自然火(1950年以前)和灭火(1950年以后)的长期响应(300年)。结果表明:灭火显著增加了落叶松面积,增加其过熟林面积,减少其幼龄林面积;同时也显著减少白桦面积,减少其幼龄林面积;灭火延长火烧轮回期,火烧次数减少,灾难性火灾发生的机率增加,火险在模拟的50年内迅速上升到高火险等级。在自然火格局下,火险在整个模拟过程中保持较低的等级。所以如果现行的高强度灭火政策继续实施的话,必须要制定大范围的可燃物管理措施(计划火烧、粗可燃物处理等),以降低灾难性火灾发生的机率。计划火烧加粗可燃物去除将成为可燃物管理和森林可持续经营的首选措施。如何评价大兴安岭地区可燃物处理措施的效果,在保持木材生产和生态作用稳定的条件下,最大程度地降低火险也是亟待解决的问题。
Since the 50 years implementation of strict fire suppression policy, the natural fire pattern in Great Xing＇ an Mountains changed greatly, and the species composition and age structure of the forests altered significantly. To understand the responses of the forests in Great Xing＇ an Mountains to the long term fire suppression could supply a sound basis for the sustainable development of forestry in this area. By using a spatially explicit landscape simulation model （ LANDIS） ; the long-term （300 years） responses of forest landscape in Great Xing＇ an Mountains to the scenarios of natural fire （before 1950） and fire suppression （after 1950） were simulated, and the changes in fuel load, fire hazard, and forest tree species abundance under the two scenarios were compared. The simulation results showed that under fire suppression scenario, larch （ Larix gmelinii） forest area increased significantly, while birch （Betula platyphylla） forest area was in adverse. Meanwhile, over-matured larch forest area increased, while young larch and birch forest areas decreased. Fire suppression prolonged the interval of fire, decreased the times of fire, increased the chance of catastrophic fire, and made the fire risk rapidly increased to a dangerous level. Under natural fire scenario, fire risk maintained at a relatively low level. Therefore, if the present strict fire suppression policy still implemented, extensive fuels management measures such as prescribed burning and coarse fuel load reduction should be adopted to decrease the occurrence chance of catastrophic fire. How to evaluate the effect of prescribed burning and coarse fuel load reduction in Great Xing＇ an Mountains, and to find the ways of keeping balance among fire suppression, maximal timber production, and sound ecological function, should be the issues to be urgently solved.
出处
《生态学杂志》
CAS
CSCD
北大核心
2009年第1期70-79,共10页
Chinese Journal of Ecology
基金
国家自然科学基金资助项目(30670363)
关键词
灭火
森林景观
LANDIS
大兴安岭
火险
可燃物管理
计划火烧
fire suppression
forest landscape
LANDIS
Great Xing＇ an Mountains
fire risk
fuels management
prescribed burning.
