摘要
应用空间直观景观模型 (L ANDIS) ,研究有采伐和无采伐预案下大兴安岭呼中林区的森林景观的长期变化。用 APACK计算每一个物种及各年龄级的分布面积。为了研究物种分布格局的变化 ,计算了物种分布的聚集度指数。研究结果如下 :(1)在无采伐预案下 ,火干扰模式为低频率大面积高强度火烧 ;在有采伐预下 ,火干扰模式为高频率小面积低强度火烧 ;(2 )在无采伐预案下 ,火会造成各种群分布面积的强烈波动 ,但是对种群的年龄结构没有很大影响 ;在有采伐预案下 ,火对种群分布面积和年龄结构都没有很大的影响 ;(3)采伐能完全改变各种群的年龄结构 ,降低种群分布的聚集度 ,但是对各种群的分布面积并没有很大影响 ;(4 )在有采伐预案下 ,各种群为增长型种群 ,增长量通过采伐取走 ,群落处于演替的干扰顶极状态 ;在无采伐预案下 ,各种群为稳定型种群 (樟子松和偃松除外 ) ,大面积高强度火烧使群落产生较大的波动。结果表明 ,在呼中林业局 ,在没有人为干扰情况下 ,火干扰是森林景观变化的主导因素。自从有了人为干扰 ,采伐开始逐渐取代火干扰成为影响森林景观变化的主导因素。空间直观景观模型的一个挑战是模型的验证。由于缺乏详细的空间数据及模型模拟中的随机性 ,很难通过模型模拟结果与实地调查或遥感数据的比较进行?
The spatially explicit landscape model (LANDIS) was used to study the long-term forest landscape change in Huzhong area located in Mt.Daxing'anling. In order to assess the effect of harvest on forest landscape change, we simulated the landscape change under two scenarios: (1) with harvest and (2) without harvest. The species percent area and species age cohort percent area for each species under two simulation scenarios were derived using APACK. The aggregation index of each species was calculated to quantity the landscape pattern change under two scenarios. The simulation results were: (1) under simulation scenario without harvest, the fire regime was characterized by low frequency, high fire severity and large fire damaged area; under simulation scenario with harvest, the fire regime was characterized by high frequency, low fire severity and small fire damaged area; (2) under simulation scenario without harvest, fire disturbances significantly affected the population distribution area, but had no substantial effect on the population age structure; under simulation scenario with harvest, fire disturbances did not have substantial effect on both population age structure and population distribution area; (3) harvest can completely change the population age structure, reduce the degree of species distribution aggregation, but had no great effect on the species distribution; (4) under simulation scenario without harvest, populations were increasing population, the increased individuals were removed by harvest, the community reached a disturbance climax; under simulation scenario with harvest, populations were stable population (except for Pinus sylvestris var. mongolica and Pinus pumila) and fire disturbance caused the community to fluctuate. Our results showed that fire formed the forest landscape pattern before anthropogenic disturbance. After human entered this area, harvest began to gradually replace fire to inform the forest landscape pattern in this area. A significant challenge facing spatially explicit lan
出处
《生态学报》
CAS
CSCD
北大核心
2004年第9期1846-1856,i001,共12页
Acta Ecologica Sinica
基金
中国科学院引进国外杰出人才资助项目 ( BR0 10 40 3 )
国家自然科学基金资助项目 ( 4 0 3 3 10 0 8)
中国科学院知识创新工程资助项目( SCXZY0 10 2 )~~
