采伐影响下森林景观服务功能变化研究

文章以大兴安岭呼中林业局亚里河林场为研究区,以遥感数据、林相图和采伐设计资料为信息源,选择水源涵养、固土保肥、固定CO2和释放O2四项服务功能,运用景观生态学原理,引用相应模型,估算了研究区1989年和2000年服务功能价值及其空间分布变化;建立历年采伐分布图,计算采伐造成的服务功能价值损失,揭示该损失值与木材生产的经济效益之间的关系,并分析了服务功能价值在各管理区域内的分布。结果表明,1989年服务功能价值为1.85×108元,2000年为1.37×108元,价值20×104元h/m₂以上的面积明显下降。生态服务功能的下降由采伐导致,1989至1999年采伐导致的生态损失价值为0.71×108元,是木材生产获利的1.9倍,采伐损失价值与年出材量呈现相同的变化趋势。最后证明了管理等级区划和限制采伐量,即“天保工程”,将有利于森林植被恢复,大幅度提高整个亚里河林场的生态服务功能。

Change of Forest Landscape Service Function under Timber Harvest

Analysis and evaluation on the forest ecosystem service function and the effect of anth-rotropogenic activity on it is a hot issue in both economy and landscape ecology.This paper aimed at identifying(1) how does the ecological function of forest landscape change after long-term management﹖(2) how does the spatial distribution of ecological function change﹖and(3)What is the quantitative relationship between econo-mic benefit from timber production and ecological benefit caused by timber harvest﹖To answer those questions,we employed forest stand map and timber harvest map as the source of information and used forest service model from cited paper,hen selected four service functions including water-holding,soil-and fertilizer-holding,carbon sequestration and oxygen release to valuate the forest service function change in space from 1989 to 2000 within Yalihe of Huzhong Forest Bureau in Greater Hinggan Mountains.Meanwhile,we created harvest patches distribution map in order to estimate and compare the ecological loss caused by timber harvest and economic benefit.The results show that the total forest service value within Yalihe decreased from 0.185 billion yuan in 1989 to 0.137 billion yuan in 2000.Area with more than 200 thousand yuan per ha declined from 47.75% in 1989 to 13.52% in 2000 and shrunk far away from the main river.Area with 50-100 thousand yuan per ha increased greatly from 11.63% to 28.46%;and patches became more in size and number.The decrease in function value is due to timber harvest and loss of ecological benefits is 0.067 billion,which is about 1.9 times as many as the loss from timber economic benefits.In fact the ecological loss is far more because it will be a long-term process.The loss of ecological benefits shows a similar trend to timber yield during the last 10 years.Finally,the service function distribution across three management grade areas revealed that in harvest-profited area,the function value per ha is the lowest,only 3 254 yuan,so harvest-profited measure will benefit forest reforestation,neverthe-less,hectare value is the highest,being 3 845 yuan in forest production,then the low harvest timber will ensure the high service value.So our the management policy was proved to be reasonable from the point of view of forest services value change.Classifying management grade area and controlling the harvest volume will benefit restoration of vegetation and service function.This work gives contribution to not only the forest ecosystem service function research but also landscape ecology.It is a particular way to reveal anthropogenic activity intensity in space.Additionally,this work provided new view to evaluate the forest management policy.