【作者】 接程月；

【导师】 江洪； 魏晓华；

【作者基本信息】 浙江农林大学 ， 生态学， 2011， 硕士

【摘要】 由于长时间对森林过度砍伐和人口增长带来的森林退化的巨大压力,我们需要可持续发展的思想来指导森林的经营管理。通过模型模拟进行新的管理体制的预测,可以使我们采取优化的措施来维持我们期望的生态系统价值。杉木林和云杉林是我国亚热带和西南林区的重要的森林生态系统,本文利用FORECAST模型模拟不同轮伐期对云杉林和杉木人工林碳储量的影响,为进一步深入研究我国乃至全球范围内的森林生态系统碳循环提供基础数据,同时为管理者制定合理的森林管理策略提供依据。研究不同轮伐期杉木人工林碳储量过程中发现短轮伐期(≤25年)的碳贮量较高,但是固碳能力较弱且土壤碳贮量呈现下降趋势;过长轮伐期(>50年),总碳贮量相对不高,且较好立地模拟表明其固碳能力亦有下降的趋势。25年轮伐期干材收获量最大,但不利于土壤有机碳的可持续,50年轮伐期有利于维持生态系统的碳贮量的相对稳定。且立地条件越好其碳贮量和固碳能力越高。选择较长轮伐期(25-50年)较有利于保持杉木人工林的可持续经营。云杉林的模拟结果显示,轮伐期为80年时茎干碳贮量和全树碳贮量的累积最高,但地力消耗较为严重。在森林皆伐的情况下,无论采取任何长度的轮伐期,其土壤碳贮量均呈现下降趋势,但是随着轮伐期的延长(不大于160年),其下降比例降低。轮伐期不大于160年时,年均固碳量随着轮伐期的延长而增大。且较好立地的碳贮量和固碳能力要优于较差立地。故而,从轮伐期和立地角度出发,保持长期立地生产力应选择较长轮伐期(120-160年)和较好立地为宜。从采伐方式上而言,粗放型采伐方式更加有利于碳储量的积累,且其固碳能力高于集约型采伐方式。在森林经济向集约型经济转变的今天,延长轮伐期无疑可以缩小两种采伐方式之间的差距,在一定程度上减少立地的损耗。云杉林的模拟结果与杉木人工林的模拟结果十分相似,单从经济效益而言,中等水平的轮伐长度有利于获得最大的经济效益,但地力消耗最为严重,这也凸显了经济效益与生态效益之间的矛盾。选择较长的轮伐期可以从一定程度上体现森林可持续发展的理念,且较长轮伐期的固碳能力高,对气候变暖这一全球问题,有一定的贡献。更多还原

【Abstract】 As a long time on deforestation and the enormous pressure of population growth, we have no time to wait for a new management system to maintain the ecosystem value we expected. In the absence of a long concrete examples of the results of the case, the emergence and applications of the models provided us some possibilities for the response of the ecosystems to disturbances. In this paper we usedFORECAST model to simulate the impacts of different rotations for the carbon storage of Chinese fir and spruce to provide some basic data for further study in China and the global carbon cycle of forest ecosystems,as well as to help forest managers to develop reasonable management strategies. Our results support that the shorter rotation (≤25 year) has the higher carbon storage, but carbon sequestration capacity is lower and soil organic carbon seems to decline. If the rotation length is too long(>50 year) ,it may cause lower carbon storage and in rich site its carbon sequestration capacity has the downward trend. It will get the most stem biomass but do not maintain the sustainable develop of soil organic carbon when the rotation is 25 year. When the rotation is 50 year, it can maintain the sustainability of the ecosystem carbon storage. So we considered that longer rotation (25 year~50 year) is relatively reasonable to keep the sustainable production in Chinese fir plantation based on the results. Results about spruce suggest that the accumulation of stem carbon and total tree carbon get to themaxium when the rotation length is 80 years,but it will consume more soil fertility.In the case of forest clear-cutting,no matter which rotation we choose,the soil carbon storage showed a downward trend,but with the rotation of the extension (not more than 160 years), the reducing proportion declines. When rotation is not more than 160 years, the average annual amount of carbon sequestration increased as the rotation length gets longer. And a better site for carbon storage and carbon sequestration is higher than worse ones. Therefore, from the perspective of rotation and site, maintaining long-term site productivity should choose a longer rotation periods (120-160 years) and better site. From the perspective of the harvesting styles, the extensive harvesting more conducive to the accumulation of carbon stocks and carbon fixation is higher than that intensive harvesting. At present, the forest economy changes to intensive economic ,and no doubt extending the rotation length can reduce the gap between the two harvesting styles, and can reduce the loss site.The simulation results of two stands are very similar. From the economic, the mid-level rotation length is conducive to the greatest economic benefit, but will consume the most serious soil fertility, it also highlights the contradiction between the economic benefits and ecological benefits. Selecting a longer rotation period can be reflected the concept of forest sustainable development, and longer rotation has higher carbon sequestration capacity, and has a certain contribution in the global problem of climate change.更多还原