【作者】 王伟峰；

【导师】 廖为明； 魏晓华；

【作者基本信息】 江西农业大学 ， 森林经理学， 2011， 硕士

【摘要】 在全球气候变化背景下,研究森林固碳计量方法及固碳量对减缓温室效应的影响意义重大。楠木作为亚热带常绿阔叶林的代表性树种,在固碳增汇方面有着独特的价值。目前,在楠木育苗造林及生物量和固碳量等方面的报道相对较多,但不同经营管理措施对楠木人工林固碳量的长期影响目前尚未见相关报道。本研究利用加拿大UBC大学开发的FORECAST森林生态系统管理模型,通过外业调查、查找相关文献资料等方式收集不同立地条件下楠木林分的生物量积累、林分密度、光响应曲线以及土壤养分等方面的数据,模型经过校准后,模拟不同造林密度、不同间伐强度以及不同轮伐期对楠木人工林固碳量的长期影响。主要研究结论如下：(1)楠木人工林以中密度(2500株/hm2左右)造林为宜,如果立地条件相对较差,可以选择高密度(4000株/hm2左右)造林以保持林地生产力的可持续性。此外,楠木人工造林还要考虑经营类型以及培育目标等多方面的因素；(2)楠木人工林宜采用低强度(15%)和中等强度(25%)的间伐方式,这样的方式有利于林地的养分循环,并可以达到较好的固碳效果。最合适的间伐时间和间伐强度需要在更广阔的环境背景下结合对生物栖息地的影响进一步模拟；(3)长轮伐期(80年)作业模式明显优于中等轮伐期(40年)和短轮伐期(20年)作业模式。从养分循环的角度来讲,在长轮伐期作业模式下楠木人工林群落结构相对比较稳定,林分内凋落物量相对也较多,加上降低了人为干扰的强度,因此对林地的保护作用效果显著,这种模式是一种可持续的经营模式；(4)经营楠木人工林对土壤的改良作用非常明显,特别是差的立地,由于楠木为阔叶树种,凋落物量较大,凋落物分解后能够产生较多的养分归还林地,促进楠木人工林的生长；(5)在生产实践中,楠木人工林经营的基本思路可以总结为：“中高密度造林、中低强度间伐、尽量延长收获周期”,在这种情况下,楠木人工林的经营不仅可以得到良好的经济效益,而且生态效益也可以达到最大化(主要指固碳能力和林地生产力的可持续性)。更多还原

【Abstract】 Evaluation of forest carbon sequestration potentials is important for designing forest management strategies to mitigate the effects of global climate change. As one of the important subtropical evergreen broad-leaved forest tree species, Phoebe has become a popular species for plantation forests in Jinagxi and Fujiang provinces. Currently, there were many reports on silviculture, nursery and biomass of Phoebe forests, but few on the carbon sequestration potentials unde different management practices. In this study, the forest ecosystem model, FORECAST was used to simulate the effects of different management strategies on carbon sequestration in phoebe forests. Data on forest biomass, stand density, light and soil nutrients, response curve under different site conditions were collected from field surveys or from published papers. After the model calibration and validation, FOREACST was run with various management scenarios including different planting densities, thinning intensities rotation lengths. The main conclusions are as follows:(i) The plantation density of 2500 trees/hm2 is appropriate. If the site conditions are relatively poor, higher densities should be chosen to maintain the sustainability of forest productivity.(ii) The thinning methods of low (15%) and moderate (25%) intensities should be used to achieve better results. The most appropriate thinning time and intensity need further simulations in a broader context considering protection of environment and habitat;(iii) The rotation length of 80 years is superior to shorter rotation (e.g.,20 years or 40 years). Rotation length is important for influencing forest carbon sequestration with a longer and higher carbon sequestration.(iv) Phoebe plantations has obvious role on soil improvement, especially on the poor site. As a hardwood species, Phoebe produces a large amount of decomposition litter and nutrients, which is important for maintaining high carbon sequestration.(v) Sustainable Phoebe plantation management can be significant not only to provide economic benefits, but also to maximize ecological services (eg., carbon sequestration capacity and the sustainability of forest productivity)更多还原