火烧和植造桉林对南亚热带退化草坡土壤种子库的影响  

Effects of prescribed fire and planting Eucalyptus urophylla on the soil seed bank of degraded hilly land in lower subtropical China

作　　者：李丹艳[1,2] 任海[1] 王俊[1,2] 李平衡[1,2] 吴建平[1,2] 

机构地区：[1]中国科学院华南植物园鹤山森林生态系统国家野外科学观测研究站,广东广州510650 [2]中国科学院研究生院,北京100039

出　　处：《生态环境学报》2009年第1期255-262,共8页Ecology and Environmental Sciences

基　　金：国家自然科学基金项目(30670370,30630015);广东省自然基金项目(07118249)资助

摘　　要：对南亚热带典型火烧草坡迹地和人工造桉林后的退化草坡土壤种子库进行了取样调查,采用种子萌发试验研究了这些不同处理的土壤种子库特征,结果表明:(1)火烧处理对土壤种子库有显著影响,具体表现为种子库储量减小、物种种类减少、优势种组成单一、物种多样性指数和地上植被相似性系数低、土壤种子库物种组成与地上植被物种组成差异显著;(2)种植桉树对土壤种子库储量、物种生活型分布、土壤种子库物种组成与地上植被物种组成差异均没有影响,但能增加草本物种种类;(3)火烧并种植桉树对土壤种子库的影响与火烧处理结果一致,能使土壤种子库中优势物种种子密度增加,但不能增加草本种类在种子库中的密度。该研究表明采用火烧处理有利于南亚热带退化草坡植被恢复;采用种桉树的方法短期内植被恢复的效果不明显;退化草坡的植被恢复需要适度的人为干预与调控。The effects of prescribed fire, planting Eucalyptus, combining prescribed fire and planting Eucalyptus on the soil seed bank of degraded hilly land were investigated by using the seed germination method in Heshan, Guangdong. Our results showed that： （1） Prescribed fire significantly reduced seed density and species richness in soil seed bank. The composition of dominant seed species was simplified and the species diversity was reduced. The Sorensen’s similarity coefficient between the seed bank and the standing vegetation was lowered. Species composition between the seed bank and the standing vegetation was significantly different. （2） Planting Eucalyptus had no effect on the seed density, life form, and the number of co-occurring species both in the soil seed bank and the standing vegetation, yet, the species of annual herbs increased. （3） The combined effects of prescribed fire and planting Eucalyptus on the soil seed bank were similar to those of prescribed fire. Seed density of dominant species increased in the soil seed bank, whereas the seed density of annual herbs decreased. These results indicated that prescribed fire was helpful to accelerate restorarion the vegetation of degraded hilly land in lower subtropical China, but planting Eucalyptus, combining prescribed fire and planting Eucalyptus had little effects in short term.

关 键 词：火烧 退化草坡 桉林 土壤种子库 

分 类 号：Q948[生物学—植物学]