西双版纳热带森林树种幼苗的组成、空间分布和旱季存活

被引:46
作者
李晓亮 [1 ,2 ]
王洪 [1 ]
郑征 [1 ]
林露湘 [1 ]
邓晓保 [1 ]
曹敏 [1 ]
机构
[1] 中国科学院西双版纳热带植物园
[2] 中国科学院研究生院
关键词
树种幼苗; 组成; 空间分布; 存活; 旱季; 西双版纳;
D O I
暂无
中图分类号
S718.5 [森林生态学];
学科分类号
摘要
林下树种幼苗是森林生态系统的一个重要组成部分,在森林的自然更新过程中发挥着重要作用。于2007年10月底在西双版纳20hm2热带森林动态监测样地内设置了450个幼苗样方(1m2),对样方内的树种幼苗(胸径<1cm)进行了调查,并观测了当年的实生苗(H≤30cm)在2007~2008年旱季期间的存活变化。结果表明,该区森林林下树种幼苗的组成比较丰富,但个体数在物种间的分布极为不均匀。除4.17%的幼苗个体未鉴定外,调查到的已知树种幼苗共计6367株,隶属于49科116属161种,并且Simpson、Shannon-Wiener和Pielou指数分别达到了0.69、2.29和0.45。个体数少于5株的幼苗贡献了50.31%的物种数;在1m2的样方尺度上,幼苗密度和种丰富度两者的平均值分别为(14.15±0.72)株·m–2和(3.73±0.10)种·m–2(Means±SE,n=450);优势幼苗为望天树(Parashorea chinensis)、短刺锥(Castanopsis echidnocarpa)和假海桐(Pittospor opsis kerrii)等,它们的空间分布格局与地形、海拔和母树分布三者之间存在着密切的相关性;旱季期间,幼苗的死亡比例较大(26.49%),主要集中在优势幼苗。幼苗在干旱胁迫环境下的死亡格局表现出了明显的种间差异:香花木姜子(Litsea panamanja)和望天树两优势幼苗的死亡率分别为62.65%和35.87%,而假海桐和蚁花(Mezzettiopsis creaghii)等7种优势幼苗的死亡率较低(<9%),除望天树等13种优势幼苗外,其余692株幼苗(共129种)仅死亡了10.40%,而且有91种幼苗均没有发生死亡。幼苗间的存活差异有待于从种子大小、幼苗的形态和生理特性及其所在空间位置的生境特征等多方面开展深入的研究。
引用
收藏
页码:658 / 671
页数:14
相关论文
共 21 条
[11]  
Effects of climate on the radial growth of tree species in the upper and lower distribution limits of an altitudinal ecotone on Mount Norikura, central Japan[J] . Koichi Takahashi,Hiroto Azuma,Koh Yasue.Ecological Research . 2003 (5)
[12]   Comparative drought-resistance of seedlings of 28 species of co-occurring tropical woody plants [J].
Engelbrecht, BMJ ;
Kursar, TA .
OECOLOGIA, 2003, 136 (03) :383-393
[13]  
Dynamics of seedling banks in beech forest: results of a 10-year study on germination, growth and survival[J] . Jerzy Szwagrzyk,Janusz Szewczyk,Jan Bodziarczyk.Forest Ecology and Management . 2001 (3)
[14]   Influence of seed size on seedling growth of Albizia procera under different soil water levels [J].
Khurana, E ;
Singh, JS .
ANNALS OF BOTANY, 2000, 86 (06) :1185-1192
[15]  
Spatial patterns of seed dispersal, their determinants and consequences for recruitment[J] . Ran Nathan,Helene C. Muller-Landau.Trends in Ecology & Evolution . 2000 (7)
[16]  
The seedling survivorship and growth of three Shorea species in a Malaysian tropical rain forest[J] . I. M. Turner.Journal of Tropical Ecology . 1990 (4)
[17]  
Survival and growth of Virola surinamensis yearlings: Water augmentation in gap and understory[J] . Brian L. Fisher,Henry F. Howe,S. Joseph Wright.Oecologia . 1991 (2)
[18]  
Tree seedling growth and survival in a Malaysian rainforest. Turner I M. Biotropica . 1990
[19]  
Climate extremes observations, modelling, and impacts. Easterling,D. R.,Meehl,G. A.,Parmesan,C. Science . 2002
[20]  
The ecoclimatology of Danum,Sabah,in the context of the world’s rainforest regions,with particular reference to dry periods and their impact. Walsh RPD,Newbery DM. Philosophical Transactions of the Royal Society London,Series B . 1999