The Influences of Underground Root Competition on Seedling Growth of Three Woody Species

摘要:

通过在广东南澳岛的野外试验样地移植外来种尾叶桉(Eucalyptusurophylla)、大叶相思(Acaciaauriculaeformis)和本地种荷木(Schimasuperba)幼苗,研究南澳岛原有定居植物的地下根竞争对这些幼苗生长的影响。结果表明,地下根的竞争对3种幼苗生长影响显著,3种幼苗的生物量和生长速率在有根竞争时比无根竞争时小。3种幼苗受到的地下根的竞争强度随着苗龄的增大而不断减小,但一定时期后可达到平稳。荷木、尾叶桉和大叶相思幼苗受到的地下根的竞争强度分别为0.22、0.19和0.13。外来种尾叶桉和大叶相思在入侵森林群落的过程中,根系竞争力比本地植物荷木更强。

Abstract:

Abstract：Root competition experiment in three woody species was carried out in six plots，each of them was 12.4 m × 10 m on Nan-ao Island situated on the east of Guangdong Province near Shantou city． The experiment site was in the community dominated by Eucalyptus robusta．The seedlings of Eucalyptus urophylla，A cacia auriculaeformis and Schima superba were respectively planted in 3 plots and another 3 with trenches around the plots so as to prevent roots from other plants． The growth rate， biomass and root competition intensity for the seedlings of 3 species were measured after the seedlings had grown for 165 days to 640 days．Th e results indicated that the biomass increment and growt h rate of all the seedlings un der root competition were lower than those of seedlings grown in plots with trenches．The influence of un derground root competition on the seedling growth was gradually decreased with the growt h of seedling age， and was then stable when reached to a certain stage． Root competition intensity ofthe seedlings ofS．superba，E.urophylla and A.auriculaeformis were 0.22，0.19 and 0.13 respectively．It was shown that seedling growth of exotic trees E.urophylla and A．auriculaeformis had more adaptation to root competition than that of native tree species S.superb