摘要
在檀香幼苗的野外栽植过程中,光照和寄主选择是限制其幼苗存活的重要因素。植物护理效应是指护理植物能够在其冠幅下改善微气候,辅助或保育其他物种生长发育的现象。作为一种新的造林方法,护理植物技术不仅会产生护理效应,而且还可减少水土流失,保持生态系统的物种多样性。因此近年来这种技术被应用于植被恢复与造林中。野牡丹、桃金娘和豆科植物金合欢是亚热带地区的常见先锋植物,但这些物种是否具有作为檀香护理植物的特征,尚未有这方面研究。以这三种植物为研究对象,通过野外定位实验测定了三种植物冠幅下的微环境特征以及檀香幼苗的生长特性。结果表明:桃金娘和野牡丹能通过冠幅有效改善檀香幼苗周围的环境因子,缓解檀香幼苗叶片光系统II的午间光抑制,提高檀香幼苗叶片的叶绿素含量、株高、地径和存活率,因此这两种植物适宜作为檀香的护理植物。金合欢虽然在初期能提高檀香的存活率,但由于其生长迅速,冠幅过大,容易造成过度荫蔽的环境而不利于檀香的生长和存活,因而光照可能成为其冠幅下檀香幼苗生长的限制因子。
The host plants selection and incident light intensity are two important factors hindering the field establishment of S.album seedlings. Nurse plant effect is a positive interaction in which individuals of one plant species facilitate the growth and development of the other species by ameliorating the microenvironment beneath their canopies. In recent years, nurse plant has been increasingly applied in afforestation and revegetation of forest all over the world because of its positive role in biodiversity conservation and erosion control. Melastoma candidum, Rhodomyrtus tomentosa and Acacia farnesiana are evergreen pioneer shrubs commonly distributed on different kinds of hilly slopes in South China. However, few reports were found to investigate whether these plants possess characteristics that can act as a nurse plant to facilitate the seedlings of S.album. In this study, an investigation in situ was conducted to evaluate the nursing effects of R.tomentosa, M.candidum and A.farnesian on the ambient microclimate, survival rate, and growth traits of S.album seedlings beneath their canopies. Our results indicated that the R.tomentosa and M.candidum could act as nurse plants by creating a more favorable vicinity microclimate beneath their canopies. In response to facilitation, the midday photoinhibition of PSII（indicated by reduction in Fv/Fm） in leaves of S.album seedlings was greatly alleviated under the R.tomentosa and M.candidum canopies. The leaf chlorophyll content, plant height, basal diameter and survival rate of S.album seedlings were higher under the canopies of R.tomentosa and M.candidum than those at the open site. The A.farnesian increased the survival rate of S.album seedlings at early stage. However, with fast growth and high biomass production ability, A.farnesiana developed a large crown that decreased the growth and survival rate of S.album seedlings by reducing their light absorption. Light may be the major factor that limits the growth and survival of the S.album seedlings beneath A.farnesiana canopy.
出处
《生态科学》
CSCD
北大核心
2014年第3期480-487,共8页
Ecological Science
基金
国家自然科学基金项目(31300371)
农业部华南热带农业环境重点实验室开放课题(KFKT-2013-03)
国家科技支撑计划项目(2009BADC6B007)
广东省现代农业产业技术体系建设专项(粤农[2009]380号)
广东省高等学校学科与专业建设专项资金(2013CXZDA007)
关键词
护理植物
微气候
檀香
野牡丹
桃金娘
金合欢
nurse plant
microclimate
Santalum album
Melastoma candidum
Rhodomyrtus tomentosa
Acacia farnesiana
