Chin J Plant Ecol ›› 2008, Vol. 32 ›› Issue (3): 639-647.DOI: 10.3773/j.issn.1005-264x.2008.03.013

• Original article • Previous Articles     Next Articles


CHEN Ya-Jun, CAO Kun-Fang, CAI Zhi-Quan()   

  1. Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China
  • Received:2007-08-14 Accepted:2007-11-06 Online:2008-08-14 Published:2008-05-30
  • Contact: CAI Zhi-Quan


Aims Lianas are an important component of forests, especially in the tropics. They strongly influence regeneration of trees and maintenance of species diversity in tropical forests, but little is known about competition between trees and lianas. In this study, we investigate the effects of lianas on the morphology, photosynthesis and growth of trees and examine the relative importance of above- and below-ground competition between tree and liana seedlings under different light irradiances.

Methods We used four different competition treatments (AC: all competition; RC: root competition; SC: shoot competition; NC: no competition) between seedlings of one shade-intolerant liana (Byttneria grandif-olia) and three tree species (shade-tolerant Litsea dilleniifolia and Pometia tomentosa and shade-intolerant Bauhinia variegata). Seedlings were grown in a shade house under two levels of light availability (4% and 35% light intensity).

Important findings Competition from lianas substantially reduced the growth of tree seedlings, but the relative importance of above- and below-ground competition differed between the two light levels. At low light intensity, the relative growth rate (RGR) and photosynthetic capacity (maximum net photosynthetic rate, Pmax) in seedlings of all three tree species were reduced more strongly by SC than RC. However, SC rather than RC greatly reduced RGR and Pmax of tree seedlings grown under high light intensity. Different competition combinations (above- and below-ground competition) of liana seedlings resulted in distinctive morphological traits in seedlings of the three tree species. The specific leaf area and leaf area ratio of the three tree species were significantly influenced by light intensity. Meanwhile, only those of the light demanding species, B. variegata, were affected by the liana competition. Tree seedlings had small diameter, low height, leaf numbers and leaf area with slight changes in slenderness (stem length/diameter) under the competitive environments of liana seedlings. In conclusion, our findings suggest that competition from liana seedlings can greatly suppress growth in tree seedlings of both shade-intolerant and shade-tolerant species and the effects of lianas on tree seedlings can differ with type of competition. Above- and below-ground competition can interactively limit the growth of tree seedlings.

Key words: lianas, trees, above- and below-ground competition, photosynthesis, relative growth rate