Chin J Plant Ecol ›› 2013, Vol. 37 ›› Issue (7): 611-619.DOI: 10.3724/SP.J.1258.2013.00063

• Research Articles • Previous Articles     Next Articles

Tree architecture of overlapping species among successional stages in evergreen broad-leaved forests in Tiantong region, Zhejiang Province, China

YANG Xiao-Dong1,2,YAN En-Rong1,2,*(),ZHANG Zhi-Hao1,2,SUN Bao-Wei1,2,HUANG Hai-Xia1,2,Ali ARSHAD1,2,MA Wen-Ji1,2,SHI Qing-Ru1,2   

  1. 1Department of Environment Science, East China Normal University, Shanghai 200062, China
    2Tiantong National Forest Ecosystem Observation and Research Station, Ningbo, Zhejiang 315114, China
  • Received:2013-03-18 Accepted:2013-05-22 Online:2013-07-01 Published:2013-07-05
  • Contact: YAN En-Rong

Abstract:

Aims Tree architecture refers to the overall shape and size of the woody plants, as well as the spatial arrangement of its components in response to changing light. Variation in tree architecture of overlapping species among successional stages can be used to indicate relationships between tree architecture and light availability, because confounding effects resulted from plant phylogenetics are excluded. Our objective was to examine how tree architecture varies among overlapping species in different successional stages.
Methods The study sites are located in Tiantong National Forest Park (29°52′ N, 121°39′ E), Nanshan Mountain (29°52′ N, 121°41′ E) and Beilun Forest Park (29°50′ N, 121°52′ E) in Zhejiang Province, China. We measured tree height, crown depth and area, stem basal diameter, leaf coverage and convergence, stretch direction of branch and crown exposure index for five overlapping species in four vertical layers among successional communities in three sites. Linear regression analysis was conducted to examine the quantitative relationship between tree architecture and crown exposure index.
Important findings With the forest succession, crown depth and area, leaf coverage and stem basal diameter increased gradually, but did not show significant differences between adjacent successional stages in some cases. The proportion of dispersed leaves increased, but the proportion of clumped leaves decreased. Among four vertical layers, crown exposure index decreased through forest succession. There were significant linear relationships between crown exposure index and each of eight tree architectural traits (p < 0.001). We conclude that variability in tree architecture among overlapping species through forest succession indicates a shifting pattern of plant functional groups from pioneer species to shade-tolerant species in evergreen broad-leaved forests. Light acclimatization is one of main factors driving variation in tree architecture.

Key words: crown exposure index, evergreen broad-leaved forest, overlapping species, secondary succession, tree architecture