Chin J Plant Ecol ›› 2013, Vol. 37 ›› Issue (10): 912-921.DOI: 10.3724/SP.J.1258.2013.00094

• Research Articles • Previous Articles     Next Articles

Variability and association of leaf traits between current-year and former-year leaves in evergreen trees in Tiantong, Zhejiang, China

HUANG Hai-Xia1,2,YANG Xiao-Dong1,2,SUN Bao-Wei1,2,ZHANG Zhi-Hao1,2,YAN En-Rong1,2,*()   

  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:2013-04-15 Accepted:2013-08-08 Online:2013-04-15 Published:2013-09-29
  • Contact: YAN En-Rong

Abstract:

Aims Variation in leaf traits with changing leaf age denotes plant life history strategy and reflects biomass allocation pattern in plant leaves. Our objective was to explore variability and correlation of leaf traits between current-year and former-year leaves for evergreen broad-leaved trees, in order to reveal effects of leaf age on the pattern of construction and cost during development of leaf area.
Methods Our one hectare study site is located in Tiantong National Forest Park (29°52′ N, 121°39′ E), Zhejiang Province. Three key functional traits (mean leaf area (MLA), specific leaf area (SLA) and leaf dry matter content (LDMC)) in each of current-year leaves and former-year leaves were measured for 2277 evergreen trees belonging to 41 species. Variability and correlations for each of three leaf traits were compared between current-year and former-year leaves at both individual and species levels.
Important findings At both individual and species levels, variability coefficients (i.e., CV) were highest in MLA (individual: 79.5%; species: 66.5%), intermediate in SLA (individual: 28.1%; species: 24.7%) and lowest in LDMC (individual: 17.0%; species: 14.1%). Variability coefficients among the three leaf traits were greater in current-year leaves than in former-year leaves. Former-year leaves had significantly greater MLA (t = -38.53, p < 0.001) and LDMC (t = -9.71, p < 0.001), but lower SLA (t = 45.30, p < 0.001) than current-year leaves. At the individual level, the values for MLA, SLA and LDMC in current-year leaves explained 86%, 48% and 41% of the total variation for MLA, SLA and LDMC in former-year leaves. More significantly, at the species level 97%, 83% and 85% of the total variation in each of MLA, SLA and LDMC for former-year leaves resulted from variability of MLA, SLA and LDMC from current-year leaves. Variation in SLA between differently aged leaves demonstrated that, at a given unit investment of biomass, a relatively larger leaf area can be structured by current-year leaves than by former-year leaves, thus having a low cost in constructing leaf area for current-year leaves. In conclusion, plant leaf traits vary and connect significantly with change of leaf age. Trade-offs between biomass construction and cost in leaf area production might affect plant leaf development.

Key words: leaf age, leaf construction cost, leaf dry mass content, mean leaf area, resource allocation strategy, specific leaf area