Slow Leaf Development of Evergreen Broad-leaved Tree Species in Japanese Warm Temperate Forests
1998; Oxford University Press; Volume: 82; Issue: 6 Linguagem: Inglês
10.1006/anbo.1998.0770
ISSN1095-8290
Autores Tópico(s)Plant responses to elevated CO2
ResumoRates of light-saturated net photosynthesis (P N max) and dark respiration (Rd) on a leaf area basis, leaf dry mass per area (LMA), leaf nitrogen content on a leaf area basis (LNa) and instantaneous nitrogen use efficiency (NUE=P N max/LNa) were followed during leaf development in six evergreen broad-leaved tree species typical of warm-temperate forests in Japan. These species were Castanopsis sieboldii, Quercus myrsinaefolia, Quercus glauca, Machilus thunbergii, Cinnamomum japonicum and Neolitsea sericea. When expansion of leaf area was complete, P N max was about one third of its peak value and increased for another 15 to 44 d. Rd at full leaf expansion was about 1.5 to 3.5-times greater than steady-state rates. These facts suggest that leaf development was still underway at the time of full leaf area expansion. Low P N max at full leaf expansion was caused both by low leaf nitrogen content and low NUE. P N max increased with the increase in LMA during leaf development in all six species; data from the literature for other species with different life forms also indicated a similar tendency. The steady-state LMA varied markedly among species. Because leaves with larger steady-state LMAs need more resources for their construction, they will also need longer periods for maturation. We hypothesized that the period required for the attainment of peak P N max, the 'leaf maturation period', depends on the steady-state LMA. Plotting data from the present study together with those from literature for other plants across several life forms showed a strong positive relationship between leaf maturation period and steady-state LMA, supporting the hypothesis. Copyright 1998 Annals of Botany Company.
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