Περίληψη:
Background and aims: Our study quantified variations leaf respiration in darkness (R D) and light (R L), and associated traits along the Franz Josef Glacier soil development chronosequence in New Zealand. Methods: At six sites along the chronosequence (soil age: 6, 60, 150, 500, 12,000 and 120,000 years old), we measured rates of leaf R D, R L (using Kok method), light-saturated CO2 assimilation rates (A), leaf mass per unit area (M A), and concentrations of leaf nitrogen ([N]), phosphorus ([P]), soluble sugars and starch. Results: The chronosequence was characterised by decreasing R D, R L and A, reduced [N] and [P] and increasing M A as soil age increased. Light inhibition of R occurred across the chronosequence (mean inhibition = 16 %), resulting in ratios of R L:A being lower than for R D:A. Importantly, the degree of light inhibition differed across the chronosequence, being lowest at young sites and highest at old sites. This resulted in R L:A ratios being relatively constant across the chronosequence, whereas R D:A ratios increased with increasing soil age. Log-log R-A-M A-[N] relationships remained constant along the chronosequence. By contrast, relationships linking rates of leaf R to [P] differed among leaves with low vs high [N]:[P] ratios. Slopes of log-log bivariate relationships linking R L to A, M A, [N] and [P] were steeper than that for R D. Conclusions: Our findings have important implications for predictive models that seek to account for light inhibition of R, and for our understanding of how environmental gradients impact on leaf trait relationships © 2013 Springer Science+Business Media Dordrecht.
Συγγραφείς:
Atkin, O.K.
Turnbull, M.H.
Zaragoza-Castells, J.
Fyllas, N.M.
Lloyd, J.
Meir, P.
Griffin, K.L.
