Extended leaf senescence promotes carbon gain and nutrient resorption: importance of maintaining winter photosynthesis in subtropical forests.(

ZHANG, Y.-J., ; YANG, Q.-Y., ; LEE, D.W; GOLDSTEIN, G., ; CAO, K.-F

OECOLOGIA

SPRINGER

Lugar: Berlin; Año: 2013 p. 721 - 730

0029-8549

Abstract The relative advantages of being deciduous orevergreen in subtropical forests and the relationship betweenleaf phenology and nutrient resorption efficiency are not wellunderstood. The most successful deciduous species (Lyoniaovalifolia) in an evergreen-dominated subtropical montanecloud forest in southwest (SW) China maintains red senescingleaves throughout much of the winter. The aim ofthis study was to investigate whether red senescing leaves ofthis species were able to assimilate carbon in winter, to inferthe importance of maintaining a positive winter carbonbalance in subtropical forests, and to test whether an extendedleaf life span is associated with enhanced nutrientresorption and yearly carbon gain. The red senescing leavesof L. ovalifolia assimilated considerable carbon during partof the winter, resulting in a higher yearly carbon gain than cooccurringdeciduous species. Its leaf N and P resorptionefficiency was higher than for co-occurring non-anthocyanicdeciduous species that dropped leaves in autumn, supportingthe hypothesis that anthocyanin accumulation and/orextended leaf senescence help in nutrient resorption. Substantial.winter carbon gain and efficient nutrient resorption  may partially explain the success of L. ovalifolia versus that of the other deciduous species in this subtropical forest. The importance of maintaining a positive carbon balance for ecological success in this forest also provides indirect evidence for the dominance of evergreen species in the subtropical forests of SW China.