[Seasonal changes of nitrogen and phosphorus and their translocation from leaves of ten tree species in central Japan].
The leaves of evergreen broadleaved Quercus cuspidata, Ilex pedunculosa, Ilex rotunda, machilus thunbergii, Pittosporum tobira and deciduous broadleaved Quercus serrata, Quercus variabilis, Celtis sinensis, Ginkgo biloba, and Evodiopanax innovans were collected from the time of full leaf expansion to the end of growing season to describe the seasonal contents of N and P patterns in leaves of these species. The N and P contents in new and old leaves of evergreen Quercus cuspidata and Ilex rotunda had high levels in initial stage, low levels in medium stage, and increased in later stage. The seasonal changes of the N and P contents in new leaves of evergreen Ilex pedunculosa and Pittosporum tobira were similar to those of Quercus cuspidata and Ilex rotunda, whereas in old leaves of the two species, they tended to decline with time. The N content in new and old leaves of Machilus thunbergii tended to increase, whereas their P content tended to decrease. The N and P contents in leaves of deciduous species decreased during the growing season. The N translocation efficiency for all species ranged from 43-75%, whereas their P translocation efficiency ranged from 62-84%. The N translocation efficiency in evergreen broadleaved species was similar to that in deciduous broadleaved species, whereas the P translocation efficiency was higher than the latter. The mean N retranslocation efficiency for all species was higher than mean P retranslocation efficiency.
Xue
Li
L
College of Forestry, South China Agricultural University, Guangzhou 510642, China. forxue@scau.edu.cn
Luo
Shan
S
Tan
Tianyong
T
D009584:Nitrogen / Q000032:analysis* / Q000378:metabolism; D010758:Phosphorus / Q000032:analysis* / Q000378:metabolism; D018515:Plant Leaves / Q000737:chemistry* / Q000378:metabolism; D012621:Seasons; D014197:Trees / Q000737:chemistry* / Q000378:metabolism
D010758:Phosphorus; D009584:Nitrogen