An important mechanism of plant nutrient conservation
Make nutrient recycle more quickly
Decrease the dependence on the environment
I focused on N resorption (NR) & P resorption (PR), which are the most essential elements for plant. NR, PR are related with plant functional type, climate, soil condition (Write & Westoby 2003; Reich & Oleksyn 2004; Richardson et al. 2005; Yuan et al. 2009)
Hypotheses
1) Big trees have higher nutrient resorption
2) Trees in the later successional stages prefer to reuse the leaves’ nutrient rather than absorbing from the outside ecosystem
Methods
Sampling:
Evergreen species: (2011 autumn) Mature leaf and newly senesced leaf at the same time
Deciduous Newly senesced leaf samples in 2011 autumn; Mature leaf samples in 2012 summer
409 individuals、818 samples
Species number: 62 (evergreen 41，deciduous 21)
SLA: leaf area/ leaf mass
Leaf P analysis: Molybdenum blue colorimetric method
Tree Height, DBH, stand age, stand species numbers were recorded
