江西阳际峰30种阔叶树叶片氮磷含量及再吸收效率

养分再吸收是植物养分利用的重要策略,体现了植物对养分留存、利用和适应环境的能力.为研究亚热带不同生活型(常绿与落叶)阔叶树养分含量与养分再吸收的关系,以江西阳际峰国家级自然保护区内30种阔叶树为研究对象,测定成熟和衰老叶片氮(N)和磷(P)含量,分析常绿和落叶树种叶片N和P含量及其再吸收效率差异,揭示阔叶树种叶片养分再...

Nitrogen and phosphorus contents and resorption efficiency of thirty broadleaved woody plants in Yangjifeng,Jiangxi, China.

Nutrient resorption is an important strategy of nutrient conservation, which reflecting the ability of plants to conserve and utilize nutrients and adapt to environment. To explore the relationship between nutrient content and nutrient resorption of broadleaved woody species of different life forms (i.e., evergreen vs. deciduous), we sampled 30 broadleaved woody species in subtropical region of China located in Yangjifeng National Nature Reserve, Jiangxi Province. The nitrogen (N) and phosphorus (P) concentrations in green and senescent leaves of each species were measured to calculate nutrient resorption efficiency. Furthermore, we analyzed the relationship of leaf nutrient concentration and resorption efficiency for the different life forms. The results showed that N and P concentrations in green leaves were significantly higher in deciduous trees than those in evergreen trees. The P concentrations of senescent leaves in deciduous woody species was significantly higher than that in evergreen woody species. There was no significant difference of N concentration in senescent leaves between evergreen and deciduous species. Nitrogen resorption efficiency (NRE) and phosphorus resorption efficiency (PRE) of the 30 broadleaved woody species were 49.6% and 50.9%, respectively. There were no significant differences between the NRE and PRE of evergreen and deciduous species. NRE and PRE negatively correlated with N and P concentrations in senescent leaves, respectively. Additionally, evergreen and deciduous species showed similar relationships between nutrient resorption efficiency and nutrient concentration in senescent leaves. The sca-ling exponent of allometric relationship between NRE and PRE was 1.18 across all the species. The nutrient resorption efficiency of all the species were affected by the nutrient status of the senesced leaves. Plants examined in this study generally re-absorbed P from senescing leaves than N.