杉木N、P代谢对土壤增温及隔离降雨的响应

bstract：Global climate change has changed the physiology of plants in terrestrial ecosystems. Besides，the ecophysiological stoichiometry characteristics of plants has changed．At present，most researches on the effects of warming and rainfall on forests are concentrated in the middle and high latitudes，and there are few researches on plants in subtropical regions with low latitudes. In order to reveal the ecological stoichiometry and the resorption efficiency of subtropical woody species under global warming and arid environment，this paper took Cunninghamia lanceolata, which a typical subtropical plant，as the research object and set contral（CK），warming (5℃，W)，precipitation exclusion (-50%，Pe)，warming and precipitation exclusion interaction (WP) 4 treatment, and each treatment had 5 replicate, according to the ＂backbone＂to determine the age of coniferous, divided into annual，biennial, triennial，four years of a total of four years leaves，at the same time to collect the litter of each treatment，were measured fresh leaves and litter of the ecological stoichiometric characteristics，and calculate its resorption efficiency．The results showed that：(1) phosphorus concentration in litter leaf was the highest under the condition of warming and precipitation exclusion interaction (WP)，but there was no significant difference in nitrogen concentration and N/P；(2) Compared with the control，the biennial, annual and four leaf fresh leaf nitrogen concentrations increased by 25.3%，18.2% and 19.1% (P <0.05) respectively when precipitation exclusion，Except contral, the concentrations of phosphorus old leaves significantly decreased compared to new leaves but the N/P increased significantly (P <0.05) under warming，precipitation exclusion，warming and precipitation exclusion interaction．(3) Different treatment and leaves of different ages was no significant difference in the nitrogen resorption efficiency of fresh leaves while phosphorus resorption efficiency decreased significantly with the increase of leaf age (P <0.05)．(4) The correlation between nitrogen concentration and nitrogen resorption increased in warming，warming and precipitation exclusion interaction, and under warming and precipitation exclusion interaction correlation is significant (P <0.05)．.However，all three treatments reduced the correlation between phosphorus concentration and phosphorus resorption efficiency, and all significantly and positively correlated with each other.．In the subtropical region，plant growth is significantly limited by phosphorus element, and temperature and moisture are both important factors of leaf phosphorus change．Plant nitrogen is more sensitive to moisture，Appropriate water deficit can increase the leaf N concentration.