文摘
The productivities of nitrogen and phosphorus (NP and PP) in plants have been greatly altered by increasing atmospheric carbon dioxide concentrations (CO2) and nitrogen (N) deposition. However, studies on this are quite limited in tropical and subtropical forests. We used open-top chambers to examine the NP and PP of five tree species in response to elevated CO2 and N addition in subtropical forests from 2005 to 2009. The five tree species included the slow-growing species (Acmena acuminatissima and Syzygium hancei) and the fast-growing ones (Castanopsis hystrix, Ormosia pinnata and Schima superba). Elevated CO2 increased the NP and PP of C. hystrix. However, the NP and PP of S. hancei were decreased by elevated CO2, and the PP of A. acuminatissima was lowered by elevated CO2 without N addition. N addition had no significant influence on the NP of all tree species, while it increased the PP of S. superba. The changes in the NP and PP were related to those in plant growth. We concluded that C. hystrix and S. superba would benefit from elevated CO2 and N addition, respectively. The results indicate that plant NP and PP in response to elevated CO2 and N addition are species specific. Our findings could have important implications for better understanding the effects of global change on species composition in subtropical forests.