Foliage Stoichiometric And WUE Characteristics Of Pinus Massoniana And The Understorey Species In Changting, Fujian

Regard nine plants foliage under four sites with different ecological restoration degree in the soil erosion area of Changting County as the research object to study C:N:P ecological stoichiometry and stable carbon isotope composition (d13C). The result indicated that:1) The mean of C、C:N and C:P of four site plant foliage was (498.03±3.09) mg/g、36.94±1.24、772.94±37.50respectively, which was significant higher than global average degree, but the mean of N (13.14mg/g)、P (0.65mg/g) was significant lower than global average degree (C、N、P、C:N、C:P was464mg/g、20.6mg/g、1.5mg/g、22.5、232respectively), it was concerned with N and P content of soil.2) As for plants life form, P. massoniana had highest carbon ((485.53±3.08) mg/g～(522±27.16) mg/g) and phosphorus ((8.58±0.32) mg/g～(19.95±0.61) mg/g) concentrations, which was significant higher than most of its understorey species. This shows that P. massoniana had higher carbon and phosphorus storage capacity. But nitrogen content of P. massoniana was between (7.10±0.23)mg/g and (18.28±0.38) mg/g, which was lower than broad-leaf arbor and shrubs. Shrubs had highest nitrogen storage capacity.3) The nitrogen use efficiency of P. massoniana and D. dichotoma was higher than most of other plants. The C:P value of P. massoniana was significant lower than its understorey species in each site. This results reflected that P. massoniana had low phosphorus use efficiency. D. dichotoma had the highest nitrogen and phosphorus use efficiency among the P. massoniana understorey species.4) Plants in soil erosion area were limited by nutrient generally. P. massoniana nutrient limiting change with the seasons. In spring, P. massoniana was mainly restricted by nitrogen (N:P<14). In summer, P. massoniana at some site were restricted by phosphorus and some were by nitrogen. In autumn, P. massoniana at low ecological restoration degree site was restricted by phosphorus or restricted by phosphorus and nitrogen simultaneously, at high ecological restoration degree site P. massoniana was restricted by nitrogen. In winter, P. massoniana was mainly restricted by nitrogen and phosphorus. P. massoniana understorey species were all restricted by phosphorus.5) P. massoniana and D. dichotoma became dominant species in this ecosystem due to they had higher water use efficiency and nitrogen use efficiency relatively.