我组成员在 Oecologia 上发表文章：Ang Wang, Yun-Ting Fang, De-Xiang Chen, Keisuke Koba, Akiko Makabe, Yi-De Li, Tu- Shou Luo & Muneoki Yoh. Variations in 15N natural abundance of plant and soil system in four remote tropical rainforests, southern China[J]. Oecologia, 2014, 174(2):567-580. 

　　文章链接：http://link.springer.com/article/10.1007/s00442-013-2778-5  

　　The foliar stable N isotope ratio (δ¹⁵N) can provide integrated information on ecosystem N cycling. Here we present the δ¹⁵ N of plant and soil in four remote typical tropical rainforests (one primary and three secondary) of southern China. We aimed to examine if (1) foliar δ¹⁵N in the study forests is negative, as observed in other tropical and subtropical sites in eastern Asia; (2) variation in δ¹⁵N among different species is smaller compared to that in many N-limited temperate and boreal ecosystems; and (3) the primary forest is more N rich than the younger secondary forests and therefore is more ¹⁵N enriched. Our results show that foliar δ¹⁵N ranged from -5.1 to 1.3 ‰ for 39 collected plant species with different growth strategies and mycorrhizal types, and that for 35 species it was negative. Soil NO₃^- had low δ¹⁵N (-11.4 to -3.2 ‰) and plant NO₃ ^- uptake could not explain the negative foliar δ¹⁵N values (NH₄⁺was dominant in the soil inorganic-N fraction). We suggest that negative values might be caused by isotope fractionation during soil NH₄⁺ uptake and mycorrhizal N transfer, and by direct uptake of atmospheric NH₃/NH₄⁺. The variation in foliar δ¹⁵N among species (by about 6 ‰) was smaller than in many N-limited ecosystems, which is typically about or over 10 ‰. The primary forest had a larger N capital in plants than the secondary forests. Foliar δ¹⁵N and the enrichment factor (foliar δ¹⁵N minus soil δ¹⁵N) were higher in the primary forest than in the secondary forests, albeit differences were small, while there was no consistent pattern in soil δ¹⁵N between primary and secondary forests.