中文摘要：

对黄土丘陵区9、17、30和37年生刺槐人工林进行调查，研究刺槐人工林生态系统碳、氮储量随林龄的变化动态及分配格局.结果表明： 各林龄刺槐人工林乔木层碳、氮含量分别为435.9～493.4 g·kg-1和6.8～21.0 g·kg-1；草本层和凋落物层碳、氮含量分别为396.3～459.2 g·kg-1和14.2～23.5 g·kg-1；土壤层碳、氮含量分别为2.7～10.7 g·kg-1和0.2～0.7 g·kg-1.树干是乔木层主要的碳、氮库，分别占乔木层碳、氮储量的46.9%～63.3%和39.3%～57.8%；37年生刺槐人工林0～20 cm土层碳、氮储量最大，分别为30.1和1.8 Mg·hm-2.刺槐人工林生态系统的总碳、氮储量随林龄增加而逐渐增大，均在37年生时达到最大值，分别为127.9 Mg·hm-2和6512.8 kg·hm-2；土壤层是刺槐人工林生态系统的主要碳、氮库，分别占人工林生态系统总碳、氮的63.3%～83.3%和80.3%～91.4%.

英文摘要：

The 9-, 17-, 30- and 37-year-old Robinia pseudoacacia plantations in the loess hilly region were investigated to study the dynamics and allocation patterns of carbon and nitrogen storage. The results showed that the ranges of carbon and nitrogen contents were 435.9-493.4 g·kg-1 and 6.8-21.0 g·kg-1 in the arbor layer, 396.3-459.2 g·kg-1 and 14.2-23.5 g·kg-1 in the herb and litter layer, and 2.7-10.7 g·kg-1 and 0.2-0.7 g·kg-1 in the soil layer, respectively. The branch was the major carbon and nitrogen pool in the arbor layer, accounting for 46.9%-63.3% and 39.3%-57.8%, respectively. The maximum storage values were 30.1 and 1.8 Mg·hm-2 for carbon and nitrogen, respectively, in the 0-20 cm soil layer in the 37-year-old R. pseudoacacia plantation. The total carbon and nitrogen storage in the R. pseudoacacia plantation ecosystem increased with increasing forest age, and the maximum values were 127.9 Mg·hm-2 and 6512.8 kg·hm-2 for carbon and nitrogen storage, respectively, in the 37-year-old R. pseudoacacia plantation. Soil layer was the major carbon and nitrogen pool of R. pseudoacacia plantation ecosystem, accounting for 63.3%-83.3% and 80.3%-91.4%, respectively.