4种广东乡土阔叶树种幼苗的生长与养分特征

用半微量凯氏法、钼兰比色法和原子吸收光度法分别对樟树Cinnamomum camphora、山杜英Elaeocarpus sylvestris、荷木Schima superba、海南蒲桃Syzygium cumini等4种幼苗叶片的N、P、K、Ca、Mg含量进行分析。结果表明，樟树的N、Ca含量高而P和K含量略低；山杜英的K、Ca和Mg含量低；荷木的N、K和Mg含量最高；海南蒲桃P含量最高而N含量最低。聚类分析表明，4种幼苗中樟树和荷木的生长特征是苗高较小而冠幅大，山杜英和海南蒲桃为苗高较大而冠幅小。

Growth and Nutrient Characteristics of Seedlings of Four Indigenous Broadleaved Tree Species in Guangdong Province

The contents of N, P, K, Ca and Mg in the leaves of seedlings of 4 tree species were analyzed by semi-micro kjeldahl method, molybdenum blue colorimetry and atomic absorption spectrophotometry, respectively. The results showed that contents of Ca and N were high, whereas contents of K, P were low in Cinnamomum camphora seedlings; the contents of K, Ca and Mg were low in Elaeocarpus sylvestris seedlings; the contents of N, K and Mg in Schima superba were the highest among the seedling of 4 tree species; P content was the highest and N content was the lowest in Syzygium cumini seedlings. Growth characteristics of C. camphora and S. superba were seedlings with low seedling height and large crown, whereas those of E. sylvestris and S. cumini were seedlings with high seedling height and small crown.