沙化程度和林龄对湿地松叶片及林下土壤C、N、P化学计量特征影响  

Effects of desertification intensity and stand age on leaf and soil carbon,nitrogen and phosphorus stoichiometry in Pinus elliottii plantation

作　　者：胡启武[1] 聂兰琴 郑艳明[1] 吴琴[1] 尧波[1] 郑林[1] 

机构地区：[1]江西师范大学鄱阳湖湿地与流域研究教育部重点实验室,南昌330022

出　　处：《生态学报》2014年第9期2246-2255,共10页Acta Ecologica Sinica

基　　金：江西省教育厅科技落地计划资助项目(鄱阳湖沙化土地与水土流失治理技术推广与示范2012)";国家自然科学基金资助项目(31270522)

摘　　要：为阐明沙化程度和林龄对湿地松(Pinus elliottii)叶片及林下土壤碳(C)、氮(N)、磷(P)化学计量特征影响,探讨C、N、P化学计量比对沙山植被恢复的指示意义,在鄱阳湖多宝沙山沿沙化梯度测定了不同林龄湿地松叶片及林下土壤C、N、P含量。结果表明:1)在叶片C、N、P及其化学计量比中叶N与C∶N对沙化程度和林龄变化反应最为敏感。对于轻度与中度沙化区的5年生与10年生湿地松林,林龄、林龄与沙化程度的交互作用均对叶N及C∶N产生显著影响;对于中度与重度沙化区的2年生和10年生湿地松林,林龄和沙化程度均显著影响叶N与C∶N。2)叶片与土壤二者C、N、P及化学计量比对沙化程度与林龄变化的响应不完全一致。林龄、林龄与沙化程度的交互作用对轻度与中度沙化区5年生和10年生湿地松林土壤全N有显著影响;对于中度与重度沙化区2年生和10年生湿地松林,仅沙化程度对土壤全磷以及林龄对土壤有机碳影响显著。3)10年生湿地松叶片N∶P平均值为20.63,10年生以下湿地松叶片N∶P平均值为15.61,随着林龄的增加,湿地松生长由N、P共同限制逐渐转向更受P的限制。Abstract： There are some sandy hills distributed along Poyang Lake, which belong to typical southern desertification. As located in subtropical climate zone, the sandy hills differed in vegetation and soil from northern deserts. During the past ten to twenty years, Pinus eUiottii was introduced in sandy hills for vegetation restoration. Since carbon （ C）, nitrogen （N） and phosphorus （P） stoichiometry are critical indicators of biogeochemieal coupling in terrestrial ecosystems, the nutrients stoichiometry has been successfully used in indicating community succession and vegetation restoration in recent years. However, our knowledge of the temporal variability of carbon, nitrogen and phosphorus stoichiometry is much less developed than its spatial pattern. Besides, it remains unknown whether there is consistent temporal pattern for various ecosystem components, such as plants and soil. In this study, leaf and soil organic carbon, total nitrogen and total phosphorus in Pinus elliottii plantation were measured along desertification gradient in a typical sandy hill close to Poyang Lake. The objectives were （1） to clarify effects of desertification intensity and stand age on leaf and soil carbon, nitrogen and phosphorus stoichiometry, as well as the role of nutrients stoichiometry in indicating vegetation restoration in sandy hills,and （2） to discuss the temporal variation pattern of leaf and soil nutrients stoichiometry during stand development. Results showed that mean concentrations of leaf carbon, nitrogen and phosphorus were （437.48 ±16.96） mg/g, （6.09±1.51） rag/ g and （0.71±0.66） mg/g, respectively. The counterparts for top 0-10 cm soil were （3.48±0.63） mg/g, （0.117±0.032） mg/g and （0.050±0.012） mg/g, respectively. The mean ratio of C ：N, C ：P and N ：P was 75.70, 1297.86 and 17.76 for leaf, and 32.45, 74.04 and 2.52 for soil, respectively. Leaf carbon, nitrogen and phosphorus concentrations were all lower than the means of global plants. However, the ratio

关 键 词：鄱阳湖 沙山 湿地松 化学计量学 

分 类 号：S791.246[农业科学—林木遗传育种]