为探究库布齐沙漠东北缘沙枣防护林土壤养分以及土壤化学计量特征,为荒漠防护林可持续利用提供理论依据,以不同林龄（3 a、9 a、15 a）沙枣防护林为研究对象,选取30 m × 30 m代表性样地,在0~50 cm土壤剖面分层取样,分析不同林龄沙枣林地土壤养分元素以及化学计量特征。结果表明：不同林龄沙枣防护林不同土层pH总体波动不大。沙枣林地养分元素受林龄和土层深度影响明显,表现为随林龄增加其养分含量显著提高,且沿土壤剖面垂直递减,呈现一定的表聚现象;其中,林龄对土壤速效钾、全磷、全钾影响较大,林龄为15 a较裸沙地分别增加152.2%、58.0%、69.5%。不同林龄沙枣防护林0~50 cm土层的C:N、C:P和N:P分别为9.25~18.99、4.78~5.96和0.31~0.63,且均受到林龄和土层深度的双重作用。综合化学计量特征分析可知,库布齐沙漠东北缘沙枣防护林对风沙土的改良效果显著,且林地土壤养分状况主要受C、N元素的影响,土壤N元素矿化能力稍弱,氮素贫乏,在后期经营管理中应适当施加氮肥。

To investigate the soil nutrients and stoichiometric characteristics of the Elaeagnus angustifolia shelterbelt in the northeastern margin of the Hobq Desert, and to offer a theoretical basis for the development of desert shelterbelt, we studied the E. angustifolia shelterbelt with different forest ages (3 a, 9 a, 15 a ) using 30 m×30 m representative sample plots. The soil nutrient content of these plots were measured by stratified sampling of the 0-50 cm soil layer. The pH of different soil layers in the different forest ages had little fluctuation; however, the nutrient elements were significantly affected by forest age and soil depth. Nutrient content increased significantly with forest age, and decreased vertically along the soil profile, illustrating a surface accumulation phenomenon. Among nutrients, forest age had a great influence on available K, total P, and total K; at a forest age of 15 a, these nutrients increased by 152.2%, 58.0%, and 69.5%, respectively, compared with bare sandy land. The C:N, C:P, and N:P of the 0-50 cm soil layer across the different forest ages was 9.25-18.99, 4.78-5.96, and 0.31-0.63, respectively, and was affected by forest age and soil depth. The comprehensive stoichiometric analysis showed a remarkable improvement effect of the E. angustifolia shelterbelt on aeolian sandy soil in the northeastern margin of Hobq Desert, with the soil nutrient status mainly affected by the C and N. The mineralization ability of soil N was weak and nitrogen was poor. As such, nitrogen fertilizer should be appropriately applied in later management.