Soil Particle Composition and Its Relationship with Nutrient Contents in a Quercus aquifolioides Forest at Different Altitudinal Gradient | 不同海拔梯度川滇高山栎林土壤颗粒组成及养分含量

chinois. 分析卧龙自然保护区皮条河上游巴郎山3个海拔梯度川滇高山栎林的土壤颗粒组成、总有机碳含量和全氮含量。结果表明：巴郎山川滇高山栎林土壤颗粒组成以粉粒为主,属中质地土壤;3个海拔梯度表层土（0～15cm）土壤总有机碳和全氮含量均高于亚层土（15～30cm）;在表层土壤中总有机碳含量随海拔增加呈现由低到高,再变低的趋势,亚层土则随海拔升高呈增加趋势;表层和亚层土壤全氮含量均随海拔降低而减少;巴郎山高山栎林土壤碳氮比值较小,平均为12.77;在2个土层中,总有机碳含量与全氮含量的相关性随海拔梯度递减由极显著正相关（P〈0.01）到不相关;表层土壤中总有机碳和全氮含量在海拔3549m处与粗粉粒含量呈极显著正相关（P〈0.01）,与粘粒呈显著负相关（P〈0.05）,3091m处与粗粉粒含量正相关性显著（P〈0.05）,2551m处与细砂粒含量呈显著正相关（P〈0.05）;亚层土壤全氮含量只在海拔2551m处与细粉粒含量呈显著负相关（P〈0.05）。

anglais. The current research focuses on soil particle separate and total organic carbon and nitrogen in Quercus aquifolioides forest in Balangshan, Wolong Natural Reserve, Sichuan, and their correlation at tree altitudinal gradient. The result shows that： The soil particle separate of Q. quifolioides forest is mainly of silts, and the soil texture is medium textured soils ; The contents of soil total organic carbon content and nitrogen content in 0 - 15 cm layer are higher than that in 15-30 cm layer in different attitude gradients; the total organic carbon content in the topsoil shows a low-high-low tendency at different altitudinal gradients, whereas that of the subsoil shows a growing tendency; The C/N ratio of Q. aquifolioides forest is relatively small, with an average of 12.77 ; The correlation analysis between the soil total organic carbon and nitrogen content and soil particle separate respectively tells us： contents of soil organic carbon is very significantly positively correlated with total nitrogen in the two soil layers （P 〈 0. 01 ） at 3 549 m, no correlation at 2 551 m; the contents of total organic carbon and nitrogen are very significantly positively respective respectively with coarse silt content in 0 - 15 cm and 15 - 30 cm soil layers （P 〈 0. 05）, but negatively with clay in different layers （P 〈 0. 05） in 0 - 15 cm soil layer at 3 549 m, significantly positively （P 〈 0. 05） and very significantly positively correlated （P 〈 0. 01 ） respectively with coarse silt content in different soil layers at 3 091 m, very significantly and significantly positively correlated respectively with fine sand content in different soil layers at 2 551 m, but negatively with fine silt content in 15 - 30 cm soil layer. Finally,-in this paper the results presented that relationships among soil particle separate and total organic carbon and nitrogen content are quite complications in Q. aquifolioides forest at different altitudinal gradient.