川西亚高山森林土壤有机层碳、氮、磷储量特征

Carbon, Nitrogen and Phosphorus Storage in Soil Organic Layer of the Subalpine Forests in Western Sichuan

同步研究了川西亚高山云杉林、冷杉林和白桦林生态系统土壤有机层(OL)和矿质层(MS)的有机碳、全氮及全磷储量特征.所有土壤剖面上的有机碳和易氧化有机碳含量均随土壤深度增加而降低,即未分解层<半分解层<完全分解层<腐殖质层<淀积层<母质层.云杉林、冷杉林和白桦林土壤有机层的有机碳储量分别为29.38(±1.28)thm-2、22.70(±1.20)thm-2和8.63(±0.95)thm-2,矿质土壤中分别为17.84(±1.92)thm-2、19.74(±1.76)thm-2和14.92(±1.64)thm-2.冷杉林和白桦林土壤剖面上的全氮和全磷含量大小顺序为半分解层<完全分解层<腐殖质层,但腐殖质层>淀积层>母质层.云杉林、冷杉林、白桦林土壤有机层的全氮储量分别为0.85(±0.11)thm-2、0.68(±0.06)thm-2和(0.36±0.03)thm-2,全磷储量分别为0.29(±0.03)thm-2、0.22(±0.03)thm-2和0.06(±0.02)thm-2.

Distribution characteristics of organic carbon （ OC）, ready oxidation carbon （ ROC）, nitrogen （N） and phosphorus （P） in soil organic layer （OL） and mineral soil （MS） were investigated to understand the role of OL in the cycles of C, N and P in the spruce （Picea purpurea Masters ） （SF）, fir （Abies faxoniana Rehder ＆ E. H. Wilson ） （FF） and birch （Betula platyphylla Sukaczev） （BF） forests. The three typical forests cover the largest area of the subalpine forest region in Western Sichuan. The contents of OC and ROC decreased with increasing soil depth, and the OC stock in OL and MS was 29. 38 （ ± 1.28） thm^-2 and 17.84 （ ± 1.92） thm^-2 in SF, 22.70 （ ± 1.20） thm^-2 and 19. 74 （ ± 1.76） t hm^-2 in FF, and 8. 63 （ ±0. 95） t hm^-2 and 14. 92 （ ± 1.64） t hm^-2 in BF, respectively. The OC stock was higher in OL than that in MS in SF and FF, but lower in BF. N and P were stored mainly in MS regardless of the forests. The contents of N and P increased with the increasing of soil depth from fragmented litter layer （FL） to humus layer （ AL）, and decreased with the increasing of soil depth from AL to parent material layer （CL） of the studied forests. In OL, the total N stock was 0. 85 （ ±0. 11 ） thm^-2 , 0. 68 （ ± 0. 06） t hm^-2 and 0. 36 （ ±0. 03） t hm^-2 for SF, FF and BF, and total P stock was 0. 29 （ ±0. 03） t hm^-2, 0. 22 （ ±0. 03） t hm^-2, and 0. 06 （ ±0. 02） t hm^-2 for SF, FF and BF, respectively. Fig 2, Tab 2, Ref 22 .