科尔沁沙地优势固沙灌木叶片氮磷化学计量内稳性

宁志英,李玉霖,杨红玲,张子谦

Nitrogen and phosphorus stoichiometric homoeostasis in leaves of dominant sand-fixing shrubs in Horqin Sandy Land, China

Zhi-Ying NING,Yu-Lin LI,Hong-Ling YANG,Zi-Qian ZHANG

表2 科尔沁沙地优势固沙灌木盐蒿和小叶锦鸡儿冠幅内土壤N、P化学计量特征(平均值±标准误差)

Table 2 Nitrogen (N) and phosphorus (P) stoichiometry in soils beneath Artemisia halodendron and Caragana microphylla in Horqin Sandy Land (mean ± SE)

物种 Species 指标 Index 算数平均值 Arithmetic average 中位数 Median 众数 Mode 变异系数 Coefficient of variation(%) 极小值 Minimum value 极大值 Maximum value 盐蒿 A. halodendron N (g·kg-1) 0.15 ± 0.01 0.14 0.17* 57.14 0.01 0.38 P (g·kg-1) 0.05 ± 0.00 0.05 0.03* 60.00 0.00 0.11 N:P 3.10 ± 0.26 2.38 0.43 73.22 0.43 12.10 速效 N Available N (mg·kg-1) 15.77 ± 1.00 16.20 21.60 56.04 1.17 38.00 速效 P Available P (mg·kg-1) 7.82 ± 0.57 6.80 9.80 64.32 1.28 20.06 速效 N:P Available N:P 2.27 ± 0.12 2.20 3.60 46.70 0.59 5.77 小叶锦鸡儿 C. microphylla N (g·kg-1) 0.23 ± 0.02 0.21 0.02 69.56 0.02 0.65 P (g·kg-1) 0.08 ± 0.01 0.07 0.03 62.50 0.01 0.19 N:P 3.08 ± 0.21 2.87 0.76 61.04 0.76 11.99 速效 N Available N (mg·kg-1) 19.38 ± 1.08 16.88 9.43* 48.81 7.39 44.86 速效 P Available P (mg·kg-1) 9.74 ± 0.55 8.60 6.10* 49.90 2.93 24.80 速效 N:P Available N:P 2.11 ± 0.07 2.11 0.35* 27.49 0.35 3.91