长期放牧和氮添加对黄土高原典型草原长芒草种群生长的影响

黄玲, 王榛, 马泽, 杨发林, 李岚, SEREKPAYEV Nurlan, NOGAYEV Adilbek, 侯扶江

Effects of long-term grazing and nitrogen addition on the growth of Stipa bungeana population in typical steppe of Loess Plateau

HUANG Ling, WANG Zhen, MA Ze, YANG Fa-Lin, LI Lan, SEREKPAYEV Nurlan, NOGAYEV Adilbek, HOU Fu-Jiang

图8 放牧和氮添加对长芒草生长的影响。A, 对长芒草生长的影响。B, 对长芒草地上生物量及其占比的直接和间接效应。A图中黑色表示路径显著(p < 0.05), 灰色表示路径不显著(p > 0.05), 线条粗细表示效应大小, 实线表示正效应, 虚线表示负效应, 箭头处的数字为标准化路径系数, R2表示解释率。*, p < 0.05; **, p < 0.01; ***, p < 0.001。RMSEA, 近似误差均方根。

Fig. 8 Effects of stocking rate and nitrogen (N) addition on Stipa bungeana. A, Effects on the growth of Stipa bungeana. B, Direct and indirect effects on aboveground biomass and the proportion of population biomass to total community aboveground biomass. In A, the black line indicates a significant path (p < 0.05), the gray line indicates that the path of action is not significant (p > 0.05), the thickness of the line indicates the effect size, the solid line indicates a positive effect, and the dashed line indicates a negative effect, numbers at arrows are standardized path coefficients, R2 indicates variation that can be explained. *, p < 0.05; **, p < 0.01; ***, p < 0.001. RMSEA, root mean square error of approximation.