密度和行距配置对毛白杨苗木质量的影响

以毛白杨新品种“北林雄株1号”苗木为试验材料，采用双因素完全随机区组设计，设置高、中、低3种育苗密度和3种行距配置、带状配置B2和带状配置B3(2行1带，窄行距0.4m+宽行距1.2m］，测定毛白杨苗木生长指标、养分含量、光截获和叶面积指数。1)密度和行距配置对毛白杨苗木生长指标影响显著，中密度带状配置A2B3的苗高、根生物量和总生物量最大，分别为294.65cm、151.92g和328.77g，较高密度行状配置A1B1分别提高30.21%、62.78%和26.96%;2)密度和行距配置显著影响毛白杨叶氮浓度，A3B3的叶氮浓度最大(16.43g·kg－1);带状配置较行状配置可显著提升苗木茎根的氮浓度;3)密度和行距配置的交互作用对毛白杨苗木光截获影响不显著，行距配置对毛白杨苗木光截获和叶面积指数影响极显著，带状配置显著增加毛白杨苗木光截获和叶面积指数;4)不同密度和行距配置下，光截获显著影响毛白杨生长指标，光截获与毛白杨苗高、地径、地上生物量、地下生物量和总生物量呈极显著正相关，与茎根比呈显著负相关，其中光截获与生物量的决定系数最高。

Taking seedlings of the new Populus tomentosa variety 'Beilin Male Clone 1' as experimental materials, a two-factor completely randomized block design was adopted, with three seedling density levels (high, medium, low) and three row spacing configurations set, including strip planting configurations B2 and B3 (2 rows per strip, narrow row spacing 0.4m + wide row spacing 1.2m). The growth indicators, nutrient content, light interception and leaf area index of Populus tomentosa seedlings were measured. 1) Both seedling density and row spacing configuration had significant effects on the growth indicators of Populus tomentosa seedlings. The seedling height, root biomass and total biomass of the medium-density strip planting configuration A2B3 were the maximum, reaching 294.65 cm, 151.92 g and 328.77 g respectively, which were 30.21%, 62.78% and 26.96% higher than those of the high-density row planting configuration A1B1. 2) Seedling density and row spacing configuration significantly affected the leaf nitrogen concentration of Populus tomentosa seedlings. The leaf nitrogen concentration of A3B3 was the highest (16.43 g·kg⁻¹). Compared with row planting configuration, strip planting configuration could significantly increase the nitrogen concentration of seedling stems and roots. 3) The interaction between seedling density and row spacing configuration had no significant effect on light interception of Populus tomentosa seedlings, while row spacing configuration had an extremely significant effect on light interception and leaf area index. Strip planting configuration significantly increased the light interception and leaf area index of Populus tomentosa seedlings. 4) Under different seedling density and row spacing configurations, light interception significantly affected the growth indicators of Populus tomentosa seedlings. Light interception showed an extremely significant positive correlation with seedling height, ground diameter, aboveground biomass, underground biomass and total biomass of Populus tomentosa, and a significant negative correlation with stem-root ratio. Among them, the coefficient of determination between light interception and biomass was the highest.