【摘要】 对杨树苗圃地重茬不同代数对苗木生长、生态生理特性、生物量分配等方面的影响进行了系统研究。研究结果表明:与1代相比,2代、3代苗的平均苗高分别下降了4.30%和20.34%,平均胸径分别下降了6.55%和20.83%,单株生物量下降了5.56%和34.46%,单株叶面积分别下降了17.08%、24.27%,叶绿素含量分别下降了9.39%、21.10%,光合速率分别下降了4.38%、19.49%,叶绿素a/b分别下降了4.37%、7.35%。经相关分析结果表明苗木的生长指标及生态生理指标之间具有较高的正相关性,光合速率与单株生物量、苗高的相关系数为0.998、1.000,叶绿素b与胸径相关系数为0.997,均达到显著水平。随着重茬代数的增加,生物量的分配结构也发生了变化,茎生物量所占比例呈下降趋势,而叶、根生物量所占比例有所上升。与1代相比,2代和3代根系鲜重分别下降了7.29%、32.6%,干重分别下降了3.53%、28.23%,根系条数分别下降了19.50%、41.09%,根系生物量与各部分生物量的相关性较强,与地上部分生物量相关系数高达0.997。更多还原

【Abstract】 Height growing, ecophysiolgical characteristics and biomass distribution of I-107 (Populus×euramercana) poplar cutting stock in continuous cropping nursery were studied. The results showed that compared to the first generation, the mean heights of the 2nd and 3rd generations cutting stocks decreased by (4.30%) and 20.34%, the mean diameters at breast height of the 2nd and 3rd generation cutting stocks decreased by 6.55% and 20.83%, the leaf areas of per tree of the 2nd and 3rd generation seedlings decreased by (17.08%) and 24.27%, the biomass of the 2nd and 3rd generations decreased by 5.56% and 34.46%, the chlorophyll content of the 2nd and 3rd generations decreased by 9.39% and 21.10%, the photosynthetic rates of the 2nd and 3rd generations decreased by 4.38% and 19.49%, and the chlorophyll(a/b) of the 2nd and 3rd generations decreased by 4.37% and 7.35%, respectively. The eco-physiological characteristics of photosynthesis transpiration were correlated with the biomass and cutting stock height, significantly. The correlation coefficient between the leaf chlorophyll b content and the cutting stock breast diameter was 0.997. The ratio of stem biomass decreased with the increase of planting generations, while the ratio of leaf biomass and root biomass increased. The weight of fresh root of the 2nd and 3rd generations decreased by 7.29%?32.60%, the root biomass of the 2nd and 3rd generations cutting stock decreased by 3.53% and 28.20%, the root numbers of the 2nd and 3rd generation cutting stocks decreased by 19.50% and 41.09% respectively,compared to the first generation. The root biomass and the other parts of biomass had a high correlation. The correlation coefficient between the root biomass and the aboveground biomass was 0.997.更多还原