西北干旱区营养钵对大叶白蜡容器苗光合特性的影响

Effects of nutrition pot on photosynthetic characteristics of containerized Fraxinus rhynchophylla biennial seedlings in the arid region of Northwest China

通过测定有无营养钵2种处理下,2年生大叶白蜡(Fraxinus rhynchophylla)的光合特征指标,以及生长量和土壤参数,阐明容器抚育对其大树容器引种苗的影响,以此探求营养钵使用的必要性,为外来优良树种的引种提供参考。结果表明,土壤方面,营养钵组土壤体积含水量和电导率均低于无营养钵组(F=18.57,P=0.00<0.05);光合参数方面,营养钵组各时刻的净光合速率(Pn)极显著高于无营养钵组(F=9.528,P=0.00<0.01);Pn对光合有效辐射(PAR)的定积分,营养钵组(56.71±3.83)亦极显著高于无营养钵组(21.35±2.18),(F=1543.46,P=0.00<0.01);生物量方面,营养钵组也极显著高于无营养钵组(胸高:4.35 m±0.34 m>4.15 m±0.23 m,F=25.83,P=0.00<0.01;胸径:63.66mm±15.58 mm>55.47 mm±13.64 mm,F=15.17,P=0.00<0.01)。一天中,营养钵组在8:00-10:00时水分利用效率(WUE)较高,蒸腾速率(Tr)较小。综上所述,在2年生大叶白蜡大树容器引种苗的培育中,使用营养钵效果较好;同时应在早8:00-10:00时段内增加灌溉频率。同时发现,营养钵对表层土壤温度影响不大,气孔限制对净光合速率影响较大。

The photosynthetic charateristics, increment and soil parameters of container biennial seedlings of Fraxinus rhynchophylla in the nutrition pot were determined, which could provide practical guidance for tree cultivation and offer references for vegetation restoration and soil water conservation. The results showed that the nutrition pot could lower the edaphic parameters, such as soil moisture and conductivity（F=18.57, P=0.000.05） compared with the non-nutritional pot. On the contrary, the net photosynthetic rate（Pn） of seedlings grown in the nutritional pot was higher than that in the non- nutritional one（F=9.53,P=0.0090.05）. The Pn value integrated from 1 to 7 by photosynthetically active radiation of the seedlings in the nutrition pot（56.71±3.83） was higher than that in the non-nutrition pot（21.35±2.18）. The transpiration rate and the biomass of the seedlings in the nutrition pot behaved better than those in the non-utrition pot（plant height： 4.35 m±0.34 m4.15 m±0.23 m, F=25.83,P=0.000.01; diameter at breast height： 63.66 mm±15.58 mm55.47 mm±13.64 mm, F=15.17,P=0.000.01）. In conclusion, it was beneficial to use nutrition pot in the seedlings cultivation in Urho District of City Karamay with an increased irrigation frequency at 8：00-10：00 am. In addition, we found that there was little difference in the topsoil temperature between the nutrition pot and non-nutrition pot, but the stomatal conductance was the most important factor for net photosynthetic rate in the two groups.