中文摘要：

以异株荨麻播种苗为试验材料,在密度为19万～96万/hm2设T1、T2、T3、T4和T5 5个处理,研究不同密度下,异株荨麻光合特征、生长量和生物量变化,寻找出合理的种植密度。结果表明,随着种植密度的增加,单株异株荨麻的净光合速率、气孔导度、蒸腾速率、生长量和生物量呈先增加后降低的趋势。异株荨麻单位面积的生物量在密度为77万/hm2时达到最大值,最佳经济生产密度为74万～77.5万/hm2。

英文摘要：

The optimal planting density is needed to achieve maximum crop yield.As an important Chinese medicinal plant,it has the vital significance for scientists and farmers to determine its reasonable planting density.In this paper,five planting densities from 19×104 to 96×104 plants/hm2 were evaluated to determine the effects of planting densities on photosynthetic parameters,growth rate and biomass accumulation.And our specific aim was to find the optimal range of planting density for the cultivation of this herb.The results indicated： when the planting density increased,the net photosynthesis rate,stomatal conductance,transpiration rate,growth and biomass firstly increased and then decreased.The biomass of Urtica dioica L.achieved the maximum value when the plant density was 77×104 plants/hm2.The best planting density was 74×104-77.5×104 plants/hm2.