In this study, the project of constructed wetland for treatment of tailwater from the wastewater treatment plant in Wudang Mountain was taken as an example, and the technological processes, pollution load, wetland bed structure, bed filler, selection of plants and hydraulic conditions of the subsurface flow constructed wetland were discussed. A subsurface flow constructed wetland, which covered an area of 7 227 m^2 was finally designed. It could treat 7 000 m^3 of tailwater from the wastewater treatment plant a day. In addition, the system could reduce the emission of COD, BODs, TN, TP and NH3-N by 25.55, 25.55, 12.78, 1.28 and 17.89 t respectively a day. The outlet water was proved to reach the Standard A of the first class in Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant （GB 18918-2002）.
[Objective] The paper was to study the distribution of main nutrients in seedlings of umbrella bamboo (Fargesia murielae) in Shennongjia National Nature Reserve. [Method] The study was conducted in Liangfengya of Shennongjia National Nature Reserve. In the field investigation, six clumps of umbrella bamboo grown independently were randomly selected and sampled. The total nitrogen, total phosphorus and total potassium of umbrella bamboo were detected by regular plant analysis method. The age classes of bamboo seedlings were ascertained by age grade backtracking method. [Result] In different organs, N, P, K contents in branches and leaves were significantly higher that than in stems. Along age grades, N and P contents performed "M" shape in branches and leaves, while K content approximately performed as normal distribution. [Conclusion] The nutrients distribution pattern of these seedlings is likely formed by its nutrition mechanism which allocates nutrients according to different needs or by external interference of environmental features. However, the specific causes still need further investigation.
研究杨树耗水量的变化特征、水分利用效率及其影响因子对杨树生理生态研究、造林树种的选择和林业生态工程建设具有重要的指导价值。以意杨(Populus euramevicana cv.‘I-214’)为研究对象进行盆栽试验,设定了4个处理组,分别为T1处理组(种植意杨,密封处理),T2处理组(种植意杨,非密封处理),T3处理组(不种植意杨,非密封处理),C处理组(不种植意杨,密封处理),定量分析了意杨耗水规律、水分利用效率及土壤蒸发量与植株生理特性、气象环境因子之间的关系。结果表明:(1)4个处理组耗水量变化曲线均呈"单峰型",且在7月份达到最大值,2月份降到最低值。(2)栽植意杨的土壤水分蒸发量占总耗水量的15.9%,全年波动状态稳定,本底流失量占30.4%。(3)在地表覆盖物下的意杨蒸腾耗水量占总耗水量的53.7%,年变化曲线为单峰型;栽培意杨的土壤水分总流失量是不栽培意杨土壤总流失量2.77倍;在裸地上种植意杨的土壤水分总蒸发量仅比没有意杨的裸地土壤多流失7.9%水分。(4)在有地表覆盖物下和裸地上的意杨叶面平均蒸腾强度分别为30.8 g cm^(-2)a^(-1),9.5 g cm^(-2)a^(-1);平均每克生物量耗水量为39.61 g。综上所述,意杨具有很强的蒸腾耗水能力,种植意杨可能会造成造林地区土壤水分大量流失,使该地区深层土壤干燥化,不利于土壤储水调节作用的发挥。
