辽河三角洲湿地资源现状及保护管理的优化策略

辽河三角洲湿地为海陆交界、淡成水交汇,地势低平,易发洪涝,河道变化频繁,人类生产活动活跃,因此,湿地的保护策略值得重视。本文阐述了辽河三角洲湿地自然资源种类、数量、分布及生物多样性,分析了湿地资源的动态消长对生态环境的影响,提出了湿地保护管理的优化策略。     

不同植被恢复模式对黄土高原沟壑区土壤水分生态效应的影响

研究了渭北黄土高原沟壑区内侧柏、荆条、20年刺槐、4年刺槐、4年苜蓿、农地不同植被恢复模式土壤水分生态效应,结果表明：不同的植被恢复模式土壤容重均低于对照农田,减小幅度为16%～8%,孔隙度增加,总孔隙度增幅为24.5%～8.1%,毛管孔隙度增幅为1.2%～13.9%,非毛管孔隙度增幅为20.5%～90.0%;土壤持水性比农地增加33%～7.5%;水分补给量在0~2m范围内,侧柏、荆条、4年刺槐是农地的2、1.5、1.71倍,20年刺槐和苜蓿比农地低22.5%和31.4%;0～1m内,侧柏、荆条、刺槐4年分别是农地的2.16、1.78、1.85倍,20年刺槐、苜蓿为农地的25%和62.3%;>0.25mm水稳性团聚体含量比农地增加56.84%～30.72%;土壤结构破坏率农地最高为41.09%,其它植被为6.67%～25.73%。相关性分析表明土壤容重、总孔隙度、水分特征曲线a、水稳性团聚体含量、结构破坏率相关性显著。不同植被对土壤水分生态效应不同,除20年刺槐、苜蓿土壤水分补给量小于对照农地外,其它各项指标均显著优于农地。表6参27     

人工湿地去除氨氮机理及影响因素研究

人工湿地的脱氮主要是通过水生植物吸收、微生物的硝化和反硝化以及氮的挥发等途径来实现的,微生物的硝化与反硝化是主要的脱氮机制。人工湿地去除氨氮的影响因素很多,不仅受到基质、微生物和水生植物这3种人工湿地构成要素的影响,还受到溶解氧(DO)、pH和温度的影响,改善这些影响因素从而达到良好的脱除氨氮效果。最后对人工湿地基质吸附饱和后再生处理问题进行了探讨。     

Natural recovery of different areas of a deserted quarry in South China

A quarry is a surface mining operated place, which produces enormous quantities of gravel, limestone, and other materials for industrial and construction applications. Restoration and revegetation of deserted quarries are becoming increasingly important. Three areas of a typical quarry in South China: terrace for crushed materials (terrace), spoiled mound, and remaining side slope, were investigated, to compare the existing plant species and to study the relationship between environmental factors and revegetation. The plant species composition of these three areas was found to differ significantly after eight years of natural recovery. The typical plant communities found over them were composed of gramineous herbs, fems, and shrubs. Soil organic matter, soil moisture, and soil bulk density were considered to be the major determining factors for vegetation succession. There existed abiotic and biotic thresholds during quarrying restoration. Suggestions had been presented that could have accelerated the process of natural recovery in quarries.     

Performance of a water hyacinth （Eichhornia crassipes） system in the treatment of wastewater from a duck farm and the effects of using water hyacinth as duck feed

Nowadays, intensive breeding of poultry and livestock of large scale has made the treatment of its waste and wastewater an urgent environmental issue, which motivated this study. A wetland of 688 m2 was constructed on an egg duck farm, and water hyacinth (Eichhornia crassipes) was chosen as an aquatic plant for the wetland and used as food for duck production. The objectives of this study were to test the role of water hyacinth in purifying nutrient-rich wastewater and its effects on the ducks’ feed intake, egg laying performance and egg quality. This paper shows that the constructed wetland removed as much as 64.44% of chemical oxygen demand (COD), 21.78% of total nitrogen (TN) and 23.02% of total phosphorus (TP). Both dissolved oxygen (DO) and the transparency of the wastewater were remarkably improved, with its transparency 2.5 times higher than that of the untreated wastewater. After the ducks were fed with water hyacinth, the average daily feed intake and the egg-laying ratio in the test group were 5.86% and 9.79% higher, respectively, than in the control group; the di erences were both significant at the 0.01 probability level. The egg weight in the test group was 2.36% higher than in the control group (P < 0.05), but the feed conversion ratios were almost the same. The eggshell thickness and strength were among the egg qualities significantly increased in ducks fed with water hyacinth.We concluded that a water hyacinth system was e ective for purifying wastewater from an intensive duck farm during the water hyacinth growing season, as harvested water hyacinth had an excellent performance as duck feed. We also discussed the limitations of the experiment.     

九段沙上沙海三棱藨草湿地植物与土壤间营养元素含量的灰色关联分析

利用灰色关联分析方法对九段沙上沙海三棱藨草中营养元素含量与不同深度土壤相应元素含量的关联度进行分析,旨在了解海三棱藨草生长过程对不同深度土壤营养元素的吸收程度.结果显示,海三棱藨草生长过程中与深层土壤中N,P,K元素含量关联最密切,关联度顺序是40～60 cm＞15～40 cm＞0～15 cm.与土壤营养元素含量的关联序为N＞K＞P,生长过程吸收的N元素最多,其次是K元素,吸收的P元素最少.不同生长阶段对营养元素的需求程度不同,生长初期与N元素含量关联最密切,旺盛生长期与N,P,K元素含量关联均密切,生长末期与N元素含量的关联程度减小,与P,K元素含量的关联程度增加.     

人工湿地处理城市污水效能的影响因素分析

为解决人工湿地占地面积大、处理效率低、容易堵塞,往往需要间歇运行等问题,通过对传统的人工湿地进行改造,设计一套新型人工湿地床系统——折流式湿地床＋侧流式湿地床,并通过试验对其处理城市污水的运行效能的影响因素进行了研究。研究结果表明,降雨、蒸腾和蒸发、温度、植物收割及堵塞作用对人工湿地运行有不同程度的影响,人工湿地受降雨因素的影响,其出水COD值比降雨前低,同时较人工湿地由于降雨作用所导致的COD稀释浓度高2．4～5．7mg/L,而降雨使出水SS比降雨前高5．0～7．2mg/L;堵塞缩短了折流湿地床的运行周期及降低了COD的去除,水力负荷为102．87cm/d时,运行周期为20d,水头损失由5．2cm增至14．8cm,COD去除率由84．35％降至21．19％;水力负荷为137．16cm/d时,运行周期为16d,水头损失由5．0cm增至15．0cm,COD去除率由81．26％降至7．35％。     

家庭危险废物管理探讨

家庭产生的危险废物因产生量少、分布广泛、难以管理等原因,尚未纳入危险废物管理体系。家庭危险废物混同生活垃圾进行管理、处置,对地下水、大气、地表水、土壤产生污染。文章对美国及欧洲的家庭危险废物管理方法进行了系统分析,其管理措施为:在法律管理体系下,以分类收集为主,宣传教育为辅,采取无害化处置方式。我国目前对于家庭危险废物的管理尚处于起步阶段,相关的法律法规不健全,处理处置设施也不完善。文章基于对国外管理特点的分析,针对我国国情对家庭危险废物管理提出以下建议:建立相关的法律法规;进一步完善收集、运输和处置系统;通过教育宣传等方法提高全民对家庭危险废物的认识。     

论保护三江平原湿地的意义与措施

20世纪后半叶,三江平原进行了大规模的开发,虽然为国家粮食供应做出了贡献,但大片湿地遭到破坏。现在为拯救中国这块唯一保持原始面貌的淡水湿地,当地政府制定了具体的三江平原湿地保护条例。建立了国家级的自然保护区,保护三江平原湿地终于纳入了政府工作的议事日程,为了加深人们对保护三江平原湿地意义的认识,本文从分析三江平原湿地的自然状况、三江湿地开发对当地生态和经济的影响入手,论述了三江平原湿地保护的重要意义和应采取的具体措施。     

沈阳卧龙湖省级自然保护区湿地现状与生态功能利用探讨

针对沈阳卧龙湖省级自然保护区的地域特点,详尽地分析了此地区的主要资源及保护、开发利用现状,从加大湿地保护的宣传力度,提高群众的环境保护意识等五个方面提出湿地保护建议和措施。保护是为了可持续发展,文中指出沈阳卧龙湖省级自然保护区湿地资源的科学合理开发利用一定要把它纳入到整体规划中去,在保护的前提下,走可持续发展之路。