| 摘要: | 植物在人工溼地中扮演了重要的角色，除了可以協助攝取水中的污染物質，還可提供表面積供微生物生長、提供氧氣、貢獻脫硝作用所需的碳源、更可協助物理性的過濾、沉降、遮蔽陽光等機制。植物在人工溼地中協助去除污染物的機制與角色已經廣為所知，然而溼地中整體的植物群聚對人工溼地環境與水質的影響，卻鮮有文獻報導，尤其台灣的人工溼地不但具有污水處理的功能，還往往須肩負起生態保育的責任，因此在台灣許多人工溼地往往選擇種植多樣性的水生植物，除了期望可以提升水質處理效益，還希望還可以保留或復育逐漸消失或少見的水生植物，然而當溼地操作或運轉一段時間之後，溼地中的植物可能逐漸發展為非原先所預期的群聚型態，進而改變人工溼地的環境因子，也可能影響水質的處理，另外，許多對人工溼地管理與維護造成困擾的陸生入侵植物，如小花蔓澤蘭、牽牛花等植物，也會對人工溼地的草生植群造成影響，因此對於人工溼地中的草生植群，有必要進行系統性的長時間調查與實驗，了解草生植群在人工溼地中的演替、變化，以及陸生入侵植物對草生植群變化的影響，並且探討草生植群變化對人工溼地環境因子的影響，以及對水質處理效益的影響。本計畫擬以三年的時間進行調查與實驗，針對選定的人工溼地場址，除了持續過去兩年進行之生態調查與人工濕地水質淨化的關係研究之外，再強化人工溼地的草生植群的普查工作，逐年完成以下工作：第一年將定期調查人工溼地中的一般生態以及草生植群，以草生植群的優勢度、歧異度、演替度等指標，分析草生植物人工溼地物種與組成，並且分析人工溼地中的水質、底泥、植體污染物濃度，以比對人工溼地生態群聚與污染物分布之關係，以了解整體生態環境受污染物分布的影響關係。第二年將持續一般生態以及草生植群的調查，並以各種常用的指標分析草生植物組成，除了調查人工溼地中的污染物分佈，另將調查人工溼地中的水生生物，以了解各種出現生物變化與污染物的關係，以及對生物棲地的環境影響。第三年除了持續調查人工溼地中一般生態以及草生植群，將種植其他種類的水生植物，在不干預植物自然演替的管理維護下，了解植物演替的關係，以及對水質的影響，並綜合三年的調查成果，比對生態變化對人工溼地的影響，進而推估生態指標與溼地處理效益之關係，並建立相關經驗式。
Vegetation plays an important role in a constructed wetland system. It cannot only absorb material from aqueous phase, but provide surface and oxygen for the growth of microorganisms and carbon source for denitrification reaction. Furthermore, plants can also provide mechanisms to achieve some physical treatment purposes, such as filtration, sedimentation, sunlight shading, etc. The mechanisms for removal materials from water are quite well understood according to many previous researches, especially in Taiwan area, the plants are also useful for environmental restoration. Therefore, macrophytes used in many constructed wetland systems in Taiwan had been chosen with diversified way so as to restore some rare species a long with water purification. However, after a period of time, many designed species in most of these treating wetlands were replaced by weeds, and possibly affected the treatability of the system on wastewater. Meanwhile, some terrestrial intrusive species, such as Mikania micrantha H. B. K., Ipomoea nil (L.) Roth., etc. are causing serious problems for development of normal terrestrial species. Hence, it is necessary to proceed long-term investigations and experiments on vegetation on the development and change of terrestrial plants as well as the intrusive species in order to understand the environmental factors of the vegetation variation of wastewater treatment efficiencies of constructed wetlands. This research project is a 3-year plan including ecological investigation and treatment experiments on chosen constructed wetland site. The research work will not only continue previous 2-year research work of general ecological investigation, but enhance the investigation on vegetation. The annual works are described as follows: First year: routine investigations on ecological systems and grassland vegetation. Try to develop indexes of predomination, variation, development, etc. by obtained information. Further analyze the species and combination of the creatures observed in the wetland system and compare with the concentrations of pollutants in the water, sediment, plant bodies. The comparisons should be useful for settling up relationship between the ecological species and the pollutants distribution. Finally, the entire ecological environments affected by pollution conditions will be realized. Second year: continue routine investigations on ecological systems and grassland vegetation. All the generally used ecological indexes would be applied to analyze the combination of all the observed species. In this year, macrophytes (hydraulic plants) in the wetland system would be focused to be investigated for comparing with the variation of pollutants in the system. So that the relationship of biological change with pollution conditions should be found and the environmental impact to the biological habitat by human contamination would also be understood. Third year: continue routine investigations on ecological systems and grassland vegetation. Some macrophytes would be introduced to the wetland system so as to understand the relationship between vegetation development and water quality in the wetland system, under conditions without interfering the natural development of plants and operation of the system, the information obtained from three years research work will be summarized and plan to reveal effects of ecological change on treatment capability of constructed wetlands. Furthermore, empirical equations for estimating the relations of ecological indexes and wastewater treatment in constructed wetlands then can be developed. |
