|摘要: ||本計劃提出三年期計畫，以期建立國內人工溼地的碳匯(亦稱為碳儲存)功能調查方法及碳匯能力資料。碳匯功能的調查將以碳質量平衡的理論為基礎，選取一處國內廢水處理操作穩定的人工溼地進行實地調查，採取兩種不同的調查途徑與方法：(1)淨初級生產量與異營性呼吸通量的分別測量，及(2)以密閉式動態氣罩法測量二氧化碳的淨生態系統交換通量。此外，分析溼地的水文、水質、底泥性質、光合成活性輻射強度、溫室氣體(甲烷與氧化亞氮)通量等，監測頻率至少每月一次，進行2~3年的長期連續監測。並將完整一年的調查與監測結果進行碳通量的收支計算，以估算出不同年的濕地碳匯能力。第一年計畫主要研究目的：(1)建立人工溼地碳匯功能的調查方法及實驗設備，(2) 獲得不同類型人工濕地的碳匯能力並與天然濕地比較，(3)估算人工濕地的有機污染物輸入、淨初級生產力、呼吸作用、甲烷生成作用分別對碳匯功能的貢獻，(4)比較人工濕的全球暖化潛勢(GWP)與碳匯能力以了解人工濕地是否為碳中和技術。第二年計畫主要研究目的：(1)探討水生植物種類對人工濕地淨初級生產量的影響， (2)建立總初級生產量與光合成活性輻射強度的關係，(3)建立生態系統呼吸量與土壤溫度的關係，(4)建立經驗公式以補差法估算人工濕地的淨生態系統交換通量，(5)探討淨生態系統交換通量的時間(日夜與季節)變化。第三年計畫的主要研究目的著重於：(1)比較不同年的人工溼地碳匯能力，(2)綜合性探討人工溼地碳匯能力與人工溼地的操作條件(如有機負荷、水生植物種類等)、氣候條件(如日照、氣溫)等的關係，(3)建立可行的經驗公式推估國內其他人工溼地的碳匯量，(4)研擬人工溼地的最佳管理策略使溼地的碳匯量能持久儲存於土壤中。本計劃的執行成果，在學術研究上預期可提供有關人工濕地碳物質循環更清楚的科學知識，在濕地保育上將可確立人工溼地的碳匯功能及在全球暖化中所扮演的角色，並可幫助各界更進一步了解人工溼地技術在水污染防治上的應用價值與對全球暖化的影響。|
In order to develop national methods for estimating carbon sequestration (or carbon storage) capacity of constructed wetlands and obtain the resulting data, we propose the three-year research project. We will select a stably operated and full-scale constructed wetland site for the survey of carbon mass balance or carbon budget. Two approaches will be conducted for the survey, one is to separately measure aboveground net primary production (ANPP) by plant harvest and heterotrophic soil respiration via closed static chamber technique, and another one is to measure net ecosystem exchange of CO2 (NEE) using closed dynamic chamber technique. In addition, water flow, water quality, properties of wetland soil, photosynthetically active radiation (PAR), greenhouse gases (methane and nitrous oxide) emissions will be monitored monthly for 2~3 years. The measured and monitored results will be used to estimate the contemporary annual carbon storage in the constructed wetland through the calculation of carbon budget as fluxes. The objectives of the first-year study will be to (1) establish the survey methods and facilities to estimate carbon sequestration capacity of constructed wetlands, (2) obtain resulting data of carbon sequestration in constructed wetland so as to compared with the data of natural wetlands, (3) determine the individual contribution of organic loading from wastewater, net primary production, respiration, methane emission to carbon sequestration, (5) calculate global warming potential of constructed wetlands to examine if constructed wetlands are climate-neutral technologies. The aims of the second-year study will be to (1) examine the effect of various species of macrophytes on net primary production of constructed wetlands, (2) investigate the relationship between gross primary production and PAR, (3) determine the relationship between ecosystem respiration and soil temperature, (4) estimate NEE of constructed wetlands through empirical interpolation, (5) investigate daily and seasonal variation of NEE. The aims of the third-year study will be to (1) make comparison among carbon sequestration data measured from the three years, (2) establish the relationship between carbon sequestration and operational conditions of constructed wetlands (e.g. organic loading rate and macrophyte species) as well as climate conditions (e.g., quantum and temperature), (3) propose empirical equations that can be properly used to estimate carbon sequestration potential in constructed wetlands of Taiwan, (4) develop best management practices for constructed wetlands to sustain carbon sink in wetland soil. The results of the three-year study will hopefully provide more meaningful data and scientific knowledge regarding to carbon cycling and carbon sequestration in constructed wetlands. That will be helpful for the public to realize if constructed wetlands or natural wetlands play a neutral role or even positive role in global warming.