海洋自然资本评估中生物能值转换率的研究

自然资本评估是研究生态系统服务与社会经济发展的重要方式。由于海洋具有特殊性和复杂性、开放性、流动性和多层次耦合性等特点,海洋自然资本评估方法的研究进展缓慢。能值分析理论通过能值转换率将生态系统内流动和储存的各种不同类别的能量和物质转换为同一标准的能值,可衡量和比较不同等级的能量价值,系统完整地反映自然资本价值,这一特点是其他评估方法所缺乏的。为精确量化海洋生物资本价值,本研究引入海洋食物网信息能流图和生态系统能量传递规律,提出了生物能值转换率的经验公式,即Tn=T1·E^1-nL(T1为初级生产者的太阳能值转换率,n为营养级,EL为林德曼效率)。为验证经验公式的可行性,选用相关案例进行了研究,得到海洋食物网中不同食性生物所处营养级及其相应的能值转换率。经验公式有一定误差,具体应用时应通过调研文献和相关数据,确定关键参数的取值范围以提高准确性。本研究得出的经验公式简化了海洋生物能值转换率的计算方法,促进了能值分析理论在海洋自然资本评估中的进一步应用。

Study on the solar transformity of organisms in marine natural capital assessment

Natural capital assessment is an important way to study ecosystem services and socio-economic development.Due to the particularity,complexity,openness,fluidity and multi-level coupling of the ocean,the methods for the assessment of marine natural capital develop slowly.The emergy analysis method converts different types of energy and substances,including the flowing and the stored,in the ecosystem into the same standard emergy through the transformity in order to measure and compare different levels of energy value.Thus it can completely reflect the real natural capital value which characterized by no other methods.To accurately quantify the value of marine life capital,this paper introduces the energy flow diagram of marine food web and the law of energy transfer in ecosystem,then proposes an empirical formula of organisms'transformity,namely Tn=T1·E^1-nL(where T1 is the solar transformity of the primary producer,n is the trophic level,and EL is the Lindeman efficiency).In order to prove the feasibility of the empirical formula,with cases studied we obtained some trophic levels and corresponding transformities of organisms in different feeding habits of a marine food web.Due to inherent error within the empirical formula and for a better accuracy,practically the value of the key parameters should be determined by literature and data surveys.The empirical formula obtained in this study simplifies the transformity calculation method and promotes the further application of emergy analysis in marine natural capital assessment.