基于物质流分析的区域食物链氮素流动规律与调控研究

以食物链物质流调控为核心的区域生态共生系统研究是当今可持续发展领域的重要研究内容。基于物质流分析方法和系统动力学建模平台,构建了区域食物链氮素流动效应评估框架,以上海市青浦区为例,对区域食物链氮素流动进行分析与情景模拟。研究结果表明:(1)2000～2014年青浦区食物链氮输入和输出量经历了急剧下降到逐渐稳定的过程,区域内农业生产无法自给自足;(2)基准情景下,食物链氮素流动对环境的负面效应总体影响较小,但2020年农业生产能力已不能满足当地人口对肉类及水产品氮的需求;(3)优化情景下,区域化肥氮投入减少了53.75%,且农业生产满足了当地常住人口的消费需要,减少区外氮产品调入量2 245.16 t,氮综合循环效率提高至25.54%,农业生产对水环境的影响降低。该优化方案在保证粮食安全的同时,较好地保护了环境免受集约农业生产的冲击。研究成果可为区域食物链氮素养分管理提供方法和思路借鉴。

Study on Mechanism and Regulation of Nitrogen Flow in Regional Food Chain Based on Material Flow Analysis

The study of regional symbiosis ecosystem with the regulation of food chain material flow as the core is an important research content in the field of sustainable development. Based on the material flow analysis method and system dynamics modeling platform, evaluation framework for nitrogen flow effect in regional food chain was constructed. Nitrogen flow in regional food chain was analyzed and simulated in Qingpu district of Shanghai. The results indicate that: (1) From 2000 to 2014, the input and output of food chain nitrogen experienced a sharp decline to gradually stable process without regional self-sufficient in nitrogen products. (2) Under the baseline scenario, the negative effects of nitrogen flow in food chain on environment are generally small, but the agricultural production capacity in 2020 can not meet the demand of local population for nitrogen in meat and aquatic products. (3)Under the optimized scenario, the input of fertilizer nitrogen was reduced by 53.75%, and the agricultural production met the consumption needs of the local resident population. The amount of nitrogen products in outside region was reduced by 2 245.16 t, the comprehensive nitrogen cycle efficiency was increased to 25.54%, and the impact of agricultural production on water environment was reduced. The optimized scheme not only guarantees food security, but also protects the environment from the impact of intensive agricultural production. The research results can provide methods and ideas for nitrogen nutrient management in regional food chain.