Under rapid industrialization and urbanization, the conservation and management of agricultural heritage systems is facing many threats and challenges, such as the massive outflow of working labor, land abandonment, and the difficulty in maintaining traditional knowledge systems. Promoting land transfer and carrying out moderate-scale management play an active role in the conservation of agricultural heritage systems. While land transfer brings economic benefits to heritage sites, its environmental impacts to heritage sites are worthy of attention. However, empirical studies are scarce. This study took Qingtian rice-fish culture system in Zhejiang Province as an example, which was designated as Globally Important Agricultural Heritage Systems (GIAHS) in 2005. Small farmer management model and land scale management model were distinguished, while the life cycle method was used to calculate the carbon footprints of two models. The results showed that the carbon footprints of small farmer management model and land scale management model were 6510.80 and 5917.00 kg CO2-eq·hm-2, respectively, while the carbon footprints per unit output were 0.13 and 0.10 kg CO2-eq·yuan-1, respectively. Compared with small farmer management model, land scale management model had lower greenhouse gas emission and lower environmental impact of per unit output. As farmers expanded the scale of land management, local greenhouse gas emissions had been reduced by 4097.20 kg CO2-eq. Furthermore, the accumulation of CH4 in agricultural production accounted for the largest proportion of carbon footprint. The input of compound fertilizer among agricultural production materials was next to CH4 accumulation, becoming the second largest source of greenhouse gas emission. Corn and wheat being used as fish feed also had a significant impact on greenhouse gas emission in small farmer management model. Therefore, the promotion of moderate scale land management is conducive to the win-win of economic and environmental benefits of traditional agricultural systems and plays an important role in the conservation of agricultural heritage systems.
在快速工业化和城镇化的影响下,农业文化遗产的保护与管理正面临着适龄劳动力大量外流、土地抛荒、传统知识体系难以维持等诸多威胁与挑战。推动土地流转、进行适度规模经营,可在农业文化遗产的保护中产生积极作用。土地流转在给遗产地带来经济效益的同时,对当地生态环境产生的影响变化同样值得关注,但现有研究却少有涉及。本研究以全球重要农业文化遗产——浙江青田稻鱼共生系统为例,将不同经营规模的稻鱼共生系统分为小农户经营模式和规模化经营模式,运用生命周期法对两种模式的碳足迹进行核算。结果表明: 小农户经营模式和规模化经营模式的碳足迹分别为6510.80和5917.00 kg CO2-eq·hm-2,单位产值碳足迹分别为0.13和0.10 kg CO2-eq·yuan-1。与小农户经营模式相比,规模化经营模式温室气体排放更少,单位产值的环境影响更小。农户扩大经营规模后,当地温室气体排放减少了4097.20 kg CO2-eq。农业生产过程中积累的CH4在碳足迹中占比最大,农业生产资料中复合肥是仅次于CH4的第二大温室气体排放来源。对于小农户经营模式,饲料中使用的玉米和小麦也对温室气体排放有重要的影响。因此,推动土地适度规模经营,有利于传统农业系统实现经济效益和环境效益的双赢,对于农业文化遗产保护具有重要作用。.
Keywords: Globally Important Agricultural Heritage Systems (GIAHS); carbon footprint; environmental impact; land transfer; rice-fish culture.