Gingrich Simone, Marco Inés, Aguilera Eduardo, Padró Roc, Cattaneo Claudio, Cunfer Geoff, Guzmán Gloria I, MacFadyen Joshua, Watson Andrew
1Institute of Social Ecology, Alpen-Adria Universitaet Klagenfurt, Klagenfurt, Austria.
2Department of Economic History, Institutions, Policy and World Economy, Universitat de Barcelona, Barcelona, Spain.
Reg Environ Change. 2018;18(4):1089-1101. doi: 10.1007/s10113-017-1261-y. Epub 2017 Dec 7.
Energy efficiency in biomass production is a major challenge for a future transition to sustainable food and energy provision. This study uses methodologically consistent data on agroecosystem energy flows and different metrics of energetic efficiency from seven regional case studies in North America (USA and Canada) and Europe (Spain and Austria) to investigate energy transitions in Western agroecosystems from the late nineteenth to the late twentieth centuries. We quantify indicators such as external final energy return on investment (EFEROI, i.e., final produce per unit of external energy input), internal final EROI (IFEROI, final produce per unit of biomass reused locally), and final EROI (FEROI, final produce per unit of total inputs consumed). The transition is characterized by increasing final produce accompanied by increasing external energy inputs and stable local biomass reused. External inputs did not replace internal biomass reinvestments, but added to them. The results were declining EFEROI, stable or increasing IFEROI, and diverging trends in FEROI. The factors shaping agroecosystem energy profiles changed in the course of the transition: Under advanced organic and frontier agriculture of the late nineteenth and early twentieth centuries, population density and biogeographic conditions explained both agroecosystem productivity and energy inputs. In industrialized agroecosystems, biogeographic conditions and specific socio-economic factors influenced trends towards increased agroecosystem specialization. The share of livestock products in a region's final produce was the most important factor determining energy returns on investment.
生物质生产中的能源效率是未来向可持续粮食和能源供应转型的一项重大挑战。本研究使用了北美（美国和加拿大）和欧洲（西班牙和奥地利）七个区域案例研究中关于农业生态系统能量流和不同能量效率指标的方法一致的数据，来调查19世纪末至20世纪末西方农业生态系统中的能源转型。我们对诸如外部最终能源投资回报率（EFEROI，即每单位外部能源输入的最终产量）、内部最终能源投资回报率（IFEROI，每单位本地再利用生物质的最终产量）和最终能源投资回报率（FEROI，每单位消耗的总投入的最终产量）等指标进行了量化。这种转型的特点是最终产量增加，同时外部能源输入增加，而本地再利用生物质保持稳定。外部投入并没有取代内部生物质再投资，而是对其进行了补充。结果是EFEROI下降，IFEROI稳定或上升，FEROI出现不同趋势。在转型过程中，塑造农业生态系统能量概况的因素发生了变化：在19世纪末和20世纪初的先进有机农业和前沿农业中，人口密度和生物地理条件解释了农业生态系统的生产力和能源投入。在工业化农业生态系统中，生物地理条件和特定的社会经济因素影响了农业生态系统专业化程度提高的趋势。一个地区最终产品中畜产品的份额是决定能源投资回报的最重要因素。
