Assessment of ecosystem contributions to provisioning services in South Korea using emergy methodology

• Ecosystem service valuations often overstate nature’s role by mixing human inputs. • Emergy accounting quantified ecosystem contributions in Korea, 2018-2020. • Ecosystem contribution varied widely across agriculture, forestry, and fisheries. • Cultivation methods strongly affected ecosystem contribution and natural input share. Ecosystem services are commonly valued using market prices, which often overestimate nature’s role by including both ecological contributions and human inputs. To address this, we applied the concept of ecosystem contribution, defined as the proportion of nature’s inputs involved in the production of ecosystem services, to provisioning services in South Korea. Using the emergy accounting method, we quantified the natural and human inputs associated with agricultural, forestry, and fishery products between 2018 and 2020. The results revealed substantial variation in ecosystem contributions across product categories. Ecosystem contribution was highest in cereals and legumes, typically exceeding 90% due to dominant natural soil processes. In contrast, paddy rice showed an ecosystem contribution of 50.0% in 2020, primarily driven by a high reliance on irrigation water (33.2%) alongside topsoil loss (13.7%). Vegetables and fruits exhibited lower contributions, with fruit crops generally ranging from 20% to 40%. Notably, greenhouse-grown crops exhibited extremely low ecosystem contributions below 3%, as natural inputs were largely substituted by technical and human-mediated inputs such as electricity, machinery, and labor. These results imply that market-based valuations, which are largely driven by human-mediated costs, fail to capture the essential biophysical work of ecosystems in the co-production process. By differentiating the biophysical share of nature from human-mediated inputs, emergy methodology provides a more nuanced understanding of ecosystem contributions that are often integrated and indistinguishable in conventional market prices.