Gains and Losses in Ecosystem Services: Trade-Off and Efficiency Perspectives

Abstract

Humans rely on nature for various ecosystem services to enhance their well-being. However, the gains in human well-being have been achieved at the losses in many ecosystem services. One of the key challenges in ecosystem service science is to determine how to manage ecosystems for multiple services in an efficient, equitable and sustainable manner due to unknown factors and processes that drive ecosystem changes. It is now commonly accepted that ecosystem services are not generated by ecosystems alone, but by social-ecological or human-environment systems. These systems are complex and possess critical thresholds, multiple drivers of change and reciprocal feedbacks between the two components. Attempts to enhance a single ecosystem service might lead to gains (synergies) or losses (trade-offs) in other ecosystem services. Therefore, determining synergies and trade-offs in ecosystem services can provide useful information to either reduce their associated costs to society or enhance ecosystem functionality and net human well-being. In this regard, application of the economic efficiency concept is relevant for decision making of how ecosystem services can best be used to fulfil human wants and desires because it is undertaken for decision making units of either individuals, communities, or the society as a whole. Although ecosystem services are becoming a popular topic of inquiry; and continued progress of and interactions between ecology and economics have contributed to the understanding of social-ecological or human-environment systems, integrating economic and ecological studies in ecosystem service science is still a key step needed for sustainable development. This is because the ecological underpinning of economic studies is often limited; and ecological studies on ecosystem service management often lack appropriate economic considerations. This thesis has been directed to improve understanding of ecosystem service science with a focus specifically on examining the gains and losses in ecosystem services. The thesis dealt with three themes under this umbrella: (i) trade-offs and drivers of changes in ecosystem services (Part A), (ii) efficiency and improvement of ecosystem services (Part B), and (iii) policy and research implications for ecosystem services (Part C). In Part A, Paper 1 determines the synergies and trade-offs between private economic benefits and environmental pollution (nitrate leaching) with different farm management practices at field plot level under the tropical monsoon climate conditions in a developed country (South Korea). Paper 2 explores the synergies and trade-offs between a provisioning and a regulating service (crop production and water runoff regulation) at sub-landscape level in a developing country (Vietnam). In these two papers, the synergies and trade-offs in ecosystem services are investigated using a combination of ecological modeling frameworks with economic analyses. Paper 3 examines the effects of climate change on a provisioning service (biomass production) that contributes to the mitigation of climate change (bioenergy) at local level (Germany) using a physiological process based model. Paper 4 evaluates the conservation potential of different crop production techniques (conventional versus organic farming) at field plot level (South Korea) using an empirical soil loss model. In Part B, Papers 5 and 6 apply the economic efficiency concept to examine the drivers and trade-offs between the private economic return and environmental performance of land users (rice farmers, South Korea). Paper 7 examines the efficiency and determinants of reforestation with a native tree species (Vietnam). The findings of these examples supplement the conventional ecosystem service trade-off analysis in Part A as they contribute to the identification of opportunity costs of preferring a specific land use alternative to another; and thus provide important implications in terms of ecosystem use and management for land use and policy decision makers. In Part C, Paper 8 identifies an output-based system of payments for forest ecosystem services and evaluates such a system under regional land use change scenarios using an empirical model derived from experimental data measurements and simulations with changes of market prices and payment arrangements. Paper 9 evaluates the effects of the institutional property right systems on human livelihoods and forest conditions in a comparative way between two developing countries (Ghana and Vietnam). Paper 10 conceptualizes the integration of ecological with economic studies for a decision support system to meet the challenges of energy shortage and climate change at local scale. Finally, Paper 11 synthesizes a general framework for examining classical trade-offs in ecosystem services and drivers of changes in ecosystem services at landscape and/or regional level. In summary, the thesis contributes to the current literature in several ways: (i) the conventional trade-off between regulating and provisioning services was examined both theoretically and empirically in much more details, with the combination of ecological models and economic analyses, and at different levels (field plot, landscape, farm, local, and regional); (ii) the provisioning and regulating services are quantified in physical and monetary terms which are more convenient and useful for land users and policy makers; (iii) synergies and trade-offs in ecosystem services could potentially be identified using the economic efficiency framework; and (iv) payments for ecosystem services were determined with an output-based instead of a traditionally common input-based approach or non-market valuation methods.