論文

A major challenge in biodiversity management is overharvesting by unsustainable harvesters. If a scenario could be created where sustainable harvesters benefit more than the unsustainable ones, even in the short term, the issue of overharvesting would be solved. Everyone would then follow the lead of sustainable harvesters. However, creating such a scenario is not an easy task; the difficulty is intensified if the habitat is open access and there is no property rights system. Swiftlets in Sarawak, Malaysia, present a special case where sustainable harvesters are believed to be more beneficial than unsustainable harvesters. Edible nests built by adult Swiftlets are used as ingredients for a traditional luxurious soup in Chinese cuisine. A rise in nest prices has increased the instances of unsustainable harvesters wrongfully collecting nests along with the eggs and fledglings, which are then abandoned. Swiftlets live in caves and build nests on cave ceilings. It is known that Swiftlets escape from cave ceilings when these harvesters take the nests, never to return to the same place. This ecological feature appears to work as the Swiftlet's indirect punishment against unsustainable harvesters. This study constructs a stage-structured population model and examines the effect of property rights and the indirect punishment by Swiftlets on the population dynamics of the bird, and on the economic return of both sustainable and unsustainable harvesters. Our findings are as follows: the indirect punishment by Swiftlets provides sustainable harvesters a higher short-term return than unsustainable harvesters under the property rights system, as long as Swiftlets return to their original cave after escaping from the unsustainable harvesters. While previous studies regarding the management of the commons have stressed the importance of rules and regulations for sustainable harvesting without considering the ecological uniqueness of each species, this study suggests that ecological exploration and the discovery of ecological features are also essential for designing a sustainable framework.

This study attempted to predict the effectiveness of prior informed consent (PIC) as a mechanism under the Nagoya Protocol (NP) through the case of Japan, a developed country with a wealth of genetic biodiversity. The NP to the Convention on Biological Diversity (CBD) aims at creating a virtuous cycle between biodiversity conservation and the utilization of genetic resources through fair and equitable benefit sharing. As PIC is a crucial component of the NP for promoting fair and equitable sharing, this study investigated whether introducing PIC creates a virtuous cycle. Considering the limitations of empirical data, this study adopted a policy Delphi comprising experts in an iterative group communication process that used consecutive questionnaires to reveal diverse issues as input for policymaking. We identified six related issues that were evaluated for the case of introduction and three for the case of no introduction of PIC. Their relative importance as a policy concern was measured through best–worst scaling to narrow down policy-relevant issues. This study revealed that contrary to the NP's intent, the overall contribution to the virtuous cycle is limited. In designing PIC mechanisms, policymakers must pay particular attention to bequest and research and development. This study identified three paths through which the negative impacts on research and development further negatively affect bequest, that is, slackening the identification of important genetic resources and ecosystems to conserve, disincentivizing biodiversity conservation for genetic resource use, and dampening ex-situ conservation efforts.

Balancing economic growth with international commitments to environmental sustaina-bility is a global challenge. One of the main objectives of this study is to address this challenge by stimulating and sustaining motivation for environmental conservation by means of a comprehen-sive rethinking of the values inherent in nature and the limitations of monetary approaches to biodiversity valuation. This is achieved based on a case study of a transboundary ecological conservation project, the Heart of Borneo (HoB) in Borneo Island, covering Kalimantan in Indonesia, Borneo Malaysia comprising the states of Sarawak and Sabah, and Brunei Darussalam. This study synthe-sizes critical insights into the multiple ranges of life-supporting environmental values embedded in the HoB natural capital to enhance stronger motivations for environmental conservation. The study also reports on evidence gathered from extensive field studies conducted in Borneo Malaysia, con-firming the correlations between environmental beliefs in value pluralism, ecological action, and environmental sustainability, and its implications for sustainable resource use and management. The synthesis is expected to serve as practical guidance for sustainable resource and environmental management decision-making, which is conceptually and universally applicable.

© 2018 The Eco-DRR (ecosystem-based disaster risk reduction) is attracting attention as infrastructure that substitutes “gray” or built infrastructure, owing to its attractive characteristics such as lower costs of introduction and maintenance, provision of various ecosystem services, and local community development, among others. On the other hand, gray infrastructure is still a central measure of DRR, as there is a comprehensive understanding of its design and functioning against natural hazards. The argument about the use of green infrastructure instead of gray infrastructure in many aspects of DRR raises an important question: under what circumstances is green infrastructure more desirable? This paper uses a theoretical approach to provide an exact condition under which introducing green infrastructure is desirable, taking into consideration the aspect of uncertainty in deriving the optimal size of green infrastructure and the disaster risk (or expected damage). Under optimal green infrastructure, we show an exact level of the population, under which using Eco-DRR is preferable to gray infrastructure, expressed by parameters reflecting the probability of occurrence of hazard, probability of preventing exposure to the hazard, population size, and vulnerability to damage accruing from exposure, as well as costs and benefits of the two infrastructures. Our results provide useful information regarding policy decision-making about whether to adopt gray or green infrastructure in an area, by applying the results to various cases by assuming the exact values of the parameters.

© 2019 by the author(s). Resilience management is gaining support as resilience studies proliferate. Quantification of resilience could help decision makers understand the complex dynamics of resilience and adopt resilience management. However, most quantifications have focused on resilience as an attribute of social-ecological systems, such as thresholds and safe operating spaces. Although informative for planning and implementing effective resilience management, they do not inform decision makers if people accept and support this management. Therefore, it is necessary to understand how people perceive resilience. We applied three metrics to measure how people perceive resilience: (1) an economic valuation of resilience, (2) motivations behind valuing resilience, and (3) the relative importance of resilience compared with other ecosystem services. We adopted coral reef ecosystems in Okinawa, Japan for our analysis. Coral reef ecosystems, which are rich in marine genetic resources (hotspots), have become endangered because of increasing anthropocentric pressures, and resilience is becoming an accepted method in coral reef ecosystem management. Our study revealed that an ex-ante willingness to pay (WTP) for expected benefits from a resilience management program ranged from 3439 to 5663 JPY for mean WTP and from 1615 to 2579 JPY for median WTP (cf. 100 JPY = 0.891 USD in 2017). Primary motivations, i.e., human values, underlying the valuation of resilience were conservation and self-transcendence, which overlap with some ecosystem services such as culture, bequest, education, coastal protection, sanitation, and habitat. Resilience is highly important compared with the other 10 coral reef ecosystem services. These findings could help decision makers plan and implement an effective, acceptable, and supported resilience management program.