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As entrenched population growth and industrialization continue to raise demand for natural resources and their exploitation, there is increasing concern over the detrimental impacts on the global environment and humanity. Economic growth was expected to save people from poverty, but conventional economic growth models simply prompted intensive resource use and undermined the basis for livelihoods that are sustainable over the long term. Whilst research and policy measures have articulated environmental risks and key factors of sustainability, compartmentalized approaches have failed to forge a scientific foundation for averting risks and promoting sustainability. Countermeasures to address environmental risks often involve trade-offs weighed against other socio-economic factors. A holistic viewpoint and trans-disciplinary science are therefore needed to foster appropriate decision making and implementation that can ensure optimal risk management and promotion of sustainability. The Leadership Programme in Sustainable Living with Environmental Risk (the SLER programme) spearheaded by Yokohama National University from 2009 to 2014, is one of the programs playing an instrumental role in addressing this need. It provides a platform for strengthening the expertise and skills graduate school students need to become environmental leaders. Moreover, the process of implementing the SLER programme has revealed both the potential and the challenges inherent in developing future environmental leaders to effectively manage environmental risk and promote sustainability.

The “Green Revolution” has increased food production to meet world population growth, therefore global food production is at present sufficient to feed all the world’s people. However, the modern agricultural system is no longer sustainable due to deterioration of soil conditions. Alternative agricultural methods that aim to conserve biodiversity and soil functioning are not intensively studied, thus the productivity of alternative methods is often not compatible with conventional agricultural practice, and most people are skeptical of the feasibility of introducing alternative methods. Recent advancements in studies of biodiversity and ecological functioning are now supporting early trials by advanced farmers, who respect biodiversity in their fields. In this review, I would like to present some ecological theories to support biodiversity agriculture and its potential to support human populations.

Soil biodiversity represents the variety of life belowground whose interaction with plants and small animals forms a web of biological activity. It improves the entry and storage of water, resistance to soil erosion, and plant nutrition, while also controlling soil pests and disease, and facilitating recycling of organic matter in the soil. Soil biodiversity is therefore the driver of healthy soil for sustainable crop production.

However, intensive agricultural activities are reported to lead to loss of soil biodiversity. This has been attributed to environmental degradation, and consequently to climate change. This paper highlights the importance of soil biodiversity and some factors associated with its loss, and presents a case study on selected soil organisms in Kenya. Results from this study indicated that land use changes affect soil biodiversity, and soil biodiversity determines the distribution of the aboveground biodiversity.

Global warming due to greenhouse gas emissions is currently receiving considerable attention worldwide. Agricultural systems contribute up to 20 % of this global warming. However, agriculture can reduce its own emissions while increasing carbon sequestration through use of recommended management practices, such as consernvation tillage (CT). The objective of this paper is to review the role of long-term CT in mitigating greenhouse gas emissions during corn production in rainfed tropical agro-ecosystems. The types of conservation tillage were no-tillage (NT) and minimum tillage (MT). In a long-term plot study, CO emission from CT throughout the corn season was consistently lower than that from intensive tillage (IT). The cumulative CO emissions of NT, MT, and IT in corn crops were 1.0, 1.5, and 2.0 Mg CO-C haseason, respectively. Soil carbon storage at 0–20 cm depth after 23 years of NT cropping was 36.4 Mg C ha, or 43 % and 20 % higher than the soil carbon strorage of IT and MT, respectively. Thus, NT had sequestered some 4.4 Mg C haof carbon amounting to carbon sequestration rate of 0.2 Mg C ha year. IT, on the other hand, had depleted soil carbon by as much as 6.6 Mg C ha, yielding a carbon depletion rate of 0.3 Mg C ha year. Assessment of the farmer’s corn fields confirmed these findings. CO emission from CT corn farming was similar to that of rubber agroforest and lower than IT corn farming. Based on carbon balance analysis, it can be concluded that corn crops in tropical rainfed agro-ecosystems were not in fact net emitters, and that NT was a better net sinker than other tillage methods.

Rice is a staple food for many people in the world, especially in Asian countries, and rice consumption increases every year. Efforts have been made to increase rice production, leading to social, economic, and environmental impacts. Rice in paddy fields is mostly grown using conventional farming systems with high inputs of agrochemicals (inorganic fertilizers and chemical pesticides). Continuous application of agrochemicals may damage the soil and cause decreased soil productivity and biodiversity, as well as increased pest attacks and methane emissions. Therefore, organic farming systems are likely to be the best practices for promoting land sustainability. In fact, farmers in many countries have shifted their rice production management from conventional to organic. However, it is argued that, in general, organic systems are related to lower yields and lower environmental impacts while conventional systems are related to higher yields and higher environmental impacts. Although the movement from conventional to organic farming systems is believed to have positive short-term impacts by improving soil biodiversity, therefore, it will also have an impact in terms of lowering rice production volumes. The achievement of food security and food availability requires government policies to promote the use of organic fertilizers and subsidize their prices, as well as regulation to support high prices for organic products. Application of organic fertilizers and biofertilizers, and the use of crop rotation, are likely to improve soil fertility, which is related to increased biodiversity, and eventually this will contribute to higher rice production volumes in the long term.

Soil erosion and environmental degradation due to the cultivation of marginal upland areas are now considered major environmental risks in the Philippines. Agroforestry may help address the situation. In agroforestry systems, the positive interactions of tree-crop combinations not only improve biophysical conditions in farms, but also enhance food security in farming households.

A combination of Participatory Rural Appraisal (PRA), a household survey, focus group discussions, field experiments, and simulation modeling was undertaken in Claveria, Misamis Oriental, Philippines. The agroforestry system adopted depended on the farmers’ motivations. The adoption of agroforestry significantly increased the households’ level of income by around 42–137 %, compared with that from continuous annual mono-cropping. Another beneficial feature of an agroforestry system was the enhanced nutrient inflow to the system through leaf litterfall, stemflow, and throughfall. A modeling study using the WaNuLCAS model showed that the -maize hedgerow system provided significant improvements to a range of biophysical and economic measures of productivity and sustainability.

It is recommended that both national and local government units mainstream their policies and efforts toward promoting agroforestry adoption in the Philippine uplands.

From 1990 to 2005 Madagascar implemented a national environmental policy comprising three successive programs. However, after 15 years of implementation, the results were not as initially expected. Forest degradation had continued unabated, resulting in significant environmental problems, such as loss of soil fertility, siltation of rice paddies and water bodies, and further reduction of water supplies in cities. As a result, food availability in rural areas had deteriorated, aggravating the already high levels of poverty. Sustainable forest management had therefore become crucial to sustainable living, yet the problem was how to implement it in the context of increasing poverty. Assuming that the forest could be sustainable only if it contributed to increasing the income of local people, a method of non-extractive valorization of forests was developed and tested. The method incorporated a range of activities that highlighted the ecosystem services of forests, including environmental education, ecotourism, no tillage agriculture, and the development of rural markets for non-wood products. These activities were expected to incentivize the local community to change their behavior and preserve forest and ecosystem services. However, the approach remained highly localized because it attracted immigration from other areas. This case study therefore concluded that sustainable forest management could not be achieved without integrated management at the regional and national levels, as well as on a local scale. Future research will need to focus on understanding migration, on successful spatial management methods, and on identifying alternative economic incentives for stakeholders.

This article discusses community-based mangrove forest management and its implications for environmental risk management. The article draws on the case study of Pred Nai village in Trat province, near the Cambodian border in southeast Thailand. The village of Pred Nai has successfully re-forested 1,920 ha of mangrove forests that were previously converted into shrimp aquaculture ponds in the mid-1980s. The village has set up a community forest committee and a community resource use regulation and management plan in order to regulate, control, and manage the use of resources by community members. In the process of community mangrove forest management, local villagers have been encouraged to participate in every single step of forest management and planning. It is the active involvement of the local people together with the support of the relevant authorities and national institutions that makes the Pred Nai example a success. The article concludes by pointing out the key lessons learned from community-based mangrove forest initiatives in Pred Nai that can be applied in natural disaster risk management processes.

The conventional theory of ecosystem and population management does not include the concept of risks. In risk management, survival rates and reproductive rates are taken into account in mathematical models describing conditions of the ecosystem, and uncertainty and environmental variation when measuring are taken into account when predicting population sizes. As a result, future prediction can only be made in a probabilistic way. Even when a general prediction is made about the future, therefore, it is rare to predict it accurately. Risk evaluation to show a prediction range with some allowance is required. Moreover, if management measures are predetermined, it is impossible to cope with a contingency. Adaptive management is therefore recommended as a management method to cope with uncertainties. This entails making a management plan based on unverified assumptions, continuously monitoring changes in the situation while implementing the plan, adjusting the management measures as required, and verifying the appropriateness of the assumptions used. It is important to predetermine how the measures will be adjusted and the assumptions verified. In this chapter, we highlight the difference in thinking before and after adaptive risk management is established, describing two cases: management of fisheries resources and wildlife management. Numerical calculations that appear in the figures in this chapter can be obtained through the website () and additional tests can be conducted with Excel files. Eager readers are strongly recommended to try this.

Food security, closely linked with environmental issues, has become one of the most important issues in the twenty-first century. In recent decades especially, ecological degradation has been spreading, and is negatively affecting food supply and food safety conditions in many Southeast Asian countries. Such degradation can include sedimentation, reduced water quality, and frequent flood occurrence, many of which are enhanced by climate change impacts. Based on an international research project conducted by RIHN (Research Institute for Humanity and Nature) in collaboration with Yokohama National University and the University of the Philippines, we discuss the recent changes in food risks and the factors contributing to expansion of such risks in Southeast Asia. Our study demonstrates that non-marketed ecosystem services from sustainable agricultural land use can provide significant economic value, and developing a mechanism to pay for ecosystem services is crucial in enhancing sustainable agricultural development.