[Workshop 4]
Biodiversity and Agro-ecosystem in Rice Paddy Landscape in Monsoon Asia

Today, the coexistence of biodiversity and agriculture has become one of the most important goals to achieve in agro-environmental policies. Agriculture had originally used natural resources in sustainable ways to promote material circulation in the ecosystem. However, in the last half of the 20th century, biodiversity in farmlands has diminished due to the modernization of agriculture with overuse of pesticides, chemical fertilizers, and excessive improvements of fields and irrigation ditches. In addition, abandonment of farmland management, which has been led by both the decrease of farmers and the competition with imported products, has become one of the serious factors of biodiversity reduction relying on the semi-natural environment in rural area. Under these situations, some European countries have started agro-environmental schemes, such as the preservation of traditional hedgerows or the development of semi-natural grasslands in field margins, aiming for both the conservation of biodiversity and the development of ecological infrastructures around field.

On the other hand, there have been few attempts to establish such agro- environmental schemes in the Asian monsoon area, where rice paddy agriculture dominates. Rice paddy agriculture, however, naturally has many ecological functions for wildlife habitation. For example, rice paddy fields as shallow water ponds provide habitats for many aquatic wildlife, such as water birds, fishes, frogs, and dragonflies. At the Meeting of the Ramsar Convention on Wetlands in November, 2008, these functions of rice paddy systems were recognized internationally. Rice paddy landscape has many elements of semi-natural ecosystems, such as streams in irrigation or drainage channels, grasslands on paddy banks, and forests around fields. These features of rice paddy landscape show that many ecological infrastructures and highly heterogeneous landscape mosaics, which European countries are newly recreating, already exist in Asian monsoon areas.

This workshop introduces several case studies on agro-ecosystems in several Asian and European countries and aims to clarify the relationship between rice cultivation and biodiversity in the Asian monsoon area. And we want to make this workshop a trigger to develop a general concept of biodiversity in Asian monsoon paddy landscapes.

Koji Yasuda and Shori Yamamoto