2007 年 11 巻 2 号 p. 141-152
Over the past century, Japan’s wetlands have been greatly impoverished, and 61% completely lost. Miyagi Prefecture, in particular, lost 92%, most of which were converted to rice paddies. Ibaraki, Chiba and other prefectures have similar histories. Better productivity and efficiency have further fueled construction of paddies so as to eliminate their remaining wetland value by keeping them dry in winter, particularly on Japan’s drier Pacific coast. This has seriously impacted many wetland-dependent species, driving some close to extinction. This paper takes a 100-year perspective in discussing enhancement of rice paddies’ value as wetlands as a way of restoring wetland environments and sustainable local communities. It presents the case of the Ramsar site, “Kabukuri-numa and the surrounding rice paddies,” where co-existence of rice agriculture with over-wintering geese is being sought through restoration of some paddies back to wetland and winter-flooding of others still under cultivation.
A proposal to dredge the Kabukuri-numa wetland became an opportunity for stakeholders to initiate a movement towards wetland protection and co-existence of wildlife with agriculture. Landholders agreed to re-convert of 50 hectares (ha) of paddy fields back to wetlands in 1998. The number of geese using Kabukuri- numa as a roosting site increased, illustrating that the restoration augmented the site’s wildlife carrying capacity. Farmers and others cooperated to implement a winter-flooding regime for nearby cultivated paddies. The project was examined from various standpoints, including as an application of the Ramsar Convention, and achievements and issues were identified.
Normally, once a wetland is destroyed, restoration requires huge commitments of time and money, but restoration through the managing of rice paddies under cultivation as “agricultural wetlands” can be a realistic and effective method for restoring natural wetland environments in Asia.
