In addition to expanding habitats for wild boars, the lack of moderate human intervention has also brought about adverse impacts on the agriculture and forestry sectors by wild birds and mammals. According to a “Survey of the Government Sector and Agricultural Groups on Measures against Damage by Wildlife (Preliminary Data)” (Ministry of Agriculture, Forestry and Fisheries, 2005), about a half of agricultural groups said that they suffered increased damage from wild boars.

To mitigate these conflicts between people and wild life, it is important to properly protect and manage wild life as well as to comprehensively prevent such harm, by measures such as adequate fencing.

Hunters (hunting license holders) have played important roles in protecting or managing wildlife. However, since 1970, hunter numbers have decreased and they have become older, which suggests that it is necessary to ensure that there are a certain number of hunters and to transfer their expertise to the next generation.

In satochi-satoyama areas, further depopulation and weaker agricultural and forestry activities in the era of declining population might upset the proper balance between nature and human activity, which results in a negative impact on conservation of biodiversity.

Trend of Hunters by Age Bracket

Farmland, Secondary Forests, and Plantation Forests

Where Wild Boars Have Expanded Their Habitats

● : Locations identified as habitats in 1978 and 2003

: Farmland, secondary forests, and plantation forests to which wild boars had expanded their habitats according to the 2003 survey

☑: Locations where wild boars had expanded their habitats in the 2003 survey, which do not belong to farmland, secondary forests, or artificial forests

Source: Ministry of the Environment

If we really want to continue sustainable use of such abundant secondary natural environments in satochi-satoyama areas while ensuring that these environments are passed on to the next generation, it is important to realize such areas have been maintained by positive use rather than restrictive measures. In such areas, human life and productive activity are closely connected with regional biodiversity. Each local community should secure activities necessary to conserve satochi-satoyama and develop systems to promote such activities.

### 2. Cities and the Environment

With consistently significant population growth and high economic growth rates in the post-war era, Japan has seen rapid population inflow to urban areas. Densely inhabited district (DIDs) populations have been increasing as a percentage of Japan's total population, while the size of DIDs has been expanding at a faster rate than the rate of population inflow to urban areas. Consequently the population density for DIDs has decreased.

As above, Japanese cities are surrounded by low-density urban areas, which are constituted mainly from residential sectors. Such expansions of urban areas have brought significant impacts on the environment.

According to analysis on DID population density and automobile dependency rate or the transport sector’s $ CO_{2} $ emissions, urban areas with lower DID population densities (i.e., more expansive urban areas) tend to show a higher automobile dependency.