Global importance

With the modernization of agricultural practices and human society, the use of plants from semi-natural grasslands has been reduced. As a result, the management of these ecosystems has been neglected and their biodiversity is being lost at an alarming rate.

The GIAHS site has maintained semi-natural grassland through with traditional techniques and semi-natural grasslands that are maintained for tea cultivation are known as “Chagusaba” in Japanese. More than 300 species have been recorded in Chagusaba and semi-natural grasslands are distributed from within inhabited villages, serving as a precious example of the Japanese traditional land use form. Chagusaba has been maintained through a balance of agricultural productivity and conservation of biodiversity.

Food and livelihood security

The area is located in Shizuoka Prefecture which is the greatest tea-producing region in Japan, where tea-related businesses and facilities have been increasing in number. The annual output of tea is 31.9 billion yen and tea is a major agricultural product in the area. About 8,300 households grow tea in the area, which represents 78% of the area’s famers, who largely depend on tea for income.

Biodiversity and ecosystem functions

Though semi-natural grasslands in Japan has been decreasing from the beginning of the 20^th century and now only 1 % of the country’s area remains as semi-natural grasslands, the area preserves semi-natural grasslands in order to produce high-quality tea. Over 300 plants including seven endangered species are found in Chagusaba. This is one of the semi-natural grassland with the richest biodiversity in Japan.

Knowledge systems and adapted technologies

Farmers cut grass in Chagusaba and it requires enormous labour to cut, dry and utilize grass in the ridges of tea fields. Approximately 600 hours per famer household is required to cut and use Chagusaba grass. It is known that adding grass to tea fields improves the colour, aroma and taste of the tea, which enables the production of high-quality tea. As tea is often planted on steep slopes, grass mulching not only mitigates soil erosion by rain fall and fertilizer runoff but also increase soil microbial activity and sustainable fertilization.

Cultures, value systems and social organizations

The area is the birth place for the novel tea making process to deep-steam tea with distinct aroma and deep green colour. The method was developed uniquely in the area in the 1950s and now it has become one of the typical processes of Japanese tea. Some Chagusaba are commons where communities may retrieve grass resources and manage jointly. The neighboring farmers help one another when an individual’s labor is in short supply or when an individual cannot manage on his own. A complementary tradition called “Yui” has maintained Chagusaba through cooperation among local communities.

Remarkable landscapes, Land and Water resources management features

Chagusaba and tea fields are distributed in a mosaic fashion creating remarkable landscape in the area. Tea has been planted on mountain slopes where production of grains and vegetables were difficult and Chagusaba has been created in steep-sloped areas where even tea cultivation was difficult.