Back in Japan, Dr Miyawaki realized that the concept of vegetation mapping or Potential Natural Vegetation was virtually unheard of. But undaunted, he made use of all the help he could get from young researchers, spent more than 10 years to research vegetation throughout Japan. Later many companies, big and small, realizing the significance of his work, extended help to his team. Describing those hectic days, Dr Miyawaki would later comment:

During the day we went out into the field, surveying every different type of plant community in places ranging from forests to grasslands, even the communities of weeds growing in cities, and at night we compiled and collated our data. This decade was perhaps the most fulfilling period of my life, and I think it was decisive in shaping my later fieldwork-oriented stance on research. We accumulated a mass of data on the vegetation around Japan, which came from the results of surveys carried out by crawling around on the ground, and these data were so important they were practically a census of the nation’s greenery.

The end product was a staggering set of 10 volumes of Vegetation of Japan. The book includes both existing vegetation maps as well as potential natural vegetation maps. It runs to over 6,000 pages, and is considered the culmination of vegetation research in Japan. The collection is also highly acclaimed as the basic reference material for vegetation studies around the world for the units of plant communities it established, which can be used for global comparisons, and for its comprehensive vegetation architecture.