Even in Japanese cities where we find plants only in small parks, as artificially designed trees along street, and as weed in vacant lots, we can observe the invisible operation similar to the photosynthesis.
Transportation and commercial activities are characteristics of the city like Tenjin, but they cannnot make Tenjin a place for people to gather and to work by themselves. Even gigantic and strong buildings cannot have people work in them if without fascilities to transmit and keep heat, air, and light.
If a city is without conditions for the existence of natural lives, without fascilities like food and drink, toilets etc., industries for them, maintenances for buildings and roads, organization of money circulation, post and tele-communication services, and circulation of information, the city/forest is destined to become a desert.

As we tried to illustrate the interdependent relation between "downtown" and "suburbs" in Museum City Tenjin '94, people and vehicles, streets and buildings, shops and offices, function and amusement are also mutually dependent, giving something to the other and receiving something from the other. This system of such interdependence only can make any activities in the city stable and alive.
It is very much like a relation between plants and animals living together through food chain and chemical exchange with air and soil.

Plants are frail in existence, in that it cannot move by themselves and protect themselves.
Animals as well are excluded from downtown areas and kept marginalized, otherwise allowed to survive in pet shops only for decoration and pleasures, just like roadside trees and decorative plants.
The situation makes us forget the function of photosynthesis so important for our lives.
Similarly, the original power of art ---- a power to absorb energy from nature and human being and, in turn, release energy for our spirits ---- has now been forgotten, weakened: art is allowed to exist only as toys and decorations.