How deep is the root system of Zizhu bamboo?

The depth of Phyllostachys pubescens root system is related to its growth years. If it is Phyllostachys pubescens, the root system will not be too deep. With the growth of Phyllostachys pubescens, its root system will crawl horizontally, and when the underground rhizome grows to a certain density, it will grow underground. But some underground roots will grow new Phyllostachys pubescens, and some one Phyllostachys pubescens will grow a whole Phyllostachys pubescens forest.