This is the Chinese sign di, it means ground, earth. One of the six parts of Garden8 is called Di.
As you can see, the calligraphy shows not only black lines, but also a lot of white spots. In the music of Garden8 this interplay of black (sound) and white (silence) is important.
The black spots are connected to build the sign, but without the white spots we could not recognize the sign. Most music contains white spots, silence.