In the beginning art was created mainly to reproduce images that our eyes can see on a flat surface. Of course, you can say that sculptures were created to re-create images in 3D, but the main purpose of art was to get as accurate a depiction as possible of another place and another time for eternity. Nowadays, we have advanced to the point where it is possible to take accurate pictures digitally, and this sort of pushed art towards abstract depictions that are difficult to do with digital cameras.
However, in China, there was a time when calligraphy was very popular, and it was the instrument used was the brush. That was the most advanced instrument available to the artist for capturing a place in time. And thus landscape paintings became one of the most popular art pieces, along with depictions of people, animals, and plants. Ability to use the brush with such skill that a whole mountain is depicted realistically in a few brush strokes became secrets of the master painters. This extended to depictions of fishes, bamboo, and people using just a brush, black ink, and calligraphy paper.
There were, of course many uses other than pictures, as Chinese use pictograms as their language. These pictograms were basically brushstrokes concatenated together in an area of a square. The great artists were able to create calligraphy styles for their Chinese words that they became art itself. Rarely do people sell calligraphy styles of words in the western hemisphere, but in Asia, how a person wrote a paragraph of Chinese words in a scroll is art itself. Even the depiction of one word, like "Tao" was considered art, especially if done in a style that produces the artist's individual style.
The subject matter of Chinese scroll paintings and calligraphy were mainly limited to the subjects of the day, and included poetry for deep thinkers. If you are interested in knowing more about Chinese scroll paintings as related to Taoism and Buddhism in China, feel free to visit:
http://www.edepot.com/taoart.html
