The trees in the dry landscape of a karesansui garden

Quick answer：

Karesansui, also known as Zen garden, is a traditional Japanese garden that emphasizes the use of rocks, gravel, and sand to represent natural landscapes. Trees in karesansui gardens are typically represented by moss-covered rocks, symbolizing the natural beauty of trees without the presence of actual foliage. These trees are an essential element in creating a sense of depth and balance within the garden.