With land-based communities, ecological succession is the process in which one community is slowly replaced by another, and that one by another, and so on. For example, a typical succession of plants in New York state can be: lichens and mosses; grasses; shrubs; coniferous woodlands; and finally, deciduous woodlands. Each type will remain relatively stable until the next succession stage, and the plants in each stage essentially “set the stage” for the next group. For example, the grasses and herbs stage can contribute organic matter to the soil and protect the soil from erosion; this adds depth to the soil, making it more conducive to the next stage, the shrubs, with their longer root systems.