the final stage of plant or animal succession, when environmental conditions have been stable long enough for an area to develop a semi-permanent biome. For example, rock crumbles, and pioneering plants begin to grow in the sandy soil. As they add mulch and humus, other plants follow ? from grasses to shrubs to pine forest. If climatic conditions and soil types are appropriate, the climax species could be the pine forest. Animal types would follow this pattern of succession, ending perhaps with squirrels and porcupines as climax species.