Pine (Pinus) and oak (Quercus) trees in chaparral shrubland, Mount Diablo State Park, California. This plant community, found primarily in the U.S. state of California and in the northern portion of the Baja California peninsula, Mexico, is shaped by a Mediterranean climate (mild, wet winters and hot dry summers) and wildfire, having summer drought tolerant plants with hard sclerophyllous evergreen leaves, as contrasted with the associated soft leaved, drought deciduous, scrub community of coastal sage scrub, found below the chaparral biome.