Pennsylvania has several different biomes, but the most dominant biome is the temperate deciduous forest biome. This biome is characterized by four distinct seasons (spring, summer, fall, and winter), moderate climate, and a variety of deciduous trees such as oak, maple, hickory, and birch. The temperate deciduous forest biome is home to a rich diversity of plant and animal species, including deer, black bears, squirrels, and many types of birds. Overall, this biome is well-suited to Pennsylvania's climate and geography, and it is one of the most important ecosystems in the state.