Which type of ecosystem is characterized by moderate rainfall and often includes mountains?

The correct choice is characterized by an environment where moderate rainfall supports diverse plant life, typically made up of grasses and a few scattered trees. This type of ecosystem, often situated in regions that can include mountainous terrains, experiences distinct seasonal changes, with hot summers and cold winters. The rainfall amounts are usually enough to sustain grasses and some blooming plants but not sufficient for dense forests.

In contrast, deserts feature very low rainfall, making them dry and arid environments where only specially adapted plants can survive. The chaparral ecosystem also experiences moderate rainfall, but it is defined by its specific shrubland vegetation and is often found in regions with a Mediterranean climate. Tundra ecosystems are noted for their extremely cold temperatures and short growing seasons, which do not align with the characteristics mentioned in the question. Therefore, the ecosystem that fits the description of having moderate rainfall and often includes mountainous areas is the temperate grasslands.