Britannica Sources used in this answer

How do savanna trees obtain water later in the dry season?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Flat savanna plain with scattered acacia trees under a partly cloudy sky in Serengeti National Park, Tanzania. — Savanna A savanna marked with acacia trees in Serengeti National Park, Tanzania. Africa's Serengeti Plain is commonly used as an example of the savanna biome—a hot, seasonally dry ecological region characterized by an open tree canopy (i.e., scattered trees) above an understory of continuous grasses.

In the context of the savanna, trees are able to survive the dry season because they possess deep root systems that allow them to tap into moisture stored in deeper soil layers, which remains available long after surface water has been depleted.1

While grasses in the savanna are typically shallow-rooted and die back or become dormant when moisture is unavailable, the deeper penetration of tree roots enables them to access water even when the upper soil levels are dry. To further conserve water during this period, many savanna trees may shed their leaves to reduce transpirational loss, though some species may still produce flowers while leafless. Additionally, soil composition plays a critical role; for instance, stony soils are particularly favorable for trees because they facilitate the deep root penetration necessary to reach these essential water reserves.1