What effectively helps in moving water up tall plants, especially due to evaporation from leaves?

The transpiration-cohesion theory effectively explains how water moves up tall plants, particularly in response to evaporation from leaves. This theory posits that when water evaporates from the stomata on leaves—a process known as transpiration—it creates a negative pressure within the plant's xylem vessels. This negative pressure pulls more water upwards from the roots through the xylem due to the cohesive forces between water molecules. Water molecules stick together (cohesion) and also adhere to the walls of the xylem vessels (adhesion), allowing water to move efficiently against gravity to reach the upper parts of the plant.

The combination of transpiration creating a pull and the cohesive properties of water molecules creates an effective mechanism for long-distance water transport in tall plants. This explains why plants can access water from the soil and transport it high into their structure, which is particularly important for maintaining hydration and nutrient transport.

Other methods such as capillarity, passive absorption, and root pressure play roles in water movement but do not fully account for the vertical transport of water against gravity in tall plants as effectively as the transpiration-cohesion theory does. Capillarity refers to the movement of water through small spaces, which is more relevant to small plants or in