Trees play a fundamental role in maintaining the stability of the water cycle in nature. They are not just green components of the environment, but active elements that regulate the movement of water between the land and the atmosphere. Through their biological processes, trees directly influence rainfall formation, water conservation, drought prevention, and soil protection. 1. The Role of Trees in Transpiration Transpiration is the release of water vapor from tree leaves through stomata. Tree roots absorb water from the soil, transport it to the leaves, where it is released as vapor. This vapor increases air humidity, which is essential for cloud and rain formation. Studies indicate that forests may release thousands of liters of water per day through transpiration. 2. Cloud Formation and Increased Rainfall Water vapor from transpiration rises into the atmosphere. When it mixes with cooler air, it condenses and forms clouds. Therefore, forests—especially tropical ones—are major sources of local and regional rainfall. In regions like the Amazon, up to 50% of rainfall originates from transpiration. 3. The Role of Roots in Water Absorption and Storage Tree roots absorb water from deep layers, which: Recycles water back to the surface through transpiration. Prevents the lowering of groundwater levels. Large trees act as natural reservoirs of water, helping to: Maintain soil moisture. Provide water during periods of drought. 4. Reducing Surface Runoff and Protecting Soil Trees slow down the flow of rainwater toward rivers. Their leaves intercept part of the rainfall, and their roots anchor the soil. This reduces: Floods Soil erosion Rapid loss of surface water Thus, water remains within the ecosystem for a longer period. 5. The Role of Trees in the Groundwater Cycle Tree roots allow water to infiltrate the soil, which: Increases groundwater recharge. Enhances the soil’s ability to retain moisture. Without trees, soil loses its capacity to hold water, leading to increased drought. 6. Impact on Local and Regional Climate Trees reduce temperatures through shading and transpiration, improving water evaporation conditions. Protecting trees helps maintain the balance of the water cycle and ensures climate stability in surrounding areas. 7. Effects of Deforestation on the Water Cycle Reduced transpiration means less water vapor in the atmosphere. Rainfall decreases and droughts become more frequent. Soil degrades and loses its ability to store water. Groundwater levels decline, and the risk of flash floods increases. These points demonstrate that deforestation severely disrupts the natural water cycle. Trees play a vital role in the water cycle through transpiration, rainfall formation, increasing air humidity, protecting soil, and regulating both surface and groundwater movement. Without tree cover, the water cycle is disrupted and the climate becomes drier and unstable. Therefore, protecting and planting trees is essential for maintaining the balance of water and life on Earth. Al-Mustaqbal University is the first university in Iraq.