How Trees Bring Water

Permaculture Instructor Andrew millison explains how trees are connected to water in the atmosphere as well as water flowing through the landscape. This video articulates the amazing role that trees play to ecosystem and climate health, and how their removal causes the drought-flood cycle. There may be some questions about the scientific validity of the concept that forests attract rain. Here are a number of peer reviewed scientific articles to support the hypothesis which suggests that forest cover plays a much greater role in determining rainfall than previously recognized. They explain how forested regions generate large-scale flows in atmospheric water vapor. How Forests Attract Rain: An Examination of a New Hypothesis. (peer-reviewed) (abstract and access to full text) Makarieva A.M., Gorshkov V.G., Sheil D., Nobre A.D., Bunyard P., Li . (2014) Why does air passage over forest yield more rain? Examining the coupling between rainfall, pressure, and atmospheric moisture content. Journal of Hydrometeorology, 15, 411-426. (peer-reviewed) doi: (abstract and access to full text) (full text) Report: Forests may play bigger role in rainfall than estimated (non-academic) (full text) Does Anthropogenic Land Use Change Play a Role in Changes of Precipitation Frequency and Intensity over the Loess Plateau of China? (peer reviewed) (full text) Estimation of Actual Evapotranspiration in a Semiarid Region Based on GRACE Gravity Satellite Data—A Case Study in Loess Plateau (Peer reviewed) (full text) New meteorological theory argues that the world’s forests are rainmakers (non-academic) (full text) Another important concept from the video is that condensation and evaporation in large areas of forest causes moist air to flow to land From the abstract of the article below: “ Intense condensation associated with high evaporation from natural forest cover maintains regions of low atmospheric pressure on land. This causes moist air to flow from ocean to land, which compensates the river runoff….High evaporation and large extent of natural forests guarantee both a stable and high throughput hydrological cycle. Forests protect a continent against devastating floods, droughts, hurricanes, and tornadoes. Sustaining natural forests is a sound strategy for water security and climate stabilization.” Makarieva A.M., Gorshkov V.G. (2010) The Biotic Pump: Condensation, atmospheric dynamics and climate. International Journal of Water, 5(4), 365-385. (peer-reviewed) (full text) Makarieva A.M., Gorshkov V.G., Li . (2013) Revisiting forest impact on atmospheric water vapor transport and precipitation. Theoretical and Applied Climatology, 111, 79-96. (peer-reviewed) (full text) Makarieva A.M., Gorshkov V.G., Li . (2009) Precipitation on land versus distance from the ocean: Evidence for a forest pump of atmospheric moisture. Ecological Complexity, 6, 302-307. (peer-reviewed) (full text) An undamaged Amazon produces its own clouds and rain (non-academic) (full text) Relationships between forests and weather. EC Directorate General of the Environment. 13th January 2012. Michael Sanderson, Monia Santini, Riccardo Valentini and Edward Pope. from the Met Office, a UK government weather resource (non-academic) (full text) Andrew Millison’s links: JOIN THIS CHANNEL to get access to uncut video content and live Q & A sessions: SIGN UP FOR ANDREW’S FREE EMAIL NEWSLETTER: