Paper presented at the 11th North American Agroforesty Conference, which was held May 31-June 3, 2009 in Columbia, Missouri.In Gold, M.A. and M.M. Hall, eds. Agroforestry Comes of Age: Putting Science into Practice. Proceedings, 11th North American Agroforestry Conference, Columbia, Mo., May 31-June 3, 2009.Florida citrus and vegetable crops generate billions in revenue every year. However, winds, freezes, hurricanes, and citrus canker (Xanthomonas campestris) impact production. Windbreaks located perpendicular to the prevailing wind can reduce soil erosion and increase irrigation efficiency and farm production mostly by simply modifying microclimate. Windbreaks can also control the spread of pathogens such as citrus canker. To study how tree windbreaks modify microclimate in southern Florida, weather stations were established in 2008 along transects behind a 1-row eastern redcedar (Juniperus virginiana) windbreak at the Southwest Florida Research and Education Center (SWFREC/University of Florida) at Immokalee, and a 1-row cadaghi (Corymbia torelliana) windbreak at C&B Farms, Clewiston, to assess spatial variation in wind speed, temperature, and relative humidity at 2m above the ground. The windbreaks significantly reduced wind speed; minimum wind speed was at two times the windbreak height (2H) behind dense (17 [percent] porosity) redcedar and at 6H behind relatively porous (20 [percent] porosity) cadaghi when the wind direction was nearly perpendicular to the windbreak. Wind speed at 2H behind eastern redcedar was approximately 5 [percent] of the open wind speed and at 6H behind cadaghi was approximately 3-30 [percent]. Wind speed at 14H behind cadaghi and redcedar windbreak was approximately 60 [percent] and 80 [percent] of the open wind speed, respectively. Temperature behind both windbreaks was relatively warmer than in the open. However, the extent of temperature and relative humidity modification was less compared to wind speed. Windbreaks are an effective use of forest trees to modify microclimate and appreciably enhance Florida farm production.Bijay Tamang (1), Donald L Rockwood1 and Michael G. Andreu (2) ; 1. PO Box 110410, School of Forest Resources and Conservation, University of Florida, Gainesville, FL 32611. 2. SFRC, University of Florida, Gulf Coast REC - Plant City, 1200 N Park Road, Plant City, FL 33563.Includes bibliographical references
