Effects of wind barrier protection on eleven-year growth black walnut seedings

Abstract

Black walnut (Juglans nigra L.) plantings in exposed, open-field sites frequently result in poor seedling growth. The use of artificial wind barriers significantly improved tree growth on such a site in central Michigan on a sandy loam soil, a well-drained Arenic Hapludalfs. The use of a wooden lath (snow fencing) barrier for the first 4 years following planting provided a wind-protected microenvironment that improved the 11-year diameter growth by 60%, and the height growth by 70%, compared to trees grown without the barriers. Annual diameter growth of the protected trees was significantly greater throughout the study, indicating that the barrier effects on growth persisted at least 7 years after the barriers were removed. Trees growing behind the barriers had greater crown and leaf area than those in adjacent exposed plots. The use of existing natural barriers, such as forest edges, fence rows, topography, and tall natural herbaceous vegetation, should be considered when planting trees such as black walnut on exposed sites. Copyright © 2006 by the Society of American Foresters.