干旱区生态环境知识资源中心

Microenvironmental conditions created by six weed control methods and the resulting survival and height growth of two species of windbreak trees were measured in three separate plantings in Nebraska. The treatments included three synthetic sheet mulches commonly used in tree plantings. Climagro, a black polyethylene mulch, and Sunbelt, a black woven polypropylene mulch, improved the growth of green ash (Fraxinus pennsylvanica Marsh.) in two of the three plantings. Survival of green ash and survival and growth of Scotch pine (Pines sylvestris L.) were not significantly different among the treatments. Positive correlations were found between August soil moisture and ash height growth. No relationship was found between soil temperature and ash growth, although significant differences in soil temperature among treatments were detected. Weed control treatment did not affect air tem-perature above the soil surface or the amount of mycorrhizal roots on Scotch pine. Economic analyses of the use of Climagro and Sunbelt mulches in a hypothetical green ash windbreak investment resulted in positive returns.(C) 2002 by The Haworth Press, Inc. All rights reserved.