Author:
Awada T.,Perry M. E. L.,Schacht W. H.
Abstract
Agroforestry systems are designed to improve the efficiency of use of available resources and to increase potential site productivity. The capability of a plant to acclimate to shade when cultivated beneath trees is important in determining the success of agroforestry projects. The objectives of this study were to determine the morphological, physiological and growth responses of C4big bluestem ( Andropogon gerardii Vitman.) and C3smooth bromegrass ( Bromus inermis Leyss) to various canopy levels of green ash ( Fraxinus pennsylvanica Marsh) in the field, and to examine the impacts of these responses on grass yield. Net photosynthesis (Anet), stomatal conductance (gs), and dark respiration (Rd) declined in response to shade in both species, but the decline was steeper in big bluestem than in smooth bromegrass. Total chlorophyll content (Tchl), specific leaf area (SLA), and N content of the leaves increased with shade in both species. In addition, Tchl, SLA, N, and gs were significantly greater in smooth bromeg r ass than in big bluestem at all canopy levels. Lower gs and N, and higher Anet in big bluestem resulted in a higher water and N use efficiencies in this species than in smooth bromegrass. Yield of big bluestem sharply declined with increased canopy cover, whereas yield of smooth bromegrass was not affected by canopy cover. Our results indicate that while both species were productive under various levels of green ash canopy, and showed similar ecophysiological responses to shade, smooth bromegrass acclimate d better to shade than big bluestem. Key words:
Publisher
Canadian Science Publishing
Subject
Horticulture,Plant Science,Agronomy and Crop Science
Cited by
8 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献