排序方式: 共有3条查询结果,搜索用时 0 毫秒
1
1.
This article documents an unexpected regional difference in the shapes of later Acheulean hand-axes. Almost 1,200 handaxes from 17 sites located in Europe, East Africa, India, and the Near East were measured using a polar coordinate technique and compared using discriminant analysis and analysis of variance. One group of handaxes, those from Israel, clearly stood apart. The reasons for this distinction are unclear but may relate to raw material, time, or, perhaps, cultural tradition. 相似文献
2.
A 70-year-old thinned northeastern Fagus-Betula-Acer stand in the Adirondack Mountains of New York was fertilized with varying combinations of N, P, K and lime.Acer saccharum Marsh. andBetula alleghaniensis Brit. foliage was collected periodically during the frost-free season and analyzed for foliage areas and weights, and levels of ash, N, P, K, Ca, Mg. Comparisons were made within species, and among treatments, expressed as concentrations on dry weight and ash bases, and as contents on per leaf weight and area bases. Elemental composition trends over time were examined to determine treatment effects and optimum sampling period. 相似文献
3.
A 70-year-old thinned northeastern Fagus-Betula-Acer stand in the Adirondack Mountains of northern New York was fertilized with varying combinations of N, P, K, and lime in the spring of 1976.Betula alleghaniensis Brit.,Acer saccharum Marsh.,Acer rubrum L., andFagus grandifolia Ehrh. foliage was collected in the autumn for 1974 through 1977 and analyzed for foliage areas and weights, and levels of ash, N, P, K, Ca, Mg, Mn, Na, Fe, Zn, Al, Cu, and Co. Comparisons are made within species and among treatments, expressed as concentrations on a dry weight basis. Elemental composition is examined to determine the differential foliar responses to fertilization.Contribution of State University of New York College of Environmental Science and Forestry, Syracuse, New York, 13210.The authors are Graduate Research Assistant, Director of Huntington Forest, Technical Research Assistant, and Professor of Forest Soil Science (now deceased), SUNY, respectively. 相似文献
1