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Stand structure and yield of the mixed white poplar and black locust plantations on sandy ridges between the Danube and Tisza rivers in Hungary
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作者 K█oly R█EI 《Journal of Forestry Research》 CAS CSCD 2002年第2期110-113,171,共5页
The paper deals with the stand structure and yield of black locust (Robinia pseudoacacia L.) forests mixed with white (Populus alba L.) in various proportions, partly applying a new methodological approach. The main s... The paper deals with the stand structure and yield of black locust (Robinia pseudoacacia L.) forests mixed with white (Populus alba L.) in various proportions, partly applying a new methodological approach. The main stand structure and yield factors were determined separately for each species, measured stem by stem, using the volume functions prepared for each species. The ratio of the volumes of the species (A and B) in mixed and in pure stands (based on volume tables) was determined. A close relationship has been found between the ratio by relative total volume and the proportion (by the number of stems) of the species. The relative surplus in the volume of the mixed stands varied between 1.24-1.55 at the age of 16 compared to the control, i.e. the yield of pure stands of the species concerned. The trial has also proven that if two species have a fast initial growth rate and a similar rotation age, they can be planted in mixed stands resulting in mutual advantages. 展开更多
关键词 Mixed stands Robinia pseudoacacia L. Populus alba L. Stand structure YIELD
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中国将开放白银市场
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作者 刘山恩 《中国宝石》 1999年第4期115-117,共3页
关键词 中国 白银产量 白银市场 市场开放 现货市场
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