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通过对豫南杉木人工林不同立地指数级标准地和生产经营经济指标的调查,利用Richards等经典方程拟合豫南杉木生长的基本模型,编制生长过程表,确定数量成熟龄和工艺成熟龄,采用净现值和内部收益率分析杉木经济成熟龄。综合考虑数量成熟龄、工艺成熟龄和经济成熟龄结果表明:8立地指数不适合营造杉木用材林;10立地指数只能培育小径材,主伐年龄为22~24 a;12立地指数以培育小径材为主,主伐年龄为20 a,以培育中径材为辅,主伐年龄为22 a;14立地指数以培育中径材为主,主伐年龄可确定为20 a。 相似文献
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通过对杉木不同造林密度试验林连续三年观测分析结果可知,密度与生长量呈极显著负相关,但对生长节律没有影响。杉木年生长过程划分为三个阶段:前期、中期、后期。影响高生长的主导气象因子是降雨量,其次是气温;影响径生长的主导气象因子是平均气温,其次是降雨量。采用数量化理论(I)建立了杉木树高和胸径旬生长量预测模型。 相似文献
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罗山县生态示范区建设评价体系研究 总被引:1,自引:0,他引:1
以提升生态示范区建设水平和可持续发展综合能力为最高目标,采用层次分析法和综合指数法,从经济发展、社会进步、生态建设和环境保护4个方面提出了4层、27个指标的罗山县生态示范区建设评价指标体系,构建了罗山县生态示范区建设评价方法.结果表明,罗山县生态示范区可持续发展能力指数增加显著,已达到优良标准,与实际情况相吻合. 相似文献
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Application of Linear Model to Testing the Universal
Applicability of Site Index Curves for Chinese Fir Provenanc 下载免费PDF全文
The theory of statistical inferences for
linear model was employed to test the effect of Chinese fir provenances on site index
curves (dominant height growth curves).The results of analyzing two experimental farms,Hongya
and Jigongshan,showed that,(1)both site indices of different provenances in the
same region and those of the same provenances in different regions were both of
significant difference,which suggested that variation in site indices was a combination
of variation both in genetics and in environment.(2)The slope parameters of site index
curves for different provenances were of no significant difference,which meant that the
dominant heights of different provenances followed the same growth
development.Consequently the dominant height growths of different provenances could be
described by a similar growth model,which provided good evidence in support of the
universal applicability of Chinese fir growth and yield models. 相似文献