修枝接干对泡桐年生长节律影响的研究

该研究以确定促进接干生长的最适修枝强度为目的 ,对 3年生修枝接干泡桐 ,分别 7种处理 ,对其 8项重要生长指标的年动态进行模拟 .结果表明其年生长过程均可用Richards函数曲线进行可靠描述 ,并分别确定了速生点、速生期开始及结束时间、速生期、生长期、最大连日生长量、平均连日生长量和最大年生长量等 8个生长参数 .分析了修枝接干对各项指标诸生长参数的影响 ,表明在修枝后保留下层 3～ 6枝具有相对较长的速生期和生长期 ,较高的平均连日生长量、最大连日生长量和最大年生长量 .从而不显著降低原主干的下部径生长 ,并一定程度的促进其上部径生长 ,同时使接干的高、径生长和接干形率达相对较高水平 ,在不显著降低其原主干材积生长量前提下 ,极显著的提高其总材积生长量 .

Effects of pruning on annual growth rhythm of paulownia trunk

Annual variations of eight growth indicators for three_year paulownia with pruning to promote trunk extension were simulated under seven treatments. The results showed that annual growth process could be modeled reliably by Richards function. Eight growth parameters are fast\|growing point, initial point of fast\|growing period, final point of fast\|growing period, fast\|growing period, growing period, maximum day increment, and maximum annual increment. Effects of pruning to promote trunk extension on growth parameters were analyzed. Paulownia remaining 3 6 lower branches after pruning had relatively longer fast_growing period, growing period, higher average day increment, maximum day increment and maximum annual increment. Therefore, lower diameter growth of original trunk did not decrease significantly, and upper diameter growth increased to some extent. Height and diameter growth of grafting trunk, and form ratio of grafting trunk were relatively higher. Total stock volume increment was improved significantly under the condition that stock volume increment of original trunk did not decrease.