摘 要：选用3年生华北落叶松和白 NFDA4 幼苗为试验材料，盆栽试验以自然光照为基础设置4个遮光率水平作为不同光照条件，设置5个密度水平，每个树种15个栽植组合方式（包括单独栽植和混合栽植），进行一个生长季节的试验和取样观测分析，以确定这2个树种在苗期对光照和栽植密度的生长和生理响应以及存活率等功能特性的差异。结果表明：华北落叶松幼苗的相对地径生长量在微光条件下显著提高，且其存活率在半光照和弱光照条件下也显著提高。白 NFDA4 幼苗的高生长量及叶片叶绿素含量表现出随光照减弱而升高的趋势，但其存活率不受光照条件的影响；在不同的栽植密度下，华北落叶松幼苗的生长和生理指标均未表现出显著差异，但适中的栽植密度可显著提高其存活率；白 NFDA4 幼苗高生长量及叶片叶绿素含量在与落叶松混栽时比单树种栽植时高，但其存活率没有任何变化。上述结果表明：适度遮荫和密植可以在一定程度上改善华北落叶松苗期生长并显著提高其存活率，从而有利于华北落叶松成功度过幼苗幼树期；同时，适度遮荫和混栽也有利于白 NFDA4 幼苗幼树的生长。
Abstract: We used the 3 year seedlings of Larix principis rupprechtii and Picea meyeri to investigate their growth and physiological changes, and survival differences and other functional traits in response to the four light regimes (0%, 55%, 75% or 95% shade) and five planting densities. After a whole growing season, the relative root collar diameter growth (RCDG) of larch seedlings was significantly increased under deep shade (95%), while the survival rates were also significantly increased under moderate shade (55% and 75%). The relative growth rate (HG) and chlorophyll content of spruce seedlings significantly increased with decreasing light, but the survival rates were not affected at all. Under different planting densities, the larch seedlings did not show significant difference in their growth and physiological performances, but the survival rates under moderate planting densities were significantly higher than those under higher and lower planting densities. Furthermore, the HG and chlorophyll content of spruce seedlings mixed with larch were significantly higher than those of pure spruce seedlings, while no difference in survival rates was observed between of them. These results suggest that moderate shade and moderate planting densities can improve the growth performance of larch seedlings to some extent and significantly increase their survival to warrant the larch successfully established, while moderate shade and mixing plantation are favorable for the growth of spruce seedlings.
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