林下叶层

The photosynthetic parameters of Sinocalycanthus chinensis in both overstory and understory, including the diurnal changes of net photosynthetic rate, intercellular CO2 concentration, dark respiration rate and stomatal resistance, were measured using a LCA4 Portable Photosynthesis System. The photosynthetic parameters of the accompanying plants such as Boehmeria platanifolia, Rhus chinensis and Weigela japonica var.

用LCA4型便携式全自动光合测定仪，在自然条件下，于7月下旬的晴朗天气测定了群落冠层和林下两种不同光环境下夏蜡梅的净光合速率、胞间CO2浓度、呼吸速率、气孔阻力的日进程，并与其伴生植物悬铃叶苎麻、盐肤木、水马桑Weigela japonica var。

A precondition was that the stand diameter grew 2 cm every year. For Evodia meliaefolia community, in the competitive living space by close cover stand, the ratio remained low for ten years with little fluctuation. However, in the unlimited open space, the ratio reached two peak values, with the first appearing in the eighth year, and the second in the eleventh year.

在假设了楝叶吴茱萸和油茶每年胸径生长2 cm的前提下，楝叶吴茱萸冠层总面积变化规律是：在郁闭林分被抑制的生长空间里，楝叶吴茱萸冠层总面积扩散速率可以长达10多年基本维持在一个很低的水平下，而且基本没有太大的变化；在获得充分开阔的生长空间里，楝叶吴茱萸冠层总面积扩散速率出现两个增长高峰，一个出现在第八年，一个出现在第十一年。

Hystrix canopy declined slightly at the midday, suggesting the occurrence of reversible photoinhibition. Owing to the lower maximum net photosynthetic rate in sun leaves and the ability to effectively and consistently utilize the scattered light and/or transmitted light, C. hystrix saplings could survive low light intensity, grow well at the edge of the forest and in the understorey, and eventually become one of the dominant species in upper layer of the community.

刺栲冠层阳生叶的最大光合能力比较低，整个冠层叶能高效而稳定地利用散射和透射光，这些特征使得常绿的刺栲幼树能在林边或林下良好生长，较好地适应不同的光环境并成功渡过幼苗期，最终成为群落中的上层优势种。

Amid the trees, half-concealed by a spreading understory, lie aluminum dishwasher parts and stainless steel cookware, their plastic handles splitting but still solid.

林木之中，郁郁葱葱的林下叶层半掩着铝制的洗碗机散件和不锈钢炊具，它们的塑料把手虽已开裂，却依然坚固。

For the leaf area index of the three forest types, there was a similar variation trend, i.e ., increased first and decreased then, with the maximum presented in mid-July or August for Q. mongolica and J.mandshurica forests while in mid-August or September for F. rhynchophulla forest. The canopy porosity of the three forest types also had a similar variation trend, but opposite to leaf area index, being decreased first and increased then, with the minimum presented in mid-June, July, August or September. The analysis of variation coefficients of leaf area index, transmitted direct gap light, and transmitted diffuse gap light indicated that the spatial pattern of leaf area index in July-September was the main factor affecting the spatial distribution of transmitted diffuse gap light.

结果表明，3种林型的叶面积指数变化总体趋势是一致的，均呈先上升再下降的单峰曲线，蒙古栎林和胡桃楸林都是在7月中旬或8月中旬达到最大峰值，花曲柳林是在8月中旬或9月中旬达到最大峰值；3种林型冠层孔隙度的变化总体趋势也是一致的，呈先下降再上升的单峰曲线，不同样地峰值出现的时间也不同，最低峰值在6、7、8、9月中旬均有出现；通过对不同月份的叶面积指数、林下散射光、林下直射光的变异系数分析表明，7—9月叶面积指数的空间格局是影响林下散射光空间分布的主要因素。

Except the single leave average area, various dissection values in seedling time are lower than canopy leave in mature phase. This is the same results compared to leaf dissection between higher layer and lower layer under ex-situ conservation.

迁地成年阶段望天树的冠层叶通过一系列的生理机制来适应冠层空间高温、强光和低湿的环境，而林下幼苗的叶片也通过另外的一套生理机制来适应林下低温、弱光、瞬时光斑和潮湿的环境。

The concept of equivalent rotationally rigidity is offered and the formula of rotationally rigidity is obtained.

主要做了如下几个方面的工作：对伸臂位于顶部的单层框架—筒体模型进行分析，提出了等效转动约束的概念和转动约束刚度的表达式。

Male cats normally do not need aftercare with the exception of the night after the anesthetic.

男猫通常不需要善后除了晚上的麻醉。