Studies in maintenance and regeneration mechanisms of a coppice forest in cool-warm temperate transitional zone

日本中部茨城县北部冷暖温带过渡带的一种灌木次生林，主要由栎属、锥栗属、雪松属、宏等属植物组成。从幼树和冠层树体的枝条结构、枝条动态和生理生态特性等方面，对锯缘栎林、疏花鹅掌杉和圆顶锦鸡儿的建立机制进行了研究。1.测定了以锯缘栎林和冠层锦鸡儿为主的灌木林的现存量。这两种树种占总断面积的66%。现存量为590.5 kg。3.研究了上层植物对锯缘栎实生苗成苗的影响。结果表明，锯缘栎光合速率最大值为1000万m；-2；-1；gt；S；通过林隙形成、修剪矮化竹、修剪灌木和对照等处理，对林隙形成、矮化竹、修剪灌木和对照进行了研究。唯一林隙的相对生长率和存活率都很高。这两个树种的更新将发生在唯一的空隙。4.锯缘栎树和冠层树在幼树和冠层树上都形成了第一次和第二次新梢。疏花锦鸡儿的枝条伸长在幼树和树冠上不同。幼树在生长季节只有一次枝条延长，在冠层中形成一次和二次枝条。5.疏花锦鸡儿的叶寿命、单株叶面积、单位茎长比叶重和茎重显著小于锯缘栎树和皱叶锦鸡儿。单位叶面积的茎长是锯缘栎长的3~5倍，是短叶蜡梅的3~5倍。稀树的高伸芽效率有利于其成苗和冠层发育。

A coppice secondary forest of cool-warm temperate transitional zone in northern part of Ibaraki Prefecture, central Japan is dominated by Quercus serrara, Castanea crenata, Carpinus, Acer and so on. The establishment mechanism of Q.serrata, Carpinus laxiflora and C.Crenata ware examined from the shoot structure and shoot dynamics of both saplings and canopy trees, and physioecological characteristics.1.The standing crop of the coppice forest dominating by Q.serrata and C.crenata (ca.20-years-old, 10-12 m in height) was measured. These two species occupied 66% of the total basal area. The standing crop was 590.5 kga^<-1>.2.Maximum photosynthesis of Q.serrata and C.crenata was ca.10 mumolm^<-2>s^<-1> and that of C.laxiflora was 8 mumolm^<-2>s^<-1>.3.The influence of upper layr plants on the seedling establishment of Q.serrata and C.laxiflora was examined. Following treatments such as gap formation, mowing dwarf-bamboo, mowing shrub and control were made. Relative growth rate and survivorship were high at the only gap. The regeneration of the two species would occur in the only gap.4.In Q.serrata and C.crenata first and second shoots were formed in both saplings and canopy trees. The shoot extension of C.laxiflora differed in saplings and canopy trees. In saplings only first shoot extended during growing season and in canopy trees first and second shoots were formed.5.The life span of leaves, area of individual leaves, specific leaf weight and stem weight per unit stem length of C.laxiflora were smaller significantly than those of Q.serrata and C.crenata. The stem length per unit leaf area of C.laxiflora was three to five times as long as Q.serrata and C.crenata. A high efficiency of shoot extension of C.laxiflora contributed to the establishment of seedlings and development to canopy trees.