Life-history syndromes promoting the diversity of perennial herbaceous communities on the forest floor of northern deciduous forests

北海道北部混交林在其纬度分布上具有较高的森林地面草本群落物种多样性的特点。本研究旨在通过对共生物种形态和物候表现的比较监测，阐明这些森林生态系统物种多样性的维持机制。主要研究地点设在Tomakomai市的Tomakomai实验林和札幌市的Nopporo森林公园。由于冬季降雪量的差异，Tomakomai森林植物的季节表现比noporo森林推迟了约1个月。无矮竹覆盖的林地群落α多样性显著增高。我们监测了地上多年生草本植物和蕨类植物的季节变化。异速生长特征在种间表现出趋同的相似性，表现为以叶片分配为主。为了定量研究植物叶片垂直结构的精细尺度，设计了一种新的“圆盘接触法”，并将其应用于Tomakomai森林地面群落。以百合科单果植物Cardicrinum cordatum的动态空间格局为研究对象，对其生殖性能进行了监测。记录了放牧对夏季森林马草场系统草本群落的影响。在noporo森林附近详细记录了蕨类植物群落结构的区域扩大。

Northern mixed forests in lowland Hokkaido is characterized by relatively high plant species diversity in forest floor herbaceous communities for their latitude of distribution. This study aimed to clarify the maintenance mechanisms of the species diversity of these forest ecosystems through comparative monitoring of morphological and phenological performance among co-occurring species.Main research sites were set at Tomakomai Experimental Forest at Tomakomai City and Nopporo Forest Park at Sapporo City. Due to the difference in winter snowfall, seasonal performance of plants at Tomakomai forest was delayd for ca, 1 month from Nopporo forest.Remarkable high alpha-diversity was recorded for forest-floor communities without dwarf bamboo cover. We monitored seasonal performance of the floor perennial herbs and ferns. Allometric characteristics showed convergent similarity among species, characterized by the dominance of foliage allocation throughout seasons. To quantify the fine-scale vertical structure of foliage, a new technique of'disc-contact method'was designed and applied to a floor community at Tomakomai forest. Reproductive performance was monitored with special reference to dynamic spatial pattern of monocarpic species Cardicrinum cordatum(Liliaceae). The effect of grazing on herbaceous communities was recorded for the summer pasture system of horses in forest. Regional scaling-up of community structure was recorded in detail around Nopporo forest for ferns.