Yukihiro Morimoto

Simulation Model of Size Frequencies of Saplings in Restored Natural Habitat in Urban Area by Using Exponential Distribution

The population dynamics of saplings taller than 50cm were investigated from 1998 to 2003 in every year in the whole 6048m² area of the restored natural habitat Inochi-No-Mori in Kyoto city. There were 1249 saplings in the area in 2003. Population density was 32.2 individuals / 100m². Celtis sinensis formed 32.3% of the total number of individuals and was dominant species of Inochi-No-Mori. Only 126 saplings had been dead from 1998 to 2003 , so mortality rate was very low. We examined the height growth characteristic of saplings. As a result, there were size dependencies on the height growth of saplings. So we approximated the height distributions of saplings by exponential functions. By using this model, simulation about the height growth of each sapling was conducted in assuming that mortality rate and number of recruitment individuals was constant. We got the calculated size distributions from 1999 to 2003 and compared the calculated size distributions with the observed ones. As a result, differences between the observed size distributions and the calculated ones were very slight. This model predicted that the frequency of saplings taller than 500cm would be highest in 2015. The simulation was very valid for predication dynamics of saplings.

Biological resources used in shinsen and the form to supply them at Kamo-wake-ikazuchi-Jinja

Shinsen are offerings offered at Shinto shrines on the occasion of shrine festivals. We investigated shinsen offerings made at Kyotos Kamo-wake-ikazuchi-jinja (also known as Kamigamo Shrine) between June 2009 and May 2010. We surveyed all offered items and investigated which biological resources were used, and how and from where they were supplied. We found that totally 2243 items were offered. There were 137 different kinds. 105 kinds of biological resources were used as ingredients. Some of the supply routes for shinsen ingredients were based on ancient customs. The Adogawa region in northern Shiga Prefecture, for example, was a supply area for the shrine based on a system through which the shrine bestowed the region with river fishing rights and rice farming land as a compensation for its supply of ayu fish (Plecoglossus altivelis altivelis) used as items in shinsen offerings. Through shinsen offerings, a great variety of biological resources were used in a sustainable way. We found, however, that some biological resources used in shinsen such as the futabaaoi (Asarum caulescens) are difficult to obtain today.

Soil water Conditions and The Root Distribution of Salix matsudana in The Mu Us Desert, China

中国の毛烏素沙地において, 土壌水分条件および主要な緑化樹である旱柳の根系分布を調査した。旱柳は低地から砂丘の上まで植栽されているが, 地下水位80-100cmの低地では根系発達が極めて悪く, 枯死木もみられた。地下水位1.5m程度の半固定砂地で最も良い生育を示した。砂丘上の砂は有効水分が少なく, 早柳の根系分布密度は疎になり, 分布範囲か広くなっていた。高さ5m以上の砂丘では, 水分不足のため, 早柳の生育は困難であった。