Characteristics of Imou Bog

　The origins of marshlands are generally classified as follows:
　　1.lacustrine marshland ( made at the final stages of lakes and marshes being reclaimed )
　　2.flovial(river) marshland (made after rivers were reclaimed)
　　3.flatlands marshland (made in the hollows of flatlands)
　　4.coast(seaside) marshland (made inside of rivers on the coast of the sea)
　Imou does not belong to any of these four categories of origins.
The famous Ozegahara and Kushiro Marshlands have thick layers of accumulated grounds . 　Imou Bog, however, hardly has any layers of accumulated grounds to foster plants in.

1)　Geographical Features
　　location of Imou:　　37゜44' 30'' N, 　　137゜27' 15'' E
　　height:　circa 65 meters high
　Imou Bog is situated in the eastern part of Toyohashi City, at the western foot of the Yumibari Mountain Ranges which lie from south to north forming the boundary of Aichi Prefecture and Shizuoka Prefecture.
　It is made up of the shallow bottom lands of ravine, surrounded in three directions by the mountains about 250 meters high .　The bog forms a U-shape.
　The hillside behind the bog has a slope of 25 degrees. Imou is situated in the transition point, where the slope becomes gentle.
　The bog is located in the fields 60 to 75 meters high and have the gentle degrees of four to eight.
　In part of the bog area there are abandoned traces of rice fields with the remains of the ridges.

2)　Geological Features
　The bedrocks of chert, in the central part of Imou Bog, are covered with black silt ・clay layers.　These layers form very thin outermost layers of soil:　10 to　20 centimeters thick on average and 40 centimeters at the thickest.
　The soil in the layers have been carried away by the water where the water runs. As a result, the outer parts expose the chert there.

3)　Formation
　As mentioned above, Imou Bog has very thin outer layers of soil. Under the thin soil there are bedrocks which water can't infiltrate into.
　This means that this bog has a very poor capacity of keeping water.
　Nevertheless constant amount of water stays in this bog and fosters life there.　The reason may be as follows:
　There is an inexhaustible source of water supply from the hillsides of the mountains behind the bog.　It is not clear whether the water comes from the underground or the rainwater is saved after the rainfall.
　Twenty to thirty tons of water comes down from the mountains to the bog daily, thereby guaranteeing the preservation of life there.
　Thanks to the bedrocks situated in the shallow places in the ground, the water, what small amount may be,can stay in the layered soils.
　Therefore, the water level is always kept high enough to for the bog.
　The water coming from the hillsides of the mountains behind the bog is literally "life line" to all the plants in the bog.
　In order to keep the water running, the plants in these mountains must be taken good care of as well as the plants in the bog.
　Without the water from the mountains, it is impossible to keep the beautiful nature of Imou Bog alive.

4)　Ecosystem of the Plants
　There are many groups of plants in Imou Bog.　It means a variety of plants grow there:　those indigenous to this region, those akin to alpine plants and insectivorous plants. And there also grow plants whose central distribution areas are in the zone of cold, though Imou Bog is in the zone of mild climate.
　Those plants in Imou Bog are of considerable scientific value.