以下、
兵庫県治山林道協会編「六甲山災害史」１９９８年刊を読んで、
特に植生の変化について参考になった部分のまとめと紹介です。
My main field,
Iwakurayama hill, Gyojayama hill and Kashigamine hill,
with altitude less than 600m,
is located at the east end of the Mt Rokko Range.
About the Mt Rokko (altitude 931m) and its surrounding forest,
there are many books written in Japanese,
and those books help us to understand the forest that I love.
"Rokko-san Saigai Shi
(The history of the disaster around the Mt Rokko)"
by Afforestation And Forestry-Road Association of Hyogo (1998)
is one of the most useful books I ever read.
It explains the change of vegetation in the Mt Rokko Range
Before the paddy cultivation begins at the outskirts,
Mt Rokko had been covered by the primitive forest.
There were the forest of beech (Fagus crenata) and oak (Quercus crispula)
in the vicinity of mountaintop,
the mixed needleleaf-broadleaf forest
(main species are Abies firma, Sciadopitys verticillata,
Fagus japonica and Quercus serrata)
in the zone at 600-800m above sea level,
the laurel forest (main species are Quercus acuta,
Quercus salicina and the genus Castanopsis)
at lower altitudes.
<From 5-6 thousand years ago to 1300-2300 years ago>
After the settlement has spread in the flat ground,
the laurel forest had cut
and changed into the red pine (Pinus densiflora)
or the Quercus serrata forest,
which were utilized and conservated for the fuel production.
<Before the 14th century>
In the middle ages, however,
the forest area became the stage of the battle,
and was dedtructively destroyed,
then turned into the red pine secondary forest.
<From the 14th century to the 16th century>
In the Edo period and the Meiji period,
mainly because farmers used forest land
to get fuel and fertilizer,
especially in south part of the Rokko range
it had become the bald mountain.
<From the 17th century to the 19th century>
Afforestation project began in 1985.
