RISS 검색 - 국내학술지논문 상세보기

부가정보

다국어 초록 (Multilingual Abstract)

The direction of scientific researches on tree improvement and forest management in several universities and research institutes in Japan can be summarized as follows:
They put a great emphasis on sugi, Cryptomeria japonica and cypress, Chamaecyparus obtusa which are two major conifer species largerly planted in the Japanese forestry.
In the research of sugi, a great concern has been made in evaluating inheritance of forest tree, quantitative characters and genetic parameter of growth, and in breeding for resistance to diseases and insects and to all the natural calamities.
Interaction between environmental conditions and genetic nature of tree can be
concerned factors in relation with forest damage, together with silvicultural conditions and pest infestation.
Selfing hybrids of F₁made from crossing twisted-leaf sugi, defomity leaf type and midori sugi, normal leaf type segregated the normal needle, twisted needle, green leaf and albino leaf type.
It seemed that separation of many defomity individuals can be governed by two
dominant complementary genes and from the near loci of which it was detected lethal genes.
52% of Japanese forestry is occupied by the small forest landowners like Korean
forestry.
This made difficulty for forest improvement such as progressive afforestation and for capital accmulation form forestry.
The Forest Corporation was established at first in 1959 to aming at productive forestry structure and forest management, and afforestation. For these purpose, 35 Forest Corporations are at moment operating throughout Japan.
However, investment in forestry business becomes less attractive since the wage in forest production duction increased in higher trend than timber price. Therefore, an artifical afforestation becomes yearly decreased.
At present, the self-sufficient rate of timber production in Japan is about 35%, and so a great effort is being made to increases self-sufficient rate of timber production.