Comparing Study On Intraspecific Type(Red Wood) And Form (White Wood) Of Larix Gmelinii (Rupr.) Rupr.

Larix gmelinii(Rupr.)Rupr.is a main species in Daxing'anling forest region. It is also a kind of growth-fast species of regeneration planting in Northeast of China. There are many types of variants because of its wide adaptability, among which Dahurian Larch of White wood and Red wood are meaningful types. The color of the former timber is a common one which is between the brown to yellow-brown, while the later one is light yellow which is hard seen in nature. The distribution of the two types in the natural forest has been investigated and it shows that Dahurian Larch of White wood mainly distributes in herb-Larix forest, and which is about 10 percent in the natural Dahurian Larch forest.Larix gmelinii(Rupr.)Rupr. has been studied by both Chinese and foreign experts. They paid more attentions to the classification in the world, but no report on these two types. So deep and systematical study about the two types that grow naturally in Daxing'anling forestry region is necessary. This scientific and systematical study was done by the way of combining on-the-spot investigation with model experiment, combining biology with timber, and combining scientific approach with productive practice, which shows the differences and genetic diversify of two types of properties in morphology, timber physical mechanics, anatomy, ecology and biology. Dahurian Larch of White wood is confirmed a growth-fast and good quality type.The method of molecular biology has been used to analyze the intraspecific variation and evolution mechanism of Larix gmelinii(Rupr.)Rupr. at population level. The results show that this species has high genetic diversity, and the diversity reduces frdm North to East. It can be used to estimate that this species spread from north to east in our country, and genetic distance of this species correlated with geographic distance. Dahurian Larch of red wood mainly decides the genetic diversity of Dahurian Larch. It has higher heterozygote and hybrid, and it can adapt to bad environment with higher genetic diversity to develop and utilize new ecosystem condition. As a modulus of this species, Dahurian Larch of white wood is a specific type for its abilities of accommodation. Based on these, evolution mechanism of Dahurian Larch of white wood is given.Seed properties of the two types of Dahurian Larch with different wood color have been studied by the way of seed biology. The results show that Dahurian Larch of white wood has lighter weight, longer wing and stronger ability of diffuse compared with Dahurian Larch of red wood, which well fits ecosystem. The study of physiology of seed budding and seed mass analysis of dissection proves that seed properties of Dahurian Larch of white wood are significantly better than Dahurian Larch of red wood.To study the main morphological differences between two types using an approach that combines logging with the morphological comparing, we can provide scientific basis for distinguishing the two types and for sample collecting and forest management, and put forwardproper proposal to develop Dahurian Larch of white wood. It can be .concluded that these results will also provide scientific principle and more effective technology support for Natural Forest Protection Project in Northeast of China.