In accordance with the characteristics of species diversity and the complicacy of tree species composition in evergreen broad - leaved forests, a ten - years' study on the evolving pattern of tree species composition, number and volume proportion in stands and their interrelation was carried on by means of the division and mergence of tree species growth types of main forest types. The results indicate that (1) the tree species composition in stands can be divided into three kinds, i. e. main fast growing species, main slow growing species and secondary (associated) species; (2) The number proportion (N%) and age (A) of main fast growing species assume linear ralation, N% and A of main slow growing species assume hyperbolical relation and this relation is mutually close; N% and A of decondary species assume quadratic parabolical relation and that is mutually close, too. (3) For the three kinds of tree species, the evolving pattern of the volume proportion (V%) is similar to that of N% with the increase of A, but for the main fast growing species the pattern of V% is larger than that of N% and for the rest two kinds the pattern of V% is smaller than that of N%; and (4) there is linear ralation between V% and N% for the three kinds of tree species, the productivity of the main fast growing species is higher than the others.

Proceeding from the most important spatial layers in forest-hydrology ecological function, i. e. forest canopy, forest litter and forest soil, the potential impacts of climate change on geographical patterns of forest rainfall interception were simulated by means of GIS. The future climatic change scenario of China in 2030 was projected according to the seven GCMs. The canopy rainfall interception model and integrated rainfall interception model of forest ecosystems were established to predict the likely changes in forest rainfall interception in response to future climate change by using the IDRISI - GIS.

The experimental stands of geographical provenance of Pinus tabulaeformis in Benxi and Liaoyang, Liaoning province, are in the areas where Matsu coccus matsumurae kuwana has occured. The study on the difference in resistance to Matsucoccus matsumurae kuwana is one part of the Pinus tabulaeformis provenance experiments. The amount of the Matsuscoccus matsumurae Kuwana nymphae occured in the 8 - year - old stands have been observed. The injury grade of trees have been classified one by one according to fourclass standard in the 10 - year - old stands. The results show that there is a significant difference in resistance to Matsucoccus matsumurae Kuwana between provenances. The 8 fine provenances arc selected based on the integrative evaluation of their adaptability, growth increment and resistance to Matsucoccus matsumurae, which are from Zunhua Huangling, Ningcheng, Chengde, Taishan, Qianxi, Huanglong, and Suizhong. The average rate of resistant tree is over 93% (86%- 100%). which is higher 1 8 percent than that of ordinary Pinus tabulaeformis stand Among ecotypes, the west - middle and east type are the best the orders are as follows: west - middle > east > northeast > middle > southwest > south > northwest the 3 latter ecotypes are unusable.

Based on the Markov theory, we simulate the density changing process of Larix olgensis industrial plantation, and the rational density and relative tending measure were proposed. It is shown that Markov theory can indeed reflect the diameter transfer process of Larix olgensis industrial plantation. It would be beneficial to analyze the diameter distribution dynamic principle of Larix olgensis industrial plantation quantitatively, so as to determine the suitable density controlling measure. For the density controlling intermediate cutting of Larix olgensis industrial plantation, we should cut the small diameter trees as the dominant not only considering from the point of cultivation forest but also from obtaining wood and increasing forest benefit, It is best to manage a 20-25-year-old Larix olgensis industrial plantation with 0.7 management density.

Fifty-eight isolates representing three Cronartium species, the pine-stem rust fungi, collected from diverse pine hosts and geographic origins in China were evaluated for their interspecific and intraspecific variation by isozyme analysis. Eight of the 13 examined enzymes produced visible banding patterns. Among them the esterase (EST) patterns provided the best differentiation, distinctly seperating C. ribicola, C.flaccidum and C.quercuum from one another. No isozymic variants were detected in the 16 C. ribicola isolates from different locations in northeastern China, demonstrating that the genetic variation in the population of this rust fungus in this area is small. Although some variants were found in the 17 C.quercuum isolates from mongolian pine in northeastern China, the isozyme patterns of the majority of the isolates, however, were uniform with those of the isolates from Masson's pine in eastern and central China, indicating the validity of considering.C.flaccidum occurring in China as a complex species. Nineteen C.quercuum isolates collected from diverse hosts and loca-tions in northeastern, eastern and central China, except some of those from mongolian pine, also provided uniform isozyme patterns and did not show the isozymic variability as big as that previously reported in northern American C. quercuum Population, possibly implicating the occurrence of C.quercuum in China is a more recent event than that in northern America.

In this paper, the simulated burning and quantitative analysts of the combustibilityof mixed forest of Schima and conifer were studied. The results show that the apreadof ground fire and canopy fire can be separated effectively by forest belt of fireprevention; through rational planning and distribution, the forest fire spread can becontrolled and large area forest burning can be prevented form the macroscopic Pointof view. In mixed stand, Schima become intermission type of restricted forest fireprevention network system and the combustibility of mixed stand of Schima and conifer is decreased to control forest burning.

The differences in wood density, MOR, MOE and crushing strength, the radial variation pattems of wood density and the relationships between mechanical properties and wood density among different heights and four cardinal sides within 15 Chinese-fir trees from Zhejiang province were determined and analysed.There were significant differences in MOR and MOE but no significant ones in wood density and crushing strength among different heights.The mechanical properties and wood density in northern and southem sides were higher than thos in eastem and western sides, however, the differences were insignificant.The density profiles at different heights and in different cardinal sides were horizontal straight lines with fluctuation within 0.1 g/cm³.There were significant correlations between mechanical properties and wood density at different heights and different cardinal sides.The correlation coefficients were greater in southem and eastern sides than in northern and western sides with larger variation in the correlations of MOR and MOE to wood density.

Fiber morphology, tissue measurements, cellulose content and basic density of bamboo wood of Phyllostachys heterocycla. var. pubescens were determined. The variations in the bamboo wood properties related to age, diameter at breast height (DBH), positions in culm from inner to outer and base to top, internode from lower to upper and node. The fiber length, was determined mainly by posidons in culm and internode, and not by age and DBH. The tissue measurements related to DBH, not to age, but cellulose contents and bisic densities all related to age, DBH and positions in culm. Judging from the variation in bamboo wood properties, small culm was superior to big culm in management when the bamboo wood used as a material of paper waking.

Wood chips of Ⅰ-72 Poplar were treated with a high pressure steam and pressed into particleboard respectably through the conversion of chemical components.The results are as follows:1.In the intense steam explosion conditions, the cellulose of the chips was degraded remarkably and the explosion yield was lower, and the content of lignin and hot-water extract increased at first and then decreased with a steam pressure increased while the content of free sugar increased; 2.By scanning electronic microscopy fibers of the explosion woods were observed to be roughed and broken; 3. The crystallinity Was found to be increased by steam explosion; 4.Through steam explosion the wood chips could be pressed into particleboard with good water—proof.

The effects of mixed rare - earth elements of La and Ce on some physiological characteristics of Robinia pseudoaeacio one - year's seedlings (tree seedling, cuttings, root - cuttings) were studied. The results show that spraying the rare - earth elements solution in 700mg/kg on the leaves of R. pseudoaeacio, the net photosynthetic rate was increased by 33.8%- 40.3%, the content of chlorophyll was increased by 22.3%-33.1%, the water applying efficiency would be increased by 10.2%-14.0%. The total nitrogen, phosphate. And potassium content of the leaves can be increased respectively by 31.7%-46.1%, 22.0%-32.7% and 42.9%- 55.6%.

Transgenosis plants of P.×euramericana Robust were analyzed by PCR technology and molecular hybridization of PCR products.The results are satisfying.It is feasible that trangenosis plants were determined on the.Basis of the electrophoretic patterns of PCR products.