Transmission of variation potential (VP) in willow (Salix babylonica) plantlet can be evoked by treating the root with 500 mmol /L NaCl solution, or by a local burn on the stem. VP transmission can still occur, if the rind is removed by ringing. but transmission fails if a portion of the central woody core(xylem) is removed furthermore, its transmission rate varies with the extent of water supply. The normal rate is kept in adequate water supply. and would slow down or come into standstill as water shortage is getting severe. The results seem to indicate that in the present case, Ricca′s factor released at the NaCl- treated root (serving as the chemical signal) can be carried along through xylem by transpiration stream. VP appears at the rind on its arrival.

A mathematical model of soil water infiltratoin was built according to the Decy's law and energy conservation energy principle. For establishing this model, soil moisture parameters were measured in the laboratory. Process of soil water infiltration in different woodlands was simulated. The paper showed that computer simulation is consistent with the experim ental results for accumulative infiltration volume and infiltration rate. Infiltration profile maps drawed through simulation results objectively showed the whole process of infiltration.

Net photosynthesis in assimilative shoot of C.arborescens Litv. rised gradually following with the increase on light intensity and light saturation point was higher. Net and ture photosynthesis and light saturation point were higher in summer than autumn. The results showed that C.arborescens Litv. is a sun ecotype plant and its assimilative shoot started decline in September.Net photosynthesis was significently decreased following with the gradual rising of temperature under saturation light, On the contrary, respiration tised, but changes of ture photosynthesis where little in those two seasons. These indicated that the decline of net photosynthesis was induced by the rising of respiration.there were many effects of drought on photosynthesis in a ssimilrtive shoot of C.arborescens Lity. Water potential declied gradually with the increase of treatment time. The change inclination of net photosynthesis, ture photosynthesis, respiration, photorespiration, light saturation point, light compensation point and chlorophyll content were similar to that of water pocential. Contrarily, Co₂ compensstion point was significently rised at saturation light, but, net photosynthesis can keep 58. 5% yet after 12 days.The plant was treated by the combination of drought and temperature. The change tendency of all aspects were similar to the effects of drought. though, the degree of damage was greater, however, the ture photosynthesis is yet. kept 41. 5%. It showed that except morphological constitution, physiological founction of the desert plant has wider adaptability to strong light, hight temperature and drought of environment.

Plots of field experiment have been established in light, medium, and heavy saline-alkaline soil, as well as soda salinized soil on Bohai bay coast land during 1989-1994. Tamarix chinensis trees had been planted as a pioneer tree species in heavy saline soil to protect dams from tide for 5 years. The content of soil salt in the dam of Dawa county, Panjing city declined from 1% to 0.4%. Elaeagnus angustifolia can be planted as pioneer tree species to resist alkaline and flood in Linghai city where the soil is solontz (pH is about 10). In the medium saline-alkaline soil, the tree height of Populus popularis and Salix No. 109 mixed with Amorpha fruticosa increased 3% and 10% respectively, D B H increased 12% and 25% respectively, comparing with those in a pure stand. In the light saline alkaline soil, Populus popularis, Fraxinus velutina, Salix No. 109, and Robinia pseudoacia can be planted so as to establish a fast-growing and high-yield plantation.

Based on the theory of Select Control Chart, a select control system was established using the stem analysis of 214 trees, by which quality control can be conducted in stand management of Cunninghamia lanceolata planta tions at any ages, on different sites and densities. The results showed that the system established in this paper can conduct quality control for plantation management measures accurately and sensitively. Therefore, it provided a new and effective method for examining and evaluating the quality of managementm easure of a stand scientificly and directly.

The system yield table can be adapted to various stand structures and forest treatments. At first, growth models at either tree level or stand level were established using the growth data of the permanent sample plots. Next, based on the growth models, a system yield table for Larix kaempferi stand was worked out and the procedure of constructing the system yield table was generalized. The distinguishing feature of this study is that the object of this study is the present stand so as to establish a growth model for the whole stand and for stand diameter groups. Total growth increment from the former can distribute to diameter groups and tree height groups by the latter to ensure the predicting results at stand level to be compatible with the growth of a single tree.

The study aws carried out under noncontrolling conditions in FenyiCountry, Jiangxi Province(27°52′N, 114°45′E, about 100m altitude).During the growing season in 1994, Pt inoculated and noninoculated seedlings were fertilized with the 4 different relative addition rates.I.e.0%, 5.3%, 6.4%, 7.5%, according to the theory of the steady state mineral nutrition.The results showed that there was a atatistic significant difference between inoculated and noninoculated seedlings in height growth, radial growth, and dry matter accumulation in the 7.5% treatment.The maximum values were found for inoculated seedlings in 7.5% treatment, which were 26.4%, 52.5%, 140.2% respectively higher than its control (0% ).While these were only 21%, 16.7%, 54.1% for noninoculated seedlings in 6.4% treatment, which were inhibited in the 7.5% treatment.The seedlings inoculated with Pt in 7.5% treatment had formed Pt ectomycorrhizae amounting to 97%, Pt index up to 95.1, At the same time, the length of tqp root, the total length of first-class lateral roots, as well as N、P concentration and their contents in the needles of the seedlings in this treatment were higher than those in other treatments, N use efficiency of the inoculated seedling in 7.5% treatment was 2.7 fold higher than that of the noninoculated seedlings in the same nutrient treatment, indicating that the 7.5% telative addition rate of mineral nutrients was suitable for ectomycorrhizae formation of container-grown slash pine seedling under this experimental conditions, which promoted the absorption and utilization of the mineral elements.The amount of fertilizer per seedling was about 39.27mg N, 19.64mg K, and 707mg, P, N:K: P=1:0.5:0.18.

Anthrone colorimetry is applied to detect the suger content from the trunk base of Chinese pine under the various intensity of leaf-fall.The result shows that Chinese pine has the ability of compensation and super compensation to the defoliation of artificial simulantion and natural endangerment resulted from pine caterpillar.With more needle loss of 2-3yrs old leaves, the normal growth of annual needles relies on the stored nutritional from the trunk base of Chinese pine.Even if there are in tensive losses of 2-3yrs old leaves for 3years, the chinese pine doesn't come to die and keeps natural growth.

A oecophorid pest boring into cone and seed of the China Fir[(Cunninghama lanceolata (Lamb.)Hook] has recently been found in the southern part of China.As a result of examination, we have concluded that this insect represents a new species of Macrobathra.We give the specific name Macrobathra flavidus Qian et Liu, sp.n.This species resembles Macrobathra quercea Moriuti, 1973, but it distinctly differs from the latter in the male and female genitalia.

Leaves and stem segments of P.×euramricana transformaed with A.Tumefaciens hauboring binary vectors pB48.214 and pB48.215 containing chimeric genes of 35S-Bt-Nos with different lengths of B.t gene respectively.Three plants selected by southern blot analysis showed IPC toxicity against larvae of Lymantria dispar.Based on the results of PCR analysis, southern blot of PCR products and genomic DNA as well as insect bioassay, three transformed plants were confirmed to be insect-resistant transgenic plants of P.×euramericana

The radial variation patterns of wood density in 17 Populus×euramericana clones were studied by x-ray wood densitometry.The main results obtained are:1)The general trends of the density profiles of the trees were similar, while there existed a certain degree of variations among clones and even within a clone.Therefore, the indefiniteness in describing the variation patterns is inevitable. 2)There existed significant differences in the average ring densities at various ages.3)The interclonal age-age coorelations of the average ring density were significant, indicating the feasibility of the early selection among clones.4)The correlations between average ring density and maximum and minimum densities in the variation affected by ages differed from those affected by clones.Significant negative correlations between ring density and ring width were shown in the variation affected by clones.

In this paper the genetic correlation analysis on wood properties of new clones of Populus deltoides×P.Simonii was studied.The results showed that ring width was closely related to both earlywood width and latewood width genetically, but hardly related to latewood percentage.Ring density was closdly interrelated to the other wood traits genetically(r= 0.84—0.95), including earlywood density, latewood density, the minimum wood density and the maximum wood density, but weakly related tO both early—late wood density rate and the gradient of wood density.Moreover, the genetic relationship between ring width and ring density was negatie and very weak.

Water—unsoakes and Water—soaked dry—procesed binderless hsrdboards sre observed by scanning electron microsope to acquire informations on the binderless hardboardinternal structure.This may be helpful in a beter understanding of strength and water proof properties of the binderless hardboard.In nanufacturing hardboard, he wood fibers break apart at the middle lamella and come in contact again when subjected to pressure during hot—pressing. The physical and mechanical properties of the haraboaed areconditioned bg coming in conact extent again of wood fibers.Electron microscopical observations on the inderless hard-boards show that the wood fibers are omtercrossed and bonded xlosely.Even if watersoaked, he bond of the wood fibers does not appera a loose siuation.The result of the electron microscopy study shows the dry-procesed hardboard winthout any adhesive Subtances can possess superior strength and waterproof properties.