Incompatible barriers were studied under artificial pollination with light microscopy, epifluorescence microscopy and scanning electron microscopy in intersectional crosses of Populus euphratica Oliv. And P. simonii Carr. The results are as follows.1. Populus euphratica Oliv.×P. simonii Carr.A considerable amount of pollen grains of Populus simonii Carr. May germinate rapidly on the stigma of P. euphratica Oliv. And penetrate into the stigmatic tissue easily. Pollen tubes of those appear in twisting, coiling, creeping and bursting fashions are in rare cases. Some of the tubes can grow normally through the style and enter into the ovarian cavity, while others cease its growth due to the deposition of the pollen tips. The megasporogenesis stagnate for 6—7 days as the pollen tubes come around the ovules. Having degenerated before the maturation of the embryo sac, the pollen tubes lost its viability to enter into the embryo sac. Thus no fertilization proceeds.2. Populus simonii Carr.×P. euphratica Oliv.The pollen grains of P. euphratica Oliv. May germinatc on the stigma of P. simonii Carr. Only a few pollen tubes penetrate a straight path to the stigma. While a lot of pollen tubes appear to have a twisting, coiling, bulging and creeping fashions. Some of them are inhibited from further growth and some do penetrate into the stigma surface finally. Callose deposits occur in the stigmatic pailla. However, pollen tubes that penetrate through the stigma may grow normally into the style and then enter the ovary cavity with two well-developed sperms. Fertilization takes place 4—7 days after pollination. A considerable amount of embryos abort at various developmental stages, especially at the proembryo stage. A small quantity of them may develop to its full size and run to mature seeds.

With the methods of principal component analysis and discriminant analysis, the genetic variations in Pinus tabularformis Carr. were studied. The result showed that the geographical variations in the species were in the character of ecotypical variations and seven ecotypes were divided. Our research can be directly used as a basis for seed zone classification in Pinus tabulaeformis Carr.。

The General Stand-Age Transition Equations (GSATE) are set up in this paper. GSATE is a dynamical model of a forest in a large area. This model can deal with clear cutting, selection cutting, tending, planting and regeneration, and predict the consequence of the operations above mentioned. The prognosis programs have been made out, that associate with the timber resource of our country.The model GSATE is able to use for the prognosis of forests in another scales.

The toxic substances are isolated and partially purified from culture filtrate of Colletotrichum gloeosporioides. The toxic preparation induces tomato seedling to wilt and stoped growth of Olive Callus following necrosis. Olive protoplasts are obtained from callus and exposured in toxin and subsequently examined survival of protoplast in optical microscope. The sensitivity of callus and protoplast to toxin is different in resistant and susceptible var. and the survival of protoplast from resistant var. "Frandoio" is more two-fold than the protoplast from susceptible var. "Zhongsan 24" during 48hr. At 100mg/ml toxin concentration.

Field test on the control of pine caterpillars (Dendrolimus tabulaeformis & D. spectabilis) with Diflubenzuron were conducted on Western Hill, Beijing and Hopei province in 1982—1984. The insecticides were applied 1. with LV and ULV spraying, the dosages used were 1, 1.5, 2.0, 3.0g. Per mu, and 2. with traditional spraying, the dosages used were 10,20, and 50ppm. More than 70% control was achieved with both methods. Even with 4th and 5th instar larvae, control of more than 70% can still be achieved at the dosage of 2g/mu. The larvae died slowly, but the amount of food taken was reduced. The body weight and the size of the larvae were also reduced. At the dosage of 2g/mu, the residual effect can last for more than 20 days.

The Whole-tree wood properties of Pinus massoniana Lamb., such as fiber form, fibril angles of the Sz layer of tracheids secondary wall, the relative crystallinity of the cellulose, chemical composition, density, shrinkage、hardness of air-dried wood, Width of growth rings, late wood percentage, and water absorbability were studied. The characteristics of paper sheets made from the wood were investigated also.In the different parts of tree the rootwood have the longest fiber (E:4269μm, L:4297μm), next are those in total bole-wood (3357μm, 3564μm) and unmerchantable top-wood (2675μm, 3224μm),and the shortest ones (2575μm, 2700μm) are in branch-wood.The paper sheets made from the pulp of total bole-wood and root-wood have better strength than that of unmerchantable topwood and branch-wood. The best tear strength was found in the paper sheets made from pulp of root-wood. It proves that with suitable technology the whole-tree wood of Pinus massoniana for making bag paper is quite feasible.

The rubber wood, Hevea brasiliensis (HBK) Muel is the most nondurable in Hainan Island. It is quickly damaged by decay fungi and termites as contacting with ground. The freshly felled wood which contains high moisture (60—80%) and some solventable sugars (around 5%) is subject to sapstain and damaged ambrosia beetles sometime. The dry wood is always damaged by many species of powder post beetles and dry wood termites. In warm moist atmosphere the mold is able to develop not only on surface of damp wood but also on dry wood. The results of the test indicate that: (1) The BBP Preservative (borax 35%, boric acid 30%, Na-PCP 35%) applied to build construction and furniture timber is the most effective in preventing decay fungi, mold, drywood termites and powder post beetles. The concertration of treating solution is more or less 55%. The preservative retention in treated wood should have 6—8kg/m^{3. (2) The BBP Preservative is safe to men, animale and environment but exist some irritation. (3) The hot-and-cold treatment which is being popularized at the state enterprises in Hainan Island is not only effective but also simple and easy to handle.}

Intensity of the moving arm of the loader is directly related to service life of an entire machine. This paper deals with the way of intensity analysis of the box-like moving arm by using the finite element, photoelastic experiments and measuring the whole machine. The above three obtained results correspond with each other. Simplifying the spacesymmetrical structure of the moving arm into a plane for analysis is reasonable. This research result has been used in designing a new type of moving arm.

Considering the present situation of the Particleboard Industry in China, the author gives a brief review on the particleboard properties with appropriated introduction of some foreign research results and experiences. This paper deals with board density, raw materials, particle geometry and resin properties, which are often considered as the basic factors for the designs of equipment and supervision in particleboard process.

Gibberellin had prominent promoting effects on breaking dormancy of seeds of Fraxinus mandshurica stratified under the condition of warmcold temperature, i.e. warm temperature followed by cold temperature, and cold temperature. One of the reasons was that gibberellin could accelerate rate of development of the embryos of the seeds, especially those which were stratified under the cold condition. Through treating the seeds with GA in the concentration of 100mg per litre or more, It was found that the rate of development of embryos of the seeds stratified at cold temperature could exceed that of seeds stratified at warm temperature. Therefore, GA treatment could substitution for warm temperature conditions of the stratification. GA had no effect on the promoting germination of the seeds stratified under the regime of warm temperature. This indicated that GA treatments could not completely substitute for the cold temperature required by seeds. In addition, the experiment showed that it was more effective to treat seeds with GA than fruits, and the quantity of GA used was much reduced. The gibberellin could be used to treat seeds stratified under the warm-cold and the cold temperature conditions for shortening the dormancy period and promoting the germination of seeds of Fraxinus mandshurica.

In this paper, the effect of protecting water source of forest is analyzed by using "large basin comparision method." The research area belongs to semi-arid stony mountain areas which located in the midtemperate zone. The two large basins are West River Basin and East River Basin which are fourth stream order in headwaters of Yong-Ding River. The influence and controlling function of forest on streamflow are analyzed on the basin of comparability investigation. In accordance with above analysis, it can be concluded that:1. Under the influence of forests, the runoff of low water increased by 80% and flood peaks decreased by 80%, thus uniformity of streamflow within a year increased by 40%. Furthermore forest can increase total annual rainfall.2. Because forest can improve soil and increase non-capillary porosity in soil, controlling capacity increased by 24.1% and infiltration capacity increased by 48% for the rain in soil layer (within 1 meter) in the basin.

In this paper we use ARIMA time series model in growing forecast. The test for a large number of practical data shows that using ARIMA models to forecast growth is an efficient method.

Pericyma cruegri (Butler) is an important defoliator of Peltophorum tonknense. It has 7 to 8 generations per year in Hainan Island. The adult likes to lay it's eggs on the forest floor of high terrain, forest fringe and the upper place or crown of the tree. It overwinters as pupa The larva las six instars. It's is likely that the pest would come in the rainy season, if the rain fall is less than the ordinary level in dry season. For chemical control, spraying the forest stock with 5ppm permethrin or 70% Carbaryl emulsion and 90% crystal Trichlorphon diluted with 2000—3000 times of water was found to be effective. To cultivate mixed forest and to lead Pericyma cruegri with lamp. Are recommended for the control of the pest.

The Brahmophthlma wallichii (Gray) is one of the most important pests of the Olea europaea L. It has one generation per year in Nanping district, Fujian province. Overwinter as the pupae in the soil about 5cm, the adult begin to appear in the middle of February the next year. The eggs are laid individually on the upside of leaves and hatch after 23—29 days. In general, there are five larval instars, and larval development lasts 30—35 days. Adult life-Span is about 11—30 days.The laboratory studies show that it is very effective to spray with Dichlorvos, Fenitrothion, Dipterex et alii in the control of 2nd-3rd instar larvae.