The amounts of used water by single dominant trees of Pinus tabulaeformis and of Robinia pseudoacacia,by using as the basis for evaluating the productivity power of available water of forest land,were measured by using ‘the measuring method of single-tree water-cycle balance’.The base amount of the available water of a forest land for stand normal growth and the productivity power index of runoff were set.The runoff coefficient is thought as a decisive factor to affect runoff productivity power.The productivity power of forest land was counted in the Loess Plateau.The results show that the minimums of annual precipitation for stand normal growth of the two species are all 500mm by collecting the runoff on nature slope.There will be only a stand with 0.3 crown densities in the area where the annual precipitation is 400 mm.

To explore distribution characteristics of root area of the evergreen shrub,Sabina vulgaris growing in the contrasting habitats in semi-arid Mu Us sandland,the methods of root excavation and asymptotic equation y=1-β^d(β=depth coefficient, d=soil depth(cm), y=fraction of root area from soil surface to depth d)were used in this paper.The results showed as follows:(1)Root area index(RAI=root area/soil surface area,m²/m2)decreased with decreased soil water availability,which benefits to alleviate below-ground competition of the plants for water and to make better economical use of the limited water resource in the long run.(2)The values of β (depth coefficient)、R_max(maximum depth of root system)、R₅₀(depth of root system including 50% total root area)、R₉₀(depth of root system including 90% total root area)increased with decreasing soil water availability,which means that depth of root system of S.vulgaris has compensation effect for decreasing water content of soil through deepening its depth.(3)Distribution characteristics of root area might record the change of water regime in the habitats,could provide some evidence on community succession to some extent as well.

Research into and apply of the overland flow model have been one of the major themes in hydrology due to the basic unit on which physically based distributed parameter hydrological model development is based. Runoff coefficient calculation of the overland, however, is the critical step in doing so. On the other hand, it is necessary to determine the coefficient for evaluating the forest plantation impacts on the surface runoff. Dynamical overland flow model under artificial rainfall simulations was developed for forested infiltrating slope based on the surface runoff generation and hydrological traits. Soil water movement was simplified as one dimensional vertical flow while overland flow kinematic wave model. Single step Lax Wendroff difference scheme and iterative calculation method were adopted to simulate the overland flow and estimate the surface coefficient. Parameter optimisation results have shown that the overland flow resistance(effective surface roughness)of Black locust(Robinia pseudoacacia L.)plantation plots are between 0.1931～0.2131, Mongolian oak(Quercus monogolica) plot 0.1701, and Chinese pine(Pinus tabulaeformis Carr.)plantation 0.1423. Optimised m values in the overland flow kinematic approximation q=αh^m are between 2.76～3.090 with are near m=3 representing sheet flow. The model and parameter verification results have shown that computed and measured rising limb and partial equilibrium hydrographs fitted very well.

It is well known that human's living depends on plant communities, so it is very important to inquire into methods for studying plant communities stability not only in the theory but also in the practice. Based on the results of modeling community succession and comparative analysis, we proposed a method and improved M.Godron's method for studying community stability in this paper. As a sample,Daqinggou forest plant community was used to test efficiency of the above two methods.The results achieved by the two methods were similar,which showed they were suitable to study community stability,and their results could be verified each other.The Godron's method could only provide information whether community was stable, the other method combined community succession model with comparative analysis could indicate whether community was stable and what the community succession orientation and tendency were. It was effective to study community stability and useful for us to understand dynamic process of communities.

By regular seedling growing monitoring and statistic analysis on height,diameter, shoot DW(abbariviation of dry weight),root DW, total DW and of shoot DW to root DW of container-grown seedlings in Toona sinensis A.Juss.Roem, Larix kaempferi sied,et iucc. Gordon, Platycladus orientalis L. Franco and Pinus tabulaeformis Carr. some growing media with productive significance were screened, and the growth laws of those four northern sub-tropical tree species which grown in containers in greenhouse were obtained. The results got from our study could provide some useful basis for production management of other containerized seedling stocks grown in greenhouse for those same tree species.

A trial lasted 18 years on 45 Chinese pine provenances collected from its whole distribution areas had been done twice in its whole and partial distribution areas. Results indicated that the growth and adaptation difference among provenances were significant, and provenance has some interaction with site. The height growth of provenance showed significantly positive correlation with age and crown diameter. Provenances tested could be divided into 3 types: high, mediate and low growth according to the principal component analysis of 17 variables. Average tree height, diameter at breast height(DBH) and stock volume genetic gain of 3 optimum provenances, Huanglin, Luonan, Nanzhao, which had remarkable effects of increase in production, were 6.5%, 10.2% and 26.4%, respectively. Provenances in Shanxi and Henan which had good adaptation and high growth could be considered as major seed collecting ranges for Gansu. Provenances distributed in marginal areas were not suitable to adoption because of their low growth.

The Ginkgo trees have a documented history of cultivation by the Chinese for close to a thousand-year. The China possesses more than 70% of Ginkgo resources in the world. For selecting leaf-used cultivators, the genetic parameters of main quantitative characters of Ginkgo leaves from fine seedling adult trees were studied in this paper. The analyses results showed that F values of thirty characters indexes were significantly different at the 0.05 or 0.01 level. Variability coefficient and repeatability(R) of characters were related to branch ages. ECV was higher than GCV on one-year-old branch, but conversely on two or three-year-old branches. Repeatabilities(R) of leaves characters on two or three-year-old branches were more than those on one-year-old branches. Rs of ten characters were more than 80%. The relative genetic advances (ΔG′) of leaves fresh wt./S.S. (on 2-year-old branch), leaves dry wt./S.S. (on 3-year-old branch), leaves area/S.S. and leaves fresh wt./m.L.S.(on two-year-old branch) were 91.6%, 80.1%, 80.0% and 75.1% respectively. The correlation anlyses showed that the genetic correlations of 34 pairs of leaves characters were significantly or more significantly different. The genetic correlations of 9 pairs of leaf characters were more than 0.80. The correlation heritabilities[h(x_i,y_j)= COV_G(xi,yj)/σ²P(x_i)·σ²P(y_j)] were more than 70% between area per leaf and leaf width, area per leaf and leaf fresh wt., fresh wt. Per leaf and dry wt., dry wt. per leaf and leaves dry wt./m.long shoot. There was a great variance among individual trees on leaves characters. The direct and indirect selection on characters indexes of Ginkgo leaves were studied in this paper.

The genomic DNA polymorph on 13 isolator of Melampsora larici－populina Kleb. from Shaanxi and Qinghai were analyzed using random amplified polymorphism DNA markers (RAPD). 81 RAPD bands were amplified with 13 decanucleotide random primers, 69 bands of them were polymorphic(85.2%).Similarity coefficient of isolates was 0.608～1.000 and difference among isolates was 0～33 1%. The tested 13 isolates of the group were divided into 4 clusters with the similarities and genetic distances among them. Two isolates from Huoditang C in Qingling were placed in one group(group I) and one isolate from Huoditang B in another group(group II). Six isolates from Xining, Huzhu in Qinghai and Taibeibaotailu, Tiantaishan, Houzhengzi(Hza) in Shaanxi were placed in the third group(group III). Last two isolates from Houzhengzi(Hza,HZb) were placed in the fourth group(group IV).However, the DNA polymorphic of isolations were not obviously related to the collecting places or hosts and pathogenicity.

The higher amount acid chemical composition in the pine wilt diseased wood caused by the pine wood nematode, Bursaphelenchus xylophilus resulted in a decline in pH-value compared with that of the healthy wood. Accordingly, the color reaction was useful for rapid quarantine detection by using a suitable pH-indicator to test the alcohol liquids extracted from the diseased and healthy wood crumb. Five pine species from Jiangsu, Anhui, Zhejiang and Guangdong Provinces were tested. The results showed that the quarantine detection accuracy by using pH-indicator No.1 was 95% for Pinus thunbergii, 89% for P.massoniana,100% for P.densiflora,92% for P.teada. The method was available for the rapid quarantine detection of the pine species, but not for that of P.elliottii from Jiangsu Province. The color reaction was visual, accurate, simple, practical and rapid. The process was finished in 15 min. for one sample. Several samples could be detected at the same time.

Sinna extrema(Walker) is the most important insect pest of Cyclocarya paliurus(Batal) Ilkinsk. In South China it infests leaves only. The paper deals with its bionomics and control measures conducted during 1994～1999 in Fujian Province. Laboratory rearing and field observation showed that this insect had six generations per year in Nanping city and SanMing city, Fujian Province. There are six larval instars, Overwintering takes place as pupa in cocoon at weeds and shrubbery and on the fallen leaves. The control methods of the pest are as follows: (1) Spraying with 50% Phoxim E.C 1000～1500× or 40% Isofenphos-methyl E.C 1000～1200× or Beauveria bassiana powder to eliminate mature larvae of the 1st and 6th generation before cocoonning. (2) Spraying with 80% Dichlorvos E.C 1000～1200×, to eliminate larvae of the 3rd～4th instar. (3) Dichlorvos used as smokes “741” was found to be effective against adults of the 6th generation.

The alcohol active extract from the plant Daphne genkwa is a strong antifeedant to Abraxas miranda, Pieris rapae. The experiments were carried out with P. rapae to find the mechanism affected by the active extract. The activities of various digest digest enzymes except trehalase, both in epithelium and lumen of mid-gut, were enhanced by the extract when they were compared to the control. The reason causing the enhancing activity of the digest enzyme may be that the extract stimulates the epithelium cells to secrete a super-amount of digest enzyme to degrade or combined the extract to coothe or wipe out the poison. So a great quantity of energy and amino acid are consumed. Another reason is probably a number of sulphur-contaming amino acids are depleted owing to secrete large amounts of trypsin and chymotryspin, resulting in imbalance of amino acids, and causing the anti-nutritional effects.

A new synthetic method to obtain resol-type phenol-urea-formaldehyde resins was developed by reacting phenol, urea and formaldehyde. The properties and structure of products were analyzed. The result showed that stability of the cocondensed resin was improved, and solidification rate of the phenolic resin was accelerated. The cocondensed resin appeared similar thermal properties with normal PF resins, different greatly with UF resin. The cocondensates were analyzed with carbon 13 nuclear magnetic resonance (¹³CNMR) spectroscopy, o-Ph-CH₂-NHCO-(δ=41.5) and p-Ph-CH₂-NHCO-(δ=44.8) were observed. Properties of MDF (medium density fibreboard) and waferboard bonded with PUF were similar with boards bonded with normal PF resins, superior to boards bonded with UF resins.

Commercial scale cottonwood veneer drying tests were conducted in continuous platen dryer with high-temperature heat-conducting oil as a heat-carrier and hot platen temperature was 192℃, platen preasure was 0.09 MPa (front section) to 0.18MPa(rear section). The research results showed that high temperature continuous platen drying with certain breathing cycle can dry the veneer from green [initial moisture content(MC) 149%] to final MC below 8% in 2 minutes. The dry veneer was basically flat and smooth with even final MC and no check. The thickness shrinkage of the veneer was average 5.3%, and the cross-grain shrinkage was 4.9%. The bonding strength was in 0 812MPa average,which slightly higher than that 0.779 Mpa of convection drying with net conveyer. The results showed that drying of veneer of cottonwood, grown in plantation with the method stated above, is feasible.

Poplar is one of the major fast growing afforestation species in China.Utilization of poplar wood plays an important role in the development of forestry and forest products industry in China.Wet heart wood,an abnormality occuring in tree growth,is a critical problem in poplar wood processing and utilization.Many studies have been made abroad on wet heart wood since early last century.This paper gives a brief introduction of the progress of the studies and some important viewpoints,involving the formation of wet heart wood,the becteria,moisture and gases in wet heart wood,the pH value,color,strength and permeability of wet heart wood and its behavior in processing such as drying,milling and wood based panel production.

The plant secondary metabolites contribute to the plant defenses bases, so the genetic result on the secondary metabolites of recent decades is summarized in the paper. As other traits, the variation of plant secondary metabolites is under genetic control too. In most case, the production of secondary compound is the result of the coordinated action of a multitude of enzymes along a pathway, so the phenotype of compounds show quantitative fashion and under multigenic or polygenic control. Because of the inevitable linkages between primary metabolism and secondary, there are limits on chemical variability. Certain kind of compound is effective to certain insect species even subspecies only, so the chemical insect resistance means specific resistance and is complicated. By recent advances in molecular genetics and biotechnology, the development of quantitative genetics and insect resistance breeding got new advance. As most of the phytochemical characters are inherited in quantitative fashion and regulated by polygenes, by using the quantitative trait loci (QTLs) technique, the progress about the phytochemical mediated insect resistance were made, the details are given by Illustrating with main crops.

Since it was found that Camptotheca acuminata Dencne contains camptothecin with anti-cancer mechanism,scientists have done a great of works on C.acuminata and camptothecin research.On C.acuminata the research focused on the tree's growth characteristic,the distribution and content of camptothecin in the different organs,some environmental factors' effect on the material's camptothecin content,the techniques of micropropagation,suspension culture and others.The results showed that it was an effective way to supply high camptothecin content material by harvesting young branch.At the same time,more attention has been paid on techniques for camptothecin extraction,molecular structure of camptothecin,the relationship between the structure and the effect of anti-cancer activity.Artificial synthesizing has been made great progress, but levo-camptothecin still has not been synthesized.Three generations of medicines based on camptothecin and its analogs have been developed,clinic trials also made great progress.All these aspects are reviewed in this paper.The authors also pointed out the future researching fields.

The biomass,productivity and the material cycle in the shrubby Chinese ash(Fraxinus chinensis)-crop intercropping system (ash+wheat+peanut)were studied in this paper.The results show that:In this system,the biomass was 30.9837～60.4399 t·hm^-2·a ^-1,the annual net productivity was 20.7482～25.1380 t·hm^-2·a ^-1,both of the two were far more than them in the monoculture crop system and artificial forest.The mathematical models were established to estimate the biomass of the shrubby chinese ash.The shrubby Chinese ash-crop intercropping system could improve the nutrient cycling rate.The average cycling rate of six nutrient elements was 20 percent higher than that of monoculture system.

There are four reproductive and regenerative countermeasures of the main woody species in MaoLan Karst Forest.(1)The seed has shorter life span.The ripe seeds germinate rapidly to form seedling when it has fallen into the soil. The seedlings grow slowly to wait till the gap emerges.The seedlings grow rapidly and join in the present population as soon as the gap emerges.(2)The seed has shorter life span.The ripe seeds germinate rapidly to form seedling when it has fallen into the soil.If there are gaps in the forest the seedling grow rapidly and join in the present population,the seedlings will die speedly.(3)The seed has shorter life span.If there are gaps in the forest,the ripe seeds germinate when it has fallen into the soil and grow rapidly to join in the present population,otherwise,the seeds will lose their germination ability.(4)The seed has longer life span.If there are gaps in the forest,the ripe seeds germinate when it has fallen into the soil and grow rapidly to join in the present population,otherwise, the seeds in the soil will wait till the gap emerges.The main woody species of MaoLan Karst Forest adopt one of the four countermeasures,or both at the same time.