Whth the development of landscape ecology and the progress of land surveys, ecological land classification has been expanded to a world scale.The basic principle of ecological land classification is that land is regarded as a landscape interactive either among various land attributes or among various land elements.Ecological land classification is characterized by the divison of space entities in territory.As descending in hierarchy of classification, land unites in territory are divided into smaller and smaller areas.Now, in the world, the ecological land classification system tends to be multi-hierarchical and unified.Based on the case study of Xiejiahe drainage in Pingshan County, Hebei Province, a classification system is proposed to include three grades, namely, land system, land association and land type, simultaneously, to put forward the definition, division standards and nomenclature principles for each grade.In the studied region, 8 land systems have been classified.

Seedlings of slash pine (Pinus elliottii Engelm.) grown in plastic film bags(15cm ×23cm) were treated with liquid fertilizer at 4 relatively different addition rates, i.e.0, 5.3 %, 6.4 %, and 7.5 %, following the theory and technique of steady state mineral nutrition.The results indicated that the basal diameter, stem length (seedling height), and dry matter production of the seedlings under the 6.4 % treatment increased by 14.9 %, 24.5 %, and 39.6 % in comparison with the seedlings under the 0 treatment, which were significantly different at 0.05 or 0.01 level.Through quantitative analyses of the available nutrient contents in the root media and the amounts of nutrient element accumulated in the seedlings of various treatments in the beginning and at the end of the experiment, it was show n that 6.4 % treatment was of the best effects with nutrient accumulations of N, P, K elements in seedlings increased by 79.4 %, 58.5 % and 41.9 % over the 0 treatment, and the increments of N, P, K, Ca, Mg nutrient element contained in this treatment system by 32.3 %, 56.9 %, 36.1 %, 92.2 % and 25.3 %, respectively in comparison with 0 treatment.A t the same time, the soil nutrient flux density of N, P, K increased by 23.7 %, 36.3 %, 30.7 % in comparison with 0 treatment, respectively, and the enzyme activities of urease, proteinase, hydrogen peroxidase, neutral phosphatase were 403 %, 45.5 %, 40%, 144.5 %higher than those at the beginning of the experiment.It is concluded that the comparatively suitable nutrient relative addition rate not only promotes seedling growth, but also induces soil enzyme activity and soil nutrient flux density, as well as nutrient use efficiency.The mechanism of steady state mineral nutrition to promote soil mineralization, and its advantage were discussed in this paper.

A study was carried out on the biomass, increment and energy of mang rove communities which were dominated by Avicernia marina, and located in Shenzhen Bay, southern Chian.The research results showed that retained biomass was 16, 583.88 g/m², for which aboveground and underground parts were accounted for 66.78 %and 33.22 %, respectively.Biomass increment of the communities in 1993 was 1, 149.8 g/m², which was mainly distributed among stem (323.96 g/m²), twig (238. 33 g/m²), and perennial branches (213.06 g/m²).Caloric values of different plant fractions varied in a range of 16.1 ~ 18.22 kJ/g, however, the caloric value of stem wood was ranked on the top and that of mid-root on the bottom.The existing energy for the communities was 291, 839 kJ/m² for which 68.51 %and 31.49 %were partitioned into the above-and underground parts, annual energy accumulation in the communities was 20, 213 kJ/m² in 1993.

With three elements design of universal quadratic rotation combination, the models are established about the effects of N, P and K fertilizer on the relative growth rate of culm output of Phyllostachys pubescens stand.By testing, the quadratic regression medel has better simulation effect than others.The analysis of the principal effect of fertilizer shows that N, P and K have different effects on the increase of the output of P.pubescens stand, and the action order is :N >K >P in this test.2-factor interaction analysis shows that there is a positive interaction between N and K to certain extent, but there is no significant interaction between N and P, as well P and K.By computer-simulating, the optimum fertilization combination is designed (within the confidence limits of 95 %), i.e.urea 325.5 ~ 413.5kg/hm², superphosphate 208.5 ~ 295.5kg/hm² and potassium chloride 198 ~ 267kg/hm².Finally, the consequent economic benefit is analyzed.

In order to forecast commercial biomass of the Masson pine pulpwood and determine optimum utilization time accurately, the commercial biomass forecast equations of various organs, above ground parts, various specifications of individual tree were established using the data of 12 sample plots and 108 sample trees on various sites, various planting densities, and at various stand ages.Growth yield model system was established using data of various trial stands and stem analysis.The forecast result of biomass and stand growth by the equations was consistent with the actual situation.According to the forecast equations of biomass and stand growth, commercial timber yield table of main stand factors, stand stem and various specifications had been compiled, which were at 6 planting densities and 14 ~ 20 site indexes.According to the demand of utilization unit, the management unit may regulate the planting density, management manner and optimum utilization time.Dynamic of biomass growth and structure of Masson pine pulp wood on various sites and various planting densities were analysed.

In this paper, a new genus and species of the pionini is reported, Type specimens are kept in the Institute of Zoology, Academia Sinica.Celata Wang gen.nov.This genus is similar to the genera Glyptorhaes Thomson and Rhorus Foerster, but can be separated from the former by :inner eye margins straight not convergent ventrad; the outer surface of minute smooth or with minute punctures; tarsal claws conspicuously pectinate and from the latter by :clypeus separated from face by a groove, its apical margin being weak arc, the upper tooth of mandible shorter than its lower tooth, ovipositor sheath about as long as apical depth of abdomen, and may be differed from both species by :propodeum without transcerse carinae and areace, nervulus opposite basal vein.Nervellus curvate at the lower part.Celata populus Wang, sp.nov.Lenghth of front wing :Female 3.5~ 4.0mm, male 3.0 ~ 3.5mm.The major characteristics as follows :Inner eye marjins straight, not convergent ventrad; the center of face clearly conex; Clypeus wider, about 3 times the length, its apical margin being weak arched, the outer surface of mandible smooth or with minute punctures, its upper tooth shorter than lower one, mesoscutum even, notaulus short and weak, scutellum convex; upper end of prepectal carina reaching to front edge of mesopleurum.Propodeum without transverse carinae and areae, the both sides of its apex with a short longitudina carina, between them having weak and arcuate sculptures.Forewing areolet present, nervulus opposite basal vein; hindwing nervellus curvate at very low part.Tarsal claws pectinate.The tergite 1 about 1.35 times as long as its apical width, glymma present, its median dorsal carinae absent and dorsolateral curina usually complete at the front before spiracle, tergite 2 with small and weak punctures; Ovipositor sheath about equal to the apical depth of gasterHolotype ♀, Shanghe County, Shandong Province, 6.V.1993;paratypes 10 ♀♀20 ♂♂, time and locatily as above.Host :Messa taianensis Xiao et Zhou.

The effect of urban air pollution on the populations of the scale insects, Eulecanium gigantea (Shinji) and E.kuwanai kanda in the planted street affo restation trees was studied in Taiy uan City from 1994 ~ 1995.The accumulative amounts of city air pollutants SO₂ and Pb in the bodies of the soft scales and their host plant Sophora japonica were determined by the methods of analy tical chemistry.The results showed as follows :1.The scale insect population density (SIP) is positively correlated with the number of cars (Aut.No) driving in a certain district.The correlation equation is Y (SIP) =-30.508 +0.0441X (Aut.No) and the co rrelation coefficient is r =0.895.The scale population density shows three undulatory levels, decreasing prog ressively from the city center to suburban districts.This regularity coincides with the gradient tendency of urban air pollution in the same area.2.The contents of sulphur and lead in the body of the scale insects and their host plant are much higher in the polluted districts than that in the relatively clear districts, and the highest values are up to 1.92 g/kg and 6.80 mg/kg respectively.The accumulative amounts of pollutants are positively correlated with the automobile number.3.Based on our study, it is sug gested that Eulecanium gigantea and E.kuwanai can absorb and tolerate pollutants and that is an important mark on their resistance to city pollution.Futhermore, other reasons which result in the increasing number of scale insect are also discussed from the point of view of biological chain "scale insect-host plant-natural enemy" in the paper.

The morphological characteristics of the spring migrant aphis(sexuparawinged), life cycle, winter host moss, natural distribution, product and quality levels of artificial culture of Kaburagia ovatirhustcola Xiang were reported in this paper for the first time.The reverse egg-shaped belly gall are produced on the leaves of Rhus potaninii maxim.

By systematic investigation on jujube pests and their natural enemies from 1994 to 1996, the jujube pests which include 5 order, 22 families, 41 species, and natural enemies which include 8 order, 25 families, 40 species were collected. Jujube insect community was divided into 5 stages, i.e. rest period, sprout leaves period, blossom and young fruit period, developing fruit period, and fruit ripe period. Community characteristics and dominant species in each stage were analysed by the method of principal components analysis. The characteristics of population change of insect pest-natural enemies in each stage was discussed.The result of investigation showed that the number of total and natural enemy species, beneficial/hamful species number ratio, diversity index and evenness of IPM orchard were 0.4, 1.5, 11.16, 1.12, 0.67times, respectively, more than those of GC orchard. Dominant degree index or GC orchard was 3.4 times more than that of IPM orchard. The IPM orchard was in favor of controlling insect pests and protecting and utilizing natural enemies and enhancing the ability of natural coordinaton, while in GC orchard, the food web was ignored by empirical pesticide treatments, causing the significant population decrease of natural enemies, resurgence of jujube primary insect pests, and going year by year up to jujube secondary insect pests, for example, scales and mites, which have become dominant species harming jujube tree.

The community dynamics and stability of insects in masson pine forests is discussed by analyzing the outbreak process of pine caterpillars (Dendrolimus punctatus). The community with high diversity, especially that during the endemic phase, tends to be more stable. Diversity of folivorus group plays an important role in the diversity and stability of the whole community. Predators mainly affect on sap sucking group, while parasitoids on defoliate group. Some insects neither phytophagous nor natural enemies can also play a role to certain degree. Diversity at the increase phase is the biggest, and if it is big enough, outbreaks of pine caterpillars can be suppressed, otherwise the outbreaks can occur. Increase of phytophagous diversity leads to more parallel connections and enhances the control feedback of the system. Complexity of parallel connection structure can turn to stability, whereas series connection can not.

In this paper it is reported that the result of early selection for increasing wood density was obtained based on the genetic variation and juvenile-mature correlative analysis in new poplar clones of Populus deltoides×P.simonii. The result showed that the stage from 5th to 6th tree age is better for early selection than other tree ages; at the 5~6th tree age, the genetic gains of early selection is about 8.72%~9.71% and the annual selective efficiency about 141.30%~152.17%. The best stage selected by early selective indexes formed with two or more traits at fifth tree age. The main properties formed indexes for increasing wood density include whole average wood density (ρ_c), annual ring density (ρ_r) and earlywood density (ρ_e). Selected by the best early selective index I=2.2791 (ρ_c) +1.1088 (ρ_r) +1.1589 (ρ_e)(i=2.06) at the tree age of 5, the genetic gain of wood density was about 0.1142g/cm³ and 151.65% higher than the result selected by only direct whole average wood density at mature age of 10.

Based on the relationship between wood properties and its merchantable classification and according to the Chinese GB(National Standard), the WCGS(Wood Classifying and Grading System) was extablished with the description of "Prolog", an AI language.The WCGS not only can classify and grade the wood, index the properties of the wood, but also provide the volume, the price and the value of the log or the sawntimber according to user's required period and required grade, which is very useful for scientific and reasonable management.

This paper reviewed the theory of forest cycle, the concepts of natural disturbance, characteristics of forest gaps and the spatial/temporal patterns of gap disturbance. Disturbane is a driving force of forest growth cycle, and gap phase, caused by disturbance, is the initiating point of the cycle. The following are very important parameters in the studies of gap characteristics: gap size, gap age, manners of formation and gap makers. Although gap disturbance regimes are different in different forest communities, the average annual disturbance frequency is about 1% in most forest types. For different forest types, the preportions of small scale and large scale disturbances are different. The combination of small scale gap disturbance and large scale catastrophic disturbance in different conditions forms the basis of landscape pattern.

To sustain human survival, the relationship between humans and nature has to be a balanced one. Unfortunately, however, human being have placed itself in a precariously unbalancd position in relation to the finite capacity of nature. Many natural resources have been depleted to the point of extinction. In addition, nature's waste assimilative capacity has been grossly abused, causing environmental problems of an alarming proportion. Human being has, in fact, created a threat to its own survival.Therefore, nature and natural resources conservation have been become the most important problem confronting the human being in the world today. WWF sees the promotion and practice of sustainable use of natural resources as an essential mean to conserve nature in today's world. Existing and traditianal approaches to conservation such as the extablishment of protected areas will not succeed by themselves in achieving conservation. In an integrated approach, however, which links ecological sustainability with human needs, the establishment of protected areas and the sustainable use of natural resources can be mutually complementary. Such an integrated approach will serve to bring human-as economic actors, social beings, and dependents of nature-into a harmonious, matually supportive, and matually beneficial relationship with their environment.

The host plants and symptoms, parasitism and pathogenic mechanism, morphology, life cycle, ultra-structure of the host-pathogen relation-ship, cultural characters, physiological properties, molecular biology of the fungi, and especially with their taxonomy were studied in this paper. The fungi belonging to the genus Exobasidium distribute over Asia, the North America, Europe and Australasia. The fungi are known as the pathogens of cell hyperplastic and hypertrophic disease of several tree plants of five families namedly Theaceae, Ericaceae, Lauraceae, Empetraceae and Symplocaceae. About 50 species of this genus have been known in the world. The symptom type of the disease caused by the fungi is diversiform and is related to phytohormones. The life cycle of the fungi is not clear, although there are a few reports on it. The germtubes of the basidiospores and conidia can enter the leaves of the host through stromata or mechanical injuries, or penetrate the epidermis directly. The mycelia were formed and developed in intercelluar space and the haustorium-like structure with inclusive bodies was observed in infected cell. The standards for classifying this fungi are varied according to researchers. Host, symptom, morphological characteristics, physiological and cultural properties, germination behaviour of basidiospore on PSA have been used as the standards for taxonomy. GC content of DNA and 28SrDNA-PCR-RFLP may be used as taxonomic characters.

Methods of vehicle dispatching for management now still stay at the level of relying on experience judgement without computerization under the condition of transporting so many kinds of goods and dealing with large amount of problems facing the enterprise management. This results in the low efficiency with frequent errors without reliance of scientific analysis.Using VCP analytical technology and production and income balance of profit and loss on different kinds of road for all types of vehicles, a mathematical model which shows the characteristics of the transportation system is established in this article in order to promote transportation productivity and reduce its cost as well as to get better economical result. Relying on computer-based analysis, the optimum dispatching design of vehicles and security rate for wood transportation enterprise have been established and accurate and reliable data have been built up for an enterprise to predict and make decisions for its management goal.