The distribution and circulation of 8 nutrient element contents and accumulation in the 10a artificial Cercidiphyllum japonicum community were studied.The results indicate:(1)The order of average content of elements in organs is Ca>N>Al>K>Mg>P>Fe>Mn.(2)The order of different organs for element accumulation is roots>leaves>stems without barks>barks>branches,and the order of elements accumulation is Ca>N>K>Al>Mg>P>Fe>Mn.(3)The amount of uptake,retention and return of 8 elements in the community is 729 82 kg·hm^-2a^-1、206.72kg·hm^-2a^-1 and 523.10kg·hm^-2a^-1,respectively.(4)51.2% of total return for K is returned through rainfall leaching,55.7%～96.5% of the rests through litter.However,41.3% of total return for Fe and 44.3% for Al is still returned through dead roots,respectively.(5)Utilization coefficient,ratio of return to uptake,circulation period were 0.23～0.54、0.57～0.82 and 2.26～7.63.Meanwhile,the calculating method of nutrient elements returning through leaching was amended,and the uptake coefficient(annual element uptake/annual available element in soil),accumulation coefficient(annual element accumulation/annual available element in soil)and return coefficient(annual element return/annual available element in soil)were put forward.Finally,the calculating method of element circulation for deciduous forest was discussed.

The correlation between the desertification of the grassland and the change of vegetation biomass in Erduosi was reported in this paper. The results showed that, in the desertification course of the grassland, the degradation pathway of the community was both from S. bungeana community→S.bungeana+died Artemisia ordosia community→S.bungeana+A.ordosica community→Stipa bungeana community→sandland and from A.ordosica community→A.ordosica+Cynanchum komarovii commmunity→C.komarovii commmunity→sandland. From S. bungeana community to A.ordosica community and then to C.komarovii commmunity, the biomass of vegetation increased firstly and then decreased, namely from 218.1g/m² to 748.7gm² and to 155.6 g/m². The biomass of every community varied seasonally, because of the changes of dominant species and companion species. Most of the biomass aboveground distributed near the surface layer, 76.9%～86.3% of the biomass in 0～20 cm. Meanwhile, the biomass decreased gradually with the increasing of height, 10.8%～16.7% of the biomass in the 20～30 cm layer, 2.2%～7.5% in 30～40cm layer, 0.6%～2.9% above 40cm. The underground, 85.5%～100% of the biomass in 0～20cm, 9.7%～12.0% in 20～40cm, 0～2.5% in under 40cm. In the course of biomass accumulation, S. bungeana community and S.bungeana+died A.ordosia community decreased firstly and then increased, the accumulation ratio is from -0.29 to 0.42 and from -0.47 to 0.74, respectively. S.bungeana+A.ordosica community and S. bungeana community decreased steadily, the accumulation ratio is from -0.04 to -0.40 and -0.23, respectively. But A.ordosica+C.komarovii commmunity and C.komarovii commmunity increased steadily, the accumulation ratio is, respectively, from 0.14 to 0.29 and from 0.52 to 0.04.

A stable silvopastoral system of stand (6-year-old Populus deltoides cv.I-69/55) and herb(exotic species and local ones) was established in the north coastal area of Jiangsu province, by the improving technique of herb breeding, stand density controlling, spatial-temporal arranging and herb sowing. The system includes 3 vertical layers, i.e., poplar trees-poplar sprouts-herb and horizontal mixed-growth pattern of several herb species in spatial niches. It is also a high yield pattern of Lolium multiflorum+Medicago sativa(November to May)-Sorghum sudanense+poplar sprouts(June to September)-Setaria faberii or Artharxon pricnodes(July to October) in temporal niches. The system drastically increases the resource utilization coefficient of the ecosystem and sustainable development capacity of the sheltering forest of the coastal area.

Based on the 2×2 contingency table, the interspecific associations of tree and shrub species in the deciduous broad-leaved forest at the elevation from 1150m to 1500m in Bao Tianman, Henan province were studied by different indices. The results show that X² test, together with percentage co-occurrence (PC) and association coefficient (AC) was effective way to measure the association. The more intense the positive association was, the larger the value of niche overlap was; the more intense the negative association was, the smaller the value of niche overlap was. In the light of the interspecific association, tree species can be divided into four ecogroups of species.

In this paper,the reproductive value and reproductive allocation of Tetraena mongolica were studied.The results showed that the curve of reproductive value (V_x) with increasing age tended to be low-high-low pattern.The change pattern of V_x in the age of 3～9,10～21,and older than 21 years was in the state of slow increase,rapid increase,and slow decrease respectively.The reproductive value was controlled by both the selective pressure of environment (K_x) and its own survival rate (L_x).The reproductive allocation value (RA) changed with the reproductive phase of T.Mongolica.RA decreased from the stage of flowering to frutiting.RA value increased with the age in the period of 4～21 years and decreased after 21 years.According to the relationship between reproductive age and reproductive allocation,the reproductive phase of the population could be divided into 4 stages:initial (less than 9 years old),increment (from 9～12 years old),peak (13～27 years old),and decline reproductive phase (older than 27 years old).

Measurement and analysis of wood basic density (BD) and fiber length (FL) of 282 wood cores,which sampled from seven year-old provenance plantations of two species of Liriodendron,Chinese Tuliptree (Liriodendron chinense (Hemsl.) Sarg) and Tuliptree (Liriodendron tulipifera L.),in Jiangxi,Fujian and Hubei province respectively,were conducted.The samples were divided into groups and the frequency of each group was counted and normally imitated.The result showed that the wood core samples were abided by the normal distribution at two characteristics.The precision analysis showed that the 6 trees sampled from each provenance were of higher precision (P>90%),and 1～2 trees sampled from each provenance were of lower precision (P<80%) which could not be taken in the variance analysis but only used for calculating the average of provenance. T-test proved that there were not significant differences in the BD and FL between Chinese Tuliptree and Tuliptree. The BD and FL average of Liriodendron,including Chinese Tuliptree and Tuliptree,was 0.397g/cm³ and 1.603mm,respectively.Liriodendron was the species with long-fiber and middle-low-density according to wood classification criterion by Cheng Junqing. The variance analysis indicated that the differeneces of BD and FL Among provenances in Chinese Tuliptree were both significant at 0.05 level,and those of Tuliptree were not significant.The difference among sites and the mutual actions of G (provenances) and E(sites) were both not significant.BD's hereditability in broad sense was 0.654 and Fl's was 0.29,which indicated that BD was strongly controlled by genetic factors,while FL was weakly controlled by genetic factors.Characteristic coorrelation between BD and FL was very weak (r=0.157) and relationship between BD,FL and growth traits was also very weak,which impressed the independent selection of each characteristics could be conducted.Age-age genetic correlations of BD and FL were analyzed and all age-age correlation coefficients only except that one between 1 a and 5 a were significantly at 0.05 level. At the base of the analysis above,the provenance selection of wood character combined two species in Liriodendron was conducted according to different selection criteria so that the selection results could meet the different breeding demands.The results showed the most excellent provenances of WD were Lushan in Jiangxi Province and Sangzhi in Hunan Province,and the most excellent provenances of FL were Liuyang in Hunan Province and Ganwuyi in Jiangxi Province.Although the hybrid clones (CK) were beyond the average,it did not reach at the top provenance.The tuliptree provenances were not selected as the excellent provenance because they were slightly varied around the average line.

RAPD——based fingerprinting was carried out for 8 varieties and clones of Castanea mollissima which had been approved by the Zhejiang Inspection Committee of Superior Tree Species.Each of the varieties (clones) was identified by fingerprints.Nine RAPD markers were obtained from repeated screening of 684 random oligonucleotide primers and DNA fingerprints were made for all the used varieties (clones).Stable amplification was obtained through modification of experimental conditions and a complete technical system was established for fingerprinting of Castanea mollissima.Preliminary results for verification of commericial seedilings showed that these fingerprints were reliable.

The niches of mites and their predatory mites in Phyllostachys heterocycia forest in Xiqin, Nanping, Fujian Province were studied.The results showed that the sequence of utilization degree of the mites on the bamboo's leaves and their natural enemy(predatory mites)to temporal-spatial resource was as follows: predetory mites(B_i=0.5550)> Oligonychus urama (B_i=0.4467)> Schizotetranychus nanjingensis (B_i=0.3097)> Aponychus corpuzae (B_i =0.2875> S. celarius (B_i =0.1674)> Bryobia sp.(B_i=0.1417); the following effects of predatory mites with S.nanjingensis, O.urama, A.corpuzae were strong in temporal-spatial resource (the values of C_ij were 0.5743, 0.4830, 0.4371 respectively.); in the mites, the competiton between S.nanjingensis and A.corpuzae was acutest (C_ij =0.6076) and between O.urama and the others was very fierce too; the egg and adult of O.urarna occupied more temporal-spatial resouce in the different stages of the mites; the competitions were acute in species and between the egg, the larva and the nymph of S.nanjingensis and A.copuzae, the larva and the nymph of A.corpuzae and the egg of S.nanjingensis, the adult of O.urama and the larva and the nymph of A.corpuzae(C_ij >0.4); the following effects of predatory mites on the larva, the nymph and the adult of S.naningensis. The adult of O.urama and the larva and the nymph of A.corpuzae were stonger than the other stages (C_ij >0.5) and the sequence of others were the egg of O.urama, the egg of S.nanjingensis, the adult of A.corpuzae, the larva and the nymph of O.urama and the egg of A.corpuzae.

The IGS of 23 isolates of Armillaria gallica from three continentals of Northern Hemisphere were amplified with primers LR12R and O-1,and digested by AluⅠ,Hae Ⅲ,Hinfl,TagⅠ restriction enzyme,respectively.six RFLP patterns were observed,the patterns of gal(A) and gal(B) were only seen in Chinese isolates,gal(C) was occurred around the northern hemisphere,including USA,Canada,Germany,Poland,Luxembourg and China,gal(D) pattern was seen in a European isolate,gal(E) was only found in American isolates.Based on the parsimony tree of RFLP results,four A.gallica sub-populations were found from these isolates and named the Chinese(CH),European(EU),North American(NA),and Asian(AS) sub-populations.The Random amplified microsatellites (RAMS) experiments were carried out with primer TCG,CGA,M13,and GAAA,respectively.Based upon the parsimony tree of RAMS results,these isolates were separated into four clades,i.e.the European (EU),Chinese (CH),North American-Chinese (NACH),and North American-European (NA-EU) geographical lineage.Two groups emerged in the NA isolates of A.gallica, and they are more close to EU and CH respective than between.The research suggested that the RAMS are quite effective way for analysis of genetic diversity of fungi.

Eulecanium gigantea Shinji(Homoptera: Coccidae)is an important pest in the cities of Northern China in recent years. Experimental districts were selected in Taiyuan City and Taigu County from 1998 to 1999. Vitamin B₂(VB₂) was determined monthly in twigs and leaves of Sophora japonica, the most favorable host of the scale insect. The results showed that the population density and biological rhythm of the scale insect were contrasted with the content of VB₂ and the VB₂ content in the two pollution districts were significantly higher than that in the cleaning district. The more the city environment polluted, the more VB₂ content in the host tree was. A positive relativity between the density of the scale insect and the VB₂ contents was found. The regression equation was made out as Y=1507.76x-170.56, and the coefficient, r=0.839. From March to October, the two peaks of VB₂ content were corresponded to the two feeding and quick development stages of the scale insect. It was concluded that a higher VB₂ content in the host plant in some degree was benefit to the scale insect occurring greatly in the polluted city environment.

The effects of the Apple-ginger inter-cropping on ecology, physiology,yields, and the land utilization efficiency in the hilly land of TaiHang Mountain were studied. The results indicated that: (1)the ginger canopy temperatures decreased 2.5℃ and the relative humidity(RH) increased by 16.0% compared with the sole ginger field(CK2); (2) the content of soil water in 0～50cm depth increased by 8.5 % compared with the pure apple tree stand(CK1); (3) the content of Chlorophyll of ginger leaves increased by 16.6 % compared with CK2 ; (4) the photosynthetic rate increased by 10.0% compared with CK1; (5) the yields of ginger and apple increased by 3.1% and 2.0% respectively ,compared with CK2 and CK1; (6) the land equivalent ration(LER) was 1.64, and the land utilization efficiency increased by 64%.

Quantitative measurements of property of electric charge on insects,Clania variegata and other common species,were conducted.Fractal property of insects electric charge was drawn from analysis of the relationship between amount of electric charge carried by still insects and those interaction with environment.The charge produced from walking on different substrates and from wing vibration by male of Clania variegata was measured.The causes and principles of the charge carried by insects were also discussed.

In this paper, the effect of the centrifugal force cutting temperature stresses and the position of roll tensioning on the dynamic behavior and the critical speed of the circular saw blade is researched with the nonlinear and the matrix perturbation theories. The optimum position of roll tensioning is analyzed under the action of the centrifugal force and cutting temperature stresses. The effect of tamped radius on the optimum position is also analyzed.

In this study,three kinds of fast growing Poplar,Poplar 72 (Populus×euramericana cv.I-72/58),Poplar 63(P.deltoides cv.I-63/51),Poplar 69(P.deltoides cv.I-69/55),in brief,it is called Poplar 72,Poplar 63,Poplar 69 in the following,grown in three different beaches of Changjiang River(River beach,Islet beach and Lake beach)with three different spaces(3m×4m,4m×5m,5m×6m)were selected as the materials.Their relationships between the wood properties and forest culture were systematically revealed.The results show that:(1)There are large differences for the wood properties of poplar grown in the beaches of Changjiang River influenced by different clones.The longest fiber length,the lest microfibril angle and the largest vessel proportion for poplar 63 grown in the beaches of Anhui and Hubei,and poplar 72 grown in Hunan were revealed.It indicates that there are significant differences for microfibril angle and main physical mechanical properties of poplar 72,poplar 63 and poplar 69 by variance analysis.(2)There are large or small differences of wood properties influenced by different beaches.It indicates that there are significant differences for microfibril angle,basic density,bending strength and rate of shrinkage of poplar 63 and poplar 69 by variance analysis.(3)The effects of spaces on wood properties of poplar 72,poplar 63 and poplar 69 change with different wood property.For poplar 72,polar 63 and poplar 69,the wider the spaces,the larger the microfibril angle and the proportion of vessel,the shorter the fiber length,the proportion of fiber and ray,the basic density,the modulus of elasticity and the modulus of rupture.It indicates that different spaces have larger influences on poplar 72 and poplar 69 than poplar 63 by variance analysis.

In this paper,the change of contact angle and surface free energy of two species of wood Chinese fir (Cunninghamia lanceolata) and Poplar Sanbei No.1(Populus nigra×P.simonii cv.`Zhonglin Sanbei-1')before and after acetylation and graft copolymerization of 1-Phenylethene were investigated.The effects of esterification and graft copolymerization on surface free energy of wood were analyzed.The result showed that the contact angle of liquid on the surface of two species of wood is enlarged after the process of estrification and graft copolymerization.The effect of the esterification on contact angle is obviously bigger than that of graft copolymerization.The surface free energy of Chinese fir and Poplar Sanbei No.1 are 42.8mN/m and 52.3mN/m respectively,which are similar to most other species of wood.The surface free energy is reduced after esterification and graft copolymerization process,the reduce degree of esterification is affected with different species,but the reduce degree of graft coplymerization is hardly affected with species.

The study was to investigate the effects of tool materials and experimental surroundings on diamond coated tool wear. It was expressed that diamond coated tools decreased tool wear with 25～45 percent, but diamond membrane was to some extent peeled off, hindering diamond coated tool from improving tool life with much higher extent. It was realized from the worn edge of tools that both chip solution and the mixed solution of hydrochloric acid and acetic acid did not corrode the diamond membrane, however etched the matrix composition. It might be convinced that the wear of diamond membrane resulted from "plastic deformation-crackle-particle peeling". The abrasive mechanism was mainly responsible for the tool wear of high speed steel in additional to the corrosion mechanism. The binder of cemented tungsten carbides was etched by chemical corrosion. In case the residual forces were not enough to hold the carbides, the carbides would disappear for abrading fatigue.

Polycarboxylic acids acted as esterification agents and inorganic salts acted as catalyst in the wood crosslinking reaction. This new and soluble crosslinking system is poison free and pollution free system. In this paper, the CP/MAS¹³C NMR spectra of wood components were determined, main chemical shifts were signed and the changes of chemical constrcture were analyzed in esterification between wood and polycarboxylic by CP/MAS¹³C NMR spectra. Results showed: after esterification, the ratios of carboxyl and ester carbon increased, the ratios of aromatic and hydroxyl carbon decreased and the ratios of alkyl carbon changed with carboxyl carbon. This conclusion is the same as that by FTIR and ESCA spectra.

In this paper, the compliance method was applied to determine fracture toughness of C.lanceolata. The results showed that: 1.the compliance method is an available and feasible experimental plotting method, the relationship between compliance and crack length may be expressed by exponent function(C=α exp(β_a/w))very well; 2.in this testing, the fracture toughness K^TL_IC of C.lanceolata is equal to 4.825 Mpa·mm^1/2 .

This paper according to the variational characteristics of wood growth ring density, by the method of time sequence statistics, the seasonal variation model of wood growth ring density was established.We can achieve short-term forecast of wood growth ring density and early-stage forecast of the quality of wood growth ring density. The results provided a scientific basis for processing of plantation forest.

The multiple character of forest beauty is emphasized, including multiplicity of modality, component and enjoy-lever. Based on modality, forest beauty is consisted of natural beauty, social beauty and artistic beauty. Based on component, forest beauty can be distinguished into beauty of forest plants, beauty of forest animals, beauty of landforms, beauty of forest air, beauty of rocks and special geological structure, and beauty of water bodies in forest area. Based on enjoy lever, forest beauty includes form beauty and artistic conception beauty. The characteristics of natural beauty of forest plants is analysed, viz., richness, multileveled, form-beauty dominated, public appreciable and consistency. The scene composing principle of forest plants was put forward, including uniformity, contrast, sequence, arrangement, salient, enframement, convergence, naturalization, and large diameter management purpose. According to distance and size of enjoying object, forest plant landscapes can be divided into 7 types, viz., detail landscape, individual landscape, in forest landscape, forest lined road landscape, foreground landscape, mid ground landscape and far away landscape. The meaning and scene composing character of each type is explained and expounded. Finally, the difference of importance of 15 scene composing factors among foreground landscape, mid ground landscape and far away landscape are listed and compared.

Pinus slyvestris var. mongolica was introduced to Zhang Gutai from Honghuaerji Sandy Lands, Hulunbeier of Inner Mongolia. During its young and middle ages, the growing was stable and fast. However, to those 35～40 years old trees, early decline occurred , growing period shortening resulted. By observation on 17 fixed positions, analysis showed that the early decline was mainly caused by the changes of its growing pattern, such as the peak growth period shifted to an early date and became shorter; peak numerical value was high and the vigorous growing period became shorter. due to moisture and heat differences between its original and present growing places. Moreover, another reason of early decline was the development of Diplodia, which was caused by the local climate, that is less precipitation in May and June and concentrating precipitation in July and August. However, Pinus slyvestris var. mongolica is the main species in afforestation which is superior in ecological and economic benefits to others, therefore, in order to reduce the development of diseases and prolong the growth period, selection of decease resistant species, establishment of mixed plantation with intensive management are adopted as the main measures to solve the problem of early decline.

Based on plot surveying of populus gansuensis shelterbelts for crop in 4 soil types of Hexi Corridor,the paper studied the shelterbelt mature age, technology mature age and regeneration age of P.gansuensis shelterbels for crop in different types of soil by stem analysis.