The structure of leaf age, distribution of needle biomass in various ring branches of crowns, and the relations between needle biomass and tree heights, and timber volume increments, as well as the effects of pruning on needle biomass and growth increments in P. tabulaeformis have been studied in this paper. Seven factors related to needle biomass, namely tree height, DBH, crown length, crown size, crown/height, numbers and total length of branches, have been selected from 11 lectors by gradual regression analysis method. The best regression assessment model for needle biomass of P. tabulaeformis has been worked out and tested in the forest land of P. tabulaeformis.

A new circultion method of vegetative propagation of Populus tomentosa and Populus hopeiensis have been studied and developed for 6 years. This method. Of propagation does not need any chemical treatment and plastic cover on the nursery bed for cuttings. The survial percent age of cuttings of the two poplars species steadily keeps 80% or over. And a new root shoot-suckers-reproduction method has been made. The successful propagation of the poplars provided much progress for clonal test, clonal breeding and clonal afforestation of the selected trees of the two poplar species.

The clearwing moth (Paranthrene actinidiae Yang et wang) is the most important insect pest of Actinidia trees in the north of Fujian Province, its injury being severe in recent years. This paper deals with its bionomics and the control measures conducted during 1984—1987 in Fujian Province. The larvae are oligophagous and bore into the stems and shoots of Actinidia trees, in this way this pest could reduce the yield of Actinidia significantly. Laboratory rearing and field observation showed that this insect had one generation a year in Jianning, Fujian Province. There are seven larval instars. It overwinters as larva in its own thin cocoon within the tunnel. Hibernation of the larvae usually begins in late November to early December. Overwintering larvae resume feeding in late February of the following year and shift boring from the branchlets to larger stems and trunks, reaching the peak in early to mid-March. At maturity they begin to pupate in their tunnels in early July. The pupal stage lasts 24—34 days. Adults appear from late July to August and sometimes by the end of mid-September, but most of which emerge in late August to early September. The females lay eggs singly on the underside of the leaves with a few on the bark of the trunk and large limbs. Incubation period of the eggs lasts 7 to 13 days. After hatching, the earlier boring larvae reach its peak in early to mid-September. Larvae feed on the xylem and pitch of Actinidia trees and construct straight tunnels. Before emergence of the adult, the pupa works its way out of the bark so that the body above fourth uromere is exposed. The adults are very active at daytime and stay on the branches or leaves of their host at night. Field experiments showed that the following control measures were effective:1.Pruning in late winter is used to eliminate the overwintering larvae.2.To inject insecticides, such as Dichlorphos, Dipterex or Sumithion, into the burrows on the trunks and branches to kill the hibernating larv- ae in early spring.3.To smear the infested areas of the tree trunk and branch with Dichlorphos, Dipterex, Sumithion or Decis etc. to kill the larvae after hibernation in late February.

This paper gaves descriptions of a new subgenus and semen species of the Triozidae from China. The types deposited in the Insect Collections of Beijing Agricultural University.Gen. Hippophaetrioza, star. N. (figs. 1, 2)Body medium size, stout, with short pubescence, genal cones strongly divergent, clypeus visible from between genal cones. Antenna moderately long, longer than the width of head. Pronotum on same plane with vertex and praescutum. Metatibia with rugosity at base and three or four spins at apex. Forewing transparent or maculated, always round at apex, without evendtly pterostigma or with pseudopterostigma. M and Cula with short common petiole. Hind wing broad and large, R, M and Cul arising from the same point or M and Cu1 with common petiole.Male genital segment complex with proctiger almost cylindic, parameres inside with convex at base, aedagus first segment stout at base and slender at apex.Female genital segment very particular, dorsal valve with very sclerotic as falciform distal parts and expanded circumanal parts, proctiger between anus and apex very convex, like a hemisphere. Ventral valve very short and shape variety.Type species: Trioza binotata Low, 1883.Distribution: Austria, Switzerland, Italy, Russia China.Host plant: Hippophae spp.Subgen. Maculatrioza, subgen, n. (figs. 2, 3, 4)Type species: Hippophaetrioza(Maculatrioza) Maculata sp. N.New subgenus differs from the subgenus Hippophaetrioza as follows: body more stout; forewing near rhombus, veins and membrance with irrgula maculata; hind wing R, M and Cula arising from same point and three tiabl spurs at apex. Female genital segment also differs from the latter in having expanded circumanal parts longer than scleroted distal parts and ventral valve nearly rectangle.The new combined list of species of Hippophaetrioza Subgenus 1 Hippophaetrioza Conci et Tamanini 1984.H. (H.)binotata(Low, 1883)H. (H.)tianshanica(Loginova, 1970) Subgenus 2 Maculatrioza subgen, n.H. (M.)xizangana(Li et Yang, 1987)1.Hippophaetrioza(Maculatrioza) maculata, sp. N. (fig.3)Holotype , allotype , paratyp 2 , Xizang Aut. Reg. Nyinchi Co. Gengzhang(3050m) 1978-Ⅵ-1.Host plant: Hippophae rhamnoides(L.)New species related to the Hippophaetrioza (M.) xizangana (Li et Yang), but differs from the latter in having both body andforewing markings brown colour(xizangana is blacked).2.Hippophaetrioza(Maculatrioza)formosa,sp. N. (figs. 2, 4)Holotype ♀, paratype 1♀, Xizang Aut. Reg. Xigaze Co. (3900m) 1978-Ⅷ-28.Host plant: Hippophae rhamnoides(L. )New species is similer to the Hippophaetrioza (M.) rnaculata,sp, n., but differs from the latter in having forewing marking little and dorsal and inner valve of female genitalia very different.3. Hippophaetrioza (Hippophaetrioza)chinensis, sp. N. (fig. 5)Holotype , allotype ♀, paratypes 120, 210♀♀, Shanxi Prov. Wenshui Co. Guandishan(1700—2000m), 1987-Ⅵ-16; 10, 9♀♀, same as holotype 1987-Ⅵ-17; 2♀♀, Ningxia Hui Aut. Reg. Longd Co. Liupanshan(2300m)1980-Ⅶ-14; 1♀, Shannxi Prov. Ganquan Co. Qingquangao 1972-Ⅲ Host plant: Hippophae rhamnoides(L.)New species is similar to Hippophaetrioza (H.) tienshanica (Loginova) from Russian in the forewing markings, but easily distinguished in the anus longer, about 1/2 length as base part or dorsal valve, inner valve also different.4. Hippophaetrioza (Hippophaetrioza) guangwui, sp. N. (fig. 6)Holotype , allotype ♀, paratypes 8, 9♀♀, Shanxi Prov. Wenshui Co. Guadishan (1700—2000m) 1987-Ⅵ-16.Host plant: Hippophae rhamnoides(L.)New species and anterior species found in the same host and locality, but differs from above new species by the body longer(to the tipe of holded wings) 3.42, ♀ 3.75mm; forewings without markings to be except of margin marking.5. Hippophaetrioza (Hippophaetrioza) nyingchensis, sp. n. (fig. 7) Holotype , allotype ♀, paratype 1, Xizang Aut. Reg. Nyingchi Co. Gengzhang(3050m) 1978-Ⅵ-1.Host plant: Hippophae rhamnoides(L.)New species is similar to the Hippophaetrioza(H.) binotata(Low)which described from Austria, Switzerland and Italy on Hippophae rhamnoides, but differs from latter in having M forked shorter and also inner valve of female genitalia distinctly different.6. Hippophaetrioza(Hippophaetrioza) incurva, sp. N. (figs. 2, 8)Holotype , allotype ♀, Xizang Aut. Reg. Nyingchi Co. Gengzhang(3050m)1978-Ⅵ-1; paratypes 1♀, Lhasa C. (3700m) 1978-Ⅷ-16, 1♀, Nedong Co. (3500m) 1978-Ⅷ-9.Host plant: Hippophae rhamnoides (L.), H. thibetana Schlechtand.New species resembles the anterior species in the shape and marking of forewing, but differs from former in having Rs-M1+2 about equal M1+2-M3+4, Cula broader and also dorsal and inner valve of female genitalia very different.7. Hippophaetrioza(Hippophaetrioza)qinghiensis, sp. N. (fig. 9)Holotype , Qinghai Prov. Datong Co. 1965-Ⅴ-11.New species differs from species of Hippophaetrioza in character parameres of cone-shaped and slightly curved of male genitalia lateral aspect. Differs from H. (H.)guangwui, sp. N. in having vertex and genal cones short and broad, male 9th sternum longer and paramers hind margin convex in lateral aspect.

The No. 11 masson pine trees in a massonian pine forest located in Yulin, shows significant resistance to D. punctatus This pine tree showed a nonpreference egg-laying of the moths and an adverse effect on the growth of the larvae. Biochemical analysis shows that there are significant differences in the amount of β-pinene, amino acids, carbohydrate and mineral components among the leaves of the pine trees and those of the other masson pine trees. These differences are supposed to be the main factors for the No.11 masson pine's resistance.

Experiments wero conducted in which the needles from different kinds of pine trees were used to feed Masson pine caterpillars in order to study the effects of the chemical components in pine needles on the growth of the insect. The regression models are obtained through statistic analysis:y₁=74.9716-5.92369x₍₁₂₎; y₂=82.205-6.11941x₍₁₂₎-15.124x₍₁₈₎+32.7815x₍₂₂₎; y₃=146.785-11.2636x₂+13.425x₄+2.50619x₅+1.98716x₆-3.04045x₃-95.1154x₍₁₃₎; y₄=143.858-4.87883x₂-0.596458x₃+12.8221x₄-3.06847x₃-88.6311x₍₁₃₎+9.19294x₍₁₄₎+0.44275x₍₁₅₎; y₅=-67.7002+3.64222x₆+85.575x₍₁₃₎-11.4652x₍₂₁₎; y₆=-64.5757+3.50711x₈+80.8537x₍₁₃₎-10.93x₍₂₁₎; y₇=117.775+127.237x₍₁₃₎-13.6729x₍₂₀₎-108.387x₍₂₂₎+26.7597x₍₂₄₎; y₈=-46.6297+122.538x₍₁₃₎ 87.2382x₍₁₆₎.In addition, another two results are obtained:1. Three components have important effects on the pupation, emergence and periodic growth rate of the insect. Vitamine B₆ is the most important factor, the substance of low boiling-point the next and threonine the last.2. Three components have important effects on the oviposition of the insect. Isoleucine is the most important factor, methionine the next and vitamine B₆ the last.

Wood density makes important effect on cutting resistance. Following the former report, we have studied the relationship between wood density and cutting resistance with Korean pine and Manchurian ash. The main results are as follows: 1) The relationship between wood density and cutting resistance varied with wood species, cutting direction, chip thickness, knife rake angle and moisture content of wood. 2) There existed a common tendency of the effects of chip thickness, knife rake angle and moisture content of wood on the relationship between wood density and cutting resistance and such tendency could be described with a simple linear equation. 3) The scatter of the data on the density-cutting resistance relation implies that besides density there exsit some other factors affecting cutting resistance. An analysis showed that being observed in a relatively wide scope, no significant difference of the distribution of such factors was shown both in the directions of height and diameter within a tree.

Researches on the rheological behaviours of particleboard with defferent densities under compression perpendicular to its surface have further confirmed the feasibility of using the Rhoological Parameter Seperating Method. The influences of density on the rheological properties are mainly due to: instantaneous elastic deformation and parameter B in the compliance formula C=A+Blogt for the retarded elastic deformation decreasing with the increase of the density; instantaneous plastic deformation decreasing also as the density increases, and the "turning point" of the curve of plastic deformation vs. compressive stress which is of special importance in the thickness tolerance control of the overlaid particleboard moving along the increasing direction of stress with the density; the parameter B in the compliance formula C=A+Blogt for the time-dependent plastic deformation decreasing with the increase of the density, and the "three-stage development" of this deformation moving along the increasing direction of stress with density. These primary results are of great importance in determining the conditions for overlaying process and for the requirement for the particleboard, and in controling the thickness tolarance of the overlaid particleboard.

The results of the determination are as follows: 1. The photosynthetic rate of E. citriodora is 58.8% (half leaf method) and 25.3% (warburg microrespirometer method) higher than that of B. hsienmu. The respiratory intensity of B. hsienrnu is 3.2 times (half leaf method) and 1.3 time (warburg microrespirometer method) as high as that of E. citriodora. The rate of photorespiration of B. hsienrnu is 70.3 times as high as that of E. citriodira. 2. The efficiency of the dry matter accumulation of E. citriodora is higher than that of B. hsienmu. 3. The cell biological characteristics (structure of leaves, amount of stomata, thickness of leaves, layers and thickness of palisade cell, density of palisade cell etc. ) of E. citriodora are more advantageous to the photosynthesis than that of B. hsienmu. 4. There are positive correlations between chlorophyll contents and net photosynthesis rate in two tree species. 5. There are positive correlations between N contents, soluble protein of leaves and net photosynthesis rate in two tree species. 6. Efficiency of N utilization for E. citriodora is 15.4% higher than that of B. hsienmu.

The trees were selected in three aspects: Qualitative characters, quantitative characters and resistance. But we paid much attention to quantitative characters evaluated by standard selection differential. The quantitative characters and resistance were assessed with independent criteria.Four most important factors have been found out by means of double selection stepwise regression from eighteen variables which include the characters of plus trees and the sampling statistics. Eleven characters of plus trees were divided into five groups and the plus trees were separated into four parts by principal component analysis(PCA).According to the results obtained from these analysis, it was shown that quantitative characters were more accurate and to be used easily by standard selection differential of the tree heights. And four criteria have been proposed to estimate plus trees.

This paper has calculated Interspecific Association Coefficients (I. A.C.) and Chi-spare values of 36 species from 141 sample areas in nondeciduous stands in the North Fujian. According to the I.A.C., when λ=0.7 the species was classified into five categories using Maximum Tree Method, it more directly reflects the intimate level of the I.A.C. of the species. In order to prove the feasibility of the I.A.C. in the application, four pairs of tree species which have the maximum were selected from the I.A.C and Spearman grade correlation coefficients (r₃) of each pair were calculated. It was shown that four r_{3, were all at extreme significant level.The results provide an inportant basis for establishing mixed plantation of broad-leaved trees.}

In this paper, a new comprehensive growth model derived from growth accelaration in the light of a concise biological principle was presented. The new model not only indicates the named Richards, Gompertz and logistics growth models as its special cases, but also includes many other growth models such as linear, quadratic and exponential ones. By simple variance analysis, the observed data can be used direcly in deciding the model which is most appropriate through the new model with statistically stale parameters. It, therefore, has a practical and applicable value.

The equilibrium moisture contents (EMC) of 19 species in both outdoor and indoor conditions were determinded in Bantou Protective Forest Farm of xiamen during 1985—1986. The results show that the mean value of EMC in outdoor condition is 15.1% and 12.4% in indoor condition. The maximum EMC is found in June, while the minimum in October.Among the 19 species, the greatest value of EMC in outdoor condition is Gryptomeria fortunei (17.1%) and the lowest is Alniphyllum fortunei (12.0%), while in indoor condition they are respectively Eucalyptus robusta (14.3%) and Paulownia fortunei (10.7%).Values of EMC for every month in outdoor condition are obviously higher than in indoor condition, with the exception of Alniphyllum fortunei.The EMC of wood varies with the relative humidity and temperature of the surrounding air, it is further found that there exists an extremely significant relationship which can be expressed in both linear and curvilinear regression equations. However, the correlative coefficient (R) and variance ratio (F) of the linear equation are slightly higher than those of the curvilinear equation. The former is likely more precise and simple in calculation than the later. It is considered that the linear equation seems to be more suitable than the curvilinear equation to express such a relationship.Finally, two graphes of t-φ-we for xiamen region are drawn up on the bases of both linear and curvilinear regression equations.

In this paper, a new method is described for determining the resin distribution on wood chip surfaces. A liquid UF resin was stained into red with rhodamin B. for spraying on the chip surfaces. The samples were photographed with color positive films used as a image. The percentage of resin coverage on the chip surfaces was obtained through a image processing method. A spectrophotometer was used to determine resin content by means of comparision sample image to standard image.The advantage of image method is not related with size and geometrical shape of wood chip and can be used to determine both the percentage of resin coverage and resin content on the same surface of wood chip.In this pater it is proposed that the image processing might be furt her developed for determining the three dimensional resin distribution on the wood chip surfaces. It is significant to develop resin distribution idea and complete method for determining resin distribution.