Spatial distribution patterns for egg-masses,small larvae,large larvae and cocoons of the pine caterpillar were measured by means of several indexes of aggregation in Zhe Jiang Province.Frequency distribution of eggmasses fits to Poisson distribution quite well,and that of the small larvae, large larvae and cocoons obeys aggregation distribution,but the aggregation indexes are highest in small larvae and lowest in cocoons. Iwao's method of regression of mean crowding()on mean density() is a good method for detecting the aggregation patterns.In the pine caterpillar, small larvae,large larvae and cocoons,all relation in a series of distribution is fitted to a single linear regression for α>0,β>1.Iwao's equations for data transformation were applied and tested for its fitness,the transformed data all obey normal distribution and the tests of heterogeneity of variance and non-additivity indicate that the results of transformation are well fitted. From this method the optimal sampling size is determined,the sequential analysis is also applied. In the pine caterpillar,the basic component of the distribution (i.e.large larvae) is a loose colony.The size of the colony and the distribution of individuals in colony remain to be studied.

Developmental anatomy and chemical analysis including isolation and characterization of some important constituents in the bark of Populus tomentosa Carr.were investigated.The basic structure of tissues and cells produced from the primary and secondary growth of this bark was described.Attention was paid to the seqential changes of thses structures, initiation of the periderm,late-formed rhytidome and the retention of the cortical region,seasonal activity of secondary phloem,and the variable surface configuration of trunk,which were traced from those in the young shoot through the aging of matured trees,Successive extraction by neutral solvents,1% sodium hydroxide,cellulose and the individual sugars,“lignin”and its methoxyl content,formaldehyde reactive phenolic acid,etc.were determined.Chlorophyll in the outer bark,two pure glucosides,a salicin and another not yet identified,five phenolic acids such as p-hydroxybenzoic acid,p-cureeric acid,syringic acid,ferulic acid,and vanillic acid,were analysed by common methods,isolated and characterized by chromatography,infra-red absorption spectrum and high pressure liquid phase spectrum.Isoenzymes from the male and female tree bark were compared by electrophoresis.Besides this species studied,about six other species of Populus were compared in the concerned problems for reference.This report is a brief summary in nature for the accumulated studies carried on intermittently during the past decade. It may fill a gap in the study on growth and development of trees in Populus, and it may also be considered as a basic step towards the physiological or biochemical approch for the related problems,at least in static concept of the end products in a living tree.The results of this study would provide some basic information for the evaluation of the possible utilization of such barks. Discussion about this study and the related problems in bark research was made briefly.Some interest findings worthy for intensive study are carrying on.Further results will be presented elsewhere.

The field spectral data collection of trees for remote sensing application has been carried out for about two years.Several variables encountered in situ for spectral measurement should be calibrated or kept in mind.The hemispherical reflection properties of several tree species were investigated. The reflex reflection performance of tree canopy as well as spectral and goniometric properties of reference panel serve as a basis for analysis of uncertainties introduced by differing illumination conditions.Large field of view (FOV)is suggested for forest canopy spectral measurement to avoid sharp radiance variations due to different FOV contents.Multiband radiometer seems more suitable to large scale data collection project in forestry than delicate spectrometers,provided the band selection of the sensor has been decided.

This paper reports the result of influences to the growth of Chinese fir caused by adopting six various planting densities of 240,167,122,94,74 and 60 trees/mu. The results demonstrate that variation in planting density has an obvious influence to diameter growth (breast diameter) of the trees.It usually increases as the planting density decreases.But there is a limitation that the diameter-growth will not increase in proportion to the rule of variance of planting density,after the trees in a plarltation of 60 trees/mu have been planted for 15 years. There is no rule derivable from the influence of variance of planting density to the growth in length of Chinese fir.The duration in terms of years for the increase of crown width and length prolongs as the planting density decreases. Growth of individual tree in terms of volume increases as the planting density decreases.The biggest volume increment per unit area belongs to the plantation of 122 trees/mu,reaching 21.1575m~3. The result of our experiment shows that the most suitable planting density for Chinese fir is 122 trees/mu and thinning is not necessary for this plantation.

Natural resistance of 165 timber species (141 hardwood species and 24 softwood species) against termites,Reticulitermes chinensis Snyder,was determined by both laboratory and field tests.Their natural resistance can be arranged as follows: Fokienia hodginsii,Madhuca hainanscnis,Eucalyptus camaldulensis,Cassia siamea,Homalium hainanense,Robinia pseudoacacia,Tectona grandis,Toona sureni,etc.are designated as“no wood damage”. Pinus Kwangtungensis,Acacia auriculaeformis,Averrhoa carambola, Castanopsis hystrix,Castanopsis sclerophylla,Cinnamomum camphora,etc.are designated as“light wood damage”. Larix gmelinii,Pinus koraiensis,Acer davidii,Albizzia chinensis,Albizzia julibrissin,Castanopsis carlesii,etc.are designated as“moderate wood damage”. Picea likiangensis,Pinus Yunnanensis,Ailanthus altissima,Alniphyllum fortunei,Alnus nepalensis,Betula alnoides,etc.are designated as“heavy wood damage”.

The technological arrangement is a key in the plan of the log yard.The article gives conception and definition of the technological flow and arrangement,points out drawing method of the technological flow chart.On the base of the study on various technological arrangements of log yard at home and abroad,we summed up the six essential types of the arrangement.There are single flow,double flow,divided flow,combine flow,counter flow and cross flow.This paper further gives features of these flows,discusses basis and calculation method of the flow forks for every yard operation.Finally it gives principle and method of the technological arrangement,especially regard the log sorting line as an important consideration.

The pine bast scal(Matsueoecus matumurae Kuwana)is one of the most destructive pest of pines.In order to find out the resistance of different pines to this pest,incoulating tests have been carried out in Fuyang,Chekiang, China since 1979.The pine species tested are Pinus serotina Michaux,Pinus taeda Linnaeus,Pinus elliottii Engelmann,Pinus rigida Miller,Pinus eohinata Miller,Pinus glabra Walter,Pinus Patula Schlechtendal and Chamisso, Pinus palustris Miller,Pinus thunberghii Parlatore,Pinus luehuensis Mayr with the Massonian pine,Pinus massoniana Lamb;as check.Through two generations of inoculating tests and examinationes for many times,it has been found that the pine bast scale cannot develop or even alive on the former eight pine species,but it can develop on the latter two pine species.In other words,among the ten pine species tested only the latter two species are injured and attacked by the pine bast scale. Through the anatomy of branches of the above mentioned pine species and the analysis of the content of protein,sugar,fat,amino acid,water,gum and gum acid,it is shown that there are no longleaf pine acid,levopimarie acid and new abietic acid in the gum acid of the former eight pine species and that the abietic-type is lower.Three kind of acids in the latter two pine species and the check pine,have been found,and the abietic-type is high. Hence,this is recognized as the main mechanism of anti-pest of the pine species.

Minthea rugicollis(Wallser),distributed in the provinces south of Yangtse River and in Taiwan,is one of the principal injurious in-sects of furniture and building construction woods.It has three generations a year in Hainan Island The first generation lasts 91.5+16.2 days,the second 93.8+14.4 days and the third 178.4+16.2 days.The beetle emerges throughout the year,with a peak from the end of March to the beginning of April.Minthca rugicollis(Walker) attacks about 80 species of woods.The more effective insecticide against it is boric acid and borax.The toxic limit of boric acid is 0.08—0.16% and of borax 0.16—0.32%.To treat the woods of building construction and furniture with the BBP mixture(borax 35%,boric acid 30%,sodium pentrachlorphenate 35%)at 6—8kg/m³,may get an enduring effect of protection of 10 years.At least also,it can be prevented with sodium fluoride,DDT and Permethrin.

The larvae of Anoplophora nobilis Ganglbauer are borers which infect the stems of poplars and cause a damage of 100% of the trees.Many trees died off in Shaanxi,Gansu,Henan,Hebei Provinces and Ningxia Hui Autonomous Region.They attack more than 10 species of trees with a growth period of three years and prefer in particular several species of Populus,This species requires two years to complete its life cycle and most of the larvae pass two winter in the poplar trunks.The injury of each larva is confined to one tree which may harbour many individuals.The mature larvae pupate in early June and the adult beetle appear from early July to early September.We should put into practice a system of integrated control measures.The damaged trees ought to be cleared away from the forest and seedlings of new species planted immediately.The application of emulsions of Sumithion,Dichlorphos,Malathion,Nuvacron and water solutions of Benzenehexachloride or Acootox to the openings of tunnels and spraying them to the trunks are effective chemical control measurer.

Growth and differentiation of the dominant trees(classes Ⅰ,Ⅱ,and Ⅲ) on the one hand and decline and death of the suppressed trees(classes Ⅳ and Ⅴ) on the other hand are two inseparable phases in the process of natural thinning in the stands of Pinus yunnanensis. In other than fully stocked stands,there are fewer dominant trees reduced to suppressed ones and also fewer suppressed trees becoming dead ones.As a result,the current annual increment of the stand basal area gradually increases.When the cumulative basal area of the dominant trees in a stand is close upon P=0.7 or that of the entire stand approaches its maximum value (P=1.0),the growth of the stand then reaches a level characteristic of a fully stocked stand. The decrease in the number of dominant trees in a stand occurring simultaneously with the decrease in the number of trees of the entire stand varies mainly with stand density,which is in fact an outcome of the intera ction of such factors as stand site quality,age and density.For stands with approximately equal average ages,the relationship between the number of dominant trees and the total number of trees may be expressed by the curve of a power function.Accordingly the number of dominant trees that should be retained in tending felling for stands of Pinus yunnanensis may be estimated with considerable accuracy.