1996 Vol. 13, No. 4
The wood properties of fast -growing Chinese fir were worse than the ones of common Chinese fir.For the former,air-trying density was 0.345gcm-3,volumetric shrinkage coeffieient was 0.444%,compressive strength Parallel to the grain,rupture strength in static bending and elastic modulus in static bending was 28.0MPa,57.0MaP and 8.5 GPa respectively.
Huangpi,a cultlvated variety of Actinfdia chinensis,sets fruits in mid May.Its fruits rapidly expande in June.The seeds take shape in Iate July and get ripened in mid and late August.Mid and late September was suitable for harvesting the fruits,when the fruit weight,size and contents of protein and soluble sugar were all at their best,and the content of vitaminC reaches(1.480.35)mg.g-1.Fruits harvested in late september have better quality.The harvesting Period could be dstermined according to the following indexes:black seed skin,greenish median skin,light dark brown ectocarp with orange star hairs,(4.700.84)% of Protein,(8.500.20)% of soluble sugar,(1.480.35)mg.g-1 of vitaminC and 6.5%~7.5% of soluble solid.
The authors invesigated 112 sample plots located on the main introductory region of the southern types populars in china ,and collected soil samples,then measured the physical and chemical properties.the objective marks of three of the quantitative site-indexes of three clones were worked by adapting the quantitative theroy I.According to the classification and combination of three leading site factors,i.e.efficient depth of soil,soluble salt content and total nitrogen content,the introductory region was divided into 27site type,and the sites quality of each site type was quantitatively evaluated.
A compatible merchant volume ratio prediction model system was developed.The program of computing theoretical merchant volume ratio based on idnividual tree was presented and merchant volume ratio of Cunninghamia lanceolata which was taken as an example was calculated.some characteristics of taper equation and results were analysed and discussed,
The Selection of salt tolerance Plantlet regeneration of three poplar clones,namely poplar NL-80105,poplar NL-80106,and poplar NL-80303,in tissues was studied.The results were as follows:(1)on MS medium with 5.0gL-1 NaCI,the most shoots formed on young stem explants among three explants,and more shoots developed from clone NL-80105 and NL-80106 than from clone NL-80303.(2)More salt tolerance shoots formed from the explants treated with EMS or ray than from those untreated.(3)MS medium with 6-BA 0.40mgkg-1 and NAA0.02mgkg-1 was suitable for solection of salt tolerance poplar regeneratde plantlet.(4)By elimination series under higher salt density,after all,the calli tolerance to 10.0gkg-1 NaCI,the shoots tolerance to 10.0gL-1 NaCI or sea saIt and 23 regenerated plantlets resistant 7.5g.L-1 NaCI,21 from clone NL-80105 and 2 from Clone NL-80106,were obtained.
Results of investigation about reproductive Phenology and number of strobili(including male and female ones) of clones in a grafted seed orchard of masson pine were reported.Discussion emphasized the effects of reproductive Phenology and the strobili number on seed Production and genetic composition of filial generations.Conclusions are as follows:a)Although reprodcutive Phenologies among clones and among ramets of the same clone did not synchronize completely,they did synchronize to a certain degree:b)There was still acomparative lack of Pollen for seed orchards in production Period;e)The dominance of male or female strobili of a few clone in seed orchards made it possible for genetic base of seed orchards'seeds to become narrower.
Seed germination and seedling growth for camphor tree were moniotred under exposure the seed and seedling to a simulated acid rain。The pH 2.0 acid treatment inhibited seed germination and seedling growth by damaging foliage,decreasing chlorophyll contents,increasing leaf cell permeability,and acidifying leaf sap and the soil.Whereae PH3.5 acid treatment increased the biomass in spite of some negative effects on seedlillg growth.No significant treament effects were observed at PH values of 5.0adn6.0.
In the Present paper,four species of the genus Coenosia,collected from Baishanzu Naturee Rserve(27.7N,119.1E),Zhejiang Province by one of the authors,are described as new to seience.They are C.breviaedeagus,C.nigricornis,C.fimbriPeda and C.longipeda.The type sPecimens are deposited in the Institute of Entomology,Shenyang Normal College.
Life tables of Taiwan Pine cones were established and analyzed on Huadingshan Forest farm,Tiantai,Zhejiang,during 1993~1994.The results showd that an important and key factor resulting in cone death of Taiwan pine was the daamge by Petrova cristata,which stared from Pine Pistilliferous flowers blossom to Pine maturity.The Period of the cone death was in May each year.There existed a close relationship bewteen the loss of Taiwan pine cones,the different years of bearing cones and the Pest densities.
Tea Cuifasu,a foliage spray preparation for tea plant,was used to test 46 tea clones in Hangzhou,Yuhang,Jiande and Anji of Zhejiang,Qi yang of Hulian and Yichang of Hubei.The results showed that Tea Cuifasu was significantly effective in stimulating tea flushing and increasing tea leaf yield in early sPring.The first plucking was 5 to 7 days earlier than control.Flushing density in a given plucking table increased 27.5%~52.4%.Shoot growth rate increased by19.4%~39.4%and shoot length of one leaf and one bud increased by 11.9%~47.2%.Fresh leaf yield increased by114.6% before Qingmin season and by12.0%~15.0%in the whole spring season.
An investigation was conducted in the year with severe freezing damage of more than 20 factors related to sites,trees and culture practice on 90 standard Plots in main growth areas of Citrus.By means of quantitative regression,the studies on the,relationship between factors and freezing demage in Critrus showed that the extent to which the trees were injured under the weather condition of 1991 was significantly influenced by earth depth,basal manure,additional manuring,insect pests and plant diseases followed by soil fertility,slope direction,tree age,depth of roots and fruit quantity.In addition,the site type,wind scale and disposal of snow accumulation was also related to the freezing damage.Culture measures were suggested.
Forestryis a basic industry that is great in ecologic benefit and social benefit,but is bad in economic effect by itself.Forestry not only must participate in market competition but alao need to be protected under the socialist market economy.
According to comparing and anlyzing the forestry literature reported by CAB Forestry Abstracts in previous period(1978~1986)and later period(1987~1985),it was concluted that the first tea countries were changless in the two periods,i.e.USA,Idnia,Germany,Canada,UK,Japan,former USSR,Australia,China and France,which reflected that the main forestry scientific research countries were of succession and stability.In research substance,the subjects on forest biology and forest cultivation were the leading ones in the two periods,and researches on the subjects of forest entomology and forest ecology were taken much more seriously in the later period than before.But the other subjects,such as forest meteorology,were standed changeless in the later Period.The speed incressing literature amout of forest scientific research in China was much more quickly than the most of other countries.Forest biology,forest entoomlogy and forest cultivation were paid more attention to in china in the two periods,and forest ecology,genetics and breeding were focused in the later period.
The methodological prineiples' of English composition are discussed based on the text features:coherence and cohesion.The case study indicates that disordsred utterances can be organized into a text according to the text features,and that gists of texts change with the variation in ways of composition.
Zhejiang Province is an important producer of economic forests in our country because of its mildness in elimatic codnitions and abundance in resources of commercial species of trees.But development of economic forests is tortuous due to some historic reasons.Within 46 years from 1933 to 1978,fruit produce of the whole province only increased by 45.37% from 105000 tons to 146100 tons,so did dry fruit produce.Since1978,production of economic forests has developed fast on account of adjustment of Policiesf or rural areas.Winth in 16 years from 1978 to 1994,fresh fruits increase about 11 times as much,dry fruits increased by 65.89%,tea by 86.90% and leaf Production of white mulberry by 102.90%.A highest level in history is reached at present in area,produce and benefit in production of economic forests.History,reasons present status,;achievements,problems and future tendency towards the development of economic forestrs in our province with corresponding measures to be taken were analised here.
This paper begins with analysing the present state of the ecological forest at Qiandaohu Lake,then it presents views on several problems about the construction of ecological forest for public profit,such as national supporting policy,compensation of ecological profit,forest form reform,forestry running rules and forestry laws,etc.
Four grafting methods for Castanea mollissima were contrasted.The results showod that veneer-scion grafting was suitable from mid September to late October。Bone removing method was best in spring.The survival rate of both methods reached more than 90%.In summer(from early July to early August),the best grafting method was to cut rootstock tops and twigs and preserve leaves,the survival rate 90%.
The spatial distribution Pattern of Petrova cristata larvae was tested by means of frequency distribution and distribution index.Sequential sampling and the confidence of tree different sampling methods were analyzed and evaluated.The results showed that the spatial distribution Pattern of Petrova cristata larvae was generally nagative binomial distribution in the young growth of Pinus taiwansist.The Parallel sampling,diagonal line sampling and chessobard sampling methods were all fitted to sampling surveys of the larvae,and the chessboard sampling was much better than others.
Brazil has 6 million hectares of artificial forests,from which about 30 percent of timber is taken.The main productive experience for it is as follows:①Directive breading has been taken as regards the maket demand at home and abroad;②The management system of making forestry,commerce and industry acoordinated proeess,which means being independant in afforestation,in lumbering,in processing and utilization of timber and in its export,has been practised:③Much attention has been paid to science and technology in order to improve the productive forces of timberland and decrease the cost of production:④Environmental protection has been laid stress on.The paper puts forth that in order to develop artificial forests of our country,we must concentrate our efforts on the reform of structure,attach importance to the support in policy,and enhance the cultivation and management of fine varietres of seedlings.
The crticle sumrnarizes the value of historical science about the notes of famous Paintings through the ages,and emphasisly commuents on the theoretical achievement of five grades discussing Painting standard,the style of Pen and ink,sparsity and density two style that affect the forming and developing of chinese painting style.