1993 Vol. 10, No. 1
The anatomical structure of old root, 1-5 year shoot, 22 years old trunk and leaf, the formation of periderm and bark, the wood structure inthree dimensional sections, the number of stoma on leaf epidermis and so on were investigated in detail by a lot of tissue micro-sections of vegetative organs in Sassafras tsumu and partly by scanning electron microscopy. The results of this observation demonstrate that the characteristics of innerstructure of root,stem, and Ieaf in S. tsumu are closely correlated with andsuited to its biological characteristics which are like light, afraid of drought. At the same time, the scientific analysis of the Phenomenon why the stems of S. tsumu are susceptible to freezing and sunscald injury in artificial forest has been made. The basic thoery stated in this paper can provide reference for the improvement of silviculture techniques and the adoption of new managing methods.
In recent years, severe outbreak of Dasyneura pyri Bouche has occurred on pear tree in various parts of Zhejiang Provinee. The cecidomyiia develops on the leaves on which galls are caused by larval feeding. The morphology of egg, larva, pupa and adult of the cecidomyiia are described, and observations on its bionomics are recorded in the present paper. There are two or three generations a year in Lin'an County. It overwinters as fullgrown larva in the surface layer of the soil. Eggs are laid on the unopened leaf buds or the newly expanded leaves of the tree, and larva feeding results in the edges of the leaves curling along the apex inwards and becoming two galls. Up to 50 larvae are noted in a single gall, inujry always withers up the pear sprouts. Effective control may be achieved by spraying with omethoate or methamidophos, and decamethrin+dimetheat as well against the early larval stage.
Chinolyda flagellicornis (F.smith) found at several counties in Zhejiang Province is a kind of destructive Pest harming Cryptomeria fortunei Hooibrenk.It has one generation each year at Lishui City and the prepupaoverwiters in the soil cell.The Pest eats the skin and leaves at biennial branch, which could cause harmed trees died down. Larvae have 5 to 7 instars and the capacity for eating inquantity after the 4th instar. Adults have not clear photokinesis. On an average, a female adult produces 27.6 ova. The ratio of male and female is 2:1.
Anthracnose of Hemerocallisis caused by Colletitrichum liliacearum Ferr., its incidence is 85%-95% and disease indexes are 28-43. The pathogen could overwiter in the disease tissues ofHemerocallis. The primary infection of the disease occurres during late March and its gleization period lasts ten to fourteen days. The disease happens from April to November and flourishes from late May to June and from late August to September. The pathogen can infect leaves and scapes. There are brown spots on the diseased leaves which would die under the serious infection. High rainfall,long rain duration, warm and moist conditions are favourable to the infection of the pathogen. The pathogen grows best on PDA medium. The suitable temperature and PH values for the growth of mycelian are 20-30℃ and 3-10 respectively, and the optimal 25℃ and 6. The suitable temperature for the germination of conidium is 20-30℃. The killing conditions of conidium are at 50℃ for 10 minutes. The results of chemical control in laboratory indicated that 0.050 percent thiram, 0.075 percent chlorothalonil, 0.020 percent tricyclazole and 0.050 percent mancozeb in solution are effective fungicides for this disease.
This Paper servayed the low yielded reasons of Plum and tested the ways to deal with situations, with results showing as follows: 1, fruitless trees and low yielded trees almost accounted for two-thirds of the total trees in the Plum orchard, high yielded trees only 29.01%; 2, imperfect flowers,as high as 45.58%, caused the low rate of fruitage, with the average being 7.12% in 4 years; 3, Plum bloomed in early spring, during which the temperature was too low and the sunlight was limited and the rainfall days were too many, which were not good for the pollinating and fertilizing, and frequent cold waves damaged the flowers and they young fruits. The test showed that the potantiality of the Plum was great. Some ways to deal with situations, such as field management, disease control, prevention from the early leave fallen and pruning, could reduce the fruitless trees and could improve the product per tree, and could increase the yield per hectare by 1.5 times. The yield was as much 1.5 times as contrast one by using the optimum set on the high position graft.
The fruit development of Tianmu Sweet Plum could be divided into 3 stages: the first of which is a 44-day fast growing period lasting from flower wilting to May 4th, during which the vertical and horizontal diameters of the fruit respectively account for 59.48% and 48.81% of those of the mature fruit;the second of which is a 21-day slow growing period called hardstone stage lasting from 5th to 25th of May, during which the vertical and horizontal diamters of the fruit respectively account for 11.48% and 13.57% of those of the mature fruit; the last of which is a 35-day fast growing period lasting from May 26th to July 1st when cells increase in volume and the fruit is largest, during which the vertical and horizontal diameters of the fruit respectively account for 29.07% and 37.62% of those of the mature fruit. The development of the fruit flesh varies in different parts of the fruit, with cells of the fruit peel increasing most slowly in area. The whole process of the fruit development coincides with that of drupe fruits showing a fast-slow-fast double s curve. Einally 3 technical measures for raising the quantity and quality of the fruit are suggested.
Withthe methods defined generalized genetic parameter, generalizedphenotypicvariance,genetic variance, heritability and genetic correlation coeffient were estimated based on covariance matrix and correlation matrix respectively, using data of provenance test platations ofPinustaiwanensis in 2 sites, Zhejiang Province. The results showed that it was unsuitable that generalized genetic parameters was estimated based on all eigenvalues, and about 95%of cumulative contribution rate was the most suitable. Generalized heritability estimated are 0.32-0.48 and 0.66-0.87 based on covariance matrix and correlation matrix respectively. And comparablity of the generalized genetic parameters were better based on correlation matrix. The detailed discussion was made about estimating methods and practical application based on the results of primary analysis.
Growth equations are fitted with the data measured at 227 plots in Suichang County based on discussing the natures and types of these equations. This Paper sellects Richards equation as the growth equation of stand inventory factors, establishes the growth model of stand average DBH,stand average height, stand basal area and stand volume of man-made forest of Chinese fir and analyses characteristics, increment and growth rate of the forest in Suichang.
On the basis of establishingheight growth models adapting Richards function as a basic model for six-five dominant treescollected from Chinese fir stands in Zhejiang Province, this papercompilesthe polymorphic site index table of the stands by the estimating parameter method. The comparison with the monomorphic modelin Zhejiang Province shows that the fitting and predicting precision of polymorphic site index model both are obviosly higher than those of the monomorphic model.
With the method of quantitative theroy I model, this paper gives a regression equation which relates to the site index of officinal magnolia and some site factors. The results show that the factors which play a leading role are soil structure, soil thickness and slope shape. This paper establishs a quantitative site index table, too. The table has a high precision and is a practical table in the management of officinal magnolia.
This Paper classified the forest land several types of productive forces and made out a solution by which the tree species and forest category matched optimally the types of productive forces of forest land according to model of linear programming. The experimental results showed that the quantity and output value of forest products and the managers' net income in Lin'an County increased remarkably after adopting the optimum matching solution so that there was a big ecological and economic effect.
The methods discussed in this paper such as utilizing aerophotograph interpretation, plotting the outline of subcompartment of forestation base could prove to be more practical, improve the designing quality of the base greatly and economize a large quantity of manpower, material and cost.In the mean time,aerophotographs could be transfered into sketches by these methods more easily than before.
The bamboo literatures published from 1951 to 1990 in China are statistically analysed by quantitating the literatures. The numerical variation of literatures in past ten years shows that the comprehensive development and utilization of bamboo resource, including the utilization of bamboo and bamboo stand environment, has been the most important research emphasis and a hot-point in bamboo research in lasts everal years. However, the aspects of comprehensive development and utilization of bamboo resource are out of balanee, because the Iiteratures of bamboo products processing and bamboo panels (the main aspects of the utilization)approximate to 50 percent of total literatures. It is discussed that the present situation, utilization methods and movement of comprehensive development and utilization of bamboo resource, and some thoughts are proposed.
The basic zymogram of Peroxidase isoenzymes of Chinese sassafras at the age of 9 years consistes of A1, A2, B, C1, C2 and C3 enzyme bands. Young leaves in a middle section of the crown are most favorable for sampling. The zymogram of samples taken from a crown's sunny side and a crown's dake side has no difference. The samples taken from April 10th to May 26th have no effect on zymogram. There is no significant differenceabout zymogram of samples from different provenance and families.
The testof spraying 3species ofDendranthema morifolium with PP333solution in different concentrations and durations indicates that PP333 can dwarf the plant, short the length between the nodes, increase the chlorophyl content in leaves, delay flowering, lengthen the blooming period and make the leaves to become smaller and thicker.
Chamaecyparis formosensis, Chamaecyparis obtusa var. fomosana, Taiwania crgptomeriodes, Pseudotsuga wilsoniana and Cunninghamia konish are all Taiwan endemic valuable timbers and ornamental tree species. We successfully raised a total of approximate 4000 vigorous seedlings of the five species using a few seeds collected from the northern part of Taiwan. Based on the one-year-old seedling performance the ranking from best to worst isCunninghamia konish , Chamaecyparis formosensis, Pseudotsuga wilsoniana, Taiwania crgptomeriodes, Chamaecyparis obtusa var. fomosana.
A forestation contrast of 41 tree species had been conducted on Hengfan Forest Farm of Lin'an County for 17 years, with the results that 16 tree species were eliminated because of extremely bad growth and low survival rate: that 5 species grew bushily with a low survival rate and bad growth; that 4 species grew ordinarily with survival rate being above 60% and that 16 species grew well with the survival rate being above 80%. Conifers such as Pinus taeda, P. ellitottii and P. serotina grew well, with the amount of growingstock per unit area for 17-year-old trees being 1.0-1.7 times as large as that of masson's pine. Of 3 varieties of Chinese fir, grey-shoot Chinese fir grew best. Of broad-leaved species Cinnamomum septentrionala, Sassafras tsumu, Choerospondias axillaris, Schima superba and Nyssa sinensis grew well, with the height, diameter at breast height and the amount of timber volume growth surpassing those of masson's pine on the same site, and the amount of annual timber volume growth per unit area being, on average, larger than that of masson's pine by 24.46%-65.96%. From the trial had come the result that the conifers and broad-leaved-species mentioned above showed great promise of development and extension on the hilly ground of northwestern Zhejiang.
The young plantation of Chinese fir had high qualities in Suichang County of Zhejiang Province during the recent three years because of a whole set of forestation measures being put in to effect, which impelling the growth of the young plantation of Chinese fir and developping the latent productive energy of forestIand.
All overwintering nymphs of Hippota dorsalisobeyedaggregation distribution at different population density. The basic part ofdistribution was individual colony.The cause of aggregation was related to not only the environmental factors but also the gathering behavior of the overwintering nymphs. Two to three nymphs ofHippota dorsalisin mean up a plant were critical value of changing the aggregation system. The sample data was transformed by Iwao's transformation formulae could get a better result. In addition, with Iwao's method, the sequential sampling table of the overwintering nymphs ofHippota dorsalis was obtained and the optimum sample size was calculated.
Employing Ontsira palliatus in the Chinese fir seedorchard that was being damaged by Semanotus bifasciatus had a good result. The parasitization of 1st generation in the forests reached 46.60-61.11 percents. The spread radius of 1st generation was about 200 metres.