1993 Vol. 6, No. 2
As part of the systematic study, the element contents in rainfall, throughfall, stemflow, surface flow and stream were measured from October 1990 to October 1991 at the secondary rain forest catchment of tropical upland in Jianfengling,Hainan Island,China. The hydrochemical properties and migratory changes of nutrient in the hydrochemistry system were studied and analyzed by the method of small catchment and orientation observation. Element contents of the throughfall and stemf low increased by 0.43~15.1 and 0.26~24.7 times more than that of the precipitation respectively. Except Ca, Si and Al, the elements of stream were less than that of the through-fall. The output contents of Ca and Si were more than the input of both. It is pointed out that the rainfall and throughfall are an input source of the hydrochemical elements of the secondary rain forest ecosystem of tropical upland. The system not only has stornger hydrochemical regulating function but also has the function of chemical filtration, uptake and store. Moreover, multivariate linear models have been established between each element content and the characteristics factors of precipitation in throughfall, stem-flow, stream.
Based on the result from teak provenance trial there are significant differences in drought resistance among the provenances, the morphological and anatomical structures and the mechanism of drought resistance were further studied. It has been found that there are highly significant differences in major morphological and anatomical characters of lamina and petiole among the provenances. This result is in accord with that of field investigation of drought resistance. The sequence of xerophilous capability of the provenances is 30723070the other provenances tested. The xerophilous mechanism is caused by joint effect of some morphological and anatomical characters including the increase of water utilization effeciency and decrease of water consumption and loss within the plant. It is incorrect that only stoma density and stomatic chamber size are used as xerophilous indexes. The thickness and area of the lamina and their ratio, the cuticular cell layers of the lamina hypodermis, the quantity and structure of vascular bundles in the petiole can be used as the indexes of xerophilous breeding and prediction of drought resistance at early stage.
The test material used in the study was the poplars planted in Baoding, Heibei Province, whose wood basic density, fiber length and width were analysed. The result reveals that: (1) there are obvious differences between the wood basic density and fiber length of different hybrid combinations and individuals. The differences between wood basic density and growth property is not significant; (2) the two properties can be selected separately, therefore the new poplar hybrids which has high wood basic density, long fiber length and fast-growth can be selected. (3) the relationship of wood basic density between juvenile and adult wood is significant, so the early selection can be adopted in poplar breeding. The crossing, which P. deltoides cv. ‘Lux' was used as mother plant and P. mgra the father plant and inter species hybrids, was the best combination for selecting fast-growing and good quality poplar in the North China area.
Based on the measurements of eight-year-old test plantation of paulownia, the juvenile-mature correlations of height,diameter and volume were analysed by means of rank correlation, genetic correlation and phen-otype correlation. The linear regression equation of the juvenile-mature correlation was set up and the annual efficiency at different selection age was calculated. The results show that the early selection of superior paulownia clones is feasible and the expression of paulownia clones at the age of three could be used to predict the growth of clones at the age of ten to fifteen. Therefore, it is possible to select good clones when they are three years old.
This paper deals with nitrate reductase (NR) activity and nitrogen storage contents (nitrate,amino acid and total nitrogen) in seedlings of Chinese Fir (Cunninghamia lanceolata Hook.) with different growing rates. The results showed that (1)the level of NR activity varied with the growing period. Generally, during the initial growing stage NR activity was low, and the maximum activity was observed at the peak of the growing season. The NR activity in seedlings of the fast growing clone was higher than that in the slow growing clone. NR activity in young seedlings of different age (1,2,3,4,5 years old) was higher in the fast growing clone than that in the slow growing clone. Positive relationship between NR activity in seedling (1-year old) and tree height (5-year-old) was observed. (2) the fast growing clone had higher ability of uptake and assimilation of nitrogen than that of the slow growing clone. Thus, during and after growing stage, the former contained higher contents of nitrate, amino acid and total nitrogen than the later did. Glutamic acid, aspartic acid and histidine contents in leaves and phloem are about 70% of the total amino acid contents.
In the present paper a new species of sawflies from China is described, which is an important destructive forest insect pest of Liriod-endron chinense (Hemsl.) Sarg. The type specimens are kept in the collection of forest insects in the Research Institute of Forestry, CAF. Megabeleses liriodendrovbrax n. sp.
Du-ensiform gall caused by Du-ensiform gall aphid, Kaburagia rhusicola on a sumac tree, Rhus potaninii, is one of the important Chinese gallnuts in China. The population of the aphids in the gall grows rapidly, increasing as much as 3 000 times in about 3 months. But it drops sharply out of the gall owing to the high mortality and low vitality. The aphids from the same gall can complete their life history in a year or two years or even more. Although the survival rate of those individuals which finish their life history in a year is about 0.3%~1.5% of the total nymphs inoculated on the second hosts, mosses, in the last year, the population can increase as much as 40~180 times. The individuals which complete life history in two years as a result of extremely high mortality on the second hosts grows poorly. So people have to make good use of the individuals finishing their life history in a year and manage to reduce mortality of the aphid during overwintering on the second hosts to obtain a high yield of the gall.
The die-back of pines caused by Sphaerpsis sapinea (Fr.) Dyko & Button widely occurred in Jiangsu Province in recent years. Pycnidia of the causal fungus developed on infected needles, sheathes and scaly-leaves. Conidia are dispersed by rain. The pathogen of die-back of pine can't dissminated by seeds. The infectious stages of pine shoots coincided with the conidia-releasing stages respectively. The tender shoots are highly susceptible when their lengths reach to about one-third of the total length. The pathogen invade the shoot by direct penetration through the epidermis. Mature pine stands may become more susceptible, but young stands surrounded by severely diseased mature pine stands is also infected severely. Pine stands on poor sites are seriously infected. Pinus massoniana is the most resistant species of the genus. The other species in order of susceptibility are Pinus riglda, P. bariksiana, P. taeda, P. elliottii, P. thunbergii, and P. yunnanensis.
Seed of Vatica astrotricha and its embryo had an increment in superoxide content and iodine number as the moisture content of the seed lost. In this process, the plasma membrane constituents of embryo cells are oxidized, so that its ultrastructure is destroyed, semipermeable function lost and then the deterioration of embryo occurs. This may be the fundamental reason for seed deterioration. Seed vigour has a true correlation with the "coleorhize" quality. Seed maturity influences the plumule growth obviously, the poor-maturity seeds lose their moisture content faster, and lose their vigour more easily.
To solve the present shortcoming of slow and complicated coventional examination and data processing in testing of tree seed quality, 1581 seed samples of 139 tree species from 18 provinces in China were collected to carry out quick examination by photo of soft X-ray, dyeing by TTC method and moisture content by kett type electronic moisture instrument and conventional examination of seed quality. Several quick examination's rectificable models for germination percentage of nursery, germination percentage of laboratory and seed moisture content were established by applying various mathematic models. The computer data processing and visa system of seed quality's examination were successfully designed in APPLE-1 and IBM computer. The system can take in all original data of each index and examining method and at last print out examination certificate of tree seed quality according to differentiation of error rate, delimitation of grade and synthetical analysis of seed quality ia computer. The system have certain advantages of quick examination: simplicity, convenience, accuracy and complete function etc.
In the natural distribution area of Chinese Hippophae, from the west to the east, Dongxia Forest Area, Datong County, Qinghai Forest Area Qinghai Province etc. 5 representative regions were selected to study the variation of main economic features and the matching condition of Chinese Hippophae by means of sample plot survey and statistical method. Differences and similarities of different populations were compared, basical parameters of every main economic features calculated and the possibility of matching of the features in overall pointed out. It's considered that the 5 populations can be divided into 2 groups. Variations among different populations are represented by the gradient of frequency of some features.
For the determination of certified values of reference materials of forest soil, two or more accurate and reliable analytical methods were used for the analysis of each chemical element. The most commonly used methods were the national standard analytical methods for forest soil. After the analysis the following certified items were accomplished: 16 for calcareous cinnamon soil, 15 for yellow-red earth, 16 for Chinese fir leaves. The statistical steps for processing the certified values are: to reject the outlier values, to examine the normal distribution, to calculate the certified values and to evaluate the uncertainty of the reference materials.
The effects of different number of egg chambers and boring holes of Anoplophora glabripennis (Motsch) on growth of Populus euramericana Guinier cv. "Sacrau-79" were observed by using artificial parasitization and damage simulation. The result showed that when the egg depicts was under 50 per tree in the two year old poplars, the growth of poplars was accelerated. Through making 1~9 boring holes in 3 year old tree annually consecutively for 3 years, the growth of poplars in these three years were: breast diameter increased by 22%~49%, height of tree decreased 5%~25%. From the dissection of the wood of 16 year old P. x dolcuanensis and P. x simöpyramdalis, we know that the boring holes of A. glabripennis can degrade 89% of the wood into 3rd grade, this makes a 46% value loss of the wood.
A comparision investigation on the mortality of white wax scale insect in relation to rainfall and annual temperature in different years at four counties and one municipality in Guangxi Province has been carried out. The results show that the average annual temperature is a negligible factor on the insect's mortality, but the annual rainfall has been proved to be a causative factor. High mortality usually appears after every heavy rain, and the female insects are more susceptive to it than the males. The upper limit of annual rainfall is about 1552.5mm, under the level of which the insects of both sexes develop normally with low mortality. Under unfavorable conditions a high mortality would follow, the percentages of which varies with the annual rainfall of the year. The results also show that in excessive rainy days the male, though not so susceptible as the female to rain, and yet its wax encrustation will be mildewed and blackened, causing the final death of the insect.
Glyphosate is a wonderful post-seedling chemical herbicide in broadcost seeding nursery of Pinus taeda and P. elliottii, as well as in the nursery of P. massoniana and Chinese Fir. The applying time is: in the nursery of P. taede and P. elliottii it can be applied before the seedling height is 15 cm (June 30 th); in the nursery of P. massoniana it should be applied before the top shoot grows to a length of 1.0 cm, but if the seedlings grow to a height of over 5.0cm then the seedlings will be seriously damaged. Applying its application in Chinese Fir nursery have will hurt the seedlings a little. Usage: content a water solution of 10% liquid Glyphosate per ha is effective to kill part of the weeds withless than three leaves and to suppress the growth of a few surviving weeds. Comprehensive weeding efficiency reaches over 90%.
The photoperiodic effects on the growth and development of pine caterpillars should be seriously considered in the application of the EAT (effective acumulation temperature) in predicting the generations of this pest. Photoperiods play a key role in determining the generation and its differentiations of Dendrolimus spp. in nature. In that short day cycles can cause the increase of instar and the prolongation of larval periods, and make caterpillar need more days to complete its life cycle. In the field,the prolongation of life cycle varies mainly according to the photoperiods received by the young larvae. A standard method which estimates the EAT of pine caterpillar is suggested in this paper.
Study on the simulation of diameter growth of Chinese Fir is conducted based on the competitive mechanism of stands. The crown and its length are taken as main competitive indexes, and the competitive function f(Cr,l) as main growth potentials to calculate potential growth function fp(Cr,l) and practical growth function fd(Cr,l) of stands. The curve of potential diameter growth of a stand can be therefore brought out from the practical growth function adjusted by coefficient K. It is considered that the potential diameter growth of a stand is the growth of diameter under the environment without any competition, namely the potentials of diameter growth of a stands is fully played. So diameter growth models can be calculated through the potential growth function adjusted by competitive coefficient C. Furthermore, the forecasting model of diameter growth can be gotten from the comparison of competitive potentials f(Cr,l). The model can be used to forecast the annual growth of stands, and provide guidance for thinning and management of stands. It is also useful for the estimation of rational rotation and comprehensive management of stands.
A simple and improved algorithm is developed which extracts the polygonal contour representation from a raster format thematic classification map. The design adopts a 2×2 window which is used to scan and extract the boundary pixels of adjacent polygons along each pair of lines of the map. Contours are thus generated as a list of (X, Y) coordinate pairs, together with the attributes of the left and right regions at both sides of the boundary point. In the process of line segment tracking and polygon tracking, various attributes and topological relations are established. The structure, attribute and topological information of the vector data obtained are integrated and standardized, and they are easy to inquire and operate, and make the postprocessing flexible. The algorithm described in this paper has been implemented on a 386 microcomputer.
There were highly significant variations within and among trees in plantation of Masson Pine for latewood tracheid length. The tree, ring and tree x ring interaction effects accounted for 13%, 39% and 9% of total variation respectively, and the radial effects were small. Variations from the pith to the bark and from the base to the top complied with the general rules of tracheid length in conifer. Theoretically, the combination of ten trees and one radius was a better sampling strategy which would estimate effectively the wood properties of a population or a strain. The age of transition from juvenile to mature wood for tracheid length of plantation was about 12 years and was more than one of natural stands in the same geographical region. The percentage of juvenile wood decreased dramatically with tree ages and varied with different individuals.
A NPV strain was isolated from sponeaneous dead mortal larvae of Catopsilia pomana Fabricius. The mortality of C. pomana larvae which were infected by the NPV of 1.2×108PIBs/ml was 100%. When this NPV was used to infected the Pierae rapae larvae of the 3rd~5th instars with the same concentration, it showed 94.6% mortality. The cross-infection test revealed that this C. pomana NPV strain is a useful natural resources in broad spectrum insecticide research.
Petrova cristata and Dioryctria rubella feed on the cones of different stage which emerged in the year before. The cones and seeds are damaged at different degrees. The effect controlling measure is to control its adults.