1989 Vol. 2, No. 3
The dynamics of leaf litter in timber stands of Phyllostachys pubescens was studied in four locations in southern China. Ninety litter traps in twenty one blocks and four hundred litter decomposition bags in another twenty blocks were set up and continuously monitored over three years. Loss of weight as well as leaching of N, P, K, Ca, Mg from the litter was recorded by periodic field collections and laboratory analysis.Results indicate that there are two peaks though the dates for these varied with the geographic locations of the stands. Litter fall during the first peak was about 80% of the annual fall. Weight loss of litter was rapid initially, stablising after twenty weeks. Nutrient release differed from element to element and seemed to be released into the soil after an initial accumulation stage.
This paper deals with the moisture content of seeds of Vatica astrotricha and the methods for measuring or controlling it in order to keep their high vigour. According to the results obtained from a series of measurements, it was suggested that the moisture content of seed, especially that of embryo is the crucial factor to affect its vigour. Using the coconut dust with 27-29% moisture content, the embryo moisture content may be controlled within 50-52%, i.e the seed moisture content within 30-36%,and let the seeds keep some respiration rate (50-60 O2μl/g·h as measured at 32℃), the seed vigour will be kept at a high level, therefore, the seed longevity will be maintained. It was found that in storage there is a best-point in safe moisture content range of seed, which is near by the low-limit and may be measured by the interrelation between moisture contents of the seeds and their wings, or of the bigger seeds and smaller ones. The methods are accurate and quick, as it is simple to determine the low-limit of safe moisture content, therefore, it may be considered as a new shortcut for all the "recalcitrant" seeds.
In this paper, six species of Chinese sesiids were described. These species belong to five genera, of which one is new to science, and two new to China. They are diagnosed as follows.
Intermediary experiment of Olive cultivation has been carried out in Hubei and Shanxi Province from the year 1980-1987. The experiment orchards distributed in Wuchang, Yichang, Badong, Chenggu etc. eight counties (towns) with an area of 133.3 ha. in total lying between 33°10' -30°36' N latitude and 115°05'-107°00' E longtitude. This paper deals with the growth, bloom, fruitage, productivity, yield inconsistency of cultivar Frantoio and crossability with its pollinators Chenggu 32 and Leccion. According to the study, Frantoio which grew well in different locations is thought to be with a wide-range eco-adaptability. This cultivar has higher percentage of perfect flowers (80-95%) and normally sufficient fruit set obtained in self-pollination (1.96-2.40%). With good care, Frantoio starts bearing early and its productivity is fairly high. Its fruits has an approximately 79.0-79.2% flesh yield, while its oil content is higher than that of the others tested. Chenggu 32 and Leccion bloom coordinatelly with Frantoio and have a satisfactory fruit set (7.13-9.35%) in controlling pollination with Frantoio as pollinators, as they are planted together with Frantoio can promote grove's productivity.
44 isolates of ectomycorrhizal fungi comprising 38 species were cultured on MMN medium at 15 temperature gradients from 5℃ to 40℃ for 2 weeks. For growth of most isolates, the optimum temperatures ranged from 22 to 27℃ with the optima of 25℃. Most isolates stopped growing at 10℃ and 35℃. A few isolates had a poor growth at 5℃ and 40℃, but at the highest growth temperature for a long time, the isolates were much weakened, even lost their vitality at all. Most isolates of genera Boletus, Leccinum, Suillus, Xerocomus and Pisolithus were fungi of slow growing type, while those of genera Laccaria, Lactarius, Cantharellus, Lycoperdon, Gomphydius, Russula and Oudemansiella were fungi of fast growing type, and fungi of genera Amanita, Boletinus, Cortinarius, Rhizopogon, Scleroderma and Tricholomopsis grew intermediately. But [there were always many exceptions. Different isolates within a species collected from different forest sites maybe react to the temperature variation diversely. For instance, the isolates of Amanita pantherina collected from the spruce forest at altitude above 3400m grew slower than that collected from the pine forest of altitude about 2000m, but it grew faster than the later at low temperature of 10℃ for it has long been adapted to the cold alpine circumstance. They were apparently fungi of different ecotypes. From the point of view of selection of ectornycorrhizal fungi, the isolates are required to possess the fast growing ability, to have a more wide range of optimum growth temperature and to be resistant to extreme temperatures.
The rust fungi of Beijing area had not been reported systematically before this study was finished. There are 34 names of woody plant rust fungi of Beijing area in 《Sylloge Fungorum Sinicorum》, among which only 22 of them are legitimate, 4 are synonyms, and the others are misapplied. The authors collected and identified the woody plant rust fungi specimens in Beijing from 1986 to 1987, as well as the specimens which deposited in the Mycological Herbarium of Beijing Forestry University and Institute of Microbiology, Academia Sinica. The authors have examined 300 specimens, which belong to 15 genera, 33 species of woody plant rust fungi in Beijing, 9 are new records in Beijing.
In this paper, the studies on biochemical and biophysical characteristics of a nuclear polyhedrosis virus of Apocheima cinerarius and its use in the research of viral insecticides were reviewed comprehensively. The characteristics of virus included its purification, serology, structural proteins and genome. The homologous relationship of insect viruses, the earliest detection of viral infection and the development of viral insecticide in China were also discussed in detail.
The paper deals with the research on the modification of shellac by the utilization of tannic acid, rosinate calcium, oxalic acid and ureaformaldehyde resin. Through a lot of tests, the results hsvc shown that the heat resistance and adhesive force of shellac were enhanced by adding tannic acid and rosinate calcium; that the corrosion resistance of shellac was increased by adding ureaformaldehyde resin; that the colour of shellac was improved by adding oxalic acid. The result of "salt-fog" experiment has shown that the corrosion resistance of coat of lac paint was increased by 1.38 times.
In order to evaluate the effect of tree introduction promptly, micro-computer has been adopted to mark various factors and to process data, in which the programe language is extended BASIC. 10 factors of young plantations of 90 tree species aging from 3 to 7 years old, such as height, annual average growth of DBH, suited situation etc., have been investigated and marked. The results show that all the species can be graded into 6 classes, among them 7 and the other 25 tree species are respectively recommonded as planting or disseminating ones there.
The purpose of this sutdy was to classify site types and evaluate the site quality of the plantation of Cunninghamia lanceolata in Nianzhu Forest Farm, Fenyi County, Jiangxi Province, by stand growth and other site factors, especially edaphic factors. Multiple regression analysis was used to study the relationships between site index and site factors. The results showed that the main site factors were slope position and the depth of humus horizon.Ⅱ site types were classified in accord with the two factors, and the forecasted equation of site index was derived to predict stand productivity of C. lanceolata. The paper also preliminarily studied the relationships between site index and foliar nutrient of C. lanceolata. The results proved that site index was correlated positively with foliar nutrient of P%, N%, Ca%.
A study on the phenology of tropical woody plants has been carried out in Jianfengling, Hainan Island. Annual range of variation in phenophase of the woody species depends upon the change of water and temperature in a year. Different species have their own phenophases. Each species has its strict order of phenophase. Phenospectrum of each species is also given.
Nitrate reductase (NR) activity and its in vivo attenuating rate of four species of poplar seedlings with different growth rate were studied. Generally high NR activity was found in the fast growing seedling. Higher NR activity in leaves were obtained, when seedlings were treated with KNO3 solution (20m mol/1). But the NR activity in leaves of fast growing seedling e. g. Populus deltcides Bartr. cv. "Lux" (ex, 1-69/55) and Fopulus euramericana (Dode) Guinier cv. I-214 were higher than in those of slow growing seedling e, g. Populus×popularis Hsü and Populus simonii Carr. The NR activity in detached leaves declined with time.The NR activity attenuation rate in detached leaves of poplar seedlings with different growth rate were different. Such as NR attenuation rate of Populus deltoides Bartr. cv. "Lux" (ex, I-69/55) was lower than that of Populus simonii Carr., they were 31% and 65% after four hours respectively. But the NR attenuation rate of Populus×popularis Hsü. was low after two hours and then it became higher. The use of NR attenuation rate in different species of poplar seedlings with different growing rates are discussed.
Dioryctria pryeri Ragonot is a serious pest that damaged cones and staminate branches of Pinus massoniana in China. The observation of binomics of this insect pest was carried out in Chunan County, Zhejiang Province in 1986-1988.The larvae bore into the cones of Pinus massoniana. The damaged rate is 10.8% in the pine forest in Chunan County. The damaged cones wilt and turn brown and then drop doun by late-fall.The larvae also attack staminate branches. The branches are killed as a result of larval boring. The data obtained were studied by regression analysis. The relationships between the damaged rate of staminate branch(X) and the difference of annual increasing branch rate(Y1), length of health-branch(Y2) were estimated respectively as follows: Y1=77.16+2.80X, Y2=7.63-8.22X.The paper is helpful to study of control index of D. pryeri Ragonot.
In this paper, the proportional method of total area of tree crown was used to establish the density control diagram of Japanese Larch stand for determining the maximum density line.In order to improve the precision of the stand density control diagram, we used the total nonlinear interative method to improve the values of equivalent diameter and equivalent tree height line. When determining the most suitable stand density that is the management index, the index of annual mean increment of the standard plot, the index of mean value of annual maximum increment of analytic trees and the ratio index of crown length to tree height were adopted. These methods were used for the first time in China,
The variation of basic investigation factors of bamboo stands such as volume, total weight of newly born bamboo individuals per year, density and d. b. h. (diameter breast height) are varied, with the least coefficient of variation in d. b. h. and largest in total weight of newly born bamboo individuals per year. Less variation was found in bamboo stands of grade I i. e. stand with high yield and more in stands of grade Ⅲ i. e. stand with low yield. For the measurement of total weight of newly born bamboo individuals per year, the size of sample plot for stand of grade I suggested is about 500 m2 and for that of grade Ⅱ and Ⅲ 600-800 m2 generally. Neither the shape of sample plot nor the location of the rectangular sample plot was found with apparent effect on experimental error.For the evaluation of volume or yield of bamboo stands, the simplest and fastest method found was to multiply the total number of bamboo individuals by the mean weight of bamboo individuals calculated from the mean value of the squared diameter in the sample plot. The average ratio of the deviation calculated by this method from real yield to real yield was less than 0.1%.For sample plots only with data of diameter of brow height (D1), it is possible to calculate the diameter breast height (D) from D1 using following formulae:D=0.02057+1.01767 D1 for stands of gradeI,D=0.16138+1.00546 D1 for stands of grade Ⅱ and D= 0.04155+1.01873 D1 for stands of grade Ⅲ.