1990 Vol. 3, No. 5
The biomass relations among different organs and the patterns of biomass change were studied in the biomass investigation with 1~8 year-old Pauloivnia elongata. Close relationship was found between the biomass of various organs and D1.32H. From the base to the top in a trunk, the biomass decreased successively. During the juvenile period, small twigs constituted the majority in the branch biomass. After 6~7 year-old, the branch biomass was contributed mostly to the large branches. Within the root biomass, 40%~60% came from the root-stake. The distribution of biomass among different types of roots varied with the tree's age. With the age increasing, the contribution of the large roots to the root biomass increased progressively and that of the small roots (the diameter4cm) decreased. According to their biomass, the organs rank was rootstrunkleavebranches before 3-year-old and trunkbranchrootsleaveflowersfruits after 3-year-old respectively.
The pine caterpillar D. punctatus is the most destructive pest of pine forests in China. It occurs in thirteen provinces and infects pine forests over large areas. In this paper, its population system has been studied and its structure model has been established by means of method of system analysis to summarize the achievements in scientific research and practical experience. Steps of modelling are as follows:1.Life cycle of the pine caterpillar being divided into five stages.2.Abstraction and analysis of factors affecting population dynamics of the pine caterpillar.3.Quantitative expression of factors affecting population dynamics of the pine caterpillar.4.Model being built of (A) Population time dynamics model of the pine caterpillar; (B) Population dispersal model.In order to predict the population dynamics through time and space, forests are divided into many grids (100m×100m). The coordinates of each grid are expressed by (i,j), including background conditions and variables in every grid respectively.Population time dynamics model and population dispersal model can be combined together and used to simulate and predict the variation in the distribution and abundance of pest population.The simulation results of the model coincide with the real occurrence laws of the pine caterpillar at Hungpu Experimental Forests in Qianshan County of Anhui Province.
The experiment was conducted on lime concretion fluvo-aquic soil. This soil with clayed texture, compact soil body and low nutrient content is a low productive soil in the North China Plain. 5 Years' trial proved that the site preparation of big pit produced remarkable growth response with 19.8% and 91.8% of increment in D. B. H. and height respectively in the first year after planting; fertilization couldn't significantly increase growth in the first 2 years after planting; but N fertilizer, organic manure and the interaction between N fertilizer and organic manure had the significant and positive effects on the tree growth while the application of P K decreased the growth from the third year to the fifth year after planting. Tree volume in the treatment fertilized with N fertilizer and organic manure was increased by 77%. Treatments N K and N P increased volume by 60% and 58% respectively and produced a high economic benefit, the values of input/output for these 2 treatments were 1:6.22 and 1:3.78 respectively. The integrated benefit of site preparation plus fertilization was remarkable, and 85.1%~88.8% of the benefit was due to available fertilization.
Under natural condition, the development of a mature pollen took 6 months to complete. The first five days after ovuliferous scale open were of efficiency for pollination. The phase of free nuclei of female gametophyte lasted for 12 months, and it took about 7 days to develop from nuclei phase to cell phase. There were two or three archegoniums in Masson Pine. The fertilization took place in the 13th month after pollination. The development phase of proembryo was about 30 days, young embryo 40 days and mature embryo 60 days. The production of mature seeds needed 24 months to go since the differentiation of floral buds. According to the observation on morphological development, we found that there usually were unnormal pollens and pollen sterility in every developing stage because of low temperature and freezing.
A cultivation technique of Gmelina arborea is reported in this paper. The suitable growing area for G. arborea is to the south of 23 癗, where the annual mean temperature is 20.5-24.5℃, extreme low temperature higher than -1.5℃, annual rainfall 1200~2 000mm, annual wind-speed less than 2.5m/s. The suitable site for planting is that of open ground, full of sunshine, loose soil, epipedon organic matter more than 2%, total nitrogen more than 0.1%, available phosphate more than 0.25mg/100g soil, pH value 4.5-6.9, and the soil moisture content is 10%~24%. Seed storage in the desiccator has a best effect, its germination rate is up to 87.4% after storing for one year. Hastening germination of seed with soaking and drying repeatedly or soaking in lime-water for seven days can help to germinate earlier for 10 days and increase 9%~12% of germination rate comparing those of the checks. Bud-seedlings with different types of cotyledon transplanted individually can enhance over 20.6% of the seedling qualified rate than those of mixed transplanting. Besides, the main quality index and the methods of seedling nursing and planting with best effect had been evaluated in this paper. The comprehensive index of cultivation technique is that the mean annual increment in volume is 12m3 per ha.
Varieties and provenances of Pinus caribaea have been tested at 4 sites on Leizhou Peninsula, Guangdong Province and Hainan Island since 1983 and 1984 respectively. The 5-year-old and 4-year-old results show that there arc significant differences in growth rate among the three varieties and the interaction between variety and environment is also significant. On Leizhou Peninsula, P. caribaea var. bahamensis and P. caribaea var. caribaea are the suitable varieties which grow fast and have high resistance to disease and insects, while P. caribaea var. hondurensis not only is subject to the infection of tip moth and leaf wilt disease, but also has a low survival rate and unstable performance. However, on Hainan Island, the growth rate of P. caribaea var. bahamensis and P. caribaea var. hondurensis is much greater than that of P. caribaea var. caribaea.Within a variety, the best provenances of P. caribaea var. bahamensis are from Abaco Island and Byfield (Queensland, Australia), the worst provenances are from Andros Island and the land race of Zhanjiang, China. All provenances of P. caribaea var. hondurensis except those of Los Limones and Santa Clara grow relatively well both on Leizhou Peninsula and Hainan Island, There is no significant differences among the provenances of P. caribaea var. caribaea.
This paper states the research about the changes of bamboo seedlings, the relation between environmental factors and the changes of both biomass and photosynthetic rate. And some progress has been made.1.The height, the length of roots and biomass of the cultivated seedlings in nurseries with better condition are better than those in nurseries with poorer condition. The biomass of the potted seedlings manured is 3 times more than that of not having been manured.2.(1) The light saturation point and compensation point of the seedlings arel ower than those adult bamboos while observing from the measurement of light and the curve of light intensity of single leaf. (2) Under the normal conditions of the density of light quantum current, the photosynthetic rate of single leaf is low in the early morning and evening, and is the highest at 10 in the morning. And small concaves will appear on the curve at about 1 p.m.. Under a low density of light quantum current when the changes of other factors are smaller, the changes of photosynthetic rate (Pn) are mainly affected by light quantum current (Q) (If Q rises up, Pn will increase. On the contrary, Pn will decrease).The results show that if the method of measuring the photosynthesis will be adopted, during the stage of cultivating through effective identification of some management techniques, seedlings cultivated in nurseries have the advantages of small amount of work, a short cycle and precise data over those cultivated in the fields.
In this paper, appling YELLOW RICE WINE RESIDUE (after making yellow rice wine) as the main component of medium instead of yeast powder and starch, the results are promising. The toxicities against the test insects (Dendrolimus tabulaeformis, Lymantria dispar, Apocheima cinerarius) of two fermentation products (e.g. the yellow rice wine residue medium I and medium I used in the factory) were similar. The cost of medium I material was reduced by above 30%.
A kind of suitable regressive model was found in the research of growth loss of young poplars infected by Dothorella gregraria. Statistical examination showed that the models have higher interrelation between variables, less residuals and better regressive curved lines than many other tested models. Besides, the models can exactly describe biological regularity of growth change. The results are of importance for some production departments to predict the growth and yield loss caused by some plant diseaes, master prevention indices and estimate economic benifits.
Apriona germari is one of the important stem boreres of clones of the Aigeiros poplars. The biological character of the adult shows that it has to feed on the bark of branches of the mulberry or paper mulberry to complete its life cycle. Three kinds of microencapsulated Decamethrin, Fenvalerate and Sumithion had been developed to spray on the mulberries during the emergence of the adults. Their residual effects maintained more than 15 days in the rainy season. Microencapsulated Decamethrin, Fenvalerate maintained more than 30 days and Sumithion microencapsule maintained 15 days in the rainless region. The results of these microencap-sules are better than their corresponding emulsions.
Sixteen endophytic actinomycetes were isolated from the nodules of Casuarina equisetifolia planted in Fujian, Guangdong and Hainan island. All of them have the typical morphological characteristics of Frankia. 12 out of 16 strains have infecting abilities, but infecting abilities of these isolates are different from each other. The strains showed differences in cultural characteristics. The tested strains grew well on BAP medium but grew poorly on Jan Blom or Qmod medium.
The tests of natural and artificial low-temperature treatments, water loss of seedlings and growth recovery of the seedlings treated under low-temperature condition, are carried out to compare the cold resistance of the new variety with that of the checks, or P. deltoides cv. 'Lux' (ex. I-69/55) and P. euramericana cv. I-214. The results show that the cold resistance of the new variety is significantly higher than that of the female parent I-G9 and slightly higher than that of I-214, indicating that the new variety has inherited the cold resistance from the male parent, P. nigra. The expected aim is gained.
This paper recommended the principle and technique for determining transpiration rate in trees by aerodynamics. The result has showed that the method is feasible for determination in the field. Some further studies are needed.
This paper deals with the selection of suitable form, concentration and pH value of nutrient solution for the water culture of and E. 12ABL seedlings. The results can be summarized asfollows:1.Among the four nutrient solution forms which are of representatives i. e. Hoagland, Plonisnicofe(Лрянишников),Cronip and Walker et al. nutrient solution forms, Hoagland one is the best for the growth of the two species seedlings.2.The standard concentration of Hoagland nutrient solution is more suitable for the growth of the seedling than the others.3.The range of pH value which is suitable for the seedling grow th is 4.0~6.0 but 5.0 is the best.
The osmotic ground value (Og) of subepidermal cells of leaves of Populus euphratica Oliv. was tested by using the method of incipient plasmolysis. The results are: (1) The Og used as the physiological index of salt resistance of P. euphratica can show the specific salt resistance of P. euphratica.(2) The salt resistance of P. euphratica gets stronger as it gets older by testing the Og.(3) The resistance power of P. euphratica varies significantly to different kinds of salts which the saline soil greatly has. The order of its resistance to these kinds of salts from strong to weak is MgSO4, NaHCO3, NaCl according to the Og.
The authors have observed the chromosomes of the somatic cells in the root tips of 20 species belonging to 20 genera and 14 families since 1988, of which 4 species are reported here for the first time.The chromosome numbers of all species are as follows: Acer yangiuenei 2n=34, Althaea rosea 2n=42, Belamcanda chinensis 2n=32, Berberis julianae 2n=28 + 2B, Bidens pilosa 2n=72, Callistephus chinensis 2n=18, Cercidiphyllum japonicum 2n=38, Chrysanthemum nankingense 2n=18, Coriandrum sativum 2n=22, Duchesnea indica 2n=84, Emmenopteris heneyi 2n=76, Firmiana simplex 2n=40, Foaniculum vulgare 2n=22, Magnolia officinalis 2n=38, Mains malliana 2n=34, Robinia pseudoacacia 2n=22, Sambucus williamsii 2n=36, Smilax china 2n=90, Vicia sativa 2n=12, Zinnia elegens 2n=24.
Sugars and amino acids of bamboo twigs damaged by Hippota dorsalis (Stal) are determined by HPLC method. Results show that total sugars and soluble sugars decrease with the injury increases. The contents of their components, such as sucrose, glucose and fructose, decrease at different degree.Free amino acids sharply increase with damage increases, among six-year-old bamboos, content of amide increases nearly 32 times, which makes up half of the total free amino acid; ARG grows up from zero to 46.49mg/100g after severe damage. LYS also increases 37 times among two-year-old ones.Total amino acids also have a marked rise after proteolysis treatment, but they have reached the highest level before severe damage comes. The total content increases 1.7 times while ARG goes up 5 times more than the contrast.The changes of different direction in nitrogen and sugars are a kind of reaction of plant to the infestation of the insect, which causes disorder of sugar and nitrogen metabolism among infested bamboos.
Lichens were studied on camphor (Cinnamomum camphora) trees of the same age along the road from Hangzhou airport to the city centre. The number of species declined from 14 close to the airport (13 km) to 0 about 5~6 km from the town centre. The pattern reflects that seen in many European, and North American cities and shown to be correlated with air pollution. It is therefore clear that lichens have considerable potential as cheap biomonitors of air pollution in the People's Republic of China. The most tolerant species was an apparently undescribed species of Lepraria.
This paper describes two species of sawfly, Pristiphora wesmaeli Tischbein and P. lands (Hartig), in Bailing, Hei-Longkiang Province, which are new records in China. According to the field observation, P. wesmaeli has one or two generations a year, but in the laboratory, three generations a year in parthenogenesis. P. laricis has one generation in the field, two parthenogenerations in the laboratory and it diapauses in the summer. For identifying the species, besides the descriptions of adult, tabulars of eggs, larvae and the damage are prepared.
Frass-drop and characteristics of spatial distribution patterns of the larvae of Dendrolimus punctatus in low population were studied by means of Frequency Distribution, Iwao's and Taylor's method, and some other aggregation indices. The result shows that:(1) The spatial distribution pattern of the overwintering larvae was aggregated, and the basic components of the distribution were single individuals which repel each other, and that of the frass-drop in the same generation tended to be uniform.(2) In the second generation, both larvae and the frass-drop were spatially aggregated, and the degrees of aggregation were higher than that of the overwintering generation. The experimental data were transformed seperately with three methods, among which the Iwao's method is the best for frass-drop data.
Selepa celtis Moore is a pest of Duabanga grandiflora and other species of trees and crops. In the field, its generations are overlapping. It has about 7~8 generations each year in Guangzhou, Guangdong Province. The females lay their eggs in masses of 30~100 on the leaves where the larvae eat the leaves of the trees, but they are skeletonizers throughout their larval life. There are 4~5 larval instars. When mature, they drop to the ground spinning their cocoons to pupate. During summer and fall, the egg, larval and pupal stages last 6~9, 13~19 and 8~13 days, respectively.The effective control of larvae are spraying with Dipterex, Dichlorvos, Malathion,Fenitrothion, Carbaryl or Pyrethrins, or destroying infested leaves and them.
Leaf rust of Picea koraiensis L. is caused by Chrysomyxa rhodod-endri de Bary. Its pycnia, aecia occur on the first-year new leaves. They reduce forest increment by causing premature defoliation. Its uredinia occur on the leaves of Rhododendron dahuricum. They are orange-coloured and exc-urrent. But a few uredinia occur on the shoots. Telia are brownish-red colour and oval in shape. It will produce basidiospores in the following summer and reinfect the shoots of Picea koraiensis.