1996 Vol. 9, No. 2
The dynamic models in stand-level are developed for square coefficient variation of the tree diameter, which can be used to describe three states(decrease, stabilization, and increase)of square coefficient variation of the tree diameter, so it is an efficient way to predict arithmetic mean diameter via the quadratic mean diameter in stands. A satisfactory fitting has been obtained based on the growth data of even-aged plantations of Chinese fir(Cunninghamia lanceolata). Compared with another method proposed by Knoebel and others, the models are of both certain mechanism and better prediction precision on the whole. It has been found that the fitting can be improved as the initial value is added. The result of this paper could be used to predict the arithmetic mean diameter and coefficient variation of the tree diameter in unthinned and thinned even-aged plantations of Chinese fir.
The research on the structure of Paulownia elongata stand indicates that the first branching height is positively relative to the site index and seedling quality, but negatively to the second branching height. The height variation of different diameter classes in P. elongata stands with sites and ages can be simulated by established H-curve function. In the prediction of the diameter structure of P. elongata stand, this paper reveals that L PRM is better than PRM(Weibull).
P fractions and their availability in soils of Chinese fir plantations in South China were studied. I-P(inorganic-P)was a major component of total-P and it accounted for 72.48% in lateritic soil, 73.20% in red soil, and 63.77% in yeillow red soil. Al-P, Fe-P, O-P, and Ca-P accounted for 2.74%, 4.70%, 84.74% and 7.81% in lateritic soil, 2.46%, 11.90%, 77.24%, and 7.81% of inorganic-P in red soil, 2.74%, 10.63%, 78.04% and 8.59% in yellow red soil, respectively. Organic-P in mountain yellow soil was a major composition of-P, and I-P only accounted for 30.56% of total-P. Al-P, Fe-P, O-P, and Ca-P in inorganic-P accounted for 1.54%, 15.67%, 78.85% and 3.94%, respectively. The distributions of Al-P, O-P, Fe-P and Ca-P in the four kinds of soils mentioned above had an obvious zonality and Al-P appeared the characteric of transitional soil, while those of O-P, Fe-P and Ca-P in the red soil region showed the complicated characteric and no homogeneity of-P fractions. The regression analysis indicated that there was a significant relationship between Fe-P and available P.
Establishing grass belt outer fringe on sandy coast shelter-forest is an effective method because nursery stocks were propagated by cuttings or vegetative offsprings in nutritive pot, and then transplanted at outer fringe on sandy coast shelter-forest. When the transplanted stocks have recovered their growth and formed root system. The transplanting success can be attained. Vitex rotundifolia, Launaea sarmentosa and Wedelia prostrata are very suitabe to be estabblished for the grass belt outer fringe on sandy coast shelter-forest. They are characterized by quick growth, easy striking of adventitious root and forming ramets. For a year after transplahtation, the coverage can reach 100%, 53% and 43% respectively, and the RGR on basis of present biomass is 0.653, 0.535 and 0.357 g/g.month, therefor the period from March to April is the best season for transplantation in South China.
This paper deals with the study of seasonal variations on leaf nutrient concentrations in Ginkgo biloba L. The result has indicated that concentrations of N,P,K,Ca,Mg,B,Fe,Zn,Mn,Cu in the leaves of male and female trees varied throughout the growing season. Leaf nutrient concentrations of N,P,K,B,Fe,Zn differ significantly between male and female trees in three years(P ≤0.05),but the concentrations of Ca,Mg,Mn,Cu do not differ significantly. The big fruit female clone has had the best ability of absobing P,K,B,Zn and the worst of absorbing Ca,but their seasonal variations of the concentration of N, Mg,Fe,Mn,Cu are similar amomg the other female clones.
In each of the three sites located at three provinces,48 provenances of three species were tested. The results showed that Casuarina equsetifolia at the age of five was superior,in growth,to both C. cunninghamiana and C. glauca,and the growth variation among provenances within each of the species was significant.Some provenances, such as C-1,C-3 and 14233 from C. equsetifolia and 13513 from C. Cunninghamiana grew well at all three sites,but 14233 and C-3 were poor in resistance to wind. The provenances of C. cunninghamiana had better adaptability to different sites.
Seed kernels at various developmental stages were used as experimental materials to systematically study the accumulative procedure of storage substances and change trend of component contents.It was showed that the seed kernel accounts for 4.8% of dry weight of the ripen cone and its storage substances change with the embryo development. The contents of gross fat, gross protein and total carbonhydrate of ripen seed kernels are 44.8%,42.5% and 6.54% respectively,while starch and soluble carbonhydrate account for 4.26% and 2.88% respectively. Enzymic protein content decreases from the maximum at early phase of proembryo stage(20.83%)to the minimum at young embryo(4.9%). Here the fat of the seed kernels consists of four kinds of fatty acid,of which the content of unsaturated fatty acid is much more than each one of the saturated fatty acid. Lindeic,oleic,palmitic and stearic acid accounting for 65.7%,21.7%, 9.2% and 3.4% of the total fatty acid respectively.It was found that seed kernels of masson pine contain mainly 16 kinds of amino acid,of which the minimum content of the 14 kinds appears at the proembryo stage and the maximum content of the 10 kinds at the early phase of young embryo stage.Among 16 kinds of amino acid,the contents of arginine,glutamic and aspartic acid are higher(from 3.0% to 7.5%),and lysine,tyrosine,histidine,cystine and methionine the lower(1%).
Based on the stand growth tables of the national Chinese fir plantations,the tending thinning tables for different site index of Chinese fir in various belts and areas in China were established. Make use of the data of 53 sample plots of Chinese fir tending thinning experiment and take y =a+bx as the mathematical model,the regression equation for the average tree height and average breast diameter after thinning was found out.Besides,make use of the tending thinning table established by the stand density control diagram of Chinese fir plantation, a precision comparison was conducted.
Nelder trial of Acacia auriculaeformis A.Cunn. has been undertaken for seven years in barren site since 1987.It was shown that their diameter in breast height,tree height and basal area×height are relative to logarithm of area per tree in downward parabola.It′s suitable to select smaller spacing such as 1×2 or 1.5×2 meter etc.for planting A. auriculaeformis because it can accelerate the growth of diameter and tree height.For different types of forests with different initial density, the thicker the forest,the shorter the rotation age.
Study on Mediums was conducted for two species, Masson pine and Chinese fir,in the past two years.There were 10 different formulations for the test.The dry weight of the 100-day seedling of Masson pine in the pot with Bamboo leaves as the medium is 93.2%,43.9%,25.0% over those growing in the yellow soil,the vermiculite,the rough powder from bark respectively.The same result was got for the Chinese fir,the increasing rate is 53.9% 104.0%,42.9% respectively.The medium made up from the pine leaves is the second one for the pot.The difference is obvious in statistics.According to the relative analysis,the unit weight and hole rate of the medium are the most important factors for the seedling.Both the total and effective content of phosphine is the second most important factor.The response to each factor is the same in both species,except having different demand for nutritive element.The phosphine is much more important for the Masson pine,while Chinese fir is sensetive to nitrogen.The mediums made up from Bamboo or pine leaves have suitable physical condition,which make seedling grow well and fungulizm earlier.
A micro-meteorological observation/study in tree-tea intercropping plantation and pure tea plantation for comparison have been carried out in Huangshan City,Anhui Province.The soil heat flux,latent heat flux and turbulence heat flux have been calculated by gradient and heat balance methods.Generally speaking, component values of heat balance are positive in day time but negative at night,the date difference of these values from Chinese fir tea intercropping plantation are smaller than those from pure tea plantation and the appearance time of the maximum and minimum values in the former plantation are coming later.Among all component values of heat balance,the latent heat flux occupies the highest proportion from net radiation, which is around 1/3～1/2 or more,generally,turbulence heat flux is lower but it is possible to come higher occasionally in short time while soil heat flux occupies only 1/6 of net radiation. There is a rather obvious difference on daily dynamic properties of latent heat flux and turbulence heat flux between the two kinds of plantations mentioned above.
samples of Eucalyptus grandis,E. saligna,E. camaldulensis and E. urophylla of 48 provenances from the experimental provenance stands in Qionghai City,Hainan Province and Changtai County,Fujian Province were collected for the test on wood structure components and wood basic density characteristics and a comparision and selection for intraspecific provenances was made. The results showed:in the two experimental plots,for the same provenance,there was no significant difference in the same plot;for the same tree species,whose wood features variances were bigger than the individual variance of the intra provenance;taking 7 features,such as fibre length,ratio of area occupied by different cells,cell wall thickness,cell walls,ratio of wall thickness to iumen diameter,ratio of cell iumen to cell diameter and wood density,which have close relation with other wood properties and uses and a comprehensive evaluation between them was made; E. grandis 14860,14849,14509, E.saligna 14429,14435,14527, E. camaldulensis 12187,15050,15062, E. urophylla 15089 from Qionghai,Hainan Province and Fujian Province were selected as the best provenances.
During the period 1986～1993,30.13 ha of low-yield stands of Camellia oleifera were transformed by grafting clones at the Tongkou Forest Farm,Fujian Province. In this paper,the results of the 0.130 ha low-yield stands reformed in 1986 were analysed. The results showed that the annual average oil yield was 261.756 kg/hm2 during 1991～1994,6.76 times than that before transformation and 5.98 folds than the controls. M15,M75 8,M75 7,M84 excellent clones were selected once more in the light of transformation of grafting clones. Their average oil yield was 567. 000～716. 400 kg/hm2,the rate of oil was 7.26%～9.22%,23.28%～55.76% higher than those of the testing stands and the fruits were not harmed by the anthraconse. The results of compatibility testing of 10 clones and the mutual cross combination of 3 excellent clones(M43,M48,and M60)showed that the average setting ratios were 21.1% and 27.4%,4.4% and 10.7% higher than that of the controls. In the meantime the four optimum combinations(M43×M48,M48×M49,M48×M56,M48×M62)were selected. Their seting ratios were over 50%. All these showed that strong mating capability was the major characteristics of the excellent clones,and the variation existed in mating capability of strains. The mating capability of clones could be raised by selection.
Brown Spot needle blight of pine is one of the most serious pine diseases in south China. Resistance studies on slash pine to brown spot needle blight in China have been made since 1980s. This paper would give a general statement about these researches. Especially,the research advances on selecting resistant slash pine and their resistance mechanisms were reviewed respectively.122 resistant slash pine individuals had been got and 4 ha resistant slash pine seed orchard has been established in Fujian Province. Their resistant mechanisms have been analyzed in general.
Needle samples of 808 two-year-old Cunninghamia lanceolata seedlings of 18 provenances from 12 provinces were analyzed by peroxidase isoenzyme method.Altogether 11 isoenzyme patterns were observed,in which 86.1% of the samples showed isoenzyme pattern I,while the geographical latitudes where these provenances located showed significantly negative correlation with frequencies of isoenzyme pattern I.More than half of these 18 provenances showed little genetic variation and only 45% of the provenances showed obvious variation.Polymorphism and bigger divergence D2 were found in 4 provenances,Yuqing, Liuba,Jinzai and Liannan,which seemed to be correlated with the original production locations of the provenances.
The technology of integrated measures to control Anoplophora glabripennis by means of selecting insect resistant poplar species was studied.The results show that Populus deltoides cv.‘Lux’(I-69/55)can make the egg chamber produce wound flow and prevent the egg from development.The reason is that the water content in bark is higher(67.1%). The intensive management for the stand can increase insect-resistance.It is also favorable to protect Dendrocopos major and Dastarcus longulus. After a rotation period,the rate of tree with insect is 0.14% in 313 hm2 high-yield stand and 0.63% in 285 km long protective forest.
This paper deals with the propagation of seeds and vine stem cuttings of Gynostemma pentaphyllum to get a general idea of the effects of different propagation techniques on its propagation and growth.The results show that the sprouting ability of the seeds varied, however,the survival and rooting rate of the cuttings is basically the same among the different species(kinds)of G.pentaphyllum. The cuttings can generally be taken out from nursery for planting in 25 days,but the seedlings have to grow in the nursery for a period of 45～50 days,sometimes even longer.So it′s favorable to use cuttings rather than seedlings.
The results of 6-year growth monitoring to a trial of 8 Eucalyptus maculata provenances indicated differences statistically existed among the tested provenances in survival rate,DBH,height, volume and biomass yields.The provenance 6169 from Queensland has the best performance with high survival rate and good growth performance(the volume and biomass is 3.1 times of that of the worst provenance 15361).The performance of provenances 13569 and 13542 are also good.The results also showed a correlation between the survival rate and the altitude and longitude of the provenances.This trial was established in poor hilly land.The results of the experiment provided useful information for provenance selection in the regions with similar site condition.
A fertilization trial of masson pine plantation was established on the red earth developed from granite in Shaowu City of Fujian Province in 1992.Two years, investigation show:The effectiveness of fertilization is tangible in the first year of planting and last to the second year.The total growth of height(H),groundline diameter(GLD)and crown width(CW)of the treatment plots is 14%～26%,8%～19% and 7%～23% higher than that of the check(CK)plots,respectively.The growth response to three nutrients compound fertilizer(50 kg/hm2 of N,P2O5,K 2O)is the best of all,with the current annual increment of H as 0.288 m(1 a),0.780 m(2 a)promoted by 44%,31% over CK.Next are to NP,PK and P,the H was promoted by 21%～46%(1 a),8%～31%(2 a)contrasting that of CK,respectively.There was no obvious difference between various P level treatments.Compared the effects of using calcium magnesium phosphate as basal or top-dressing alone,only basal manure has significant response,there was no difference between P top-dressing and CK.There is no obvious response to N or K fertilizer.So P is the deficient nutrient in such site.The application amount of 25 kg/hm2 of P2O5 is enough for the soil.