1995 Vol. 8, No. 4
The relationship between teak seedling density and stump growth,formation of main root,seedling yield per unit area and seedling quality are studied through adopting biomathematics method.35 mathematic models are established using 10 curve equations i.e.exponential function,power function,logarithmic function etc.. The results show that:1. The seedling growth above and under the ground in Jiangfeng good site are far inferior to the growth in Guangzhou poor site at the same seedling density.The difference between them will be increased as density increases. THis is why there are differences between two sites in sunshine/day and coordination of water and hot.2.Adjusting seedling density on the basis of different ecological condition in different sites is more effective than prolonging the time of breeding seedlings in one site to increase seedling yield and quality.3.The suitable seedling density in Jiangfeng and Guangzhou are 100～200 and 300～400 seedlings per square meter respectively. There are four density classes(50 seedlings per square meter is taken as one class).The best seedling quality and yield could be got by adjusting the seedling density to the most suitable condition.
A comparative nutrient diagnosis on young stands of slash pine by DRIS and critical concentration value approach(CCVA)was conducted.The results showed that the DRIS produced more accurate nutritional diagnos is than that by CCVA when diagnosing phosphorus nutritional status in leaves. That is,the phosphorus application enhanced the growth of slash pine and the growth was significantly interrelated to phosphorus DRIS indexes,but there was no response for phosphorus concentration in leaves. DRIS diagnosis was also influenced by the age of trees and site environment as the CCVA. So, high-yield populations for calculating diagnosis parameter should be chosen from the stands of the same age at the local site. According to the diagnosis results by DRIS,the mechanism of N P K fertilizers to the growth of young slash pine was considered as follows:N application increased the N concentration and the unbalance of leaf nutrition and was not benefitable to the growth.The application of calcium-magnesium phosphate alone at the rate of P 21.82 kg/hm2 would improve the N,P,Ca and Mg nutritional status in leaves significantly, reaching the optimum balance. Besides,it was found that P nutritional status in the control treatment was obviously improved in the third year after planting,indicating the young trees were able to use soil P to meet the need of P for their growth.
Eucalyptus grandis×E.urophylla microcuttings in vitro were encapsulated with alginate as the gel bead style and maintained in agar medium without nutrition.It was found that this style was a suitable method for the conservation of Eucalyptus germplasm.Regenerative rates of shoot were 52% after ten months' conservation.High vigor of germplasm was observed in low concentration(1.5%～2.0%)of encapsulated sodium alginate.The tests of basic components supplemented in the alginate by single factor or multiple factors orthogonal design showed that sucrose concentration was the key factor limiting the vigor and regenerative rate of germplasm.Low concentration of sucrose(0.5%)and minerals showed the benefited effect,but 5.5% sucrose induced blackening of microcuttings,decreasedthe vigor,and decreased the regenerative rate of germplasm.During the conservation period,changes of alginate bead colour from green to white or to black were the two main apparent indicators of losing vigor and regeneration capacity.The results suggest that apparent colour of gel bead might be used to estimate the vigor status of conserved germplasm.Light was a necessary factor for conservation of the encapsulated culture germplasm.
After analyzing the present condition of tropical forest in the world and the features of tropical forest in China as well as its research in the past.Two problems that happened at first in the research of tropical forest have been emphatically studied,i.e.the classification method and inventory plan.Based on the research of the tropical forest in China,the method Of remote sensing was put forward to study the regional or even the globe's tropical forest.Meanwhile,it should be pointed out that under the premise of macroscopic monitoring,the remote sensing method can't be replaced.In the aspect of classification,a method was suggested, which was based on the pre-classification of using weather conditions(precipitation and temperature)and elevation,and then used remote sensing data(density value)to identify vegetation coverage.In the aspect of inventory plan,the method of assessing area and growing stock in a certain area or in a large area,was put forward.Inthe meantime,among the experimental data,a comparison was made between the trozical,subtropical and temperate forest.It shows that the method is promising.
The fertilization trial of Pinus elliottii plantation was established on the Quarternary red earth in Yongfeng County of Jiangxi Province.Three year's results show that:(1)The effectiveness of P application alone or combination application of NP,PK,NPK was tangible in this young plantation.The total growth of tree height(H),groundline basal area(GBA),basal area of breast-height(BA) and crown width(CW) of trial plots were higher than those of the control by 35%～45%, 52%～109%,119%～195%, 29%～49% respectively.(2)The current annual increment of H, GBA of various P treatments(P, NP,PK, NPK)over CK was obvious higher than those of the control by 26%～55% and 119%～195%,respectively in the first year after the basal fertilization,and so it was the similar for those of H,GBA in the second year.Meanwhile,the increase of H,GBA and BA of P treatments after another top dressing was still favorable in the third year.The effect of NPK combined application was the best,but there was no significant difference between the effectof NP,PK,P application.There was no obvious difference between various P level treatments.The effect of the P application with same amount as basal fertilization was better than the application of top dressing,or the application of half the amount of the basal fertilization and half of the amount of the top dressing.Excess application of N fertilizer(Urea) with the amount of 100 kg/hm2 N showed obvious nagative effects to the growth of slash pine.3)The final results show that according to the response of young slash pine plantation to fertilization,25～50 kg/hm2 of P2O5 as basal fertilization is enough in the soil type of this test.
The seasonal growth of leaf area,height and diameter in six poplar clones(one-year old shoot/two-year old root)in 1993 was simulated with Richard function.The absolute growth rate,mean absolute growth rate,duration of growth and the point of inflexion were calculated using the parameters in the fitted functions respectively.There were significant differences among the six clones in growth rate,point of inflexion and duration of growth.A more than sixfold difference was found between the total biomass production of the best introduced clone Populus×euramericana cl.'N3106'and that of the worst native clone Populus simonii×P.pyramidalis cv.'Chifengensis 34'.There is a linear correlations between the total biomass productions of these six clones with their total leaf area,individualleaf area,mean AGR of leaf area,and daily total net photosynthesis per tree,but a negative correlation with daily total net photosynthesis per unit leaf area.The high biomass production depends on the growth rate of leaf area,height and diameter,and the duration of growth.
Somaclonal variants of Populus × xiaozhuanica cv.'popularis'-39,which is tolerant to 30‰～3.5‰ NaCl,is successfully obtained through the establishment of NaCl-tolerant pressure cell culture to produce calli and control the conditions of adventitious bud and root induction. The friable calli are well produced on the medium M4 MS+0.45 mg/L 2,4-D+0.3mg/L NAA+0.1mg/L Kinetine.The best suspension liquid medium is LM3:MS+0.5mg/L2,4-D+30g/L sucrose.The addition of amino acids was beneficial for the growth of the suspension cells.The relative parameters about cell growth are also measured.The culture test of NaCl-tolerant cells indicates that NaCl restrains cell growth and the higher the concentration of NaCl,the stronger the restraint.Calli can be produced from all the cell lines tolerant to the every NaCl level from 3.0‰～6‰;The test,in which the shoots can be induced only from the calli tolerant to 3.0‰～4.0‰,indicates that the high concentration of NaCl exerts an obvious restraining impact on the shoot induction.The root differentiation is also highly sensible to NaCl and the roots can only be induced on the medium with 3.0‰ and 3.5‰ NaCl.
In the middle belt area of Chinese fir,data of 194 sample plots(among which,39 clear-cutting plots)and 4821 felled trees(breast diameter 6～40cm)were collected and studied.According to the International Regulation GB8415-84 and GB8416-84,on-the-spot bucking was conducted and appropriate mathematical model was selected to establish the table(rate)of economic volume of individual tree of dimension and non-dimension lumber of Chinese fir pole-timber.Based on this,economic volume rate table of Chinese fir pole-timber of different site index stands was also established and the precision of these tables are in accordance with the requirements of the production.
The undergrowth vegetation positively plays a role on soil fertility maintenance in forest plantation.The improvement of soil fertility can be achieved through the development of the undergrowth vegetation.In this paper,the study was conducted to explore the influence of undergrowth vegetation in Chinese fir plantation by thinning.The study sites were located at the hilly areas with 14 and 16 site-index in Shanxia Forest Farm,Fenyi County of Jiangxi Province.The study showed that thinning intensity could influence the development of undergrowth vegetation significantly,i,e,the species composition,important value,structure,coverage and biomass of the undergrowth vegetation varied greatly by different thinning intensities.The undergrowth vegetation coverage and biomass in the stands without thinning(CK) or with thinning of low intensity were 35%～60% and 1500～3000 kg/hm2 respectively,which were much less than those in the stand with middle and high intensity thinning,i,e,70%～80% and 5000～7000 kg/hm2 respectively.It was concluded that the middle and high intensity thinning can promote the development of undergrowth vegetation in Chinese fir plantation.
The studies show that thermoperiod,as one of the enviromental factors,plays an important role in the photoperiodic response of the pine caterpillar. The critical photoperiod of the larvae treated with the temperature varying from 23 to 30℃ (average 27.5℃)is about 13 h 46 min,a 13 min longer than that in the constant temperature(27.5℃).Thermoperiods can not only make the larvae to have a longer critical photoperiod but also make larvae to prolong its larval developmental period and make larvae have a relatively higher diapause ratio. In Gaoan,Jiangxi Province,the investigations demonstrate that considering the coeffect of photoperiods and thermoperiods a more accurate model can be established through fixing the critical date of differentiation of the pine caterpillar,which is the key facfor in the predicting of the population dynamics of the pine caterpillar.
A comparison was made between symmetrical organic phosphorus insecticides fenthion and dichlorvos.This paper studied the inhibition effect of structure unsymmetrical organic phosphorus insecticide prothiofos to acetylcholinesterase(AchE) by means of Ellaman's method,then measured the touching toxicity and field effect of the three insecticides to the larva of Setora postornata.The result shows that the inhibition of prothiofos is the weakest to AchE of house-fly,but its toxicity is the strongest to the larva of Setora postornata and its field effect is also the best among the three insecticides.The study indicates that there is probably a relationship between the characteristics of higher effect and lower toxicity of prothiofos and its unsymmetrical structure and unique toxicity effect.
A new species of the genus Soleella Darker(Rhytismatales),Soleella chinensis Y.-r.Lin,Z.Li & S.-m.Yu sp.nov.,on Pinus taiwanensis Hayata from Huangshan Scenic Spot,Anhui Province is reported in this paper.Latin and Chinese descriptions and figures are given for the new species.The holotype specimen is deposited in the Forest Protection Laboratory of Anhui Agricultural University,Hefei.
genera 5 species of the Rhytismataceae on conifers in Anhui Province are reported in this paper.Among them,Lophodermium wannanense C.-1.Hou is a new species and four others including Soleella cunninghamiae Saho and Pleioderma handelii(Petrak)Y.-r.Lin et Hou,which are known species.Latin and Chinese descriptions of the new species are given.The main ecological characteristics are recorded for the known species.
I-69(Populus deltoides cl.'Lux'(I-69/55),as a female parent plant,I-63 (P. deltoides cl.‘Harvard'(I-63/51))、P. nigra and P.× euramericana cv. ‘Serotina 272')as male parent plants,artificially controlled pollination was conducted in 1983.Cross combinations were numbered as No.34,No.32 and No.37 respectively. After selection in the nursery and clone test in Mian County of Shanxi Province from 1985 to 1993,2 super poplar clones(34-301 and 34-286),Which grow fast,resistant to insect and with good quality,were selected by using method of principal components analysis,cluster analysis of genetic distance of principal components and selection index. The volume of 34-301 and 34-286,which grow for 9 years,were 24.9% and 16.6% higher than that of I-69 respectively,and 16.7% and 8.9% higher than that of 34-314 respectively. Resistance to Batocer horsfieldi of 34-301 and 34-286 were significantly higher than that of I-69,their population per tree were 0.4 and 0.5,(for I-69 was 5.38).There was apositive correlation between the resistance to B.h. and the content of tannins and phenolics according to the analysis of chemical composition. Resistance to B. h.was controlled by genes according to the analysis of molecular biolfogy(RAPD analysis).Molecular marker of RAPD (OPAD-01)was found,which linked to genes of resistance to B.h.
The wood property of 3-year-old trees of Populus cathayana from 24 different provenances were measured.It has been revealed that there are variations both in the wood properties of different individuals and provenances. The variation of basic wood density between different provenances was higher than those of different individuals. The wood density increased with the increase of latitude. There was variation in the characteristics of the fibres and vessels from different provenances when the number of the measured individuals was larger. There was a weak negative relationship between the fibres and vessels and the latitudes. There was a higher variance within the fibres and vessels of the same individual,for this reason it's necessary to have a large number of samples for the measurement of fibres and vessals. When making a breeding improvement,it's better to adopt suitable strategies for different purposes.
Laboratory rearing and simulated field overwintering of Agriosphodrus dohrni were conducted in bothe Dayi County,Sichuan Province and Beijing in l993～1994.It has one generation a year and overwinters in the 5th instar in nymphal stage. The eggs aggregate in the form of egg masses and hatch in 27.08±1.00 days after oviposition. There are altogether 5 instars in nymphal stage and its development lasts for 334.75±4.30 days. The adults mate in 16～18 days after emergence and oviposit 18～19 days later. Not only its morphology and changes in color after moulting in all stages but also the bionomics were described.Experiments both in the laboratory and in the field showed that it is a promisingpredator and can prey on Lymantria dispar,Clostera anachoreta,Apocheima cinerarius, Pristiphora beijingensis,Stilpnotia salicis,Aphis robiniae etc. and many other species of forestpests.
A tea-picking experiment has been laid out both in pure tea garden and peachtea intercropping garden,for two summer seasons running at Linan and Fuyang Counties of Zhejiang Province which are located at north-mid subtropical area of China where the microclimate has been measured simultaneously.Results indicate that comparing with those in the pure tea plantation,in the peach-tea intercropping garden its light intensity,air temperature and wind speed reduced by l0 000～60 000 lx,0.3～2.1℃,and 0.1～0.3m·s-1 respectively but its air humidity increased by l%～5%.Working in the intercropping garden,the temperature of workers' clothes reduced by 0.5～1.5℃ while the most reduction appeared from those dressing in white and the workers' effective temperature and the most uncomfortable time during a day,the discomfort index and the most discomfortable time reduced by 0.3～0.8℃ and 2.5 hours,1～3 and l hour respectively.Due to the worker's comfortableness in the intercropping garden,the worker's productivity increases around 22.6%～29.5%.
In this paper,the change of tropical forest,the causes of deforestation,the forest biodiversity and its reducing situation in Hainan Island of China have been described and analyzed.The results indicated that the annual average deforestation rate in up to11.48% from 1933 to 1990 and now the original tropical forest coverage rate is only 7.9%.More than 102 species of wild animals and 93 species of plants were in danger,and the protected rate of animals' and plants' habitat is only 3.03%.Judging from the current situation,the protective strategies for tropical forest and its biodiversity in Hainan Island have been put forward in the paper.
A comparison was made between a masson pine stand under atmospheric pollution with the one in a normal area and the content of needle nutritional elements(N,P,K,Na,Ca,Mg,Mn,Zn,Cu,Fe)of masson pine.P,K deficiency in needles in air pollution area are significant,but Fe in needles in pollution area is five times as much as that in the normal area.The mean needle length of masson pine in pollution area is shorter than that in the normal area and the percentage of yellow needles is higher.The productivity loss is about 50% by preliminary assessing.
An investigation on soil status was carried out in three different agroforestry models namely,Rubber tree+Amomum villosum,Rubber tree+Coffee tree and pure rubber plantation.From the investigation of soil water,soil fertility,soil aeration and soil temperature,it showed that no significant influence on soil fertility was found in the rubber plantation intercropping with coffee tree,while intercropping with Amomum villosum,whic is favorable to increase soil fertility.Taking pure rubber plantation as a control,in the soil layer within 0～40 cm,the mean soil organic matter content increased by 2.28 g/kg,total nitrogen increased by 0.15g/kg,available phosphorus increased by 2.0mg/kg and available potassium increased by 20.8mg/kg in the rubber plantation intercropping with Amomum villosum.The soil structure and water and soil conservation properties have also been improved and increased.In the 0～10 cm soil layer,absolute capacity of the soil waterstable aggregateof 2～5mm soil grain increased by 18.8%,soil cation exchange capacity increased by 3.8 cmol(+)/kg and the absolute capacity of soil moisture in dry season increased by 70.0g/kg.The rubber plantation intercropping with Amomum villosum has lower soil temperature which provides favorable condition for retention of the soil organic matters.The same result was obtained by means of quantification for comprehensive evaluation of different fertility factors of soil.