1996 Vol. 9, No. 3
This dissertation,applying the model of soil layered water balance of agro-forestry,calculates the water uptake by the roots of wheat and shelterbelt,the evapo-transpiration, and the extent that the effects of shelterbelt exerted on the field soil water,then to study the evapo-transpiration of agroforestry.The results show that:(1) Water uptake byroots of the shelterbelt mostly come from the field at the jointing-filling stage of winter wheat,which is obviously indicated in 0.0H～1.5H.(2)If the field is protected by the shel-terbelt,the average evapo-transpiration is 12.3% lower than that of the open wide field.(3)The field soil water content reduces in 0.0H～0.5H and raises in 0.5H～5.0H because of the shelterbelt effect.In general,the soil water capacity at the field soil depth of 0～200 cmcan be raised by 11.2%.
Through the field survey and analyses of total 403 Paulownia elongata stan-dard san1pling plots,it was discovered and concluded that the DBH distribution of P.elongata stand can be predicted by L-PRM. Stand mean DBH diameters at free heights,timberyield of plywood,purlin and rafter in unit area can also be predicted by the models of standmean DBH,stem curve, and timber output.The predicting accuracy checked can meet the practical demands.The conclusions drawn by the comprehensive evaluation on plywood timber yield and ecnomic benefit are as follows:(1)for site index 40,the optimum densities form iddlelarge, middle diameter class plywood-oriented P.elongata plantation are 200 and 250 trees per ha with 13 years as crop age,76.37 and 81.39 m3 per ha of plywood timber yield,36.14% and 34.66% of IRR,respectively.(2)for site index 36,the ontimum density formiddle diameter class plywood-oriented P.elongata plantation is 200 trees per ha with 13years as crop age,53.21 m3/ha of plywood timber yield,30.82% of IRR.
A multi-regression equation was established by using density value, band ratid of sample points on TM image,which were corresponding to the field sample plots,3 qualitative factors and the stock value measured from the field sample plots.This equation can beused to estimate the stock values of forestry bureaus,forest farms,or forest compartments inforest management inventory.Finally,the data obtained from the remote sensing estimationwas compared with that obtained from the field inventory.It proved that this method is effective.It provides scientific basis for remote sensing application in forest management inventory.
Components of insect fauna,dominant species,similarity with other domesticinsects,in relation to heat and insect generation and the geographical distribution of the specific moths produced here as well as the vertical,ecological distribution of some forest insectshave been described in this paper.
By the modern method of grey relative analysis in combination with the traditional methods of variance analysis and multiple examination,the paper dealt with the disturbance effect of four arbor mangrove populations,which were introduced artificially into a secondary shrub community eight years ago. Two shrub populations(Agiceras coruiculatum and Ceriops tagal)and the whole comrnunity as well as the disturbance intensity, properties and mechnism were studied. Which revealed the ecological characteristics of above shrub populations after being disturaed.Therefore,guidance is provided for improving the same types of other shrub communities by using the arbor populations to control the shrubs by means of biological measures.
Jianfengling tropical forest region is rich in resources of Boletales fungi,which are the largest macrofungus population both in species and quantity.Based on the primary study,there are 50 species in 12 geners in 2 family of Boletales(Form 1).of which,15species are edible,7 species medical,22 species mycorrhizal fungi,2 species toxic. Amongthem,2 species, Boletus nigerrimus Heim,B. porrentosus B. et Br. are new record species to China. Preliminary analysis and discussion have been done on the ecological conditions andthe distribution feature of each group of Boletales.
In the light of the principles of insect embryo development,6 typical developing stages of this lac insect embryo may be divided as follows:lst stage-blastoderm formation; 2nd stage-germband formation,3rd stage-protopod;4th stage-polypod; 5th stage-olo-gopod; 6th stage-larva formation. To forecast the due time for broodlac collection,it’s necessary to observe the advancement of the embryo development, the volume of“yellow spots”(hatching cavities under lac encrustation) and in combination with the initial days of swarming. This is a way,which is not only practicable in cutting stick broodlac in situ but available for distribution and allocation to other regions far away.
The nutritional diagnosis of the leaves shows that in the reclaimed area bycoal ash, the trees of P.×euramericana are in a state of nutrition deficiency,so the application of N not only raised the N concentration of the leaves,but promoted bothe tree growthand its absorption of K,Ca,Mg etc.nutritional elements.The application of P mainly raisedthe P concentration of the leaves and solved the problem of P deficiency.(2) The correlation analvsis shows that the application of K helps to promote the absorption of P. From the result of K application,it shows that the appropriate K value of 1.5% proposed by J. Garbayeis obviously on the low side,which is not suitable for the poplar clone we’re dealing with.(3)The application of green manure can raised the Mg and P concentration of P.×euramericana’s leaves,but its mechanism of significant effect has to be studied further.(4)The N,Kconcentration of the leaves has a positive correlation with the growth of P.×euramericana,which shows that the higher the leaf concentration,the bigger the tree increment.On thecontrary,the P concentration of the leaves has a negative correlation with the tree growth,which shows that in face,the relationship between P concentration and tree growth is a kindof“diluted effect”.
Through the field investigation and analysis of Pinus taiwanensis community from the natural forest and plantation,it can be seen that the biodiversity in the natural forest was obviously higher than that in the plantation,and there was a difference of species composition with 19～29 species in natural forest and 9～17 in plantation.Shannon-Wiener Diversity Indices of the undergrowth and herb laver were 2.8242～2.8763 and 1.7998～1.8366 in the natural forest,and 1.6073～2.0775 and 1.836 6～1.9394 in the plantation,respectively. The DBH increment of the natural forest was 0.47 cm/a lower than that of the plantation.The maximum current annual increment of tree height in the natural forest happened at the twentieth year,and it was 5 years later than that in plantation. The significantvolun、eincrement(0.01 m3/a)of the natural forest occurred after the growth of 40 a,which was 20 a later than that of the plantation. Evenness Index,Coefficient of Community(CC),Coefficient of Similarity,and coenological difference of Pinus taiwanensis between them were discussed,and tree growth process from two origins of stands was also compared and analyzed.
In order to make a systematic study on the growth characteristics of the mixed stand of Chinese fir with Huangshan pine in the northern limit of Chinese fir distribution,six plots were set up at high altitude in Dabeshan Mountain of Anhui Province.The results showed that the production of the mixed stand was higher than that of pure Chinese fir plantation in the same site,density and management level.The stand volume and total basalarea of the mixed stands were 188.78～289.67 m3/ha and 36.31～42.15 m2/ha respectively,which were higher than those of the pure one at the same age by 60.27%and 19.85% respectively.Biomass of the mixed stands were 128.27～179.18 t/ha,which was higher thanthat of the pure one by 21.99%.here were significant differences in the above groundbiomass between the two types of plantations,a range of 12～16 t/ha·m in the mixedstands,and 10～12 t/ha·m in the pure ones. Results from analysis of tree height-DBH relation of individual tree indicated that growth of tree height of Chinese fir in the mixed stand atyoung growth was significantly promoted,and after 10～12 year-old, DBH growth was evi-dently increased.There was a clear distinction between the DBH growth curves in two types of plantations,that the DBH increment in the mixed stands showed an increasing tendencyand kept a certain increment after fast growing stage,while in the pure Chinese fir stand,after the age of 14 years,DBH increment decreased with the increase of its age. Never the less,the DBH increment of Huangshan Mountain pine decreased evidently with the increase oftree age after 10～12 years old in both types of plantations.
Egg-laying habit, gall-making ability, larval behaviour and species quantitative dynamics of the eurytomid wasp, Aiolomorphous rhopaloides and the torymid, Diomorus aiolomorphi,were observed for identifing the interspecific relationship of the two species.A. rhopaloides lays eggs in newly-sprouted buds and a gall develops at the site of egg-laying as the bud develops into a new branchlet.D. aiolomorphi lays eggs in the young gall developed by A. rhopaloides and its larvae kill the eurytomid larvae,occupy the gall and feed on the internal tissue before maturing. It is suggested,based on the results,that the torymid,instead of a pest insect of bamboo,can be regarded as a natural enerny of A. rhopaloides.
Germination tests were conducted in two nurseries for two successive vearsby using slash pine seeds of 3 different size classes. The results show that seed sorting has changed the seed size and weight distribution of seed lots,which influenced the speed of seed germination,and then the early growth of the seedlings. In the germination stage and early growing period,there were significant differences between the seedlings from different seed size classes,but there was no difference in the late growing period.Using different size ofseed lot could not achieve the objective of increasing the seedling quality and uniformity.Innursery practices,the genetic makeup of seed lot would be of the first factor considered,then the seed size or weight.
This paper deals with the population structure features and eco-economic results of the various white wax plantations. The results show that the mixed plantation of eco-economic type can rnake full use of the natural conditions to produce various products,thus increasing the unit productivity and and maitaining high and stable yields. For example,the harvest of white wax brood-scales may go up to 30% and the crop production value amounts to 5400 yuan/ha.
Microscopy and scanning electron microscopy was used to observe the amount,distribution,kinds and density of the female and male adult’s antennal sensilla in Acleris fimbriana .The results show that there were kinds antennal sensila in the adults antennae,i;e. Sensilla trichodea,S.chaetica,S.coeloconica,S.styloconica,S.squamiformia,S. auricillica and Bohm’s bristles.There are differences in amount, distribution and densityof antennal sensilla between female and male.
From 1986 to 1991,an intensive investigation on the disease index and ecological factors of larch needle cast was made in forest farms in Jilin Province.The data analysis of three hundred olots of larch plantations,Larix olegensis,revealed that the disease index of larch needle cast has a lot to do with ecological factors. The ecological model of larch needle cast was thus established as follows :y=15+21C11+6C12+9C13-23C21-15C22-C23+3C31+19C32+19C41+9C42+8C51-10C61(PAN SHI Model)y=21+16. 5C11+2.9C12+4. 9C13-22.6C21-15C22-1.7C23+0.4C31+15. 8C32+16. 9C41+7.4C42+7.9C51-9.5C51(JI LIN Model)where y stands for forest disease index and C11～C42 stands for ecological factors(level).According to the investigation and analysis,the occurrence and development of larch needle castis the integrated result of different ecological factors over a long period of time. From them odels,forecasting technique and ecological control for larch needle cast by afforestation were put forward.
Researches on the relations of tree disease resistance to the changes of biochemical substracts before and after the infection by pathogen,and to the differences of some metabolisms induced by pathogens are reviewed.The current researches on disease resistanceare concentrated mainly on the comparison analysis of related factors. The molecular mechanisms and gene orientation of resistance to diseases in trees should be further studied.
This article is to expound the concept of agroforestry system as the basis toclassify into six types of the system with descriptions :farm-forestry type,forestry-farm type,forestry-animal husbandry type,farm-forestry-fishery type,forestry-cash crop type,regional farm-forestry type. Typeical examples of the application of the agroforestry system vvere introduced.Their common characteristics is based on the principles of ecology and economics,and made use of the reasonable space and time distribution of plant species to maintain the dynamic balance and to increase the comprehensive benefits of the systems.
The test of fertilizer application in Ph.pubescens grove progressed between 1989～1993 in Longhu Forest Farm of Shaowu,Fujian Province. According to the main results and mathematical statistical analysis,the regression equation between soil nutrient(N、P、K)and output value of Ph.pubescens are important basis for fertilizer practice in Ph;pubescens grove. As a result,the standard of soil nutrient,with which the highest yield ofPh.pubescens would be produced,is set up.The amount of nutrient contents required in thesoil in other Ph.pubescens grove and the contrast should be determined.Then,how muchnutrient and what kind of nutrient are needed in the soil can be determined.
The influence of various temperature and media on the mycelial growth of the Elfvingia applanata (E-1～3),Fomitopsis castaneus(N-1)and Lloydella bicolor(L-1)were studied. The result shows,the optimum temperatures for the mycelia growth of E-1～3 and N-1 is 32℃,L-137℃;the maximum temperature for E-1～3 and N-1 37℃,L-1 42℃;minni-mum temperature for E-1～2 and L-1 10℃,for E-3 and N-1 17℃,inhabited temperatures for E-1～3 and N-1 42℃,L-1 47℃,the lethal temperature for E-1～36 hrs at 50℃,N-1 8 hrs at 47℃,L-1 5 hrs at 54℃. At the same temperature and on the same media,the mycelia growth of 3 isolates of E. applanata is different.