1998 Vol. 15, No. 3
Anatomical st ructure of bamboo wood for 17 species of tuf ted bamboos is studied .The result indicates that there are many differences in internal structure (mainly in shape and density of vascular bundle)among different bamboo species .Vascular bundle of bamboo wood can be divide into two types :slender waist and broken waist .The latter can be classified deeply as four subtypes: Bambusa albo -lineata subtype , B .subtruncata subtype , Dendrocalamopsis stenoaurita subtype , and Neosinocalamus affinis subtype .Different usages of bamboos with their special st ructure are discussed .
The moisture content , carbohydrates and protein contents of Lei bamboo rhizome during the period of the mixed bud differentiation were measured by use of constant weight , colorimetric method and biuret method .The results showed that moisture content of young rhizome was higher in turn than sound and older rhizome , and moisture content was the most aboundant during August and September , while in this period proteins and carbohydrates were the lowest ,and then gradually increased , and then decreased with the growth of bamboo shoot and at last reached the lowest point in March and April of next year .The analysis indicated that the variation had relation with nutrient consumpation during rhizome development and mixed bud differentiation .According to the analysis of nutrient states it was important to improve bud differentiation rates that fertilizer and moisture management was well done to meet the nut rient needs of rhizome growing and bud differentiation.
Amount of soil microorganism in Lei bamboo forest of protected cultivation is studied by means of plate count .The results show that soil microorganism in quality increases in Lei bamboo forest mulched with organic materials .Amount of soil microorg anism of three treatments with bamboo leaf , rice hull and rice straw is 30 to 60 times that of check .Bamboo leaf and rice hull are superior to rice straw , but all of them can lead to increase of soil microorganism , especially bacterial population .
Study of two-year-old Phyllostachys pubescens forest in suburb Lin'an , Zhejiang Province , suggests that the acidity of rhizosphere soil (R)under the forest is lower than that of bulk soil (S);R/S values of exchangeable hydrogen and aluminum are 0.76 and 0.79 respectively.There are much more hydrolyzable nitrogen , available phosphate and exchangeable potassium and calcium in rhizosphere soil.Total carbon is more in rhizosphere soil than in bulk soil (R/S =1.05), but composition of humic matter is obscure (R/S = 1.02).It indicates that Phyllostachys pubescens is able to activate soil nutrients .
This study , done on Quxian Forest Farm of Zhejiang Province in the years 1990 ～1997 , showed that Myrica rubra (Chinese strawberry)of improved varieties planted on hillock krasnozem grew vigorously and fruited well with highyield and good quality by taking some cultivation measures .Some of the trees began fruiting in the 5th year after planting .The yield in the 8th year reached 23.436 t per hectare on average with a value of RMB 61 795.50 per heatare , which covered the amount of money invested and high profits .The ratio of input to output in the same year was 1∶7.5 .In addition , they grew better and more virgorously than other evergreen fruit trees .Therefore , Chinese strawberry is a good commercial species suitable to grow on hillock krasnozem and has significant effects on improving ecological environment of downland .
Soil fertilities of dif ferent mixed models in plantations of Pinus massoniana were analysed .The results were as follows :The annual litter productions of different plantations were different.Soil moisture conditions, soil structure and permeable capacities in different plantations were improved in varying degrees .Moreover , Soil nutrition and enzyme activities were increased.Soil fertilities were ameliorated slightly .The ameliorating effect of different plantations came in the follow ing :Mixed Michelia macclurei plantation, mixed Helicia cochinchinensis plantation, mixed Schima superba plantation and pure forest of Pinus massoniana .Therefre ,mixing Michelia macclurei in plantation of Pinus massoniana is a practicable plantation model .
The experiment was carried out in randomized block design and variance analysis in Anhui Province .Data from the experiment for 3 years indicated that Pinus massoniana seedlings of cutting roots at 9 ～ 10 cm during the second ten days of August to the second ten days of September grew better than that of check and their survival rate in field reached 97 percent .
Physical and mechanical properties of clone Chinese fir wood and seedling are studied and compared .Tested wood for both is of nine-year-old , from Kaihua Forest Farm of Zhejiang Province .Results of 15 clones show that some physical and mechanical parameters of clone Chinese fir wood are superior to seedling , and the other inferior to .Air-dry density of clone Chinese fir wood is 0.340 g cm-3 , basic densi ty 0.280 g cm-3 , coefficient of radial shrinkage 0.131 %, coefficient of chordwise shrinkage 0.217 %, coefficient of volumetric shrinkage 0.401 %,bend strength 44.355 MPa , bend elastic modulus 8.296 GPa , and impact ductility kJm-2 .
Cymbidium defoliatum Y .S .Wu et S .C .Chen is reported as a new record of Cymbidium from Zhejiang Province , and its values on science is reviewed .The sample is planted in the flower nursery of Zhejiang Forestry School.
Based on embryology research in Liriodendron chinense , the abortive female gametophyte in its development was checked up by light microscope .The development of pollen tube in fertilization was detected by fluorescence microscope or by scanning electron microscope .And the rate of seed-setting was also investigated .Results were as follows : (1) The main embryology reason for low seed-setting in Liriodendron chinense was self-incompatibility .(2)The main site of incompatibility was in stigma-canal , where pollen tube was blocked .The reasons for self-incompatibility were discussed and a method to improve the rate of seed-setting was put forward .
Based on analysing the shortcomings of the logistic model which is a limited space growth model for population , the paper deals with the quantitative dynamics of Pinus taiwanensis population in Longxi Mountains Natural Reserve by a generalized logistic curve , and points out the highest growth rate at breast-height diameter range in different comunity types of Pinus taiwanensis forest and in pure forests with different densities .The results show that generalized logistic curve do fit the quantitative dynamics of the population .This study provides a theoretical basis on the production and management of Pinus taiwanensis .
Early-w arning system is a technological supporting system of regional forest resources sustainable development .Based on historical recall , the paper analyses the necessi ty of developing early-w arning sy stem of regional fo rest resources f rom sustainable development , macroscopical management modernization and shortening macroscopical regulation time lag .
A information standard is important to build management information system of improved tree varieties .This paper mainly introduces the peocess and principle of building the standard, and puts forward the system structure of the standard .
Quantity valuation on working plan of state-owned farms was made in aspects of management, economic benefits and index system of implemented plan , etc , with the example of Changhua Forest Farm , Lin 'an , Zhejiang .The valuation indicated :in 1991 ～ 1995 , total standing crop of the forest farm increased from 71 426 m3 to 87 463 m3 , and its total sale income increased 0.62 million yuan to 3.39 million yuan (RMB).The implementing level of the plan arrived a good grade .
Biomass is one of the important items for today's regional forest resources inventory and monitoring , but the current biomass models have two big problems , that is , biomass estimator is not compatible with volume estimator , and total biomass estimators is not compatible with stem , branch , leaf biomass estimators .A new super-population tree biomass model for Pinus massoniana was presented based on linear simultaneous equation system and 2-stage weighting least squares .The model could solve the two problems above and have higher precision and better applicability than the currently-used biomass models
Let G be a simple graph with n vertices and n (G )be the least eigenvalue of G .If G is a unicyclic graph with n vertices , G＊is the graph obtained by joining each vertex of C3 to a vertex with degree one of P k-1 , P k 1-1 , P k 2-1 , respectively , w here k k1 k2 1 , k -k 2 1 ,k +k 1 +k2 = n , then n(G) n(G＊)and the equality holds if and only if G≌ G＊.
On the basis of ample historical materials and from the point of view of history and landscape aesthetic appreciation , this paper axpounds the evolution and reasons of setting up rockeries in Chinese historic gardens and the criteria of appreciating rocks.The purpose is to select the essence to serve modern garden architecture .
Chinese calligraphy in classical gardens is not only the carrier of lang uages that point garden 's artistic conception out , but also an independent aesthetic object .The forest of stelae ,which is for appreciating calligraphy , is an important factor following three garden factors of building , landscape and plant .
Barricading , clearcut ting and eradicating to control pine wilt disease must remove so many healthy pines that Monochamus alternatus are enforesed to fly a long distance for their new host and resulting in spread of pine wilt disease .New strategic thought of keeping , killing and unharming that means keeping vectors in pine forest , killing all M .alternatus in dead pines and unharming of pine wilt disease to pine forest , is practised in Ningbo east part pine forest , reducing the rate of dead pines infested with pine wilt disease by average of 69.2 %.
Before mulching with rice straw , bamboo shoots forest of Phyllostachys dulcis has been watered thorough .Mulching material of 50 cm in thickness falls into two layers.Sublayer of 25 ～ 30 cm is watered as heating , and upper layer of 20 ～ 25 cm covering with a plastic film uses as heat preservation .The results show that in all mulching plots , the season of bamboo shooting is moved up 74 d earlier than check .Bamboo shoots output and pure income increase by 29.6 % and 2 347.9 % respectively .Mean ratio of input to output is 1∶10.95 .