2008 Vol. 25, No. 2
This objective is to determine the process parameters and control way in drying wood stick. A model for heat and mass transfer during high temperature convection drying of Chinese fir(Cunninghamia lanceolata) wood stick was developed for use with Chinese fir oriented laminated stick lumber(CFOLSL). From the model,an equation of internal moisture migration and heat transfer at the point of fiber saturation was created. Model authenticity and feasibility were validated through an experiment with Chinese fir wood stick. Results of measurements versus the simulation model for moisture content(RMC2=0.96-0.99) and temperature(RT2=0.97-0.98) showed strong agreement. The high-accuracy of the model used to analyze high temperature drying of wood stick could contribute to the theoretical basis for calculation of technical parameters as well as to a working solution for drying wood stick.
Researches in wood physical-mechanical of Taiwania flousiana were few,in order to judge the wood,wood physical-mechanical properties for 8,14,and 28 years old T. flousiana grown on the Shankou Forest Farm of Nandan,Guangxi Province were studied and compared to Cunninghamia lanceolata. Generally,wood density and mechanical properties of both trees increased as tree age increased. Results of a t test for the two wood types showed highly significant(PPPPPPPPPPC. lanceolata,the following properties of T. flousiana were lower: air-dried density (moisture content of wood is 12%) (2.3%), basic density (4.4%), radial shrinkage coefficient (1.6%), tangential shrinkage coefficient (2.6%), volumetric shrinkage coefficient (1.5%), tangential section hardness (3.6%), the modulus of elasticity in static bending (3.8%), compression strength parallel to the grain (3.4%), radial shearing strength parallel to the grain (17.5%), and tangential shearing strength parallel to the grain (14.4%), but greater for the following properties: cross section hardness (6.6%), radial section hardness (6.1%), bending strength (3.4%), toughness (2.3%), radial cleavage strength along the grain (15.0%), and tangential cleavage strength along the grain (16.3%). These results could provide a scientific basis for plantation establishment and rational utilization of T. flousiana.
The distribution,morphology,content,and nanostructure of crystals in axial and radial distributions of Eucalyptus citriodora were studied using Scanning Electron Microscopy and Energy Dispersive X-Ray Analysis(SEM-EDXA).The samples were 30-year-old trees,having 30 annual rings,20-23 cm of diameter at breast height. The results were as follows: (1)crystals were mainly deposited in the ray cells and had a diamond shape; (2)elemental Ca content was above 22%; and (3)crystals in E. citriodora were between 350 to 400 nm decreasing gradually from the lower part of the tree to the upper part.
Using vegetable fibre to ferment ethanol can relieve energy crunch and improve environment protection. Here batch and continuous fermentation of xylose and glucose mixtures with Pichia stipitis were studied to provide basis for industrialized fermentation of ethanol. P. stipitis was cultured in a single-stage reactor with a mixture of 10.0,20.0,30.0,40.0,50.0,60.0 g·L-1 glucose and 5.0,10.0,15.0,20.0,25.0,30.0,60.0 g·L-1 xylose. Results showed that with a residual glucose concentration of not more than 10.0 g·L-1 in a culture medium with batch fermentation,glucose and xylose could be fermented by P.stipitis synchronously. Then,for continuous ethanol fermentation,glucose had great effect on fermentation with xylose. When P. stipitis was cultured in a single-stage reactor with a mixture of 30.0 g·L-1 glucose and 15.0 g·L-1 xylose, at a dilution rate of 0.08 h-1,9.40% of the xylose was consumed,and the ethanol concentration was 12.55 g·L-1. However,when the dilution rate was 0.04 h-1,66.07% of the xylose was consumed,and the ethanol concentration was 16.93 g·L-1.
Atractylodes macrocephala(Compositae),for its rhizomes used medicinally,are cultivated widely in over 20 provinces in China,especially in Zhejiang. But the qualities are in difference and hard to distinguish. To identify components in original herbs of A. macrocephala,permanent slides of these materials were made with the pushing-slice method,and structural characteristics of rhizomes from twenty origins(Ningguo City of Anhui,Mount Xitianmu,Waijiusi,Dingcun,Wushan, Pan'an of Zhejiang,and Anfu County of Jiangxi,etc.) were compared using by microscopic examination with thirty replication for one index. Results indicated significant differences(PA. macrocephala for xylem width,bark width,ratio of xylem to bark,density of vessel lines,diameter,and density of oil cavities. This showed that there were structural differences among A. macrocephala with different origins. However,diversity caused by genetic and environmental factors was difficult to explain. Nevertheless,the proportion of area for the oil cavities was a good index for measuring the content of the effective components.
In order to select superior high-resin-yield families of Pinus kesiya var. langbianensis,the resin-producing capacity,diameter at breast height(DBH), and tree height of 25 high-resin-yield families and a control that was 4.5 years old were measured and analyzed by field test and using ANOVA. Results showed that the resin-producing capacity among the families was significantly greater(P<0.01) than the control; on the average it was 56.6% higher. Also,the family heritability was 0.62. Thus,five superior families with high-resin-yields having a genetic gain of 70.9% and a realized-gain of 114.3% were selected.
To reveal the regularities of cone and seed variation,the phenotypic traits of cones and seeds of seven species and 141 families in natural populations of Pinus tabulaeformis provenances of Shaanxi Province were analyzed. Statistical analyses,such as analysis of variance,correlation analysis among provenances and within families for a provenance of P. tabulaeformis,and genetic variation,were used. Result showed that significant differences were found between in provenances and in individuals within provenances in cone length(PPPPPPPP<0.05) negative correlation; and for cone and seed traits at a latitude,≥10 ℃ accumulated temperatures and the frost-free period were not significantly correlated. The variations of seed traits and the thousand-seed weight comply with annual mean temperature. The variations of cone width and seed width mainly follow the variation of altitude.
In order to understand the successional dynamics of Castanopsis fabri forests,which widely distributed in Guangxi Province,the plant species composition and structure of the evergreen forests were investigated by sampling method. The important values of the whole plant species were calculated. According to dominant species in shrub and herb layer,six common Castanopsis fabri Associations in Guangxi were classified as follows:(1)Castanopsis fabri-Itea coriacea-Maesa japonica-Plagiogyria distinctissima Association,(2)Castanopsis fabri-Ardisia crenata-Elatostema acuminata Association,(3)Castanopsis fabri-Lasianthus longicauda-Woodwardia japonica Association,(4)Castanopsis fabri-Ardisia quinquegona-Cibotium barometz Association,(5)Castanopsis fabri-Psychotria rubra-Cibotium barometz + Blechnum orientale Association,and (6)Castanopsis fabri-Maesa japonica-Woodwardia japonica Association. The research is a theoretical basis for the restoration,conservation and scientific management of the disturbed Castanopsis fabri forests.
Hamamelidaceae Shaniodendron subaequale,an endangered plant species endemic to China,has a narrow distribution range. To understand why it is endangered,diurnal changes of photosynthetic rate,light compensation point,light saturation point,and chlorophyll content in different months for S. subaequale and its accompanying species were determined using the LCA-4 portable photosynthesis system from May to November. Results indicated that diurnal change curves for photosynthetic rate were double-peaked with a photosynthetic depression at midday. S. subaequale was higher in photosynthetic ability than Platycarya strobilacea,which was lower than the mean level. Also,due to changing leaf development and chlorophyll content,S. subaequale had a higher light compensation point and lower light saturation point. This indicated that the adaptable range of light for S. subaequale was narrower than its neighboring species. Thus,its ecophysiological traits can partly account for its endangerment.
To determine if in a drought environment there was an adaptation for Acacia richii due to rhizobia,this experiment analyzed the accumulation of metabolites,such as proline,soluble sugar,and chlorophyll,after inoculation with SMD rhizobia separated from Tephrosia candida,YHH from Leucaena leucocephala and TWXS from A. richii under artificial drought conditions in a PEG-6000 solution. The contents of PEG-6000 were 0(control),0.010,0.025 and 0.037 respectively. Results showed that different rhizobia increased metabolite accumulation in drought conditions,but there were different levels of accumulation depending on rhizobia strains. The rhizobia SMD had a stronger potential to promote seedling resistance in a drought environment than rhizobia YHH and TWXS. Thus,it is advantageous to choose rhizobia to promote growth of A. richii in drought conditions.
To optimize the inter simple sequence repeat(ISSR) reaction conditions with Ginkgo biloba,the concentrations of template DNA,Taq DNA polymerase,primers,deoxyribonucleotide triphosphate(dNTP),along with annealing temperature and their influence on polymerase chain reaction(PCR) amplification were studied. The sample leaves were collected in 97 old ginkgo trees from more than 20 provinces in April and May,2006. Results showed that the optimum reaction conditions for ISSR-PCR of ginkgo were: 0.3 μg Taq DNA,2 μL 10×Taq buffer(including 15 mmol·L-1 MgCl2),40 ng template DNA,0.2 mmol·L-1 dNTP,0.5 μmol·L-1 primer,and 1.5 mmol·L-1 Mg2+ with a total volume of 20 μL. Amplification consisted of one cycle with initial denaturation at 94 ℃ for 5 min,followed by 38 cycles of 30 s at 94 ℃,30 s annealing at 48-53 ℃(depending on the primer used), 1 min at 72 ℃,and a final 10 min extension at 72 ℃. Afterward,the samples were maintained at 4 ℃.
Eucalyptus grandis is the most widely cultivated eucalyptus. The undergrowths of E. grandis forest are few. To identify the components of litterfall from E. grandis that could affect other species,organic compounds of litterfall from E. grandis were ultrasonically extracted with hexane and identified with a gas chromatograph-mass spectrometer(GC-MS). Results showed that extracts of litterfall from E. grandis contained 35 components within 8 different categories,including alkanes,alkenes,arenes,alcohols,aldehydes,ketones,hydroxybenzenes,and esters with the main allelochemicals being alkanes,arenes,and esters. These results could have important implications on seed germination and seedling growth and could be used as a reference for research of allelopathic influences on plants in the E. grandis understory.
Taxus chinensis var. mairei,a rare and endangered species,both is a beautiful garden tree and a good timber tree,especially,its extract(taxol) can be used for medicine to treat cancers. This trial studied the macronutrients and allocations to different organs in T. chinensis var. mairei seedlings in order to improve its cultivation level. T.chinensis var. mairei were planted in Tonglu County,Zhejiang Province,treated with fertilizer (N∶P2O5∶K2O=16∶16∶16) in the end of March every year. The N,P,K,Ca,and Mg contents in leaf,root,and branch organs of T. chinensis var. mairei and the organs' drought weight for one- to three-year-old seedlings were analyzed in November 2006 by random sampling with three replications. Results showed that drought weight of the three different organs increased 10 times every year first three years,and the root/crown ratio also increased. Nutrient elements for one- and two-year-old seedlings were in the order of leaf > root > branch,while in three-year-old seedlings the order was leaf > branch > root. As the seedlings grew,leaf N,P,K,and Ca increased,but Mg decreased; branch N and Mg increased,whereas P,K,and Ca decreased; and root nutrient elements all decreased. Of the five nutrient elements in the three organs,N and Mg accumulated faster increasing about 10 times each year. Accumulation in the first year was: N > K > Ca > P > Mg,whereas in the second and third years the order was N > K > Mg > Ca > P. A shading treatment(25% shading from April to November in 2006) increased N in leaves but decreased N in branches and roots; increased P in leaves,branches,and roots; increased K in roots and leaves but decreased K in branches: and had little influence on Ca and Mg content. For the shading treatment,accumulation of the 5 nutrients in T. chinensis var. mairei decreased 6.8%.
Seedless wampee (Clausena lansium ‘Yunan Seedless’) is a new and nutritious fruit tree,but lack in research of cultivation and management. This objective is to provide a basis for rational fertilization to improve fruit quality. The seasonal variation for mineral concentrations of nutrient elements in leaves during growth of seedless wampee were determined for different phenological phases,including autumn shoot growth,bud differentiation,flowering,fruiting,fruit growth,and harvest stages in three different orchards(Xincheng,Nongkesuo,and Nongwei) of locations fertilized with organic and combined fertilization. Results showed that the concentrations of N,P,and K decreased from autumn to the next fruiting,but recovered with fertilizer application. Ca and Mn concentrations increased from autumn shoot growth to fruit maturity. The concentration of Cu in Xincheng Orchard decreased to a minimum during maturity,but increased to a maximum the following autumn; in Nongkesuo Orchard Cu was maximum in the fruit growing stage,but decreased to a minimum the following autumn; and in Nongwei Orchard Cu was highest with bud differentiation and lowest in the fruit growing stage. The seasonal variation of Zn in Xincheng and Nongwei Orchards decreased to a minimum in the flowering stage and peaked at harvest(Xincheng) and the following autumn shoot growth(Nongwei),whereas in Nongkesuo Orchard Zn decreased in the fruiting stage and increased during the following autumn shoot growth. The Fe concentration in Xincheng Orchard decreased to a minimum in the flowering period and increased to a peak in the fruit development period; however,in Nongkesuo and Nongwei orchards Fe peaked in the autum shoot growth stage,decreased to a minimum the following autumn shoot growth(Nongkesuo) and flowering stage(Nongwei). Concentrations of B for the three orchards were lowest in the flowering stage,maximum during the harvest stage in Xincheng and Nongwei Orchards,and highest the following autumn shoot growth in Nongkesuo Orchard.
To increase future forest research efficiency and management,a model of branch biomass and growth increment for mid-young-aged Pinus elliottii was determined. Estimates were made using the branch analysis method with regression models of crown biomass and increment-established. Results showed a significant power correlation existed between branch biomass(WB) and branch diameter(DB) (WB=0.017 8 DB3.006 1) with r2=0.840 8(PATB) and diameter at breast height(DBH) was well fitted by ATB=1.850 2 DBH1.541 8 with r2=0.750 9(PWC) and DBH(WC=7.105 9 DBH2.596 5) with r2=0.920 5(Py) and DBH increment(x) was also well fitted by y=29.354 1x0.255 4 with r2=0.956 6(P<0.01).
To understand variations in soil moisture dynamics with afforestation of karst regions,simulation experiments in the intelligent climate-control chamber(RXZ) and in the fields were conducted in typical karst formations of the Huajiang Valley,the southwestern Guizhou Province. We used three types of much,including litter,stone and plastic film,with 0,30%,60% and 100% coverage,and conducted having seedlings(one-year-old pepper) and no seedlings. Results showed that soil moisture use was related to mulch type,mulch quantity,and whether having plants with continuous mulching best. To reduce mold due to moisture,plastic mulch excelled stone mulch with litter mulch being worse. However,results with afforestation showed that at least 60% mulch should be applied. The plant survival rate with stone mulching was higher than with litter which was much higher than plastic mulch. Even though plastic mulch had the lowest moisture for mold,plant survival rates with the plastic mulch were poor. So,in a typical karst valley area,afforestation under plastic mulching should be studied further.
Mingling of dominant plant populations in an evergreen broadleaf forest,one of the most important plant types in the Mount Tianmu National Nature Reserve of Zhejiang Province,were studied to supply a theoretical basis for evergreen broadleaf forest protection,restoration,and reconstruction. A typical plot in the reserve,100 m×100 m,was surveyed for tree diameter at breast height(DBH) above 5 cm with Total Station(Leica TCR702Xrange) equipmentused to measure tree coordinates. Also,dominant plant populations were determined using the Dominance Index with edge correction applied and the mingling index calculated for tree species diversity. Results showed that the dominant plant populations of evergreen broadleaf tree species(Cyclobalanopsis gracilis,Cyclobalanopsis glauca,and Lithocarpus brevicaudatus) exhibited diverse and dominant species characteristics. The average mingling index for the plots was 0.505 1; while the evergreen broadleaf tree species mingling index was 0.483 6, and the non-evergreen broadleaf species mingling index was 0.582 3. Overall,these tree species maintained the evergreen broadleaf forest biodiversity.In addition,as dbh increased,the mingling index increased. Since C. gracilis,C. glauca,and L. brevicaudatus predominantly reproduced through sprouting,the mingling index was low. This study showed that these evergreen broadleaf tree species showed moderate mixing.
This study determined a set of management techniques for improving a secondary Pinus massoniana forest. Using existing forest management as a classification scheme,the forest was divided into ecological and commercial forests having different management objectives,such as protection forests,timber products forests,and forests for fiberboard or chipboard. Temporary plots of different management types were surveyed; a set of experimental plots were set up and measured for age class in the Duyun area of central Guizhou Province. Appropriate management techniques for this area included restricting access to hillsides to protect the forest,preventing forest fires,retaining 15-30 seed trees per hectare,thinning seedlings rationally in the second year after renew,and retaining a density of 3 000-5 000 seedlings per hectare. For the managed ecological forest,seedlings of broadleaf species were necessary to provide cover in cleared areas,and thinning of young and middle-aged trees,as well as fertilizing middle-aged trees was not necessary. If managing a commercial forest,P. massoniana seedlings should be planted in open areas. A young stand of P. massoniana required tending once per year for 2-3 years with a 30%-50% thinning at age 7; a middle-aged stand needed a 20%-40% thinning at ages 13-14 along with fertilizer applications of 1 000-1 500 g calcium phosphate per tree and 150-300 g of urea.
Qinhuai River is the main river in Nanjing City,the overall length is more than 100 km,having 16 prongs and 2 630 km2 river valley. This objective is to rebuild and protect ecological system of the Qinhuai River riparian zone,pollution levels of five heavy metals(Cd,Zn,Cu,Cr,and Pb) in a riparian zone along the Qinhuai River of Nanjing were analyzed with sample plot method. Five plots were set,including Dongping of Lishui City,Yinxiang and Chalukou of Jiangning District,Dajiaochang of Qinhuai District and Zhongheqiao of Nanjing City,and each plot fell into near-riparian zone(0-30 m near river) and far-riparian zone(5-10 m near river). Results indicated that soil heavy metals in the riparian zone manifested spatial heterogeneity. Soil heavy metal content of the near-riparian zone was much than the far-riparian zone,and for topsoil(0-10 cm in depth) it was much than the subsoil(10-20 cm in depth). In different plots soil heavy metal content was distinctive. Also,in the upper reaches,due to less human interaction,soil heavy metal content was less than the middle and lower reaches.Both Cd and Cr content of the soil in Yinxiang were much than the standard level(Pn > 3.0); so soil pollution was heavy. Soil from Chalukou had an intermediate degree of pollution(Pn > 2.0),and soil came from Daojiaochang was lightly polluted(Pn > 1.0). The pollution index ranking for these five heavy metals in the riparian zone was Cd > Zn > Cu > Cr > Pb. There were positive correlations between soil Cu with Cd(PPPPPPP<0.05).
The last-instar larval external morphologies of Diaphania pyloalis(Walker), Diaphania indica(Saunders) and Diaphania perspectalis(Walker) are described and illustrated. All specimens examined are deposited in the larva Collection of Department of Plant Protection, Zhejiang University, China.
Urban forest was of great interest to a variety of scientific and urban planning applications. This paper presented the process and results of analysis using remote sensing imagery in this area. There were mainly two key steps in the analysis: the first was to analyze urban forest abundance utilizing regression tree techniques and advanced spaceborne thermal emission and reflection radiometer(ASTER) images; the second was to analyze the ecological benefits of urban forest using CITYgreen model. The analysis of urban forest abundance was accomplished implementing classification models,which were based on relationships between urban forest abundance and the spectrum on ASTER imagery,and were generated using regression tree techniques. Subsequently,the calculation of forest coverage,carbon storage and the amount of air pollutants removal about urban forest was carried out introducing CITYgreen model. According to the analysis,the total area in Tongzhou District was about 11.62 km2; the forest coverage was about 7.6%; the carbon storage and the amount of air pollutants removal amounted to 123 589 t and 267.1 t·a-1 respectively. At the end,the advantages and disadvantages,as well as some of the conceivable improvements of this strategy were discussed.
The relationship between the landscape title and text,the title and the author and reader,the title and the background of the society and the time were studied. It focused on the function and significance of the titles of landscapes,analyzed how to name a landscape and how the title functioned. According to the relationship of the title and text,we could see the title directly or indirectly reflected the content or the theme of the text,thus performing the function of indication. From an expository view,the significance of the two could be divided into realism and symbolism,and different scope of contents covered by the title manifested two aspects of indication and implication. According to the relationship of the title and the author and reader,the title was a part of the author's creation. It not only revealed the author's mentality and intention,but also took the reader into consideration. Whether or not the text contained author's emotion in could be clearly read from the title. Whether or not the title of landscape was created for the first time could be divided into singular and series. Literary practice and comfortable psychology made the titles of landscapes reach unanimity. While the titles of landscapes could cause counteraction to the society and the time which showed benefits as well as utilitarianism. Therefore the titles of landscape could be the extendibility landscape. Reader could obtain more information through the titles of the landscapes and make it as another insight in landscape works.
As an important raw material,wood has been widely used in many areas,such as building,furniture,and interior decoration. However,wood can be easily attacked by termites,which limits the application of wood and reduces the wood's service life. Generally speaking,the attacking way of different termite species are not the same,and the sufferance vary from one another in wood species. The most popular termicides include arsenicals,metal salts,inorganic acids,organochlorine compounds,organophosphates,silicons,pyrethroids,heterocyclic compounds and so on. The inorganic and organochlorine termicides will be replaced by the pyrethroid and other environment-friendly termicides in the future. The kind of termicides which can protect wood not only from termites but also from fungi or fire will be popular. Chemical modification of wood will also be a way of termite-resistance.
Micropropagation of Sasa fortunei was studied with shoots of young culms and rhizomes as explants. The results showed as follows:germination rate of rhizomes was better than that of culms. 6-Benzylaminopurine(6-BA) had a better effect on proliferation than thidazuron(TDZ). But TDZ was able to improve rooting. The highest proliferation rate(3.60) was obtained from the combination of 3 mg·L-1 6-BA and 0.5 mg·L-1 NAA. The combination of 3 mg·L-1 6-BA and 0.01 mg·L-1 TDZ also had a high proliferation rate (3.43),achieving 100% rooting percentage and good growth performance. Therefore,it was potentially propitious to mass production.
Catharanthus roseus seed oil was extracted with n-Hexane,then esterified with potassium hydroxide and methanol. After esterification,the oil was analyzed by gas chromatography-mass spectrum (GC-MS). 9 peaks were separated and 5 peaks were identified,the compounds were quantitatively determined by normalization method,and the identified compounds accounted for 99.91% of total GC peak areas. The contents of the main fatty acids,namely,oleic acid,linoleic acid,palmitic acid,arachidic acid relative contents were respectively 73.92%,16.93%,5.58% and 3.40%.
With hydrodistillation and GC-MS,the volatile oil extracted from Mosla chinensis was separated and studied. Of 34 identified components,the most abundant component was thymol,accounting for 83.32%; p-cymene and acetylthymol accounted for 6.14% and 2.32% respectively. Of the 34 components,phenol compound accounted for 85% and benzene accounted for 7.32% and alkene accounted for 3.80%.