2007 Vol. 24, No. 2

Articles
Moisture diffusion coefficient of Cunninghamia lanceolata board with non-steady state conditions
LI Yan-jun, LI Liang, ZHANG Bi-guang
2007, 24(2): 121-124.
[Abstract](1063) [PDF](134)
Abstract:
Cunninghamia lanceolata(Chinese fir)boardwas tested systematically in non-steady state conditions to determine the moisture diffusion coefficientwhen the temperature of the drying medium, the initial moisture content(IMC), and the texture direction varied. Results showed that the moisture diffusion coefficient increased with the increase of the drying medium temperature or IMC, reaching a maximum near the fiber saturation point(FSP).When the moisture contentwas below the FSP, the moisture diffusion coefficient increased with the increase of the initial moisture content, but when the moisture content was above the FSP, the coefficient remained stable. The longitudinal diffusion coefficient was signifcantly larger than the radial and tangential diffusion coefficients, with ratios between 5- 7, and the radial diffusion coefficient was clearly larger than the tangential diffusion coefficientwith a ratio of about 1.0- 1.5.[Ch, 3 tab. 11 ref.]
Analysis on gradual mechanical properties by the depth of bamboo wall of Dendrocalamus giganteus and Dendrocalamopsis oldhami
JI Wei-bing, YAO Wen-bin, MA Ling-fei
2007, 24(2): 125-129.
[Abstract](1158) [PDF](196)
Abstract:
To analyze the characteristic of bamboo as composite material, taking Dendrocalamus giganteus and Dendrocalamopsis oldhami as specimen considered thatbamboowoodwas composed of several axisveneers along the thickness. The modulus of elasticity(MOE)of integrative bamboo and two axis veneerswas tested by the apparatus of omnipotence test-bed while the MOE of the other veneers was evaluated by Lagrange interpolation. The results were as follows:Amechanical model ofMOEbetween integrative bamboo and axisveneerswas developed.Besides, the MOE of integrative bamboo acquired from the model above and tested by the apparatus of omnipotence test-bed was almost uniform.[Ch, 3 fig. 2 tab. 10 ref.]
Development of forest resources transfer office system
WUDa-sheng, FANG Lu-ming, XUAi-jun
2007, 24(2): 130-134.
[Abstract](2362) [PDF](122)
Abstract:
The forest resources managementwas oriented to the forest resources administratorof a county or a city,andwas aimed to design a transfer management model which integrated forest resources transfer business process,such as application, approval, investigation and assessment, information publishing, property license issuance and task design etc. Based on a great deal of requirement investigation and analysis, designed the business process,data flowand function architecture of the forest resources transferoffice systemby softengineering, and developed a platform which is advanced, useful, safe, open, interoperable and personal. From the usage result of its application in Jiande City of Zhejiang Province, the system runs stably and the management work efficiency and benifit are increased greatly.[Ch, 5 fig. 13 ref.]
Moisture-holding capacity of different plant cover types in the Jianshan River drainage area
LONG Wu, YANG Yun-hua, WANG Ke-qin, LI Jian-zeng, LI Bao-rong, LI Yun-jiao
2007, 24(2): 135-139.
[Abstract](1062) [PDF](167)
Abstract:
In orderto find foresttypeswith bettermoisture-holding capacity,to logically adjustthe foreststructure,and to maximize forest use in the Jianshan River drainage area,moisture-holding capacity of vegetation, litter, and soils fromsixdifferentland covertypes,namely,a Pinus yunnanensis secondary forest,a Cunninghamia lanceolata secondary forest, a shrub forest, terraced field, farmland on slopes, and moor, were compared.Moisture-holding capacity of the vegetation and litter were determined with immersion mensuration, while the soil moisture-holding capacity wasestablished as the productof soil porosity and soil thicknessof the land.Results showed thattherewere significant differences(P 0.01)in moisture-holding capacities for vegetation, litter, and soils of different land cover types.Moisture-holding capacities were in the following order: terraced field(5 473.1 thm- 2) Pinus yunnanensis secondary forest(5 464.2 thm- 2) Cunninghamia lanceolata secondary forest(5 433.0 thm- 2) moor(5 203.2 thm- 2) farmland on slopes(5 039.1 thm- 2) shrub forest(4 610.5 thm- 2).[Ch,4tab. 12 ref.]
The LEAFY gene in RNA interference(RNAi)transgenic Liquidambar formosana mediated by Agrobacterium tumefaciems
QIAOGui-rong, LUANWei-jiang, PANHong-wei, ZHUO Ren-ying
2007, 24(2): 140-144.
[Abstract](1119) [PDF](177)
Abstract:
It is incompatible between production and need of timber, the aim of the test is breeding fast-growing,super-quality and large-diameter tree cultivar. The LEAFY gene affects plant flowering. Using polymerase chain reaction (PCR) with the primers 5-CACCTCAGAGAGAGAAAAATAGATTATGGATCC-3' and 5- GTCGACAGTTCGGGGGGGAAATATAAT-3', a conservation sequence of the LEAFY gene for Liquidambar formosana(Chinese sweetgum)was cloned. An RNA interference(RNAi)pBIN vector of the LEAFY gene was constructed byGateway technology, and then agrobacteriummediationwas used to transfer the aimgene into the the first two to three leaves of Chinese sweetgum seedlings.Then the transgenic leaveswere cultured to plants in vitro.These plants leaveswere analyzed with PCR and Southern blotting. It is sure that the foreign gene was integratedinto the genome, resulting in four transgenic plants. However, the transgenic four plants development and timber quality has not been analyzed as they are so young. The study is carried on.[Ch, 5 fig. 12 ref.]
Biomass reproductive allocation in Dolichomitriopsis diversiformis in Mount Fanjing of Guizhou Province
WANG Ya-qin, LI Jing, CHEN Jun, WEI Hua
2007, 24(2): 145-149.
[Abstract](1306) [PDF](153)
Abstract:
Dolichomitriopsis diversiformis(Lembophyllaceae)is an endemic species of east Asia. Its distribution area inChina isbecoming smallerand smallerforenvironmental stress.Its reproductionmay be one of the reasons to be endangered. The seasonal dynamics of biomass allocation to reproductive organs and to vegetative organs of Dolichomitriopsis diversiformis by weighting were studied in its each phenological periods in Mount Fanjing of Guizhou Province. The results showed that reproductive organs did not grow during nutrient growth and dormancy,so biomass allocation did notoccurin these two periods.In the reproductive growth period,biomass allocation to the reproductive organs was 0.74%. In the young reproductive period, biomass allocation to the perichaetium was 0.57% and to the young sporophyte, 2.36%. During the mature reproductive period, biomass allocation to reproductive organswas 4.77%, and in the old reproductive period itwas 3.06%. This research is the basic work to study the species reproductive ecology.[Ch, 1 fig. 2 tab. 9 ref.]
Leave source from callus induction and flavonoid content in callus from different tissues of five Ginkgo biloba cultivars
CHEN Ying, CAO Fu-liang
2007, 24(2): 150-155.
[Abstract](1136) [PDF](136)
Abstract:
The objectives of this study with Ginkgo biloba were to establish a callus culture system for leaf sources and to determine the flavonoid contentin callus fromdifferentgingko tissues.Five elite cultivars(Number44, 45,28, 79 and 53)with mediums of N6, MS(MurashigeSkoog medium), improved MS and DCR(Douglas-fir cotyledon revised medium), and growth supplements of NAA(naphthalene acetic acid), 6-BA(6-benzylaminopurine), and KT(kinetin)were tested with roots, leaves, cotyledons, and stems as cultured explants. The induction rate, growth, and flavonoid contentin the callusfromdifferentcultivars and explantswere canpared. Results indicated thata supplementof 0.1- 0.5 mgL- 1 ofNAAand 0.5- 1.0 mgL- 1 of 6-BAin the mediumfavored leaf size(P 0.01). The induction rates of leaf callus in cultivars` 28' and` 79' were significantly higher(P 0.01)than the other cultivars.MediumN6 was better for inducing callus than MS, but N6 was not better for a subculture. The 6-BA supplement in a medium more readily(P 0.01) induced callus thanKT.Also, the flavonoid content in the callus of cultivars`28' and`79' was higher(P 0.01) than the other cultivars.Forall cultivars,flavonoid contentin the callusfromdifferentexplantswas root leaf cotyledon stem.[Ch, 2 fig. 4 tab. 18 ref.]
An inter simple sequence repeats(ISSR)reaction system for Lycoris(Amaryllidaceae)
ZHANG Lei-fan, GAO Yan-hui, ZHUYu-qiu, LIUZhi-gao, TONG Zai-kang, HUANG Hua-hong
2007, 24(2): 156-161.
[Abstract](1338) [PDF](154)
Abstract:
To study the genetic diversity of Lycoris Herb.(Amaryllidaceae), an orthogonal design was used to optimize an inter simple sequence repeats(ISSR) amplification system on Lycoris using five factors(Mg2+,deoxyribonucleotide triphosphate(dNTP), primers, DNA template, and Taq polymerase) at four levels of concentrations respectively. A suitable ISSR reaction system was constructed with the 20L reaction system containing 1 polymerase chain reaction(PCR)buffer,2.5 mmolL- 1 MgCl2,150molL- 1 dNTP,0.5molL- 1 primer, 50 ng DNA template, and 25.05 nkat Taq DNA polymerase. According to the gradient PCR, the optimal annealing temperature for the ISSR reaction was 57C.[Ch, 7 fig. 2 tab. 23 ref.]
Branch growth of Pinus elliottii in the hilly red-soil area of the mid-subtropical climatic zone
TUJie, LIUQi-jing
2007, 24(2): 162-167.
[Abstract](788) [PDF](136)
Abstract:
From a review of the Pinus elliottii(mash pine)domestic and overseas literature on branching, the branch growth at the whorls was analyzed at the Qianyanzhou Experimental Station of the Chinese Academy of Sciences in Taihe County, Jiangxi Province, China and its relationship with several meteorological factors was determined. Branch growth for internode length(IL)and basal diameter(BD)was determine by vernier caliper,and their partial correlations with respect to the whorls were calculated. Additionally, the response to these meteorological factors during the growing periods was described in a multiple linear regression model. Results showed that branch ILgrowth for a givenyeardeclined from the upperwhorls to the lowerwhorls.Also,branch BD increased gradually from the upper whorls to the lower whorls, but slightly declined near the base of the crown.Distribution of the annual total branch volume waswell fitted to skewed leftnormal distribution curves.This showed that large brancheswere mainly concentrated in the middle-lower part of crowns.The linear regression accuracy for branch volume versus(BD2 branch length)was not very strong(r2= 0.45). However, the adjusted R2 of the multiple linear regression equations for ILand BDwith several meteorological factorswere all highly significant(0.96)(P 0.01), and the partial correlations were all highly significant(P 0.01). The partial correlations showed thatILgrowthmainly depended on canopy relative humidity.Also,BDgrowthwas negatively correlatedwith a cumulative temperature of 10℃ , while it was positively correlated with total precipitation.[Ch, 6 fig. 41ref.]
Morphological and physiological changes accompanying the induction of salt tolerance in Neolitsea sericea seedlings
WANG Wei, HUANG Sheng-li, DING Guo-jian, HUANG You-jun, HUANG Jian-qin, ZHENG Bing-song
2007, 24(2): 168-172.
[Abstract](1210) [PDF](173)
Abstract:
To understand the mechanism of salt tolerance in Neolitsea sericea(sericeous newlitse), physiological and morphological expression studies were done. Water culture of sericeous newlitses one year old seedlings were conditioned by a stepwise increase in NaCl(from 0 to 9 gL- 1) added to the nutrient solution(Hiller)over 20 days respectively. The results showed that the proline, Na+ K+ and membrane permeability were increased,chlorophyll were decreased and the growth of stem and base diameter, the number of new shoots and roots were reduced. But the proline, conductivity and chlorophyll recovered lightly overtime.Analysisof variance showed that the one-year-old seedlingsgrowth in 9 gL- 1 NaClwere inhibited and significantly different(P 0.05)contracted with other treatments.Sericeous newlitse is a moderated salt tolerated tree species.[Ch, 5 fig. 21 ref.]
Cephalotaxus fortunei seed-physiological changes and differences among three seed sources during low temperature priming
JIAO Yue-ling, ZHOUZhi-chun, JINGuo-qing, LI Yin-gang
2007, 24(2): 173-178.
[Abstract](1227) [PDF](141)
Abstract:
Cephalotaxus fortunei seeds from three seed sources, namely Liping,Guizhou Province;Mingxi,Fujian Province; and Yanyuan, Sichuan Province, were used to determine physiological changes during low temperature priming(direct sand storage in 5℃ for 10 days, 20 days or 30 days)as well as variation among seed sources by measuring fattiness, amylum, amino acid, POD(peroxidase), CAT(catalase), IAA(indoleacetic acid), GA3(gibberellin), ABA(abscisic acid) and ZR(zealin) concentrations in seeds. Results after low temperature priming indicated that the average germination rate of Liping seeds(30.9%) was greater than Mingxi seeds (9.9%)and Yanyuan seeds(1.9%). Of the different treatments, the 10 days low temperature priming had the highest seed germination rate. In addition, during low temperature priming, active metabolism, decreased levels of fat and starch, increased amino acids, and enhanced POD CAT activity were detected. In the endosperm, seeds fromMingxi possessed lower levels of ABA after low temperature treatmentwith no obvious change or little increase of GA3 ABA ratio.Thismightbe one reason for seed dormancy-breaking. In spite of a lowABA content and a high GA3 ABAratio in the endospermof Yanyuan seedsbefore lowtemperature priming,germination did notoccur;ABA in the seed endospermincreased mostly after lowtemperature priming.This indicated thatwith Yanyuan seeds some unknown factors controlled seed dormancy; also, the lack of germinationwith lowtemperature primingmightbe the result of a long adaptation to warmerwinters in Sichuan.Moreover, the low germination rate of seeds fromMingxi with direct sand storage seemed to be related to high ABA content in the endosperm.[Ch, 5 tab. 8 ref.]
Evaluation of nursery soil fertility and relationship between fertility coefficients and seedling growth
ZENG Shu-cai, YUYuan-chun
2007, 24(2): 179-185.
[Abstract](1001) [PDF](140)
Abstract:
The soil fertility of Heyuan Central Nursery in Guangdong Province, which had 5 different sites coded A, B, C, D, E,was evaluated with modified Nemoro formula.The correlations between fertility coefficients and seedling growthwere analyzed.Soil texture,bulk density,pH,organic matter,totalN,available N,P andKwere selected as main properties for the integrated quantitative evaluation of soil fertility. Results revealed that the soil fertility coefficient Pmeanof the 5 sites was between 1.06 and 2.48, the Pminwas 0.03- 0.97 and the integrated coefficient p was between 0.66 and 1.65,withobvious differencesexisting in the 5 sites and differentlayersof each site. According to the evaluation result, the fertility of the surface layers(0- 20 cm)of site A, B and D and the subsurface layer(20- 40 cm)of site A was low and all other sites and layers was infertile. Significant positive correlationswere found between height of broadleaved seedlings and soil fertility coefficients Pmeanand p. Single seedling biomasswas observed to be significantly positively correlated to Pmean, Pminand p.Therefore, Pmeanand p could be suitable coefficients of nursery soil fertility and seedling biomass could be a reasonable bio-index to evaluate soil fertility.[Ch, 7 tab. 11 ref.]
Salt balance with a Populus simonii×(Populus pyramidalis+ Salixmatsudana)`Poplaris' shelterbelt
LIUJing, JIAZhong-quan, DONG Feng-xiang
2007, 24(2): 186-191.
[Abstract](1560) [PDF](116)
Abstract:
To calculate a)the total salt in water consumed during the entire growth period of 12-year-old Populus simonii(Populus pyramidalis+ Salixmatsudana)`Poplaris and b)the total extractable saltwhen harvested and to analyze this cultivars water metabolism influence on salt balance in the soil-groundwater system under the tree,water consumption and the saltion concentration in differentplantparts aswell as biomassof sample tree were measured. Results indicated thatof the saltin thewaterthat`Poplaris absorbed about92% had entered in the soil-groundwater system under the tree; the rest of the salt remained in the tree when harvested.Also, the composition ratio of Ca2+ to soluble salts in the soil-ground water system decreased.However, salt accumulation in soils under `Poplaris' shelterbeltswas only a small proportion of salt accumulated in irrigated areas.Thus, selective absorption of nutrientswith P. simonii(P. pyramidalis+ S. matsudana)`Poplaris' and its resistance to harmful ions influenced the soluble salt ion component in the soil-groundwater system under this shelterbelt.[Ch, 9 tab. 15ref.]
Flame retardancy of wood bark from Keteleeria evelyniana, Pinus yunnanensis and Pinus armandii in Yunnan Province
LI Shi-you, LI Xiao-ning, LI Sheng-hong, JINGui-jun, ZHOUQuan, HUXiao-long, WANG Qiu-hua
2007, 24(2): 192-197.
[Abstract](985) [PDF](143)
Abstract:
In central YunnanProvince,frompreviously burned standsof Keteleeria evelyniana, Pinus yunnanensis,and Pinus armandii having different forest fire behavior, wood bark structure was analyzed to determine flame retardancy factors, such as average thickness,moisture content,heat conduction coefficient,oxygen index, thermal weight loss, and inner surface temperature of the wood bark during external heat radiation. Results showed that the flame retardancywas: K. evelyniana P. yunnanensis P. armandii.Flame retardancy of the wood barkwas the main cause of fire resistance differences among the three coniferous species.Thiswas due to: 1)the integrated internal bark layer and loose external bark layer of K. evelyniana, 2)an average thickness of wood bark in K. evelyniana thatwas 1.38 times greater than P. yunnanensis and 3.07 times greater than P. armandii, 3)a heat conduction coefficient of the wood bark in K. evelyniana that was 67.66% greater than P. yunnanensis and 54.85% greater than P. armandii,and 4)an oxygen indexof the wood bark in K. evelyniana thatwas 1.4 times greater than P. yunnanensis and 1.6 times greater than P. armandii.Accordingly fire protection measures for the three specieswere putforward based on flame retardancy of thewood bark and fire resistance of the coniferous trees.Special measures neednt be done for Keteleeria evelyniana, removing surface litters and cultivationmeasures should be adopted for P. yunnanensis and P. armandii, cleaning combustibles around the bark especially should be done for P. armandii.[Ch, 3 fig. 3 tab. 11 ref.]
solation of Alternaria alternata toxin using macroporous resins
ZHOUBing, AN Chuan-fu, DONG Yun-fa, QIANG Sheng
2007, 24(2): 198-202.
[Abstract](1214) [PDF](129)
Abstract:
To obtain right separation methods of Alternaria alternata toxin, absorbility of macroporous resins,DA201, D101,HZ-803, 1300 and activated carbonwere compared, and the filtrate load, pH, and concentration of ethanol that influenced adsorption and desorption were designed. Results showed that DA201 had the greatest absorbility with best absorption and desorption in culture condition, a filtrate volume load of 60 to 70 times than resin volume, a pHof 4.12- 4.62, and a 90% ethanol eluting solvent.Thus,DA201 was suitable forpurification and enrichment of the Alternaria alternata toxin.[Ch, 1 fig. 3 tab. 12 ref.]
Foraging sites during the early breeding stage of Syrmaticus humiae in the Nanhua Part of Ailaoshan National Nature Reserve
CAOMing, LI Wei, ZHOUWei, ZHANG Xing-yong, ZHANG Ren-gong
2007, 24(2): 203-208.
[Abstract](1122) [PDF](131)
Abstract:
Humes pheasant(Syrmaticus humiae)is an easy to endangered species. The object is to effectively protectHumes pheasant in its breeding season. Foraging sites ofHumes pheasantwere surveyed fromMarch 11 to April 16,2005.Fifteen foraging plotswere established alongwith the same numberof control plots and 22 variables were measured. A t-test and Mann-Whitney U-test to compare variables in forage and control plots showed significant differences(P 0.01) for the five vegetation characteristics of tree density, shrub density, shrub coverage, herbage coverage, and leaf litter coverage; crown canopy was also significantly different(P 0.05).Additionally, significant differences(P 0.01)for two food characteristics, namely seed density and density of edaphic animals, were noted. A principal component analysis indicated that fine shrub, tree, herb, andlitter layers;abundantseed resources in the understory;and being faraway fromhuman disturbance characterized optimal foraging sites forHumes pheasant.Thus,when selecting a foraging site in the breeding season,safety and nutrition were the pheasantsmajor concerns. Therefore, they would choose foraging habitats with strong camouflage cover from shrubs or treeswith ample food sources in the understory, such as seeds from the Fagaceae family and edaphic animals.[Ch, 3 tab. 26 ref.]
Social factors of Phyllostachys pubescens management in Huangyan District of Taizhou City
Lu Yu-long, JINAi-wu, WANG Guo-hui
2007, 24(2): 209-213.
[Abstract](1367) [PDF](135)
Abstract:
To develop moso bamboo(Phyllostachys pubescens)industry efficiently, a primary analysis and discussion on management of moso bamboo was conducted after interviewing 123 farmers from several primary production areas in Huangyan District of Taizhou City, Zhejiang Province. The study employed socioeconomic methodswith a factor analysis having a single village as the basic unit. Results showed that farmers held a positive attitude toward developmentof moso bamboo industries and desired advanced technology and information.However,due to restrictions on production and management of moso bamboo forestry, developing highly efficient management was dependent on financial support and improved policies, especially with information dissemination, by the local forestry department.Meanwhile, farmers could also assist the government by modernizing their lowproduction moso bamboo sites aswell as by improving site conditions and the structure of their moso bamboo stands.[Ch, 3 tab.11 ref.]
Extensional evaluation of urban green engineering tenders and bids standardization
SHUMei-ying, XIAZi-qian, FAN Yi-rong
2007, 24(2): 214-220.
[Abstract](1200) [PDF](159)
Abstract:
In order to assess the standardization of tenders and bids activities of urban green engineering accurately and objectively, 5 initial factors, 29 secondary factors and 36 ultimate factors are chosen based on the extensional theory using methods of the divergent tree and the decomposition chains, according to the Law of the Peoples Republic ofChina on Tenders and Bids and relative national standards of urban greeny. Four evaluation index elementswere chosen,i. e.,openness,fairness,impartiality and good faith.The evaluationmatterelementmodel of urbangreenwas setup,and the extensional evaluationmethod according to correlative functionswas putforward.Finally, the author applied the model to evaluate the standardization of a real tender and bid activity. The results showed that the main factors of tenders and bids standerdization could be catched accurately with extensional evaluational method.[Ch, 6 tab. 13 ref.]
Developing brand images for agricultural products
YANG Wen-jian
2007, 24(2): 221-224.
[Abstract](1228) [PDF](167)
Abstract:
Agricultural products are specialty goods that are characterized by high popularity aswell as a by having a close relationship to traditional culture and the daily life of farmers. This paper discusses the importance of developing brand images for agricultural products. To solve prevalent problems, such as out of date brands, poor brand image design, and a lack of concern about brand development, plus to facilitate marketing of agricultural products, brand images should be created bearing in mind long termeffects.Traditional cultural associations linked to the agricultural products should be used for an integrated image design, and promotion and dissemination of the products should incorporate the jointefforts of enterprise, large-scale farms, and farmhouseholders.[Ch,10 ref.]
Reviews
Function and structure of phosphate translocator in plant
ZHENG Bing-song, HUANG You-jun, WANG Zheng-jia, CHUHuai-liang, HUANG Jian-qin
2007, 24(2): 225-230.
[Abstract](956) [PDF](193)
Abstract:
As one of the key protein regulating translocation of photosynthetic products, the phosphate translocator(PT)is an important part in the photosynthesis research, especially focused on its physiological and biochemical function. This report gives an introduction of the gene structure and characteristics of the phosphate translocators,and also gives a comparison of the specificity of the phosphate translocators in various plastids. The phosphate translocator(molecularweight 36 kD)is encoded by nuclear DNA. The different translocators are derived from a common ancestor and are subsequently diversified. In a single plant, different genes encode different phosphate translocators.Whereas the phosphate translocator of the C3plant mediates a counter exchange between inorganic phosphate(Pi), dihydroxyacetone phosphate(DHAP), and 3-phosphoglycerate(3PGA), but seldom or not between 2-phosphoglycerate(2PGA), phosphoenolpyruvate(PEP), and glucose 6-phosphate(G6P), the phosphate translocators in chloroplasts from C4and CAM plants transport PEP in addition to the above mentioned three metabolites. In plastids from plant roots, the phosphate translocator also transports. There are different chloroplast phosphate translocators in different cells of one leaf.[Ch, 1 tab. 36 ref.]
A review of forest root respiration-determinants and response to global change
LI De-hui, LI Xian-wei, WANG Qiao, RONG Li, YANG Miao, LIUShuo
2007, 24(2): 231-238.
[Abstract](1768) [PDF](186)
Abstract:
This paper summarizes the determinants of root respiration and the reaction of root respiration to global climate change, and then it suggests and discusses further research, including how root respiration works,controlling methods, and responses to forestmanagement and other disturbances. In the global cycle, respiration of the forest ecosystem is one of the majorpathways for carbon flux.Therefore, root respiration, as a major component of soil respiration, plays an important role in global change. Dynamic changes in root respiration strongly influence the carbon balance aswell asglobal carbon flux and, consequently,otherecological factors. Root respiration in the forest ecosystem,which global change can greatly affect, is the basis of carbon efflux for the whole ecosystem.For example, in the forest ecosystem, forest root respiration is sensitive to both canopy and soil conditions with soil temperature, soil moisture, forest type, forestmanagement, and other natural climatic properties being the primary determining factors.Overall, root respiration in the forest ecological system actively responds to global ecological changes.[Ch, 53 ref.]
Scientific notes
Ultrasonic and backflow technologies to extract ursolic acid from Eriobotrya japonica leaves
LI Kai-quan, ZHOULan-jiang, ZHANG Ying-hua
2007, 24(2): 239-241.
[Abstract](1083) [PDF](135)
Abstract:
The conventional methods to extractursolic acid is not satisfied. Ethyl alcohol with ultrasonic waves and backflowwere used to extract ursolic acid from Eriobotrya japonica(loquat) leaves to determine the methods effects. A single raw material source(E. japonica dry leaves) and medium(ethyl alcohol) were filtered,centrifuged, and filtered againwith amicropore filterdiaphragm;then,two differentmethods,ultrasonicwaves and backflow, were used to extract ursolic acid which was quantified using high performance liquid chromatography(HPLC)with the external standard method. The extracting efficiency of ultrasonic waves was 2.63 times greater than hot backflow.The ultrasonicwaveshad unique mechanical,cavitating,and thermal reactions,which increased the speed and penetration of the mediummolecules, thereby enabling greaterextraction of the ursolic acid.[Ch,3fig. 2 tab. 7 ref.]
Seedling techniques of Magnolia wufengensis and M. wufengensis var. multitepala
WANG Luo-rong, MA Lǜ-yi, WANG Xi-qun, HE Sui-chao, LIUXin
2007, 24(2): 242-246.
[Abstract](1216) [PDF](330)
Abstract:
The discovery of the new species of Magnolia wufengensis and the new variety M. wufengensis var.multitepala is of great importance for research and application. To expand the plantsapplication, the seeding techniques of the species and the variety were studied from 2001 to 2004 in Wuhan and Xianning City. The seeds harvesting, preservation and germination rates, the growth of one to three yearsold seedlingswere investigated. In Xianning the average basal diameter of one-year-old seedlingswas 0.69 cm and the average heightwas 78.18 cm.For two-year-old transplanted seedlings, the average basal diameter(1.64 cm)and average height(107.55 cm) was greater than three-year-old transplanted seedlings baving an average basal diameter of 1.57 cm and an average height of 81.66 cm. This indicated that seedlings of M. wufengensis and M. wufengensis var. multitepala needed rich fertilizer. Since the seed collected fromthe original source between 2001 and 2003 was amixture of the species and the variety, further seed selection is required. Meanwhile, the introduction of the plants and regional experimentation should be developed.[Ch, 4 tab. 11 ref.]