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Nanchang, China

Yin Y.,Chinese Academy of Forestry | Bian M.,Chinese Academy of Forestry | Bian M.,State Academy of Forestry Administration | Song K.,Chinese Academy of Forestry | And 2 more authors.
IAWA Journal | Year: 2011

Radial variations in microfibril angle (MFA) and their effect on the mechanical properties of plantation-grown Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) were investigated with the aim of achieving an effective utilization of the wood. Correlations between MFA and mechanical properties, including longitudinal modulus of elasticity (MOEL), static bending strength (MOR) and compression strength parallel-to-the-grain (CS), were analyzed for predicting the quality of timber. The results indicated that MFA had a greater variation in juvenile wood than in mature wood. The biggest change occurred close to the pith in Chinese fir. The outer-rings (rings 9-30 from the pith) have a relatively low MFA, together with high mechanical properties and high density, when compared with the inner-rings (rings 1-8 from the pith). The MFA had significant negative curvilinear correlations with all the mechanical properties (MOEL, MOR and CS) of Chinese fir, with the value of r 2being 0.88,0.69 and 0.74 respectively.The correlation between the MFA and basic density (BD) was strong in certain consecutive rings (rings 5-30 from the pith), but this did not apply across the whole billet, i.e. from the pith to the bark.

Song K.,Chinese Academy of Forestry | Yin Y.,Chinese Academy of Forestry | Salmen L.,Innventia Ab | Xiao F.,Jiangxi Academy of Forestry | Jiang X.,Chinese Academy of Forestry
Journal of Materials Science | Year: 2014

Changes in the chemical, viscoelastic and hygroscopic properties of wood cell walls in Chinese fir (Cunninghamia lanceolata) during the transition from sapwood to heartwood were studied to provide insights into the formation of heartwood. In situ imaging FTIR measurements indicated that the composition of the main components of cell walls remained almost unaltered, but more extractives were deposited in the wood cell walls during the sapwood-heartwood transition. Compared to the sapwood and transition wood, the heartwood had a higher softening temperature and greater activation energy, suggesting that the mobility restrictions of cell wall biopolymers were due to extractives obstructing the accessing of the plasticizer (ethylene glycol). The moisture sorption was the same from the sapwood to heartwood at a low relative humidity (RH), while the heartwood adsorbed less water at a high RH, probably caused by the extractives deposited in the matrix and mesopores of heartwood cell walls. © 2013 Springer Science+Business Media New York.

Liu P.,Jiangxi Academy of Forestry
Dong wu xue yan jiu = Zoological research / "Dong wu xue yan jiu" bian ji wei yuan hui bian ji | Year: 2012

Habitat selection of four sympatric pheasants (Syrmaticus ellioti, Lophura nycthemera, Pucrasia macrolopha and Bumbusicola thoracica) was studied in Guanshan National Nature Reserve, Jiangxi, China from October 2009 to November 2010. We measured seventeen ecological factors across 388 sites used by the four pheasants by direct observation in six transects. The results show that the pheasants preferred broad-leaved forest and coniferous forest and a sunny or semi-shaded slope. There were differences in elevation, degree of slope, arbor coverage, shrub coverage, shrub quantity, shrub height, herbage cover, herbage species, herbage quantity, leaf litter coverage, distance to water and arbor species between the habitat selected by the four pheasants. Canonical scores indicated that the four pheasants differed in habitat selection to some extent. A stepwise discriminant analysis revealed that elevation, herbage quantity, shrub height, distance to water, shrub cover, arbor cover, degree of slope, leaf litter cover, shrub quantity and herbage cover were the critical factors distinguishing habitat selection between the species. Predicted classification accuracy of the model was 74.7%.

Shao Q.,Zhejiang Agriculture And forestry University | Deng Y.,Jiangsu Academy of Agricultural Sciences | shen H.,Changzhou Health College | Fang H.,Jiangxi Academy of Forestry | Zhao X.,Zhejiang Agriculture And forestry University
International Journal of Biological Macromolecules | Year: 2011

A 15-run Box-Behnken design (BBD) was used to optimize the extraction conditions of polysaccharides from Tetrastigma hemsleyanum Diels et Gilg. Three factors such as extraction temperature (°C), extraction time (h), and ratio of water to raw material were investigated. The experimental data were fitted to a second-order polynomial equation using multiple regression analysis and also examined using the appropriate statistical methods. The adjusted coefficient of determination (RAdj2) for the model was 0.9754, and the probability value (P= 0.001) demonstrated a high significance for the regression model. The optimum extraction conditions were found to be: optimized extraction temperature 83.3 °C, extraction time 1.55. h and ratio of water to raw material 29.48. Under these conditions, the mean extraction yield of polysaccharides was 5.182 ± 0.093%, which was in good agreement with the predicted model value. © 2011 Elsevier B.V.

Wang Q.,CAS Shenyang Institute of Applied Ecology | Xiao F.,Jiangxi Academy of Forestry | He T.,CAS Shenyang Institute of Applied Ecology | He T.,University of Chinese Academy of Sciences | Wang S.,CAS Shenyang Institute of Applied Ecology
Annals of Forest Science | Year: 2013

Aims: Globally, extensive areas of native forest have been almost replaced by plantations to meet the demands for timber, fuel material and other forest products. This study aimed to evaluate the effects of forest conversion on labile soil organic C (SOC), soil respiration, and enzyme activity, and to quantify their relationship in subtropical forest ecosystems. Methods: Surface mineral soil (0-20 cm) was collected from a Cunninghamia lanceolata Hook. plantation, Pinus massoniana Lamb. plantation, Michelia macclurei Dandy plantation, and an undisturbed native broadleaf forest. Soil microbial biomass C, dissolved organic C, permanganate-oxidizable C, basal respiration, and six enzyme activities were investigated. Results: Soil microbial biomass C was higher by 45.9 % in native broadleaf forest than that in M. macclurei Dandy plantation. The ratio of soil microbial biomass C to total SOC was 27.6 % higher in the M. macclurei Dandy plantation than in the native broadleaf forest. The soil respiration increased by 25.2 % and 21.7 % after conversion from native broadleaf forest to P. massoniana Lamb. and M. macclurei Dandy plantations respectively. The effects of forest conversion on the soil enzyme activities differed among the tree species. Soil microbial biomass C had higher correlation with soil respiration than with the other SOC fractions. Moreover, soil microbial biomass C was positively correlated with urease and negatively correlated with cellulase activity. Soil respiration had higher correlation with soil microbial biomass C, dissolved organic C and permanganate-oxidizable C. Conclusion: Forest conversion affected the soil microbial biomass C, soil respiration, invertase, cellulase, urease, catalase, acid phosphatase, and polyphenol oxidase activities, but their response depended on tree species. Soil respiration was mainly controlled by labile SOC, not by total SOC. © 2013 INRA and Springer-Verlag France.

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