Showing papers on "Cunninghamia published in 2002"

Labdane-type diterpenoids from the wood of Cunninghamia konishii.

Abstract: Five new labdane-type diterpenes, 12beta,19-dihydroxymanoyl oxide (1), 8(17),13-labdadien-12,15-olid-19-oic acid (2), 12,15-epoxy-8(17),13-labdadien-18-oic acid (3), 8alpha-hydroxy-11E,13Z-labdadien-15-al (4), and (13R)-13-hydroxy-8(17), 11E,14-labdatrien-18-oic acid (5) were isolated from the wood of Cunninghamia konishii. Their structures were elucidated by two-dimensional NMR spectroscopy.

Biomass, litterfall and the nutrient fluxes in Chinese fir stands of different age in subtropical China

Abstract: Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.), a fast-growing ever-green conifer tree with high yield and excellent quality, is the most important tree species of timber plantations in subtropical China. We investigated the characteristics of biomass, litterfall and nutrient fluxes in the 8, 14 and 24 year-old stands, representing the young, middle-aged and mature stands. The results showed that Chinese fir plantations in central Fujian province had high productivity, and the proportion of stem mass in total biomass was between 50%–70%. Chinese fir was low nutrient-return tree species with litterfall. Nutrient withdrawal from senescing needles was a strong age-dependence for nitrogen, phosphorous and potassium in Chinese fir. With a management system of such short-rotation and continuously pure-crop planting, harvesting timber can lead to great nutrient loss, which may be one of the causes for site degradation.

Thinkings of the Problems of Tree Species Structure Adjustment in Fujian Province

Abstract: According to the forest resource status and structure characters in Fujian Province,the necessity of tree species structure adjustment and some problems of tree species structure adjustment should be considered were put forward,simultaneously,the direction and way of structure adjustment of some major tree species of Cunninghamia lanceolata,Pinus massoniana and broadleaved tree,etc.as well as the reasonable utilization of existing resources,etc.were emphatically raised.

Labdane‐Type Diterpenoids from the Wood of Cunninghamia konishii.

Abstract: Five new labdane-type diterpenes, 12beta,19-dihydroxymanoyl oxide (1), 8(17),13-labdadien-12,15-olid-19-oic acid (2), 12,15-epoxy-8(17),13-labdadien-18-oic acid (3), 8alpha-hydroxy-11E,13Z-labdadien-15-al (4), and (13R)-13-hydroxy-8(17), 11E,14-labdatrien-18-oic acid (5) were isolated from the wood of Cunninghamia konishii. Their structures were elucidated by two-dimensional NMR spectroscopy.

Dynamics of Litter Fall in Cunninghamia lanceolata Forest Using Wave-type Time Series Analysis

Abstract: According to the data collected for litter fall from Cunninghamia lanceolata-broadleaved mixed forest and C lanceolata forest in Wuyishan National Nature Reserve in Fujian, a model of wave-type time series for analyzing the dynamics of litter fall was used to simulate the monthly change in litter fall in the two forests Result showed that the model could satisfy the actual data It is suggested that this method can be applied to the study of litter fall dynamics

Integrated Evaluation of Soil Chemical and Biochemical Fertility under Different Vegetations

Abstract: Comprehensive evaluation of soil chemical and biochemical fertility under different vegetations (broadleaved forest, mixture of broad leaved and coniferous trees, Pinus massoniana, Cunninghamia lanceolata) were conducted using fuzzy mathematics and multiple statistics principle. It is found that the integrated chemical and biochemical fertility ranged as following order : broadleaved mixture Pinus massoniana Cunninghamia lanceolata (integrated fertility index for 020 cm horizon were 0.741 2, 0.579 6, 0.479 8 and 0.347 6 respectively).The result of integrated fertility evaluation is consistent with single factor of fertility evaluation, but it is more convincible. 

Study on the Effect of Mixed Afforestation of Castanopsis hystrix and Cunninghamia lanceolata

Abstract: The study shows that Cunninghamia lanceolata and Castanopsis hystrix are mixed in star mixture(7 C. lanceolata∶ 3 C.hystrix),when they were 7 years old,the inter specific relation is relatively coordinative,the stand spatial distribution pattern is reasonable,the nutritive space is fully utilized and effect of improving soil fertility is evident,the stand yield and quality are evidently increased,the stocking and biomass of mixed forest stand relatively are increased by 42 82% and 57 08% as compared with those of C anceolata pure forest But on the condition of present planting density,the mixed stand structure isn't stable enough at the moment,there is an urgent need to improve inter specific relation further and adjust stand structure through proper thinning C lanceolata and C hystrix artificial mixture is one of effective ways of improving C lanceolata low yield forest,controlling soil fertility reduction and expanding planting scope of excellent indifenous broadleaved trees,which may be further popularized and afforested in suitable areas

Analyses of the Planting Effects of Different Patterns of Castanopsis hystrix

Abstract: The results show that the mixed effect of Castanopsis hystrix and Cunninghamia lanceolata is best of mixed effects of 3 different mixed patterns.Not only can the mixture evidently improve the afforested survival rate of C.hystrix, but the interspecific relations are relatively coordinative with the mixture of them,the spatial distribution pattern is reasonable,the nutritional pattern is fully utilized,the yields and quality of mixed stands are improved evidently.The average tree height,dbh and single tree volume of C.hystrix in 18 year old C.hystrix and C.lanceolata mixed forests respectively reach 14 75 m,16 50 cm and 0 1561 m 3,which increase by 10 00%,14 34% and 36 93% as compared with those of C.hystric pure forests,respectively,the stand stocking reaches up to 271 47m 3·hm -2 ,1 30 times as large as that of pure forests,it is thus clear that C.hystrix and C.lanceolata mixture is the broadleaf conifer mixed pattern worth popularizing and applying in south Fujian areas.

Fractal Features of Soil Aggregate Structure under Mixed Plantations of Phyllostachys edulis and Cunninghamia lanceolata

Abstract: Fractal characteristics of soil aggregate structure under Cunninghamia lanceolata and Phyllostachys edulis mixed plantations in Fujian were studied by using fractal theory. Six plots with different Cunninghamia lanceolata and Phyllostachys edulis densities in mixed plantations, and two plots of pure stands of the two species were chosen. All the plants in plots were 19-year-old. Regression models for fractal dimension (D) of aggregated structure and water stable aggregate (0.25 mm) content, and for D and destroyed structure percentage, were established. The effect of fractal dimension of aggregates on soil properties were evaluated by elasticity and limit analyses. The results showed that the higher the content of water stable aggregates (0.25 mm or 5.0 mm) in soil, the smaller the fractal dimension of aggregates, and thus the better structure and stability the soil. The regression relationships of all the modelswere remarkable. Fractal dimension variation of aggregate structure had a great effect on soil properties, which will provide a scientific basis for the culture of such mixed forest.

Effect of phenolics on ~(15)N nutrient absorption and distribution of Cunninghamia lanceolata

Abstract: Pure Chinese fir (Cunninghamia lanceolata) plantations, a major commercial tree species in South China, have been extensively replanted on the same site in successive rotations, in response to the growing need for timber. The resultant soil degradation has led to poor establishment and decline in productivity which has become a major barrier to the sustainable management of Chinese fir plantations. Recently, many documented studies indicate that allelopathy within Chinese fir plantations is likely one of the causes of soil degradation. According to some laboratory studies, extracts of Chinese fir roots, fresh leaves, and litter including phenolics such as vanillin, ferulic acids and P-hydroxybenzoic acids, inhibit Chinese fir seed germination. However, no allelopathic responses have been demonstrated. How do the allelochemicals, e.g. phenolics, affect the growth of Chinese fir seedlings? This has not yet been studied. In this study on nutritional aspects of allelopathy in Chinese fir, the effects of different concentrations of vanillin and P-hydroxybenzoic acid on 15NO - 3 ion absorption and distribution in Chinese fir seedlings was examined using the 15N isotope tracer technique. Vanillin, P-hydroxybenzoic acid, and a combined 1∶1 solution of these two materials were diluted to four different levels: 10 mmol·L -1, 1 mmol·L -1, 0.1 mmol·L -1, and 0.01 mmol·L -1. Distilled water was used as the control. One-year-old Chinese fir seedlings were planted in separate pots, fertilized with 200 mg NaNO - 3 enriched 21.97 percent Na 15NO - 3, and grown outdoors in overshadow. Each pot was treated every half month with 100 ml of a particular concentration of vanillin, P-hydroxybenzoic acid solution, or the 1∶1 mixed solution. Each treatment consisted of five replicates of Chinese fir seedlings. After six months height, stem diameter at ground line, total biomass, total N, and 15N content of Chinese fir seedlings were recorded. Results showed that vanillin inhibited both growth and 15NO - 3 ion absorption. The mixed 1∶1 solution at the concentration of 10 mmol·L -1 caused even greater reduction in growth of Chinese fir seedlings. The biomass of roots, stems and leaves of Chinese fir seedlings was reduced by 25.3%, 13.5% and 5.7%, respectively, and 15N absorption in roots, stems and leaves was reduced by 38.5%, 48.1% and 46.5%, respectively, with the treatment of 10 mmol·L -1 of vanillin. Using the 10 mmol·L -1 concentration of the 1∶1 mixed solution, the biomass of roots, stems and leaves of Chinese fir was reduced by 33.5%, 36.0% and 21.8%, respectively, and 15N absorption was reduced by 34.3%, 58.4% and 49.3%, respectively. This indicates that there is likely a synergistic effect between vanillin and P-hydroxybenzoic acid. Vanillin and its mixture with P-hydroxybenzoic acid at the higher concentration affected N nutrient distribution by increasing the proportion of N in roots and decreasing the proportion in stems and leaves. We conclude that the vanillin and phenolics in soil might produce allelopathic effects on Chinese fir by inhibiting N absorption and distribution which then result in productivity decline.

Comparison of the Biomass Estimation Methods for the Forest at Heishiding Nature Reserve

Abstract: Two regression equations for estimating biomass of broadleaf trees at Heishiding nature reserve, one based on D and the other based on D 2H(H means height), were compared. The results showed that the regression equations based on \%D 2H\% were more suitable for calculating the biomass of broadleaf trees at various kind of communities. In order to calculate the biomass of Cunninghamia lanceolata at Heishiding nature reserve, we used four regression equations used at neighbor regions to calculate the biomass of the trees. The calculating results of total biomass were similar.This meant that the regression equations for estimating biomass of Cunninghamia lanceolata used at neighber regions can be applied at Heishiding nature reserve.

Nutrient Dynamics of Litterfall in A Mixed Forest of Cunninghamia lanceolata and Tsoongiodendron odorum

Abstract: This paper deals with nutrient characteristics and dynamics of litterfall in a 27-year-old mixed forest of Cunninghamia lanceolata and Tsoongiodendron odorum, compared with a pure stand of Cunninghamia lanceolata, located in Xinkou Teaching Forest Farm, Sanming of Fujian province. The results show that mean concentrations of N, P and K elements of litterfall were almost in the order of N>K>P both species and fractions. The mean concentrations of N and K of litterfall in the mixed stand were higher but P slightly lower than those in the pure stand, and the mean concentrations of N and P of litterfall of Tsoongiodendron odorum were higher than those of Cunninghamia lanceolata in both stands, with the concentration of K higher than that of the pure stand but lower than that of the mixed stand. The monthly dynamics of concentration of N, P and K of litterfall were different in all fractions of different species. The annual nutrient return through litterfall amounted to 48.528 kg · hm~(-2) N, 2.324 kg · hm~(-2) P and 19.843 kg · hm~(-2) K in the mixed stand and 37.163 kg · hm~(-2) N, 2.339 kg · hm~(-2) P and 18.406 kg · hm~(-2) K in the pure stand. Nutrient return peaked in March, August and December in both stands with N and P highest in March and K highest in December. Total return of N in the mixed stand was obviously higher than that in pure stand, which benefitted the maintenance of long-stand, which benefitted the maintenance of long - term site fertility in mixed stand. Seasonal dynamics of total N, P and K return of the mixed stand litterfall, which in the order of winter>spring>summer>autumn, winter or spring>summer>autumn and winter>autumn>spring>summer, respectively, agreed with the dynamics of nutrient return of Cunninghamia lanceolata litterfall in the mixed stand.

Biomass Production and Productivity of Natural Regenerated Sassafras tzumu Trees

Abstract: Biomass production and productivity of a Sassafras t.zumu forest were measured by models of allometry method in Jianyang Shufang Forest Farm of Fujiang Province. The forest was naturally regenerated by dominant S. tzumu after final cutting of Cunninghamia lancenlata plantation at about 20 year's succession with density of S. tzumu trees ca. 480 individuals per ha. The results showed that mean total biomass production and mean annual productivity of S. tzumu trees were 58 693 kg hm-2 and 4 259 kg hm-2, respectively. Vertical distribution of biomass indicated that most biomass was accumulated below middle height of trees. In accordance with the diameter class distribution of biomass, the maximum biomass appeared at trees with 20 cm dbh. This research is useful for broad-leaved forest planting.

Plant Species Diversity of Artificial Recovered Pinus Massoniana Community in Bashilihe Watershed of Fujian Province

Abstract: The understorey plant diversity of artificial recovered Pinus massoniana community by intercropping with shrub species was studied in Hetian town, Changting county, Fujian province. The results showed that the understorey plant species increased 18 years after the seriously eroded land was restored by fertilizer applying and Lespedeza bicolor intercropping, with 22 plant families, 30 genus, and 33 species. The areal types of genus were mostly tropical distribution. The major life form was evergreen shrub, and perennial and annual herbs were few. Phanerophytes took the dominant position. The importance value of Lespedeza bicolor, Adinandra millettii, Cunninghamia lanceolata, Camellia oleifera and Syzygium buxifolium were high in the shrub layer. Dicranopteris dichotoma took the dominant position in the herb layer. Shannon wiener diversity index was highest in the shrub layer, followed by herb layer, and lowest in the vine layer. Shannon wiener uniformity indexes was highest in the vine layer and lowest in the herb layer.

Biomass and its distribution of Chinese-fir treated with aqueous extracts of several tree species after six years

Abstract: The biomass of different organs and biomass distribution of Chinese fir treated with aqueous extracts of the Cunninghamia lanceolata,Schima superba,Castanopsis fargesii and Pinus massoniana under different concentrations after six years was measuredThe result showed that the biomass of different organs of Chinese fir treated with aqueous extracts of Schima superba,Castanopsis fargesii and Pinus massoniana after six years were increased in some degree,the higher the concentration was,the higher the positive effect was,and low concentration had positive effect on the bark,branch and litter biomass distribution,high concentration had positive effect on the leaf,root and stem biomass distribution;That the biomass of Chinese fir treated with Cunninghamia lanceolata after six years were decreased,the higher the concentration was,the higher the inhibited effect was,and low concentration had positive effect on the leaf,bark,root,branch and stem biomass distribution,high concentration had positive effect on the litter biomass distribution

Studies on the Effect of Fire Prevention of Biological Network of Michelia macclurei

Abstract: The simulated burning and quantitative analysis of the combustibility of different pattern mixed stand of Michelia macclurei and Cunninghamia lanceolata have been studied. The results show that the extension of ground fire and canopy fire can be separated effectively by forest belt of fire prevention; The combustibility was cuted down and the capacity of resisting forest fire of oneself was raised after cultivated mixed stand of Michelia macclurei and Cunninghamia lanceolata. The mixed stand of 3:1 Cunninghamia lanceolata and Michelia macclurei was the best pattern and it was a high benefit and low combustibility plantation by multi-objective analyses.