2011 Vol. 24, No. 2
Non-linear models with heteroscedasticity are commonly used in forestry modeling, and logarithmic regression and weighted regression are usually employed to estimate the parameters. Using the single-tree biomass data of large samples, the bias correction in logarithmic regression and comparison with weighted regression for non-linear models are studied in this paper. The immanent cause producing bias in logarithmic regression is analyzed, and a new correction factor is presented with which three commonly used bias correction factors are examined together, and the results show that the correction factors presented here and by Baskerville (1972) should be recommended which could insure the corrected model to be asymptotically consistent with that fitted by weighted regression. Secondly, the fitting results of weighted regression for non-linear models, using the weight function based on residual errors of the model estimated by ordinary least squares (OLS) and the general weight function (W=1/f(x)2) presented by Zeng (1998) respectively, are compared with each other that show two weights works well and the general function is more applicable. It is suggested that the best way to fit non-linear models with heteroscedasticity would be using weighted regression, and when the total relative error of the estimates from the model fitted by the general weight function is more than a special limit such as ±3%, a better weight function based on residual errors of the model fitted by OLS should be used in weighted regression.
In order to research the biomass of mangrove based on remote sensing, the biomass of mangrove with the method of KNN was estimated by extracting spectral information and textural features from TM images, combining the field survey biomass data and compared with that of multiple regression analysis. The results showed that with KNN method, the accuracy increased with the extension of the scale, and K=10 was better than K=5 in the accuracy. Estimating biomass of mangrove in the pixel scale, the multiple regression analysis was better than that by using KNN method.
Vascular epiphytes are important components of species richness in monsoonal broad-leaved evergreen forest. Field data collection on vascular epiphytes was based on 0.81 hm2 plot (including 9 subplots) in different restoration stages (community of 15 years restoration (15 a), community of 30 years restoration (30 a)) and primary monsoonal broad-leaved evergreen forest distribute in Caiyanghe Nature Reserve, Yixiang Township and Xinfang reservoir, Pu’er city, Yunnan, China. On the basis of analyzing vascular epiphytes species richness, abundance, distribution, similarity coefficient, the relationship between epiphytes and phorophytes was discussed. The results showed that: (1) 3 116 vascular epiphytes, belonging to 22 species in 20 genera and 9 families were recorded in all plots. (2) The diversity of vascular epiphytes was low in restoration stages (15 a, 5 spp. and 30 a, 7 spp.) compared to primary forest (17 spp.). (3) The composition of epiphytic species in primary forests and the stand in restoration stages differed markedly: 15a harboured no orchid species but more fern species and primary forest hold more orchid species. Probably the families occurring only in primary forest sites which the authors studied may be used as bioindicators to determine the degree of restoration in monsoonal broad-leaved evergreen forest. (4) The epiphyte abundance was also lower in restoration stages. The declines in species number and abundance as well as the differences in species composition were mainly due to the less diversified phorophyte structure and less differentiated microclimate in the disturbed and secondary vegetation compared to the primary forest. Sørensen coefficient between 15 a and primary forest was higher than that between 30a and primary forest. (5) The vascular epiphytes were clumped horizontally in 3 community types. Vertically, vascular epiphytes of 15a were mainly distributed at 0~5 m and that of primary forest was up to 20 m. (6) Both the richness and abundance of vascular epiphytes species were significantly positively correlated with host tree size but no correlation existed for restoration stages.
This paper provides a new method of improving the classification accuracy of wetland in Long Baotan area in Qinghai Province,by studying the image transformation and band combinations of three angle images of +36°, 0° and -36°,which were devived from the multi-angle CHRIS hyperspectral remote sensing data. Firstly, the tasseled cap transformation was used to the 0° CHRIS image. Secondly, a new color composite image of RGB was generated by combining the humidity image of 0° with the 4-band (0.461μm) of +36° and -36° images, and then, the Support Vector Machine,SVM, a supervised classification method was carried out on the new RGB image.The studies showed that the classification accuracy of the new combination method in different angle images of CHRIS approached to 90.02%, which was greatly improved then 75.46% of traditional supervised classification accuracy, and it also provide an effective method to extract wetlands information.
Antisense pepc gene expression vector was constructed by the 597 bp sequence of pepc gene ligated to pBI121 in the antisense orientation. And sense expression vector was recombined by the full-length (3 000 bp) sequence inserted to pCAMBIA2300. Mediated by Agrobacterium tumefaciens, the sense and antisense genes were transferred into the tobacco using leaf-disk method. Results of PCR and PCR-Southern determination indicated two gene sequences were integrated into the tobacco genome in the sense and antisense orientation. The activity of PEPCase was determined. It was found that the fat content of transgenic tobacco with sense pepc was 44.3 percent lower than that of control, and that with antisense pepc was 26.3 percent higher than that of the control.
Through sequences analysis of Paeonia suffruticosa ESTs (expressed sequence tags) deposited in NCBI, only 335 SSRs (simple sequence repeats) were found. These SSRs are distributed in 324 ESTs out of the 2 204 ESTs examined, accounting for 14.70% of the total. The frequency of SSR was 15.20%, in which, the repetitive proportions of dinucleotide, trinucleotide, tetranucleotide and hexanucleotide were 84.14%, 15.22%, 0.30% and 0.30%, respectively. 51 candidate SSR primers were designed according to the ESTs sequences that containing SSRs, by using serafer 1.3 software. The 51 candidate SSR primers were screened against genomic DNA of 6 different flower color groups in P. delavayi, of which, 10 primer pairs amplified visible bands with polymorphism among 50 genomic DNAs from 10 color groups in P. delavayi. The results proved that the development of EST-SSR markers based on ESTs in P. suffruticosa is an effective and feasible approach, which will conduce to study on genetic diversity and genomics in P. delavayi.
Light responses for net photosynthetic rate of four Azadirachta indica provenances in different growing seasons within crowns were measured with Li-6400 Portable Photosynthesis (Li-Cor Inc., USA).The results showed that light response curves of the four provenances exhibited different characteristics with different aged leaves and positions within the tree crowns. There were obvious differences in the light saturation point (LSP) and light compensation point (LCP) among the four A. indica provenances in different growing seasons. For the same provenance, the LCP of initiation phase was the highest and that of prosperous phase was the lowest. For the seasonal variation of the LSP, there was a trend of initially increasing from initiation phase to prosperous phase, then decreasing in the last phase. Rankings of LCP and LSP in the different layers in the tree crowns were similar, i.e., the upper crown > mid crown >lower crown, which expressed the ecological adaptability to the variant light conditions. Among the four provenances, the maximum net photosynthetic rate of A. indica originating from Kalyani (KA) through the light response measurements was the highest (about 18.95 μmol·m-2·s-1 ), and that of other three provenances was between 13.98-16.35 μmol·m-2·s-1 . According to those photosynthetic characteristics, i.e. the higher LCP and LSP, the stronger adaptability to high light intensity and the higher photosynthetic capacity, the four provenances of A. indica all showed typical heliophyte properties.
The indicators of water quality of rainfall and stream water from secondary forested watershed in Qianjiangyuan Forest Ecology Station were measured from monthly collected samples, and then analyzed through comparing and contrasting. It was found that the average of concentrations of DO in water from secondary forest watershed was 8.10 mg·L-1, 1.12 times of that in rainfall. The corresponding value for TN was 7.68 mg·L-1 and 4.49 times. The average of concentrations of BOD5 in rainfall water was 2.10 mg·L-1 and 1.31 times of that in secondary forest watershed.The corresponding values for CODMn were 2.05 mg·L-1 and 1.16 times, for NH3-N were 0.97 mg·L-1 and 7.46 times, for TP were 2 times of that in secondary forest watershed. The results showed that most water quality index (DO, COD, BOD, TP and NH3-N) under secondary forest ecosystems were improved significantly. Except TN and pH, other water quality index conformed grade I of "Environmental Quality Standards for Surface Water".
The genetic diversities of 17 walnut cultivars(Juglans sigillata Dode) authorized or approved by Yunnan Province Forest Tree Cultivar Registration Committee were investigated with FISH-AFLP technical system. Eight pairs of E+3/M+3 primers were used to amplify the genomic DNA. The results showed that 987 AFLP bands were obtained, 942 of them were polymorphic markers and the average percent of polymorphic bands was 95.44%. The genetic similarity indexes among all the 17 cultivars are ranged from 0.606 9 to 0.796 4 with an average of 0.734 9. These investigations would be significant in utilizing walnut germplasm resources and cultivating new varieties.
In order to establish stable ISSR-PCR reaction system of Machilus thunbergii, single factor and orthogonal experiment design were used to optimize the reaction system after exploring M. thunbergii DNA extraction. For finding optimal concentration of factors of ISSR-PCR, the different levels of concentration of Mg2+, primer, template DNA, dNTPs were trailed by single factor experiment. Meanwhile, in order to improve the reliability of the results of the single-factor test, the authors also adopted orthogonal design by four factors, three levels for further optimizing and screening the best conditions of Mg2+, primer, template DNA, and dNTPs. The best ISSR-PCR reaction system of M. thunbergii was eventually established by comparing the two method’s results, which included 20 μL reaction system, Taq enzyme, 0.05 U·μL-1,Mg2+ 2.0 mmol·L-1 template DNA 1 ng·L-1,dNTPs 0.3 mmol·L-1,primers(835) 0.5 μmol·L-1, and 1×PCR buffer. The establishment of the better repeatability and stability ISSR-PCR reaction system could provide technical support for further research of genetic structure and genetic variety of M. thunbergii group.
An F1 pedigree of Eucalyptus urophylla×E. tereticornis was used to detect quantitative trait loci (QTLs) controlling four cutting-related traits, i.e. number of roots per cutting, the maximum length of roots, percentage of rooted cuttings and root dry weight, as well as two growth traits, height (H) and breast-high diameter (DBH) of 13-, 18- and 46-month-old Eucalyptus trees. For cutting-related traits, six and seven QTLs were detected on genetic maps of maternal Eucalyptus urophylla and paternal E. tereticornis, respectively, with logarithm of odds (LOD) ranging from 2.0 to 3.9, variance explained from 15.2% to 26.8% and map distance with the closer flanking marker 0.0 to 15.0 cM. For growth traits, two and one QTLs were detected on the maternal map in 46-month-old H and DBH, respectively, though no QTL was found for 13- or 18-month-old growth, and a number of QTLs were located onto the paternal map for all the ages, including four, four, one, two, two and two QTLs for H13, DBH13, H18, DBH18, H46 and DBH46, respectively. No QTL was found to affect significantly the rooting ability of cuttings and field growth simultaneously, implying probably the difference in genes responsible for the two types of traits. Several markers had zero cM of map distance to or linked very closely with QTL, which might act as sound candidate markers for future marker-assisted selection in related traits.
The research focused on heavy metal concentrations of soil and plants in Wenzhou’s tanning zone in Zhejiang Province of East China and relationship with soil pollution. The available plant germplasm resources for Cr contaminated soil restoration were initially definited. Twenty-five species belonging to 13 families were found in the polluted area, including 8 dominant species: Cynodon dactylon (L.) Pers., Chenopodium glaucum Linn., Ageratum conyzoides Linn., Malachium aquaticum (L.) Fries, Eleusine indica (Linn.) Gaertn., Rorippa indica (Linn.) Hiern, Amaranthus retroflexus Linn. and Oligostachyum lubricum (Wen) Keng f. The investigation showed that Cynodon dactylon (Linn) Pers., Chenopodium glaucum, Eleusine indica (Linn) Gaertn, Rorippa montana (Linn) Hiern, Amaranthus retroflexus Linn. were the adaptive pioneer species for soil ecological restoration. Cr concentrations in the aboveground were 110.26-774.05 mg·kg-1, and the average value was 280.95 mg·kg-1;concentrations in roots were 774.05-2 334.56 mg·kg-1, the average value was 1 229.75 mg·kg-1. Cr concentrations in the aboveground and root of Cynodon dactylon were the highest, 774.05 mg·kg-1 and 2 334.56 mg·kg-1, respectively. According to correlation analysis, the heavy metal content in aboveground plants and the roots had weak correlation with the content in soil. The result of regressive analysis indicated that the root content and bioaccmulation coefficients of Cr was both closely associated with the aboveground plants. The root bioaccmulation coefficients were enhanced with the increased aboveground plants.
To study the characteristics of pollen germination in vitro of six Camellia oleifera species, the orthogonal test using six C. oleifera species as the materials was aimed to examine the effects of the 4 factors consisting of temperature, boron consumption, sucrose, and agar usage on pollen germination. The results indicated that temperature was the most significant factor among the 4 factors and the optimum temperature was 25 ℃, sucrose markedly affected the pollen germination of most species and the optimum sucrose was 10%, and boron consumption and agar usage markedly impacted on individual clones and the optimum were 100 mg·kg-1 and 0.5%. Combining multiple comparision, the optimum extractive condition is T9; the growth of pollen tube followed the "slow-fast-slow" trent. When the concentration of Ca2+ was high, the pollen germination was markedly inhibited. If the concentrations of Zn2+ and Mo6+ were low, the pollen tube growth would be enhanced.But when the concentrations of Zn2+ and Mo6+ were high, the pollen germination of pollen tube was negative effected.
The fast-growing plantation of Casuarinae quisetifolia were selected for establishing the polymorphic site index model by parameter replacement method based on the nonlinear Richards equation. The results shows that: (1)The Richards equation has much higher precision and a good adaptability, the difference of dominant height between theoretical value and actual value is not significant by testing, which indicates that the dominant height increment of Casuarinae quisetifolia can be properly evaluated; (2) The reference age of site index for fast-growing C.quisetifolia is 3 years in this area; (3) With the analysis of inflection point, it shows that the dominant height increments under different site conditions can be objectively reflected by the polymorphic site index model; (4) It provides a reference for the research and application on the mathematical tables and models of domestic C. quisetifolia. And it also provides scientific and technological bases for site quality evaluation and management.
Classical statistics and geo-statistics were used to analyze the spatial variations and distribution pattern of soil organic carbon(SOC), total nitrogen(TN) and C/N ratio of forestland in three ecological areas of Pangquangou National Nature Reserve in Guandi Mountain of Shanxi Province,China. The results showed that the SOC and TN increased firstly but fell off afterwards, the C/N decreased continually with the succession level from artificial forest to secondary broad-leaved forest composed of Betula albo-sinensis, Betula platyphylla and Populus davidiana in early phase succession, to secondary Picea, Populus, Betula mixed forest in later stage succession. The coefficient of variation of SOC, TN and C/N varied from 11.74% to 64.71% which showed medium variations. The Range of SOC and TN in artificial forest was larger but still smaller than that in secondary forest, this explained a lower variation degree and more homogeneous spatial distribution of SOC and TN in artificial forest than that in secondary forest. The structural variance ratio of SOC, TN and C/N in artificial forest was in the range of 0－64.8%, which meant a weak or medium spatial autocorrelation, while the structural variance ratio of SOC, TN and C/N in secondary forest was more than 75%, appearing high spatial autocorrelation, and structural variance ratio of the narrated above 3 index showed a increasing trend with progressive succession. Kriged maps showed that SOC, TN and C/N in artificial forest present a high fragmentized distributions but a regular patched distributions. Forest succession, disturbance and toporographic condition have important effects on spatial variation and its characteristics of SOC, TN and C/N of forestland.
To reveal the natural active component variation rule in barks of Eucommia ulmoides Oliv., which provided basal reference for the plus tree screening and effective utilization of the medical woody plants, the active components in barks of different Eucommia ulmodies variance-types were detected by RP-HPLC. The results showed that the content and allocation of the five active components in barks was evidently different among four variance-types. Comparing to the deep-vertical splitting and the chap variance-types, four natural contents including geniposidic acid, geniposide, pinoresinol diglycoside, chlorogenic acid and total amount of the five constitutes were detected to be relatively higher in barks of the smooth and the shallow-vertical splitting types. Community of the smooth type could be given priority to breeding selection for cultivating excellent Eucommia ulmoides medicinal variety.
Research was carried out on the growth and wood relevant properties of six provenances of 27-year-old Tectona grandis in Ledong Country, Hainan Island. The results showed that there existed significant differences among these provenances in bark thickness, heartwood width, basic density as well as tree height, tree volume, height of fresh branch and sapwood width. For the DBH, the number sapwood rings and the heartwood content, there were not significant differences. It has great potentials to improve the growth and wood property of T. grandis in provenances level and the good results could be obtained in growth properties, basic density and sapwood width by provenance selection. The broad-sense heritabilities for tree height (0.601 6), tree girth (0.593 2), tree volume (0.586 8), height of fresh branch (0.686 5), bark thickness (0.796 3), sapwood number (0.543 4), sapwood width (0.670 0), heartwood width (0.723 0), heartwood content (0.473 7), and basic density (0.937 3) of the six provenances were calculated. The results indicated that growth and wood properties were controlled by moderate or high-moderate genetic heritability. So, high genetic gains could be obtained by inter-provenance selection with suitable intensity. In addition, the growth and wood relevant properties of the 6 provenances were comprehensively evaluated which could provides a base for the selection of T. grandis provenances.
Soil erosion is a main factor determining the ceasium-137 (137Cs) content and its redistribution in soil. Based on the field investigation in October, 2005 and the interpretation and analysis of TM images, this paper discussed the distribution of 137Cs in karst mountainous region in northern Guangdong, the soil erosion rate and erosion characters in rocky desertification land of different degrees. The 137Cs activity in soils in rocky desertification region of northern Guangdong averages (6.54±0.57) Bq·kg-1, and the 137Cs level in soils tends to decrease at first and then increase with the increase of the degree of rocky desertification, which shows that in severe rocky desertification stage, the soil particles around the bare rock adsorb the 137Cs collectively and the 137Cs is gradually enriched in depressions. The 137Cs reference inventory in the study region is (1 433.60±131.40) Bq·m-2, which is lower than the mean value of northern hemisphere. The 137Cs distribution in soil profile roughly conforms to an exponential distribution pattern, and the highest point appears in the range of 2-4 cm deep. The mean erosion rates of non-cultivated soil at slight and moderate rocky desertification land are 1 369.0 and 1 833.5 t·km-2·a-1 respectively. The erosion rate of cultivated soil is much higher than that of non-cultivated soil, and is much affected by slope.
The development status of UPOV and international protection system of new plant varieties were introduced. The research status of DUS testing was summarized, which focused on the application of molecular markers. Establishment and developmet of Chinese new plant variety protection system was expounded, and the situation of application and authorization was analyzed. On this basis, some suggestions were made on how to perfect new plant variety protection and DUS testing in China.
In order to obtain more and detailed information, the chemical experiment methods were used to analyze the main nutritional components of mineral Ca, Mg, Fe and Vc, acid value in the nuts of 9 Fagaceae species. Some conclusions are as follows:(1) Among the 9 species, the Castanea seguinii nut has the greatest content of Ca, followed by Castanea henryi and Lithocarpus litseifolius, that in the Cyclobalanopsis gracilis nuts is the least; meanwhile, the Castanea seguinii nuts contain the most Mg, followed by Castanopsis sclerophylla and Castanopsis tibetana, but the Castanea henryi nut has the least mineral Mg. In addition, the Castanopsis sclerophylla nuts contain the greatest content of Fe, but the nuts of some species such as Castanea seguinii, Castanopsis eyrei, and Castanea henryi contain also more mineral Fe. (2) the nuts of Castanea seguinii contain rich content of Vc, followed by Castanea henryi. (3) Among these 9 species, Cyclobalanopsis gracilis nuts contain the highest acid value, followed by Cyclobalanopsis glauca, the fruits of Castanea seguinii, Castanea henryi and Castanopsis sclerophylla nuts have the moderate acidity value, which taste better and have a higher development value. In a word, the nuts of these 9 species contain rich mineral nutritional ingredients and Vc. It is considered that these species could meet the need of food industry in great scale.
The full-length cDNA of a presumed glycine-rich ribonucleic acid (RNA) binding protein (ThGRP1) gene was isolated from a cDNA library of Tamarix hispida leaves. The ThGRP1 gene with 800 bp in length contains 432-base pair (bp) open reading frame (ORF) and encodes a 143-amino-acid polypeptide with a predicted molecular weight of 14.95 kDa and pI of 5.36. Expression of ThGRP1 in roots, stems and leaves of T. hispida with PEG, NaCl, NaHCO3 or CdCl2 treatments was studied using real-time PCR. The results showed that ThGRP1 can be induced by these stresses. Especially, the expression of ThGRP1 in roots of T. hispida was induced under all stresses at 6, 12, 24, 48 and 72 h.
An evaluation of the impact of scattering limestone powder on acidified soil surface on the growth of young trees of Schima superba under crowns of a Pinus massoniana plantation (three years and four months after treatment) were made by a long-term field fixed position experiment, which was conducted in the Tieshanping Forest Farm of Chongqing City in 2004. The randomized complete block experiment had five treatments and three replicates: the doses of one-time scattering of 0 (control), 1, 2, 3 and 4 t·hm-2 finely ground limestone respectively. The effect was significant: surface limestone could ameliorate health condition of the young trees of S. superba and among them the optimum dose was 2 t·hm-2. The mean canopy thickness, crown size, height and diameter of the base at 20 cm above the ground of the young trees of S. superba treated by 2 t·hm-2 increased by 96.84%, 52.68%, 77.47% and 61.19% respectively (P<0.05) compared to the control.
Carbon partition in plants is one of the key points for carbon cycle research. In order to estimate the carbon storage of shelterbelts in plain areas of China accurately, the method of biomass inventory was used to study the individual biomass, organ carbon storage and partition in different organs of 8, 10, 13 and 16 year-old poplar shelterbelts in Yuncheng, Shandong Province. The results indicated that the biomass of different poplar organs followed the pattern of trunk>branch>root>leaf, and the biomass of trunk and branch accounted for about 80% of the total. The carbon concentration of the different organs followed leaf>branch >trunk >root. The carbon concentration of different organs ranged between 43.51% and 70.49%. The carbon concentration of the four age groups’ shelterbelts were higher than 50%, which was slightly higher than the average carbon concentration of poplar in Northern China(48.80%). The variation coefficient of carbon concentration was the smallest for leaf, and the largest for root. As for the difference of carbon concentration, it was significant among different organs for all the four age groups, and not significant among the whole trees for the four age groups. The carbon storage was closely related to its biomass for all tree organs, and its sequence was trunk>branch>root>leaf. The proportion of trunk carbon storage obviously increased with tree age.
70 candidate trees, 350 dominant trees and 560 neighboring trees were selected out from 6.5-7.5 a Paraserianthes falcataria( L.) Nielsen provenances/families trials in six different areas of Guangdong province. Using the method of 5 dominant trees comparison and 8 neighboring trees standard, combing with form indexes synthetical appraisement, the criteria of superior tree selection were discussed. The result showed that as a superior tree, the DBH ( diameter at breast height) should not be less than 1.43 times of average DBH of 5 dominant trees, the height should be higher than average height of 5 dominant trees, the individual volume should not be less than 2.23 times of the average volume of 5 dominant trees, and, the sum of 0.64 times of stem form score and 0.36 times of branch score should be less than 2; or 8 neighboring trees standard value should not be less than 4, and, the sum of 0.64 times of stem form score and 0.36 times of branch score should be less than 2. The latter criteria are considered as better one for superior tree selection in the future.