• 中国中文核心期刊
  • 中国科学引文数据库(CSCD)核心库来源期刊
  • 中国科技论文统计源期刊(CJCR)
  • 第二届国家期刊奖提名奖

2013 Vol. 26, No. 2

Display Method:
Variation of Cation Flux with Rain Water in a Larix principis-rupprechtii Plantation on Liupan Mountains
DU Min, WEN Shi-zhi, YANG Li-li, WANG Yan-hui, XIONG Wei, CAO Gong-xiang
2013, 26(2): 133-139.
Abstract:
At a selected stand of Larix principis-rupprechtii plantation growing in the small watershed of Xiangshuihe of Liupan Mountains, NW China, the variation of pH-value, cation concentration and cation flux were measured in the rain water from open field precipitation, throughfall, stem flow, leakage under humus layer and under the mineral soil layer (30 cm) in the growing season of 2011. The results showed that the mean pH-value of open field rain water was 7.13, while it was 6.73 in throughfall, 6.00 in stem flow, 6.87 in the leakage under humus layer and 7.28 in the leakage under the soil depth of 30 cm. In the rain water under canopy, which is composed of throughfall and stem flow, the concentration of nearly all cations increased more or less, but the concentration of Zn2+ decreased. Although the depth of rain water under canopy decreased as a result of canopy interception, the cation exchange or wash out from canopy led to an obvious increase of flux of most cations. The cation flux (mmol·m-2) for K+, Mg2+, H+, Mn2+, Cu2+, and Fe3+ increased from 17.23, 12.51, 0.06, 0.09, 0.13, and 0.19 of open field precipitation to 141.87, 32.93, 0.10, 0.68, 0.24, and 0.56 of rain water under canopy. However, the fluxes of Na+, Ca2+, Zn2+ decreased by the canopy, from 33.73 to 30.70, 112.91 to 75.75, and 2.05 to 1.10 respectively. In the leakage under humus layer, the concentration of most cations decreased more or less, only the concentration of Mg2+ increased slightly. Affected by the humus layer interception and the cation exchange with humus layer materials, the flux of all cations in the leakage under humus layer obviously reduced compared with the flux carried by the rain water under canopy, with a flux (mmol·m-2) of 83.06 for K+, 12.30 for Na+, 23.96 for Mg2+, 65.73 for Ca2+, 0.04 for H+, 0.12 for Mn2+, 0.09 for Cu2+, 0.13 for Zn2+, and 0.32 for Fe3+. In the leakage under the soil layer of main root system, the concentration of some cations (K+, Mn2+, Cu2+, Fe3+) reduced, while the other cations (Na+, Mg2+, Ca2+, Zn2+) increased, especially the remarkable increase of Ca2+ concentration. Affected by the volume decrease of soil leakage and the cation exchange with soil, the flux of Na+, Mg2+, Ca2+, Mn2+, and Zn2+ in soil leakage increased compared with that of humus layer leakage, with the flux (mmol·m-2) of 37.49, 62.83, 202.41, 0.22, and 1.05 respectively; but the cations of K+, Cu2+, Fe3+ decreased, with the flux (mmol·m-2) of 27.14, 0.07, and 0.09 respectively. Compared with the cation input flux carried by the open field precipitation, the canopy played a role of net leakage (increase) for most cations (except Na+, Ca2+, Zn2+), while the humus layer played a role of net adsorption (decrease) for most cations (except K+, Mg2+, Mn2+, Fe3+), and the soil of main root layer played a role of net leakage (increase) for the base cations (Na+, K+, Mg2+, Ca2+) and Mn2+, and a role of net adsorption (decrease) for other cations (H+, Cu2+, Zn2+, Fe3+).
Sensitivity Analysis for Sensible Heat Flux from a Mixed Plantation Using LAS Measurements in Hilly Zone of North China
ZHENG Ning, MENG Ping, ZHANG Jin-song, YIN Chang-jun
2013, 26(2): 140-144.
Abstract:
Based on the LAS data from May to September and MOST in the BLS, the sensible heat flux (H) of a 30-year-old mixed plantation in the hilly zone of the North China in 2009 was calculated. The sensitivity effects of Bowen ratio (β), zero-plane displacement height (d), beam height (ZLAS), wind speed (v) and air temperature (Ta) were analyzed. The results showed that under arid and semi-arid atmosphere conditions in the study area, β was a less sensitive factor in the rang 0.4 4.0; when ZLAS fluctuated by 20%, the difference between estimated value and reference value of H was 35%; when d fluctuated by 50%, the difference was 1%; when Ta fluctuated by 10%, the difference was 0.2%; when v fluctuated by 20%, the difference was 10%.
Stem Sap Flow Characteristics of Acacia auriculaeformis in Dry-hot Valley and Their Relations to Meteorological Factors
WANG Xiao-fei, SUN Yong-yu, LI Kun, ZHANG Chun-hua, LI Bin
2013, 26(2): 145-150.
Abstract:
The thermal dissipation probes(TDP) were applied to measure the sap flow of Acacia auriculaeformis in dry and wet seasons in Yuanmou dry-hot valley, southwest China. The meteorological factors such as photosynthetic active radiation(PAR), air temperature(T), relative humidity(RH), water vapor pressure deficit(VPD) and wind speed were measured at the same time. The diurnal, seasonal variation of liquid flow rate and its relationship with meteorological factors were analyzed. The results indicated: (1)The diurnal variation of sap flow displayed a typical single-peaked curve during the wet and dry seasons. (2)The value of sap flow velocities in south side was higher than that in the north side. (3)There were obviously difference between the wet season and the dry season in the mean and the maximal value of sap flow velocities. The mean and the maximal values of sap flow velocities in wet season were 2.8 and 2.5 times that in dry season. (4)The sap-flow velocity was significantly correlated with PAR, air temperature and VPD and was negatively correlated with the atmospheric relative humidity. The ranking of correlation coefficients was PAR>air temperature>VPD>relative humidity>wind speed. The dominant factors were PAR, RH, and VPD.
Analysis of the Taxonomical Position of Pinus tabulaeformis. f. Shekannesis Based on RAPD Markers and Morphological Traits
XIE Qing, LIU Zhi-hong, LI Zhou-qi, YUAN Zhong-lin, WANG Zhong-yu
2013, 26(2): 151-155.
Abstract:
In this study, the taxonomical position of Pinus tabulaeformis f. Shekannesis Yao et Hsu was estimated on the basis of morphological characters and RAPD data. For RAPD analysis, 20 random primers were selected and 176 bands, within 172 polymorphic bands and a polymorphism rate of 97.73%, were obtained. Twenty four morphological characters data were also recorded. The RAPD and morphological characters data were then respectively analyzed with an unweighted pair-group method using an arithmetic average (UPGMA).The results based on different data are similar and it indicates that the Pinus tabulaeformis f.Shekannesis Yao et Hsü has not yet reached a variant or relatives of Pinus tabulaeformis.
Variation of Functional Traits of Quercus Seedlings from Different Provenances of Temperate Zone of NSTEC
LI Dong-sheng, SHI Zuo-min, LIU Shi-rong, XU Zhong-qi, HUANG Xuan-rui
2013, 26(2): 156-162.
Abstract:
The differences in functional traits among species may be the result of both genetic differences and plasticity if species are measured in different environments. Common garden experiments can help determine the extent to which trait differences observed among species are genetic induced. Seeds of 6 Quercus species from 8 core distribution areas in temperate zone of North-South Transect of Eastern China(NSTEC)were pretreated and sown in the same environment. 5 functional traits of one year-old seedlings were measured, i.e., leaf mass per area (LMA), photosynthetic rate per unit leaf area (Aarea), photosynthetic rate per unit leaf mass(Amass), total dry matter content(TDMC), and root-shoot ratio(RSR). The difference and overall variation of different functional traits among intra-species and inter-species were analyzed, and the relationships between functional traits of seedlings and seed mass were discussed. The results show that: the interspecific variation coefficients of all functional traits were higher than intraspecific variation coefficient, and the interspecies differences of functional traits were also more significant, while variation of LMA and leaf photosynthetic rate were lower whatever among intra-species or inter-species; two functional traits(TDMC, RSR)were obvious correlated with seed mass, while the relationships of leaf photosynthetic rate and LMA with seed mass were relatively lower. It could explain that in temperate zone of NSTEC, the change of functional traits of Quercus species partly were the expression of difference among species affected by genetic evolution, so when studying the relationship among Quercus species and environment, the interspecies variation of functional traits cannot be neglected, and LMA could serve as a better index, and leaf photosynthetic rate take the second place.
Isolation of Ethyl Acetate Extract from Periplaneta americana and Its Antimicrobial Activity
WANG Kui, FENG Ying, SUN Long, HE Zhao, CHEN Zhi-yong
2013, 26(2): 163-166.
Abstract:
Antimicrobial chemical components, which isolated from the ethyl acetate extract of Periplaneta americana L., were tested for the ability to inhibit Staphyloccocus aureus, Escherichia coli, etc., based on bioassay-guided method. The results indicated that the ethyl acetate extract of P. americana showed some inhibiting effects to all gram-positive bacteria tested, and the best inhibition effect was against Bacillus subtilis. Nine factions were obtained after silica gel column chromatography. Among them, the faction Fr7 showed inhibiting effects to all bacteria tested. Applying the isolation method of silica gel column and gel chromatography, seven unsaturated fatty acids compounds were isolated from the faction Fr7 and Fr8. All these compounds showed the best inhibiting effects against Micrococcus luteus. The results suggested that unsaturated fatty acids were antimicrobial chemical components of the ethyl acetate extract from P.americana. The inhibition effects of the unsaturated fatty acids against gram-positive bacteria were stronger than against gram-negative bacteria.
Effect of Improvement Measures on Soil Labile Organic Carbon of Low-efficiency Pinus massoniana Forest
LAI Jia-ming, LI Kai-zhi, HUANG Cong-de, ZHANG Jian, YANG Wan-qin
2013, 26(2): 167-173.
Abstract:
Forest management plays an important role in soil carbon sequestration and global climate change mitigation. Soils were collected to determine the total organic carbon (SOC) and labile organic carbon under the low-efficiency Pinus massoniana forest (CK) and the improved forests, including clear cut and reforestation (QKCZ), closing for afforestation (FSYL), and replanting and mixed plantation (BZHJ). The results showed that SOC, microbial biomass carbon (MBC), dissolved organic carbon (DOC) and easily oxidizable carbon (EOC) significantly increased by 1.06 3.3 g·kg-1, 16.81 142.29 mg·kg-1, 12.83 43.71 mg·kg-1 and 0.16 0.54 g·kg-1 under the improved forests (including QKCZ, FSYL and BZHJ) respectively as compared with the CK. The MBC/SOC ranked as FSYL > CK > QKCZ > BZHJ, the EOC/SOC ranked as CK > BZHJ >FSYL >QKCZ, and DOC/SOC ranked as BZHJ > CK >FSYL >QKCZ. The results suggest that QKCZ is the best measure for low-efficiency Pinus massoniana forest improvement to increase carbon stability and sequestration in soil. Therefore, selecting suitable measure for low-efficiency Pinus massoniana forest improvement is an important measure to enhance soil carbon sequestration.
Leaf Area Estimation Model and Specific Leaf Area of Chinese Pine
DIAO Jun, GUO Hong, LU Jun, LEI Xiang-dong, TANG Shou-zheng
2013, 26(2): 174-180.
Abstract:
Leaf area and specific leaf area are important parameters in the process of plant growth. 522 needles of Chinese pine (Pinus tabulaeformis) in Mulanweichang were sampled and the needle surface area LA, needle length L, needle width W and needle perimeter P were obtained by winSEEDLE software. The models for leaf area and shape attributes including leaf length, leaf width, leaf perimeter and models for leaf area and leaf dry weight were developed, respectively. The total relative error, average relative error, average absolute relative error, root mean square error and predicted precision were used to verify the errors and the goodness of fit of the models. The models LA=-2.761+0.464 L+6.608 W and LA=1.345+0.501 X were proved to be the best, where X is the leaf dry weight. The specific leaf area of Chinese pine is 7.08 m2·kg-1 derived from the comparison among the arithmetic average method, ratio estimation method, and the least square method. It provides a simple and reliable method for estimating leaf area of Chinese pine.
Fruit Phenotypic Diversity and Variation of Xanthoceras sorbifolia Artificial Population
CHAI Chun-shan, LU Juan, CAI Guo-jun, WANG San-ying, QI Jian-li, WANG Zi-ting, XUE Rui
2013, 26(2): 181-191.
Abstract:
19 phenotypic characters of fruit were investigated for 44 Xanthoceras sorbifolia Bunge. The phenotypic variation was studied by using variance analysis, correlation analysis and variation coefficient. The results of variance analysis and variation coefficient analysis showed that the phenotypic characters of fruit were significantly different among individuals of X. sorbifolia, and had great variation in test area. Among 19 phenotypic characters, the variations in fruit number and seed yield were the biggest among different X. sorbifolia individuals and all theirs variation coefficients were over 76%, followed by fruit weight, seed weight and kernel weight with the variation coefficient about 30%, the seed number per fruit and stalk length with variation coefficient over 20%, whereas the characters of seed length, seed width, seed shape index and number of ventricle had smaller variation and their variation coefficients were less than 10%, the least variation was the oil yield of seed kernel and its variation coefficient was only 6.13%, which showed there was evident differences in fruit-bearing capacity for individuals of X. sorbifolia, and had determinate hereditary stability. The correlation analysis results indicated that the correlation of various phenotypic characters of fruit had significant differences. Among them, the correlations of characters for fruit length, fruit width, fruit weight, seed weight, kernel weight, seed length, seed ratio, 1 000-seed weight and stalk diameter of fruit were strong, and significantly related to many phenotypic characters, whereas the characters of fruit shape index, kernel ratio of seed, fruit number and seed yield were only significantly related to a few phenotypic characters, but the correlation of characters for number of ventricle and stalk length was weak and hardly related to any phenotypic characters of fruit. The genetic diversity of fruit phenotypic characters and their significant differences among X. sorbifolia individuals would play an important role in its elite tree selection and breeding.
The Physio-ecological Response of Acanthus ilicifolius Seedlings to Different Degrees of Light Intensity in Tide Environment
LIU Bin-er, LIAO Bao-wen
2013, 26(2): 192-199.
Abstract:
By using tide simulation control system, the physio-ecological response of Acanthus ilicifolius Linn. seedlings to different light intensities (5%, 15%, 20%, 45%, 60%, 75% and 100% relative to natural light) from germination to the 10th month were studied. The results showed that as light intensity increased, the survival rate, height, ground diameter, dry weight of root, dry weight of stem, dry weight of leaf, individual biomass, root/shoot ratio, root vigor, leaf area and the content of chlorophyll a and b rose at first and then fell; the content of soluble sugar, net photosynthetic rate, water transpiration rate, stomatal conductance, maximum net photosynthetic rate rose. Under 30 minutes of immersion, the net photosynthetic rate rose and stomatal conductance decreased, all of which stabilized at a lower level than the initial rate. Most of physio-ecological indicators showed the seedlings grew well under the light intensity of 45%. The seedlings enhanced their efficiency of harvesting light by decreasing root/shoot ratio, light compensation point and increasing height, leaf area, apparent quantum efficiency and the content of chlorophyll a and b with the light intensity of 20%. 5% light intensity inhibited seedlings growth significantly, and the preserved rate was still above 60%. Very low light intensity could lead to slow growth of seedlings, but did not have strong impact on the density of their natural establishment. Meanwhile, the light saturation point and light compensation point of A. ilicifolius seedlings were very low. The reason why high density seedlings of A. ilicifolius emerge on mangrove wetlands from the Pearl River estuarine zone is that this shade-tolerant species has very strong adaptation to the decrease of light intensity.
Cloning and Express Analysis of PeAP2 Gene and Its Promoter in Phyllostachys edulis
CHEN Dong-liang, PENG Zhen-hua, GAO Zhi-min
2013, 26(2): 200-206.
Abstract:
APETALA2 (AP2) gene plays an important role in plant development. A full-length cDNA sequence of AP2 homologous gene was cloned from Phyllostachys edulis by reverse transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE) methods, and named as PeAP2. The PeAP2 is 1 750 bp and consists of a 5'-untranslated region (UTR) of 106 bp, a 3'-UTR of 174 bp and an opening reading frame of 1 470 bp. The sequence analysis showed that PeAP2 encoded a protein of 489 aa containing two AP2 domains which indicated that it belonged to the AP2 subfamily of AP2/EREBP family. Comparison analysis showed that PeAP2 protein shared high homology with AP2 protein from other monocotyledon plants, especially with that of Brachypodium distachyon up to 74.85%. Real time PCR analysis showed that PeAP2 expressed all in root, stem, leaf, sheath and joint. The highest expressed level presented in leaf, followed by sheath and much lower in root, stem and joint. A 1 359 bp promoter sequence of PeAP2 gene was cloned by hiTAIL-PCR methods. The sequence analysis showed that it contained many cis-acting elements that response to light, hormone, and other factors.
The Effects of Nitrogen Deposition on Leaf Physiological and Photosynthetic Characters of Schima superba Seedlings from Three Provenances
ZHANG Rui, WANG Yi, JIN Guo-qing, ZHOU Zhi-chun, CHEN Ai-ming, CHU De-yu
2013, 26(2): 207-213.
Abstract:
To evaluate the responses of physiological and photosynthetic character of Schima superba leaf to elevated nitrogen (N) deposition, dissolved NH4NO3 with different treatments (0, 50, 100 and 200 kg·hm-2·a-1 N) was sprayed on one-year-old seedlings of three S. superba provenances. The photosynthetic light response curve, leaf N/P/pigments and soluble protein contents were determined. The results indicated that the treatment of 100 kg·hm-2·a-1 N deposition increased the apparent quantum efficiency (AQE), light saturation point (LSP), and maximum net photosynthetic rate (Pmax), but reduced the dark respiration rate (Rd). Meanwhile, the leaf N and pigment content were higher, but leaf P and soluble protein content were lower than that of the control. However, the treatments of 200 kg·hm-2·a-1 N deposition had a negative effect on the seedlings. There was large difference among the three provenances. The Hangzhou provenance from Zhejiang Province(HZ) had higher Pmax and could use low light easily. However, it was hard to accumulate the assimilation product. The Jian’ou provenance (JO) from Fujian Province showed stronger ability in using high light and the Rd was lower too, so this provenance was easier to accumulated assimilation product than other provenances. The leaf net photosynthetic rate, pigment and soluble protein content of HZ increased under the treatment of 50 kg·hm-2·a-1 N deposition, however, the Rd was reduced. The leaf pigment and soluble protein content of JO provenance was lower, but the production was largest under 100 kg·hm-2·a-1 N. The N deposition of 50 kg·hm-2·a-1 N promoted the photosynthetic rate of the Xinfeng provenance (XF) from Jiangxi Province increased the soluble protein content and improved the ability in using low light and the Rd was not increased either.
Dynamics of Litterfall at Different Altitudes in Moso Bamboo Plantations
TANG Yi-lin, ZHOU Ben-zhi, DENG Zong-fu, TANG Rong-qing, WANG Xiao-ming, GE Xiao-gai, CAO Yong-hui
2013, 26(2): 214-219.
Abstract:
To assess the effects of altitude on litterfall dynamics and changes of periodic rules on moso bamboo (Phyllostachys edulis), the seasonal and annual dynamics at different altitudes (350 m and 650 m) from June 2008 to December 2011 in Mount Dagangshan, Jiangxi Province, were studied. The results showed that: (1) The annual average litter production of moso bamboo plantations at different altitudes during the period was estimated to be (1 695.05±87.23) kg·hm-2. The ANOVA analysis suggested that the influence of elevation to litter production was not significant. (2) There existed periodic rules in on-year and off-year, with a length of about 12 months and dividing point of every June. Compared with on-year, the seasonal variation of litter production in off-year was more remarkable. Litter production in spring and summer contributed 68.71%-72.39% of the total in off-year. (3) The moso bamboo plantations at high elevation site were more seriously affected by the 2008’s ice storm disaster compared with that of the low elevation site. Based on the study, it could be concluded that by June, 2010, the moso bamboo plantations may have recovered to be normal.
Physiological and Biochemical Responses of Thuja sutchuenensis and Platycladus orientalis Seedlings to Natural Cooling
ZHU Li, GUO Quan-shui, JIN Jiang-qun, LIU Jian-feng, LI Zhi-yong, YAN hua
2013, 26(2): 220-226.
Abstract:
The paper focused on two species seedlings, Thuja sutchuenensis and Platycladus orientalis. Their adaptability to low temperature stress was compared by detecting and analyzing the leaves variable characteristics of antioxidant enzymes, osmotic adaptive substances and malondialdehyde (MDA) in the process of seasonal cooling in autumn and winter. The results showed that: during the process of seasonal cooling, the daily minimum air temperature decreased from 12.5℃ to -13.96℃, the superoxide dismutase (SOD) activity of T. sutchuenensis was strengthened significantly, however, the change of Peroxidase (POD) activity was not obvious, and both SOD and POD activities of P. orientalis were strengthened. The content of proline (Pro) and soluble sugars in leaves increased significantly in two species, T. sutchuenensis was lower than P. orientalis. The MDA content in leaves of the two species increased significantly, while T. sutchuenensis increased more than P. orientalis. The daily minimum air temperature was significantly correlated with the SOD, POD activity and soluble sugar content in P. orientalis, but it just correlated with the SOD activity in T. sutchuenensis. All these suggest that, during seasonal cooling, P. orientalis is more adaptive to low temperature stress than T. sutchuenensis through establishing better defensive system and conducting self-adjustment. The results of the research can provide reference for the T. sutchuenensis ex-situ conservation and cultivation management.
Influence of Ectomycorrhiza on Nutrient Absorption of Pinus massoniana Seedlings Under Water Stress
WANG Yi, DING Gui-jie
2013, 26(2): 227-233.
Abstract:
The effect of ectomycorrhiza on nutrient absorption of potted seedlings of Pinus massoniana under water stress was studied in greenhouse, by inoculating Pisolithus tinctorius, Cenococcum geophilum, Cantharellus cibarius Fr., Suillus luteus(L.:Fr.) Gray respectively. The results showed that ectomycorrhiza could significantly improve the absorption of content of N, P and K in drought stress. The contents of N, P and phosphatase activities of mycorrhizal seedling increased at first and then decreased with the water stress increase, and reached the maximum in moderate stress. The seedling of inoculation Suillus luteus1 had the best absorption to N, P, and increased 56.65% and 44.32% respectively compared to control group. The content of K in mycorrhizal seedling inoculating Pisolithus tinctorius and Suillus luteus1 increased at first and then decreased with the increase of water stress, and reached the maximum in the light stress. They increased by 222% and 119% respectively compared to the control group. N and K mainly distributed in the leaf, while P equally distributed in root, stem and leaf. The formation of mycorrhizal benefited the transportation of N and K upward. Inoculating Suillus luteus1 in mild and moderate stress had the best comprehensive effect in absorption and content of N, P and K, and at the same time it could promote seedling growth and enhance seedling drought resistance.
The Photosynthetic Response of Musella lasiocarpa and M. lasiocarpa var. rubribracteata to Light Intensity and CO2 Concentration
ZHOU Cui-li, LI Zheng-hong, MA Hong, WAN You-ming, LIU Xiu-xian, HOU Jian-hua
2013, 26(2): 234-239.
Abstract:
The photosynthetic responses of Musella lasiocarpa and M. lasiocarpa var. rubribracteata to light intensity and CO2 concentration were measured with Licor-6400. The results showed that the maximum light-saturated net photosynthetic rate (Pmax), light compensation point(LCP)and dark respiratory rate(Rd)of the protospecies were higher than those of the variety by 20.42%, 34.88%, and 31.95%. But the light saturation point(LSP)was lower in the protospecies than that of the variety. The Pn-Ci curves revealed that the protospecies had higher photorespiratory rate (Rp), carboxylation efficiency (CE), and maximum CO2 concentration-saturated net photosynthetic rate(Amax)than those of the variety by 2.73%, 14.79%, and 21.35%. This indicated that the photosynthetic capacity of the protospecies was stronger than that of the variety. The results also showed that M. lasiocarpa was a heliophile C3 type plant, and a shade-tolerant plant as well. The chlorophyll a, b and a/b content of the protospecies were also higher than those of the variety by 22.60%, 32.46%, and 25.06%.
Changes of Soil Organic Carbon and Total Nitrogen at Different Altitudes in West Slope of Sejila Mountain of Tibet
MA He-ping, GUO Qi-qiang, LIU He-man, QIAN Deng-feng
2013, 26(2): 240-246.
Abstract:
In order to explore the effects of total nutrient on surface soil (0 20cm), the alpine shrub, Rhododendron forest, Abies georgei var. smithii forest and Picea likiangensis var. linzhiensis forest were selected as experimental sites, the soil organic carbon (SOC), total nitrogen (TN), microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), readily oxidizable organic carbon (ROC), and particulate organic carbon (POC) were studied at different altitudes. The results showed that compared with lower-elevation vegetation types, the higher ones were found significantly higher in their SOC content and proportion. The SOC and TN contents were increasing along the elevation gradient in Sejila Mountain. The surface SOC of alpine shrub was the largest (77.167) and P. likiangensis var. linzhiensis forest the smallest(22.351). The TN of alpine shrub was the largest(2.430) and P. likiangensis var. linzhiensis forest the smallest(0.830). The surface C/N ratio of A.georgei var. smithii forest was the largest(43.57) and P. likiangensis var. linzhiensis forest the smallest(26.93). The elevation and wood stand had a significant impact on MBC and MBN. With lower altitude, the ratio of the POC in TOC decreased from 44.81% to 19.32%, the ratio of ROC in TOC decreased from 41.72% to 7.07%. The POC and ROC of different wood lands were significantly related to SOC. And the active SOC was significantly related to total SOC. The relationship between soil microbial biomass and readily oxidizable organic carbon was significant(p<0.05).
Study on Soil Microorganism Quantity and Biochemical Activity of First- and Second-Generation of Pinus massoniana Plantations in Qianzhong
CAI Qiong, DING Gui-jie
2013, 26(2): 247-251.
Abstract:
The quantity of different microorganisms, biochemical activity and the enzyme activity of the first- and second-generation of Pinus massoniana under similar condition were studied by using the methods of microorganism cultivation and laboratory analysis on soil microorganism biochemical activity and enzyme activity. The results showed that all the indexes of the soil microorganism quantity, biochemical activity and the change of soil enzyme activity (except Nitrification) in the first- and second-generation stands of P.massoniana showed the vertical distribution characteristics. The indexes decreased with the increase of soil depth, which reached significantly different. All the indexes of the second-generation P.massoniana about the soil microorganism quantity, biomass, biochemical activity and the change of soil enzyme activity were higher than those of first-generation. There was a significant positive correlation between bacterial amount and biomass carbon, and between bacterial amount and respiration. There was a very significant or significant positive correlation between the quantity of actinomyce, fungus and biomass carbon, respiration, invertase and catalase.
Dynamic Changes and Accumulation Rules of N, P and K Contents in Winter Shoot of Phyllostachys edulis
SU Wen-hui, FENG Huan-ying, FAN Shao-hui, XU Qing-biao, ZHOU Jin-ming, YANG Song-hong
2013, 26(2): 252-256.
Abstract:
In order to find out the nutrient requirement of Phyllostachys edulis in winter shoot growing period, the dynamic changes and accumulation rules of N, P and K contents in winter shoots were studied. The result showed that the N, P and K contents in shoot body were much higher than that in sheath. As shoot growing, the contents of the three elements in shoot body showed the change trend of decreaseing at first and then increasing slightly, but in sheath, the dynamic changes of N, P and K contents were not obvious. After sprouting, the nutrient accumulation speed and amount in winter shoot increased gradually as its growing up. By February, the N, P and K in winter shoots accumulated up to 2 807.62 g·hm-2, 305.57 g·hm-2 and 610.23 g·hm-2 respectively. The nutrient accumulation (Y, g) in shoot had a significant correlation with the shoot high (H, cm) and diameter (d, cm), and the model of N accumulation to H and d is Y=-2.068 9+0.001 0 H+0.626 6 d(R2=0.807 2).
Relationship between Planting Density and Tree Growth Process of Betula alnoides Mid-young Plantations in Pingxiang, Guangxi
WANG Chun-sheng, ZHAO Zhi-gang, ZENG Ji, GUO Jun-jie, SHA Er, GUO Wen-fu, ZENG Jie, ZHENG Hai-shui
2013, 26(2): 257-262.
Abstract:
11-year-old Betula alnoides plantations for density trial with five planting spacing treatments were investigated through stem analysis at Pingxiang City, Guangxi, to assess the effects of initial density on tree growth process. The results showed that the initial density had no remarkable effects on tree height growth and stem shape index, while there were significant differences in diameter at breast height (DBH), individual tree volume and stand volume among treatments of initial density, and the stand volume of treatment of 2 m×3 m was significantly higher than that of other treatments. The fast growing period of DBH trended to increase with the decrease of initial density, the DBH growth commenced to decrease since the sixth year after planted under the 1.5 m×2 m treatment, while it decreased mostly since the eighth year under other treatments, indicating that thinning should be conducted at the sixth year for 1.5 m×2 m treatment, and at the eighth year for 2 m×3 m and 3 m×3 m treatments, while for other treatments, it was delayed with the decrease of density. All the current and mean annual increment curves of tree height crossed when 5-6 years old, and did not reach quantity mature until 11 years old for all density treatments, while remarkable differences of the current annual increment of individual tree volume were seen among treatments. Taking factors such as growth performance, stand volume, and use efficiency of forest land, etc. into consideration, 2 m×3 m was determined as the most optimum planting density in the present study.
Study on the Differences of Eco-physiological Characteristics of Male and Female Rhus typhina
LI Guo-hui, WEN Guo-sheng, ZHANG Ming-ru, ZHOU Ze-fu
2013, 26(2): 263-268.
Abstract:
In order to compare the differences in eco-physiological characteristics between male and female plants and to further understand the ecological adaptability of Rhus typhina Linn., the diurnal variations of photosynthetic parameters and the fluorescence characteristics of male and female plants were determined respectively with photosynthesis system (CIRAS-2) and portable chlorophyll fluorometer (PAM-2100). The relative chlorophyll content was determined with relative chlorophyll content determination (SPAD-502). The length and width of leaf were measured with ruler. The results showed that the SPAD of male was greater than that of the female by 9.6%. The diurnal variation of net photosynthetic rate of male and female plants showed obvious midday depression. The daily mean of net photosynthetic rate of male plant was greater than that of the female by 22.7%, and there was significant difference between them. The daily means of transpiration rate was greater than that of the female by 18.5%. The water use efficiency of male plant was 2.3 μmol·mmol-1, which was greater than that of the female by 21.7%, and there was significant differences between them. The diurnal variations of light use efficiency of male and female plants were similar but the light use efficiency of male was higher. The Fv/Fm of male plant was higher than 0.76 and was higher than that of the female during the measurement period. The female reduced to the lowest which was 0.69 at 13:00 p.m. Both the leaf length and width of female were smaller, but the ratio of length and width was greater compared with the male, and there was significant difference between them. The net photosynthetic rate, water use efficiency and light use efficiency of male were higher than that of female, and it had stronger adaptability to environment.