Table of Content

10 March 2008, Volume 27 Issue 03

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Articles

Characteristics of soil seed bank in the regions with different groundwater levels in lower reaches of Tarim River.

XU Hai-liang¹; LI Ji-mei¹; YE Mao²

2008, 27(03):  305-310 . 

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Twenty-five natural vegetation plots with different groundwater levels in the lower reaches of Tarim River were selected, and their soil seed bank density, plant species diversity, life-form proportion, and similarity between plant communities and soil seed bank were studied byusing-seed-emergence method. The results showed that in arid regions, groundwater level not only affected the species and composition of plant communities, but also affected the density and composition of soil seed bank. With decreasing groundwater level, the degradation of plant communities also reflected on the changes of soil seed bank, e.g., the decreases of soil seed bank density and plant species diversity, the simplification of life-form, and the decrease of the similarity coefficient between plant communities and soil seed bank. This study could help to the enrichment of theoretical knowledge of soil seed bank in arid regions, and also, the practice of ecological restoration in the lower reaches of Tarim River.

Relationships of runoff- and sediment yield under Eucommia ulmoides plantation in hilly red soil region of South China with rainfall characteristics.

HUANG Zhi-gang^1,2;CAO Yun¹; OUYANG Zhi-yun¹; LI Feng-rui²; LI Xi-quan³; TIAN Yu-xin³; WANG Zhong-jian⁴; LIU Hui⁵ 

2008, 27(03):  311-316 . 

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Eucommia ulmoides is an important economic and soil and water conservation tree species in hilly red soil region of South China. In 2002-2005, runoff plots were installed in a typical E. ulmoides plantation to make observations, aimed to illustrate the relationships of surface runoff and soil erosion under E. ulmoides plantation with rainfall characteristics. In the observation period, the rainfall (R) and rainfall intensity (I) in most rain events were <25 mm and <5 mm·h^-1, respectively, and the runoff and soil erosion showed significant linear relationships with R, R·I, and rainfall erosivity (R₃₀). In a given rain event, R₃₀ could be a better factor than R·I to predict slope erosion, and more approached to the connotation of Modified Universal Soil Loss Equation. The product of runoff depth (Rd) and R₃₀,Rd·R₃₀, had a very significant linear correlation with the soil erosion under E. ulmoides plantation (r=0.685,P<0.01), suggesting its better ability than Rd for predicting slope erosion.

Linear compatible models of tree layer biomass of Pinus tabulaeformis plantations in Xiaolong Mountains.

CHENG Tang-ren^1,2; FENG Jing³; MA Qin-yan²; FENG Zhong-ke²; ZHANG Song-zhi⁴ 

2008, 27(03):  317-322 . 

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相容性线性模型； 生物量； 乔木层； 油松； 小陇山； 代数和法

Vertical distribution patterns of plant species diversity in northern Mt. Gaoligong, Yunan Province.

XU Cheng-dong¹; FENG Jian-meng²; WANG Xiang-ping²; YANG Xue³

2008, 27(03):  323-327 . 

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Seventeen sampling plots were established along an altitudinal gradient in northern Mt. Gaoligong, and the vertical distribution patterns of plant community, species composition, and species diversity were studied by using quantitative classification. The results showed that with the increase of altitude, the forest community had a transit of evergreen broad-leaved forest (2 000-2 300 m) to mixed coniferous and broad-leaved forest mainly composed by broad-leaved trees (2 300-2 600 m), mixed coniferous and broad-leaved forest mainly composed by coniferous-leaved trees (2 600-3 000 m), and coniferous forest (3 000-3 100 m). The species richness and β diversity of woody plants decreased obviously with increasing altitude, while the species richness of herbaceous plants had an increase after an initial decrease with increasing altitude, and increased obviously over timberline. The lowest β diversity of herbaceous plants was found in mid-altitude region. With the increase of altitude, the proportion of tropical and subtropical components decreased, while that of temperate and cosmopolitan components increased. China endemic elements were limited in mid-altitude region. As a whole, temperate plants dominated the flora, and the floral balance point existed at 2 100-2 200 m.

Observation on blossoming and bearing characteristics of Tamarix hispida under different groundwater levels.

WANG Jian-gang; LI Xia; SHI Rui-hua; NIU Ting; CHEN Hao 

2008, 27(03):  328-332 . 

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In this paper, the single inflorescence length, flower number, bearing rate and fruit quantity, and the seed germination rate of Tamarix hispida under different groundwater levels at the riverside in the lower reaches of Tarim River were investigated after the water transportation having been stopped for 30 years, with the normal water condition as the reference. The results showed that all the parameters except single inflorescence bearing rate and seed germination rate had significant differences among the observation points. After 7 years urgent water transportation, the single inflorescence length and flower number were assured at the point 300 m away from the river when the groundwater level was about 5.5 m, and the single inflorescence fruit quantity was assured at the point 500 m away from the river when the groundwater level was about 6 m. The single inflorescence bearing rate and seed germination rate were still relatively high at the point 1 000 m away from the river when the groundwater level was less than 7.5 m. Drought condition first restricted the single inflorescence length and flower number, and then, restricted the single inflorescence fruit quantity. Under water deficit, certain rates of inflorescence bearing and seed germination could be still maintained so as to insure the existence of T. hispida population.

Spatial distribution pattern of surface soil organic carbon based on TM image.

LI Xin-yu; YU Wan-tai; LI Xiu-zhen

2008, 27(03):  333-338 . 

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Soil organic carbon (SOC) is one of the core indices of soil fertility. To understand the spatial distribution pattern of SOC is of importance in promoting the development of precision agriculture and in implementing scientific fertilization. The objective of this study was to examine the feasibility of using TM image combined with field observation data in approaching the spatial distribution pattern of surface SOC in Heilongjiang Phaeozem region. The results indicated that the SOC had a significant positive correlation (r=0.553, P<0.01) with TM 5 band, and a binomial regression (R²=0.6791, P<0.05) with the image intensities of TM 4 and 5 bands. Regression model could better predict the spatial distribution pattern of SOC (R²=0.7097, P<0.05), and the SOC concentration was significantly higher in the regions with an altitude >200 than those with the altitude of < 200 m (P<0.05).

Changes of Citrus unshiuMarc. leaf temperature as affected by saturation pulse light of chlorophyll fluorescence apparatus.

CHEN Ping-zhao¹; KANG Dao-kun¹; WU Wei-hua¹; XUE Mei¹; WU Yin-mei¹; GUO Yan-ping²

2008, 27(03):  339-343 . 

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By using solution culture, this paper studied the effects of 3 000 μmol·m^-2·s^-1 saturation pulse light of chlorophyll fluorescence apparatus on the leaf temperature of Citrus unshiu Marc. under different phosphorus supply and light intensity. The results showed that after treated with the saturation pulse light of chlorophyll fluorescence apparatus, the leaf temperature difference (△t) of C. unshiu increased in the sequence of phosphorus deficiency blaze group (-P₉₀₀), phosphorus deficiency midblaze group (-P₆₀₀), and phosphorus deficiency low-light group (-P₁₀₀). A wider rising scope was observed with the weaker intensity of culture light and longer processing time. On the contrary, there was no significant difference in △t among the phosphorus supply blaze group (+P₉₀₀), phosphorus supply midblaze group (+P₆₀₀), and phosphorus supply low-light group (+P₁₀₀). When 1,4-dithiothreitol (DTT) was applied, the difference of △t among the groups became remarkable whether phosphorus was supplied or not. The diurnal changes of △t increased with increasing light intensities. The contents of chlorophyll a, chlorophyll b and carotenoid of each group decreased with increasing light intensity, while the transpiration rate, stomatal conductance and intercellular CO₂ concentration had less difference among the groups. This study suggested that the leaf temperature difference of C. unshiu was related to light intensity, phosphorus supply, processing with DTT, and duration of phosphorus deficiency stress.

Leaf N and P concentrations and their stoichiometric ratios of different functional groups of plants in Nanchang City.

GAN Lu; CHEN Fu-sheng; HU Xiao-fei; TIAN Qiu-xiang; GE Gang; ZHAN Shu-xia 

2008, 27(03):  344-348 . 

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The study on the leaf N and P concentrations and their stoichiometric N/P ratios of 89 main plant species in the Qianhu Campus of Nanchang University showed that the leaf N concentrations of arbors and shrubs, evergreen trees, conifers, seed plants, gymnosperms, and monocotyledons were lower than those of herbages, deciduous trees, broadleaved trees, ferns, angiosperms, and dicotyledons, leaf P concentrations of arbors and shrubs, evergreen trees, and gymnosperms were lower than those of herbages, deciduous trees, and angiosperms, and leaf N/P ratios of arbors, broadleaved trees, angiosperms, and dicotyledons were higher than those of shrubs and herbages, conifers, gymnosperms, and monocotyledons, respectively. No significant differences were observed in the leaf N concentrations between C₃ and C₄ plants, P concentrations between conifers and broadleaved trees, ferns and seed plants, monocotyledons and dicotyledons, and C₃ and C₄ plants, and N/P ratios between evergreen and deciduous trees, ferns and seed plants, and C₃ and C₄ plants. In a word, different functional groups of plants had different preferences for N and P, and their adaptation strategies to different soil N and P supplies were differed. Based on the soil nutrients status of study area, it was suggested that evergreen trees, conifers, gymnosperms, and monocotyledons could be preferentially selected as the urban garden plants in Nanchang City.

Gene polymorphism and its geographical distribution of aquaporin in Stipa. 

HAN Bing¹; WANG Yan-fang²; YANG Jie¹; SU Jing² 

2008, 27(03):  349-354 . 

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By the method of polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP), this paper studied the genetic polymorphism of exon 1 and intron 1 in the aquaporin gene of seven species of Stipa in the meadow steppe (forest steppe), typical steppe, and desert steppe of Inner Mongolia. The results showed that exon 1 had the genotypes of AA, BB and CC, while intron 1 had the genotypes of DD, EE, FF and GG. There existed gene polymorphism in inter-species but not in intra-species. All the test species displayed genetic monomorphism and 100% of purity. From the viewpoint of genotype′s geographical distribution, AA existed in the Stipa species on meadow steppe (forest steppe), typical steppe and desert steppe, BB and CC only existed in the species on desert steppe, DD was found in the species on meadow steppe (forest steppe) and typical steppe, and genotypes EE, FF and GG were detected in the species on desert steppe. The plants on desert steppe exhibited the strongest xeromorphic characteristics, and 3 species of Stipa on the desert steppe had abundant genetic polymorphism.

Effects of N, P and K nutrition on photosynthesis and water use efficiency of winter wheat.

XING Qian²; GU Yan-fang^1,2; GAO Zhi-ying²; DING Sheng-yan^1,2

2008, 27(03):  355-360 . 

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This study was based upon a longterm fertilization experiment at the Fengqiu Agricultural Experiment Station of CAS. Four fertilization treatments including NP (T₁), NK (T₂), PK (T₃) and NPK (T₄), and nonfertilization (CK) were compared to investigate the effects of longterm application of N, P and K on the daily variations of net photosynthesis rate (P_n), transpiration rate (T_r) and water use efficiency (WUE) of wheat(Triticum aestivum) at its heading and filling stages. The results showed that the daily accumulative P_n at the two stages was in the order of T₄>T₁>T₂>T₃>CK, but statistically significant difference only occurred between T₄ and CK. N, P or K deficiency reduced the P_n, with the order of N>P>K. The curves depicting the daily variations of T_r at both stages were all singlehumped and similar in shape, and no significant differences in daily T_r variation were found among all treatments. N, P or K deficiency reduced leaf WUE. At heading stage, T₁ and T₄ had significantly higher daily accumulative WUE than CK, while the daily accumulative WUEin T₁ and T₄ was not significantly differed with CK, indicating that WUE was affected most strongly by N or P deficiency. At filling stage, the daily accumulative WUE in T₄ was significantly higher than that in CK. Different fertilization treatments affected the range, but not the rhythm, of the daily photosynthetic variations of winter wheat. Our results suggested that applying N, P and K in combination could improve the P_n and WUE of wheat more effectively.

Relationships between farming system and effective accumulated temperature in East China.

LI Jun¹; GAO Ping²; CHEN Yan-chun³; CHEN Hui⁴; YANG Tai-ming⁵; HUANG Jing-feng⁶; JIN Zhi-feng⁷; PENG Dai-liang⁶ 　

2008, 27(03):  361-368 . 

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Based on the 1971-2004 agricultural data of East China and the 1961-2004 daily mean temperature data from 26 local meteorological stations, this paper analyzed the relationships between farming system and effective accumulated temperature in East China. The results showed that in 1961-2004, the date of daily mean temperature rising steadily over 10 ℃ came earlier, while that dropping steadily below 10 ℃ was later, resulting in a steadily increased effective accumulated temperature. The multiple cropping indices in Zhejiang, Shanghai and Jiangsu decreased with increasing accumulated temperature, and the correlation coefficients were -0.605, -0.582, -0.615 (n=34), respectively; while the indices in Shandong and Anhui were in adverse, with the correlation coefficients of 0.655 and 0.441 (n=34), respectively. The grain yield per unit area increased with increasing accumulated temperature, and the correlation coefficients for Fujian, Jiangxi, Zhejiang, Shanghai, Anhui, Jiangsu and Shandong were 0.602, 0.370, 0.454, 0.761, 0.518, 0.621 and 0.489 (n=34), respectively. The planting area of grain crops decreased, while that of vegetables, melons, economic forests and oil plants increased with increasing accumulated temperature. The consumptions of fertilizers and pesticides also increased with increasing accumulated temperature.

Spectral reflectance characteristics of spring wheat on Longzhong Loess Plateau.

ZHANG Kai¹; GUO Ni¹; WANG Xiao-ping¹; WANG Run-yuan¹; SI Jian-hua² 

2008, 27(03):  369-373 . 

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In a field experiment, the spectral reflectance, leaf area index (LAI), and aboveground biomass of spring wheat varieties Gaoyuan 602, Longchun 8139 and Dingxi 24 with different planting densities were measured at their different growth stages, and the correlations among the test parameters were analyzed. The results showed that within the range of test wave bands, the maximum value of canopy spectral reflectance was the highest for Gaoyuan 602 and the lowest for Dingxi 24, and the maximum value of leaf spectral reflectance was the highest for Dingxi 24 and the lowest for Gaoyuan 602. The canopy spectral reflectance in visible and mid-infrared wave bands at maturing stage was obviously higher than that at booting stage, while the leaf spectral reflectance in near infrared wave band at booting stage was obviously higher than that at maturing stage. The canopy and leaf spectral reflectance in near infrared wave band increased with increasing planting densities. For the three varieties, there existed “double peak” phenomenon at the red edge of canopy spectra; and from booting to maturing stage, a “blue shift” phenomenon occurred at the red edge. The LAI and aboveground biomass were better correlated to the canopy spectral variables.

Community structure of Sarcomastigophora and its relationship with water quality in Linxia section of Daxia River.

MA Zheng-xue; KANG Rui-qin; NING Ying-zhi 

2008, 27(03):  374-382 . 

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The species diversity and distribution of Sarcomastigophora in Linxia section of Daxia River were studied from February 2005 to March 2007. A total of 135 species belonging to 16 orders of 5 classes were recorded, with the dominant of Euglenida and Amoebida. For different sampling sites in the same water period and for different water periods at the same sampling site, the Jaccard similarity index among Sarcomastigophora communities was all lower, suggesting an obvious spatial heterogeneity. Such a character of the community structure of Sarcomastigophora suggested that the water body of Linxia section of Daxia River had been polluted to some extent, and the pollution was heavier in low water period than in plentiful water period.

Avian diversity on mangrove wetland of Leizhou Peninsula.

ZOU Fa-sheng¹; YANG Qiong-fang¹; CAI Jun-xing²; John HOWES²; Tom DAHMER²; ZHANG Wei²

2008, 27(03):  383-390 . 

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From May 2000 to November 2003, an investigation was made on the aviandiversity at seven sites on the mangrove wetland of Leizhou Peninsula. A total of 133 species was recorded. The individuals of water birds and migratory birds accounted for 81.7% and 70.4% of the total, respectively. Among the species recorded, nine species were listed in the China Red Data Book of Endangered Animals, two species were listed as vulnerable by IUCN, sixteen species were listed bythe Convention on International Trade in Endangered Species (CITES), twelve species were Chinese National Key Protected species, sixtythree species were listed in the China and Japan Agreement on Conservation of Migratory Birds, and thirtytwo species were listed in the China and Australia Agreement on Conservationof Migratory Birds. The species number of the avian at the seven sites had a greater difference, with the greatest (83) at site Gaoqiao and the least (40) at site Wuli, and the Jaccard’s species similarity among the seven sites was very low. The population amounts of Kentish Plover (Charadrius alexandrinus), Eurasian Curlew (Numenius arquata) and Black-headed Gull (Larus ridibundus)in the Peninsula satisfied the criterion for internationally important wetlands. The numbers of species and individuals were greater in winter than in summer, and there was a significant difference in total avian abundance (P=0.043) and water bird abundance (P=0.001) between these two seasons. For the conservation of avian diversity on the mangrove wetland in Leizhou Peninsula, it’s necessary to protect the whole coastline mangrove wetland in the Peninsula.

Avian communities on Qi’ao Island of Zhuhai City in wintertime.

PENG Yi-sheng¹; WANG Xiao-lan¹; CHEN Gui-zhu¹; YANG Xiong-bang² 

2008, 27(03):  391-396 . 

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Seven transects were set up on the mangrove wetland of Qi’ao Island to study the characteristics of avian communities in January, 2005-2007. 63 species of birds were recorded, which belonged to 12 orders and 23 families. Passerine was most abundant in species. Among 63 species, the proportions of resident, winter migratory, and summer migratory birds were 66.7%, 31.7% and 1.6%, and waterfowls and terrestrial birds occupied 28.6% and 71.4%, respectively. The overall α diversity index (H) and evenness (J) of the avian communities were 3.171 and 0.765, with a variation of 0.602-2.853 and 0.336-0.919, respectively. Among the 7 habitats tested, mudflat and mangrove had the lowest H and J. The β diversity showed that there was a greater difference in the avian communities among mudflat, mangrove-pond wetland, and villages. Based on hierarchical clustering analysis, the avian communities on Qi’ao Island in wintertime were grouped into three types, i.e., mudflat waterfowls, mangrove-pond wetland birds, and farmland-forest birds.

Adaptability of common microalgae in shrimp ponds to light intensity, temperature and salinity.

LI Zhou-jia¹; LIANG Wei-feng^1,2; CHEN Su-wen¹; WEN Guo-liang¹; CAO Yu-cheng¹ 

2008, 27(03):  397-400 . 

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By using Smith’s and Pianka’s indices, this paper studied the niche breadths and overlaps of four common microalgae populations in shrimp ponds along radients of light intensity, temperature and salinity. The results showed that he niche breadth of Nitzschia closterium andChlorella pyrenoidosa was higher than that of Cryptomonas erosa and Nannichloropsis oculata.N. oculata and C. pyrenoidosahad the highest niche overlap in all different resources imensions, but C. erosa appeared with the lowest niche overlap, compared to other icroalgae in all the different resources dimensions. Nitzschia closterium and Chlorella pyrenoidosa grew well in wide range of light intensity. When the emperature reached 16.9 ℃ and 25 ℃, N. closterium and C. erosa would be breeding in the ponds, respectively. When the temperature reached 30 ℃, N. closterium, N. oculata and C. pyrenoidosa were suitable for breeding. N. oculata and C. pyrenoidosa were suitable for breeding in the ponds with a salinity anging from 9 to 26, Cryptomonas erosa was suitable with the salinity ranging from 9 to 17.5, while Nitzschia closterium was better with higher salinity. N. oculata and C. pyrenoidosa would not be breeding at the same time in the same ponds, because they have the highest overlap in all resources dimensions.

Plankton community and primary productivity in waters for culturing freshwater pearl mussel (Hyriopsis cumingii)under different stockings and management models.

ZHU Sheng-bo¹; WANG Yan²; WANG Xiao-dong¹; WANG Wei-liang¹; DONG Xiang-quan¹

2008, 27(03):  401-407 . 

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The plankton community and primary productivity in waters under three stocking types and two management models were evaluated in an enclosure experiment. The stocking types included monoculture of freshwater pearl mussel (Hyriopsis cumingii), polyculture of H. cumingii, silver carp Hypophthalmichthys molitrix) and bighead carp(Aristichthys nobilis), and polyculture of H. cumingii and gibel carp (Carassius auratus gibelio), while the management models included fertilizing and fertilizing plus feeding. During the period of the experiment, the phytoplankton was mainly consisted of the species with grain size <20 um, and Cyanophyta, Chlorophyta and uglenophyta were dominant, while the number and mass of Bacillariophyta, Cryptophyta, Xanthophyta and Pyrrophyta were lower. The number and the mass of hytoplankton varied within the ranges of 0.35×10⁹-1.26×10⁹ ind·L^-1 and 32-86 mg·L^-1, respectively. In the enclosure under polyculture of H. cumingii, H. molitrixand A. nobilis, biomass of phytoplankton were relatively higher, and the proportions of Cyanophyta and Chlorophyta in total phytoplankton was higher than those in the other enclosures. Protozoa was highest in number, while rotifer highest in weight of zooplankton. Number of cladocera and opepod was low in the enclosures. In the enclosure under monoculture, ooplankton biomass was the highest, and the proportion of rotifer in total ooplankton’s biomass was lower while that of copepod was higher, compared with those in polycultured enclosures. In the enclosure under polyculture of H. cumingii, H. molitrix and A. nobilis, the proportion of protozoa in number of zooplankton was higher while that of copepod was lower than those in the enclosures under monoculture or polyculture of H. cumingii and C. auratus gibelio. In the experiment, the primary productivity varied within 4.11-5.45 g O₂·m^-2·d^-1, water respiration within 2.39-4.12 g O₂·m^-2·d^-1, and the ratio of primary productivity to water respiration (P/R) within 1.25-1.99. The primary productivity was highest in the monocultured enclosure, but lowest in the enclosure under polyculture of H. cumingiiand C. auratus gibelio. This study indicated that the phytoplankton and zooplankton in the waters for culturing freshwater pearl mussel tended to become smaller-sized, and high number and mass of phytoplankton (especially Bacillariophyta) might be the factors resulting in an enhanced growth of the pearl old mussel in the enclosure under polyculture of H. cumingii, H. molitrixand A. nobilis.

Community structure and its seasonal change of litter invertebrates in Changgangshan Natural Reserve of Guangzhou, China.

WANG Jun, YAO Hai-yuan, MAI Jun-wei, ZHANG Wei-qiu, TONG Xiao-li 

2008, 27(03):  408-413 . 

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To understand the community structure and its seasonal change of litter invertebrates in urban forests of Southern China, the litter invertebrates in Changgangshan Natural Reserve of Guangzhou were sampled monthly from July 2004 to June 2005. A total of 21817 invertebrate individuals belonging to 22 orders in 9 classes under 3 phyla were collected. Acarina and Collembola, the dominant groups of the litter invertebrates, had the individuals accounting for 70.3% of the total, and the individuals of the ordinary groups Helminthomorpha, Araneae, Isopoda, Thysanoptera, Coleoptera, Hymenoptera, Lepidoptera larvae, and Diptera larvae occupied 27.0% of the total. The relative abundance and density of these 8 groups changed with seasons, and orrelated with litter humidity to a certain degree. The highest density of Acarina occurred in heavy rainy seasons, i.e., from May to August, and that of Collembola appeared from February to July. Thysanoptera showed a high density from August to December, but the higher or lower litter humidity caused its low density in rest months. Coleoptera showed three density peaks, i.e., MayAugust, November, and next February. Helminthomorpha had the highest density in May and June, but very low density in the other months. The individuals ratio of Acarina to Collembola (A/C value) varied with sampling season significantly even at the same sampling site, and did not necessarily reflect the distribution characteristics of litter invertebrates in the same climate zone. To remain urban forest litter would be of significance in improving the invertebrate diversity in urban forest soil.

Effects of TN∶TP ratio in eutrophic water on the growth of Vallisneria spiralis.

WEN Ming-zhang; ZHENG You-fei; WU Rong-jun

2008, 27(03):  414-417 . 

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In an outdoor controllable experiment, the effects of different TN∶TP ratios (12.5∶1, 25∶1, and 50∶1) in eutrophic water on the growth of Vallisneria spiralis were investigated. When the TN∶TP ratio was 25∶1,V. spiralis had the best growth, with a biomass increment being 54% and 31% higher than that when the TN∶TP ratio was 12.5∶1 and 50∶1, respectively, while the growth of periphyton, especially of epiphytic algae, was the worst, giving the least dverse effects on V. spiralis, indicating that a 25∶1 of TN∶TP ratio in eutrophic water was optimal for the growth of V. spiralis. However, such an optimal TN∶TP ratio only worked when the nutrients concentration in eutrophic water was below the limited level, otherwise, it could be failed to be applicable.

Characteristics of N, P and K cycling in Phragmites australis wetland ecosystem in Jiuduansha shoal of Shanghai.

LIU Chang-e; YANG Yong-xing

2008, 27(03):  418-424 . 

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The study on the contents and distribution patterns of N, P and K in Phragmites australis wetland ecosystem in Jiuduansha shoal of Shanghai showed that horizontally, the contents of soil total and available N, P and K were the lowest at the middle section of the shoal, and increased gradually from the middle to the upper and lower sections of the shoal, being most notable for the available nutrients. Vertically, the contents of soil total nitrogen (TN) and potassium (TK) decreased in the order of upper layer>lower layer>middle layer, total phosphorus (TP) was in the order of middle layer>upper layer>lower layer, and available nitrogen (AN) was in the order of upper layer>middle layer>lower layer. Soil available phosphorus (AP) content was the highest in upper layer but differed in middle and lower layers in different wetlands, while available potassium (AK) content was the lowest in middle layer and changeful in upper and lower layers in different wetlands. The differences of soil available nutrient contents in different wetlands were greater than those of total nutrient contents. At the soil depth of 0-60 cm, both total and available nutrients were in the order of K>N>P. The nutrients content in plants was the lowest at the middle section of the shoal, which was consistent with that in soil. In most plants of P. australis wetland, the nutrients content was in the order of N>K>P, which was not inconsistent with that in soil. The absorption coefficient of nutrients in different wetlands was N>P>K, and the utilization coefficient was in the order of P>K>N. N had the greatest cycling coefficient, while P had the least one.

Phyllosphere and endophytic microflora in greenhouse cucumber leaves.

WANG Zhen-yue; WANG Min, GAO Shu-feng; ZHANG Meng; YUAN Hong-xia; LI Hong-lian 

2008, 27(03):  425-428 . 

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The phyllosphere and endophytic microflora in greenhouse cucumber leaves at different growth stage were analyzed by diluting isolation with selective media. A total of 248 microbial strains were isolated, and 13 genera of phyllosphere fungi with Alternaria and Penicillium as the dominant, 4 genera of endophytic fungi with Aspergillus as the dominant, 10 genera of phyllosphere bacteria with Bacillus and Xanthomonas as the dominant, 6 genera of endophytic bacteria with Bacillus and Pseudomonas as the dominant, 6 genera of phyllosphere yeasts with Cryptococcu as the dominant, and 2 genera of phyllosphere actinomycetes (Streptomyces andMicropolpspora) were identified. No endophytic yeasts and actinomycetes were isolated.

Effects of chromium(Ⅲ) on the seedling growth of mangrove species Avicennia marina.

FANG Yu, ZHENG Wen-jiao, WAN Yong-ji, CHEN Chang-xu, SHENG Hua-xia

2008, 27(03):  429-433 . 

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By the method of sand culture, this paper studied the effects of different concentration chromium(Ⅲ) (0, 100, 200, 300, 400, 500, 600, 800 mg·L^-1) on the matured hypocotyl germination and seedling growth of Avicennia marina on 25, 45 and 150 days of treatment. The results showed that the germination of matured hypocotyl was not obviously affected by Cr(Ⅲ) during the early germination period. When the stress reached 45 days, the growth of stem height, root, and component and total biomass was decreased with increasing Cr(Ⅲ) concentration, but the decrement was not remarkable. With the stress prolonging to 150 days, low Cr(Ⅲ) concentration (100 mg·L^-1) didn’t have obvious negative effects on the seedling growth, but > 100 mg·L^-1, especially >200 mg·L^-1 of Cr(Ⅲ) inhibited the growth of root, stem length, leaf size, and biomass distinctly, and the effects would be more severe with extending stress time.

Assessment of organic pesticides pollution of commercial bamboo forest soils in Zhejiang Province.

GUO Zi-wu¹; CHEN Shuang-lin¹; ZHANG Gang-hua²; YANG Qing-ping¹; XIAO Jiang-hua¹

2008, 27(03):  434-438 . 

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Twenty-seven plots of commercial bamboo forest in 4 counties of Zhejiang Province were chosen, and soil samples were collected to investigate the residual of organic pesticides. Organochlorine pesticides including HCH, DDT, chlorothalonil, pentachlornitrobenzene and dicofol, organophosphorus pesticides including parathion, parathionmethyl, methamidaphos and dimethoate, and pyrethroid including cypermethrin and esfenvalerate were detected. The detection rate of HCH, DDT, parathionmethyl, cypermethrin and esfenvalerate was 100%, 70.37%, 96.30%, 18.52% and 62.90%, respectively. The concentrations of test organic pesticides were below 150 μg·kg^-1, except esfenvalerate with the concentration of 1 227.14 μg·kg^-1. All the detections suggested that in the commercial bamboo forest soils in Zhejiang, organic pesticides pollution was ubiquitous, and the residual of organochlorine and organophosphorus pesticides was lower than that of pyrethroid. In addition, the management type and level of bamboo forests and the ways of landuse affected the organic pesticides pollution in some extent. The residual of the pesticides was higher in the soils under intensive management bamboo forests, shoot-used bamboo forests, and bamboo forests converted from cropland than in those under extensive management bamboo forests, Phyllostachys pubescens shoot-timber-used forests, and bamboo forests established on mountains, respectively.

Heavy metals distribution in greenbelt soils under different land use patterns in planning site of 2010 Shanghai World Exposition.

FANG Hai-lan¹; HAO Guan-jun¹; PENG Hong-lin², Lü Zi-wen¹ 

2008, 27(03):  439-446 . 

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The planning site of 2010 Shanghai World Exposition was a typical old urban district speckled with factories and residential areas. The study on the heavy metals distribution in greenbelt soils under different land use patterns in the district showed that the soil Ni, Cr, Cu, Zn, Pb and Cd contents in parts of the district exceeded the National secondlevel standard, but the Hg and As contents were not. 69.83% of the green-belt soils were clean, 6.94% were relatively clean, 12.87% were slightly polluted, 2.56% had a medium degree of pollution, and 7.81% were severely polluted. The soil heavy metals content varied significantly with land use patterns. Residential or business area had no soil heavy metals pollution, but the soils near chemical-reagent factories were partly polluted by heavy metals. Soil heavy metals pollution was mainly occurred in the green belts of ship-building, mechanical, and iron-steel factories. Correlations among- soil heavy metals also varied with land use patterns, which was in accordance with the pollution produced from different land use patterns. The distance from pollutant sources and the improper management of wastes were the main factors resulting in the green-belt soil’s heavy metals pollution. To reduce the probability of the pollution, wastes and pollutant sources should be well managed to keep them away from the greenbelts.

Impacts of land-use change in Fuxian and Qilu basins of Yunnan Province on lake water quality.

LIU Yang¹; WU Gang¹; GAO Zheng-wen²

2008, 27(03):  447-453 . 

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Based on remote sensing and correlation analysis, this paper examined the relationships between land-use change and lake water quality in Fuxian and Qilu basins of Yunnan Province in 1989-2005. The results showed that in the two basins, forest/shrub land and construction-use land increased largely, while unused and crop lands had somewhat decrease. Qilu Lake was more heavily polluted than Fuxian Lake, and the water quality of the two lakes became worse. The impact of land-use change on lake water quality was more obvious in a 200 m buffer zone around the lakes. Urbanization and intensive farming were the two major factors causing the continued degradation of lake water quality, and the difference in land use structure between the two basins also resulted in the difference in water quality of the two lakes.

Stomatal conductance and its scaling in vegetation-atmosphere interaction: A review.

WANG Xiao-ying¹; LI Li-guang¹; XIE Yan-bing¹; LI Rong-ping¹; LI Guang-xia²; ZHOU Guang-sheng^1,3 

2008, 27(03):  454-459 . 

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Stomatal conductance is a key indicator in evaluating the balance and cycle of heat, H₂O and CO₂ fluxes between vegetation-atmosphere interface, and its simulation is a basis for discussing the heat and H₂O transfer in soil-vegetation-atmosphere continuum system. The study on the scaling and cumulative effect of stomatal conductance between leaf, canopy and regional scales is helpful to better understand the heat and H₂O transfer processes between vegetation-atmosphere interface, and to properly evaluate the status and functions of vegetation in land surface processes. In this paper, the recent studies on stomatal conductance modeling at leaf level, cumulative effect of stomatal conductace at canopy level, scaling from canopy to regional scale, and functions of cumulative effect of stomatal conductance in land surface processes modeling were summed. The problems exsisting in related studies, such as heterogeneities, were pointed out, and the multi-scale synchronous observations that should be emphasized in the future studies were discussed.

Conservation of oceanic island biodiversity: A review.

WEI Na, WANG Zhong-sheng, LENG Xin, ZHENG Jian-wei, AN Shu-qing

2008, 27(03):  460-468 . 

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Oceanic islands, due to their discrete geographic isolation, offer great opportunities for species conservation, being the natural laboratory for the study of biogeography and evolutionary ecology. The colonized species from continents or nearby islands are subjected to unique evolutionary processes, e.g., geographical isolation, character displacement and adaptive radiation, can accumulate mutations gradually, and ultimately evolve into new indigenous species that are genetically different from the original species on the oceanic islands. One of the most distinctive features of the biota on oceanic islands is the large number of endemics occurring in small areas. Owing to the limited distribution area, habitat frangibility and small population size, the oceanic island populations are suffering from much higher risk of extinction than mainland populations. This review introduced the origin, evolution, and genetic structure of oceanic island species as well as the conservation strategies for the endemic and endangered species, and discussed the formation mechanisms of oceanic island biodiversity, factors causing risks, and conservation urgency of oceanic island biodiversity.

Research advances in phytoremediation and its mechanisms of POPs-contaminated soils.

PENG Sheng-wei¹; ZHOU Qi-xing^1,2

2008, 27(03):  469-475 . 

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There is an increasing organic pollution in the environment, because human being is more and more relying on chemicals. Phytoremediation of organic pollutants-contaminated soils is an on-site remediation technology based on the plant absorption, degradation, and passivation of organic pollutants, and characterized by low-cost, low-risk, and low side-effect to the environment. In this paper, some recent research advances in phytoremediation of organic pollutants-contaminated soils both at home and abroad were summarized, with the focus on the phytoremediation of PCBs, PAHs, pesticides, and nitrylaromatic compounds. The key mechanisms of phytoremediation for soils contaminated by organic pollutants were expounded, and the limitations of this technology as well as the affecting factors that should be considered in an actual project were analyzed. Future directions of this research field were pointed out.

Research progress in aging behaviors of soil organic pollutants.

ZHAO Qing^1,2; LI Pei-jun¹

2008, 27(03):  476-479 . 

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The aging behaviors of soil organic pollutants have become a major concern, and the study of the aging mechanisms could help us to control the target pollutants in soils. This paper summarized the research process at home and abroad about the aging behaviors, their essence, and affecting factors of soil organic pollutants, introduced the evaluation methods of the aging, discussed the existing problems in related researches, and gave some suggestions on the further study.

Biological performance and suitable planting areas of unseasonable strawberry in Fuping mountainous region of Hebei Province.

WEI Rui-jiang, ZHANG Wen-zong, DAI Li-qin

2008, 27(03):  480-483 . 

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Based on field experiment and corresponding meteorological data, and by using GIS and climatic elementscomputing model, this paper studied the biological performance and suitable planting areas of unseasonable strawberry in Fuping mountainous region of Hebei Province. The results showed that in study region, strawberry could over-winter, blossom and seed. Its growth period was lagged behind of that in Hebei Plain, and thus, could mature unseasonably. The quality of unseasonable strawberry was excellent, with higher soluble solid and vitamin C contents than those planted in Hebei Plain. The suitable planting areas of unseasonable strawberry in Fuping mountainous region were at the altitudes of 900-1200 m.

Application of digital photogrammetry in tree stem analysis.

LIU Qi-jing^1,2

2008, 27(03):  484-490 . 

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A new method for tree stem analysis by digital photogrammetry was introduced in this paper. By direct quadrature, the section area of a definite tree ring was measured, and the theoretical diameter was then derived, instead of measuring the so-called average diameter, a traditional method applied for timber volume estimation. Comparing with manual survey, the accuracy of this method was significantly improved, especially when the trunk form is irregular. In our case study, the accuracy for the measurement of ring width was 10% higher than that by single-direction measure. This method could be more accurabe for bark measurement, because the gear-formed section could cause larger errors in biomass or volume estimation with conventional method. Also, digital photogrammetry could be an ideal way to archive information on disks and to use it whenever necessary.

Application of morphological image processing in the study of marsh fragmentation pattern.

KONG Bo^1,2; ZHANG Shu-qing¹; LU Xiao-ning³; PAN Xin¹; HU Mao-gui^1,2 

2008, 27(03):  491-496 . 

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Taking Sanjiang Plain marsh as a study unit, the morphological image processing was applied to classify the spatial patterns of marshes at pixel level on binary marsh maps, and the morphological module and classification statistic module were used to analyze the spatiotemporal patterns of marsh landscape fragmentation in 1980-2000. The results showed that within the 20 years, the overall change tendency of the marsh area in Sanjiang Plain was first decreased rapidly, and then decreased slowly. The area of core marshes was decreased rapidly, from a dispersible spatial pattern to a gradually centralized pattern in the basins of Bielahong and Naoli rivers in northeastern Sanjiang Plain. The perforated marsh area decreased largely and disappeared gradually, and transferred from the original heterogeneous landscape into homogeneous landscape. Most core and perforated marshes were transferred into patch marshes, which were situated in the northwest, central, and south parts of Sanjiang Plain, and had a trend to gradually replace the core marshes in the northeast part of the Plain. The annual growth of edge marshes was the fastest, and the edge pixel became wider and wider. The core marshes in the west, south, and east parts of Sanjiang Plain were substituted by edge marshes, easily resulting in edge effects and intense interspecies competition.