Table of Content

18 May 2013, Volume 24 Issue 5

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Effects of sampling plot number on tree species distribution prediction under climate change.

LIANG Yu, HE Hong-shi, WU Zhi-wei, LI Xiao-na, LUO Xu

2013, 24(5):  1183-1191. 

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Based on the neutral landscapes under different degrees of landscape fragmentation, this paper studied the effects of sampling plot number on the prediction of tree species distribution at landscape scale under climate change. The tree species distribution was predicted by the coupled modeling approach which linked an ecosystem process model with a forest landscape model, and three contingent scenarios and one reference scenario of sampling plot numbers were assumed. The differences between the three scenarios and the reference scenario under different degrees of landscape fragmentation were tested. The results indicated that the effects of sampling plot number on the prediction of tree species distribution depended on the tree species life history attributes. For the generalist species, the prediction of their distribution at landscape scale needed more plots. Except for the extreme specialist, landscape fragmentation degree also affected the effects of sampling plot number on the prediction. With the increase of simulation period, the effects of sampling plot number on the prediction of tree species distribution at landscape scale could be changed. For generalist species, more plots are needed for the long term simulation.

Effects of road construction on regional vegetation types.

LIU Shi-liang, LIU Qi, WANG Cong, YANG Jue-jie, DENG Li

2013, 24(5):  1192-1198. 

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As a regional artificial disturbance component, road exerts great effects on vegetation types, and plays a substantial role in defining vegetation distribution to a certain extent. Aiming at the tropical rainforest degradation and artificial forest expansion in Yunnan Province of Southwest China, this paper analyzed the effects of road network extension on regional vegetation types. In the Province, different classes of roads had different effects on the vegetation types, but no obvious regularity was observed in the effects on the patch areas of different vegetation types due to the great variations of road length and affected distance. However, the vegetation patch number was more affected by lower class roads because of their wide distribution. As for different vegetation types, the vegetations on cultivated land were most affected by roads, followed by Castanopsis hystrix and Schima wallichii forests. Road network formation contributed most to the vegetation fragmentation, and there existed significant correlations between the human disturbance factors including village- and road distributions.

Scale-dependency of spatial variability of surface soil moisture under different land use types in Heihe Oasis, China.

GUO De-liang1, FAN Jun1,2, MI Mei-xia1

2013, 24(5):  1199-1208. 

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To study the surface soil moisture spatial variability and its scale effect is of significance to understand the real variability of soil moisture and to objectively provide a reference for constructing a logical sampling scheme. By using “re-sampling” method, this paper studied the scale-dependency of the spatial variability of soil surface moisture in the woodland and farmland in the oasis ecological system in the middle reaches of Heihe River. The results showed that the variation degree of the surface soil moisture in the test woodland and farmland increased with increasing soil moisture content, and the coefficient of variation (CV) became closer to the true value when the sampling scale increased. Under both dry and moist conditions, and when the sampling amplitude increased within a definite range, the CV, Moran’s I index, nugget, and sill of soil moisture in the woodland and farmland as well as the variation range in the woodland all increased, while the variation range in the farmland under arid condition did not show a stable regular pattern. When the sampling density increased within a definite range, the nugget and variation range increased, but the CV, Moran’s I index, and sill showed less change.

Optimization of urban green space spatial arrangement based on supply-demand analysis: A case study in Nanjing City, China.

GUI Kun-peng1, XU Jian-gang1, ZHANG Xiang2

2013, 24(5):  1215-1223. 

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Urban green space has the functions of ecological and social services, and the two services levels are decided by the supply-demand relationship. However, the supplydemand of green space not only involves in quantity, but also refers to spatial distribution. Therefore, only greening indicators can not wholly reflect the true levels of green space services. Based on the supplydemand analysis and supported by the ArcGIS, this paper examined the ecological and social services levels of the urban green spaces in Nanjing City by using the evenness indicator and the rate the people could enjoy the public green space in their accessible area. Accordingly, the ecological and social services levels of the green space in the City were investigated. The results showed that in the east of Nanjing City, green spaces were rich, but high accessible ones were lack, which resulted in a moderate social service level. In the center of the City, green spaces were lack and distributed unevenly, resulting in the low levels of ecological and social services. In Hexi area, due to the shortage in ecological green space and its uneven distribution, the green spaces had a high level social service but a low level ecological service. In the southern and northern areas of the City, green spaces were in deficiency, uneven distribution, and lack in high accessible.

Landscape regionalization of agro-pastoral transitional zone  using self-organizing feature maps (SOFM) network: A case study of Inner Mongolia Autonomous Region, China.

HAN Yi-nan, PENG Jian, WANG Yang-lin

2013, 24(5):  1224-1230. 

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Taking the agro-pastoral transitional zone of Inner Mongolia Autonomous Region, which has the most extrusive landscape differentiation in Northern China, as the object, a landscape spatial differentiation index was established based on the NDVI, integrated index of land use degree, and aridity index, and the characteristics of the landscape spatial differentiation were quantitatively identified by using SOFM network. The study area could be divided into six landscape zones, i.e., forest zone, foreststeppe transitional zone, agro-steppe mixed zone, typical steppe zone, steppe-desert transitional zone, and desert zone. As compared with the traditional schemes of physical geographical regionalization, our landscape regionalization could quickly regionalize the large scale landscape spatial differentiation in a quantitative way, and the regionalization results were basically in accordance with the original landscape characteristics and the landscape spatial differentiation pattern of the study area.

Land use change and its effects on ecosystem services value in Ji’nan City of Shandong Province, East China.

LIU Jin-yong1, KONG Fan-hua1, YIN Hai-wei2, YAN Wei-jiao1, SUN Chang-feng1, XU Feng1

2013, 24(5):  1231-1236. 

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Based on the GIS software platform, referring to the China ‘Terrestrial ecosystem services per unit area value’, and by using transition matrix, Costanza evaluation formula, and sensitivity analysis, this paper studied the change characteristics of land use and ecosystem services value in Ji’nan City in 1989-2009. During the study period, the builtup area in the City increased by 99.65 km², while agriculture land and green space reduced by 103.21 km², 90.4% of which was taken by the built-up land. The total ecosystem services value decreased from 256.22×10⁶￥ to 214.16×10⁶ ￥, with a decrement of 42.06×10⁶ ￥, mainly due to the decrease in the areas of agriculture land and green space. For the sustainable development of the population, resources, and environment in Ji’nan City, future urban planning should pay more attention on the natural resources protection, reasonable planning of land use structure, and maintenance of ecosystem stability and balance.

Assessment of ecosystem and its services conservation: Indicators and methods.

LU Yi-he, ZHANG Li-wei, WANG Jiang-lei

2013, 24(5):  1237-1243. 

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To conserve ecosystem and its services is a frontier and hot topic in the researches of conservation ecology. This paper reviewed the newest concepts and methods in the assessment of ecosystem and its services conservation, with the focus on the indicators and criteria for assessing the conservation status and the endangerment level of ecosystem as well as the main methods of ecosystem services assessment and conservation (including benefit transfer, systematic modeling, and quantitative indicatorbased estimation). With the consideration of the research progress and the demands of ecological conservation in China, some issues to be urgently solved were put forward: 1) formulating the indicators, criteria, and methods suitable for the assessment of ecosystem conservation in China, 2) developing the methodologies for the quantitative assessment of ecosystem services, 3) determining the demands and optimal spatial arrangement of ecosystem and its services conservation in China, and 4) establishing the policies and incentive mechanisms for ecosystem and its services conservation. The resolution of these issues would supply important guarantee to the development of ecological civilization in China.

Coupling coordination measurement of urbanization and eco-environment system in Huaihe River Basin of China based on fuzzy matter element theory.

GUO Yue-ting1, XU Jian-gang2

2013, 24(5):  1244-1252. 

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Based on the statistical data of urbanization and eco-environment of 35 cities in the Huaihe River Basin of China in 2010, an index system of urbanization-ecoenvironment system was established by using fuzzy matter element theory, and the weight of each indicator was calculated by entropy method. The improved function of the coupling coordination degree of urbanization and eco-environment was constructed to measure this coupling coordination degree in the Huaihe River Basin. In 2010, the development level of urbanization subsystem in the Basin was lower than that of the eco-environment subsystem, and the integrated coordination index of urbanization and ecoenvironment was 0.186, indicating that there was a gap between the two types of indicators. The average coupling degree of urbanization and eco-environment was 0.475, indicating that the urbanization-eco-environment system was at antagonistic stage. There was a greater difference in the development level of urbanization subsystem, but a smaller difference in the development level of eco-environment subsystem among the cities. The average value of the coordination degree of all the cities was 0.706, indicating that the Huaihe River Basin was at high coordination coupling stage, and the integrated coherence and synergistic effect of urbanization and eco-environment construction in the Huaihe River Basin was higher.

Effects of reclaimed water recharge on groundwater quality: A review.

CHEN Wei-ping, LU Si-dan, WANG Mei-e, JIAO Wen-tao

2013, 24(5):  1253-1262. 

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Reclaimed water recharge to groundwater is an effective way to relieve water resource crisis. However, reclaimed water contains some pollutants such as nitrate, heavy metals, and new type contaminants,  and thus, there exists definite environmental risk in the reclaimed water recharge to groundwater. To promote the development of reclaimed water recharge to groundwater and the safe use of reclaimed water in China, this paper analyzed the relevant literatures and practical experiences around the world, and summarized the effects of different reclaimed water recharge modes on the groundwater quality. Surface recharge makes the salt and nitrate contents in groundwater increased but the risk of heavy metals pollution be smaller, whereas well recharge can induce the arsenic release from sedimentary aquifers, which needs to be paid more attention to. New type contaminants are the hotspots in current researches, and their real risks are unknown. Pathogens have less pollution risks on groundwater, but some virus with strong activity can have the risks. Some suggestions were put forward to reduce the risks associated with the reclaimed water recharge to groundwater in China.

Carbon storage of Pinus thunbergii and Robinia pseudoacacia plantations on Nanchangshan Island, Changdao County of Shandong Province, China.

WANG Xiao-li1, WANG Ai1, SHI Hong-hua2, PENG Shi-tao1, GONG Li-peng1, QIN Xue-bo3

2013, 24(5):  1263-1268. 

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Using indigenous tree species to transform large area pure plantations has been an effective closetonature forest management mode in China islands. By using the biomass allometric equation and combined with the investigation data from sampling plots, the carbon storage of the dominant species Pinus thunbergii and Robinia pseudoacacia in the plantations on the Nanchangshan Island of Miaodao Archipelago in Changdao County of Shandong Province was estimated．The average carbon storage in the arbor layer of P. thunbergii and R. pseudoacacia plantations was 56.81  and 37.26 t·hm^-2, respectively, being higher than the  average carbon stock (27.62 t·hm^-2） of tree plantations in Shandong Province. Slope aspect and stand density were the important environmental and biological factors affecting the tree’s carbon stock in the Island, respectively. There was no significant correlation between the average cumulative rate of biomass in the arbor layer of P. thunbergi plantation and the stand age. The P. thunbergii with good carbon sequestration function could be an ideal tree species on Nanchangshan Island.

Seasonal dynamics and vertical distribution pattern of bud bank in different erosion environments on hilly-gully Loess Plateau of Northwest China.

DU Hua-dong1, JIAO Ju-ying1,2, KOU Meng3, WANG Ning1

2013, 24(5):  1269-1276. 

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This paper studied the vegetation composition, bud composition, and the seasonal dynamics and vertical distribution pattern of bud bank in five erosion environments (sunny gully slope, sunny hilly slope, hilltop, shady hilly slope, and shady gully slope) on the hilly-gully Loess Plateau of North Shaanxi. In the study area, the perennial species with perennial bud bank accounted for 80.3% of the total species, while the annual species with seasonal bud bank took up 19.7% of the total. In vegetation turning-green season, there was a relatively large perennial bud bank stock on the sunny hilly-gully slope where serious erosion occurred, while seasonal bud bank showed a higher bud bank density in blossom and fruit-setting season on the hilltop and two shady slopes where soil erosion intensity was relatively gentle. The proportion of underground bud bank to total perennial bud bank in different erosion environments was relatively stable. On the land surface, the perennial bud bank stock was larger on the sunny slope where the soil disturbance often occurred, whereas the seasonal bud bank stock was larger on the shady slope and hilltop. Due to the different species composition of plant communities in different erosion environments, in addition to the disturbance of soil erosion and the seasonal plant regeneration, the seasonal dynamics and vertical distribution pattern of bud bank changed. It was suggested that bud bank played an important role in the vegetation regeneration after the disturbance of soil erosion on the hilly-gully Loess Plateau of North Shaanxi.

Effects of elevated O₃ concentration and UV-B radiation on the chlorophyll content and active oxygen metabolism of soybean leaves.

ZHAO Tian-hong, LIU Yi-ou, WANG Yan, LIU Bo, ZHAO Yi-xin, CAO Ying

2013, 24(5):  1277-1283. 

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Taking the soybean (Glycine max) cultivar Tiefeng 29 as test material, and by using open0top chamber, this paper studied the effects of elevated O₃ concentration and UVB radiation on the leaf chlorophyll content, lipid peroxidation, reactive oxygen species (ROS) production rate, antioxidation enzymes activities, and the grain yield. During the growth period of soybean, as compared with the control, the leaf Chl a, Chl b and Chl(a+b) contents under the stresses of O₃ and UV-B had a decreasing trend, the relative electrical conductivity, malondialdehyde  content, superoxide anion (O₂^-·) production rate, and hydrogen peroxide (H₂O₂) content increased, and the activities of superoxide dismutase, peroxidase  and catalase as well as the grain yield decreased. O₃+UV stress aggravated the leaf membrane lipid peroxidation, promoted the ROS production, and decreased the plant antioxidant capacity and leaf chlorophyll content. The negative effects of O₃ stress on soybean leaves were more close to the impacts of O₃+UV-stress, suggesting that O₃ might play an important role in the combined stress.

 

Effects of soil PAHs pollution on plant ecophysiology.

XU Sheng, WANG Hui, CHEN Wei, HE Xing-yuan, SU Dao-yan, LI Bo, LI Mei

2013, 24(5):  1284-1290. 

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Polycyclic aromatic hydrocarbons (PAHs) are the ubiquitous organic persistent pollutants in natural environments (especially in soil), giving serious potential risks to the ecoenvironment, plants, and human beings. At present, the remediation of PAHs-polluted soil is one of the hot topics in the research fields of soil and environment. Phytoremediation is one of the environmental restoration techniques with most potentiality. This paper reviewed the newest progress in the researches of the effects of soil PAHs pollution and its combined stress with other pollutants on the plant growth, morphological structure, photosynthesis, and antioxidant system, and prospected the important fields and hotspots of related researches in the future.

 

Effects of filamentous macroalgae on the methane emission from urban river: A review.

ZHANG Xiu-yun, LIANG Xia, HE Chi-quan

2013, 24(5):  1291-1299. 

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The global warming caused by greenhouse gases emission has raised serious concerns. Recent studies found that the carbon dioxide (CO₂) and methane (CH₄) emissions from river ecosystem can partly offset the carbon sequestration by terrestrial ecosystem, leading to a rethink of the effects of river ecosystem on the global carbon balance and greenhouse gases emission inventory. As an important primary producer in urban river ecosystem, filamentous macroalgae can deeply affect the carbon cycle process of river system through changing the abiotic and biotic factors in the interface of water-sediment. This paper reviewed the effects of filamentous macroalgae on the CH₄ emission from urban river system from the aspects of 1) the effects of urbanization on the river ecosystem and its CH₄ emission flux, 2) the effects of filamentous macroalgae on the CH₄ generation and emission process in natural river systems, and 3) the effects of filamentous macroalgae on the primary productivity and CH₄ emission process in urban river systems. The current problems and future directions in related researches were discussed and prospected.

Effects of temperature and density on the mortality and reproduction of cotton aphid Aphis gossypii.

GAO Gui-zhen1,2,3, LU Zhao-zhi1, XIA De-ping1, SUN Ping1, MA Ji-hong1, XU Yang-cheng1

2013, 24(5):  1300-1304. 

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A laboratory cotton leaf disc experiment was conducted to study the effects of different temperature (32, 34, 36, 38, and 40 ℃) and density (5, 25, 50, and 75 individuals per dish) on the mortality and reproduction of Aphis gossypii.  With the increase of temperature, density, and culture duration, the cumulative mortality  of A. gossypii presented an increasing trend.  The parameters estimated by complementary loglog (CLL) model showed that the β value decreased with the increase of density, indicating that the effects of temperature weakened with increasing density. The γ_j value, a parameter for the time effect of temperature, changed with  culture duration, indicating that the morality of A. gossypii was co-affected by the temperature and culture duration. The two-way ANOVA analysis of variance showed that temperature and density had significant effects on the fecundity of A. gossypii, and there existed interactive effect. At 32-36 ℃, the reproduction rate of A. gossypii decreased with the increase of density, but at 40 ℃, no significant difference was observed in the reproduction rate under different densities, suggesting that the density effect was weakened with increasing temperature, i.e., the contribution of temperature and density to the survival and reproduction of individual varied with the ranges of the temperature and density. This study could provide reference for the monitoring and forecasting of A. gossypii population and for the improvement of pests control.

Effects of different landscape patch structure on the diversity of arthropod community in tea plantations.

LI Jian-long1,2, TANG Jin-chi2, ZHAO Chao-yi2, TANG Hao2, LI Xiu-di2, LI Hua-shou1

2013, 24(5):  1305-1312. 

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A field survey with random block design was conducted to study the effects of different landscape patch structure on the arthropod community in tea plantations. In the tea plantations with small woodland (QM) or Acacia confuse (XS) patches, predatory spider had the highest proportion, occupying  62.3% and 69.5% of the total arthropods, respectively, being significantly higher than that in the tea plantations close to paddy field (DT) or near a village (RJ). The tea plantations with QM had the highest diversity index and species richness of arthropod community, while the evenness index and dominance index were not significantly different from the other tea plantations. The tea plantations with QM and XS had much richer natural enemies, and the order of the diversity index, evenness index, and richness index of natural enemies in the tea plantations ranked as QM>XS>DT>RJ. It was suggested that landscape patch structure had great effect on the diversity of arthropod community in tea plantations.

Effects of thinning intensity on Pinus tabulaeformis plantation in Huanglong Mountain, Northwest China: A comprehensive evaluation.

GAO Yun-chang1, ZHANG Wen-hui1, HE Jing-feng1, WANG Jin-tang2

2013, 24(5):  1313-1319. 

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A sampling plot investigation was conducted on the seedling regeneration, stand growth, species diversity, and soil characteristics in a Pinus tabulaeformis plantation in Huanglong Mountain on the Loess Plateau of Northwest China after 7 years of closetonatural management thinning 15% (light thinning), 30% (medium thinning), and 45% (heavy thinning), with the effect of different thinning intensities evaluated. With the increase of thinning intensity, the amount and growth indices of 1-7 years old P. tabulaeformis seedlings increased, but the mean annual increments of the growth indices decreased after an initial increase, with the maximum under medium thinning. As compared with the control (unthinned plantation), the individual volume under light, medium, and heavy thinning was increased by 20.9%, 32.1% and 52.6%, the volume per hm² decreased by 4.4%, 15.1%, and 25.3%, and the mean annual growth rate of volume increased by 28.6%, 46.2% and 82.0%, respectively. The species diversity and soil characteristics were improved under thinning, with the order of heavy thinning > medium thinning > light thinning > un-thinning. In this study, 45% thinning was most suitable to the management of P. tabulaeformis plantation in Huanglong Mountain.

Health assessment of individual trees in natural Larix gmelinii forest in Great Xing’an Mountains of China.

ZHU Yu1, LIU Zhao-gang1, JIN Guang-ze2

2013, 24(5):  1320-1328. 

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To integrate the health assessment results of individual trees into the health assessment of subcompartment (or stand) scale could improve the accuracy of subcompartment (or stand) scale health assessment, and realize the coupling process between the individual tree scale and the subcompartment (or stand) scale, providing a theoretical basis for the realization of forest health management. Taking the natural Larix gmelinii forest in Great Xing’an Mountains as the object, a health assessment indicators system of individual trees was established, which included root state, canopy defoliation degree, crown transparency, crown overlap, crown dieback ratio, live crown ratio, crown skewness, and vertical competition index. The principal component analysis (PCA) was employed to eliminate the correlations, the entropy value method was adopted to confirm the weight of each indicator, and the health status of individual L. gmelinii was assessed by fuzzy synthetic evaluation (FSE) method. Based on the health assessment results, a prediction model of the individual tree health was established by discriminant analysis (DA) method. The results showed that the trees in subhealthy gradation were up to 36.7%, and those in healthy gradation only reached 12.9%. The proportion of the trees in unhealthy gradation exceeded that of the trees in healthy gradation, occupying 21.1% of the total. The prediction accuracy of the established model was 86.3%. More rational and effective management measures should be taken to improve the tree health grade.

Distribution pattern of Rhododendron aganniphum var. schizopeplum population at the timberline of Sejila Mountains, Tibet of China.

GUO Qi-qiang1,2, LUO Da-qing1,2, LU Jie1,2, MA He-ping1,2

2013, 24(5):  1329-1334. 

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Rhododendron aganniphum var. schizopeplum grows at the elevation of 4300-4500 m in Sejila Mountains, being a dominant species of shrub layer at the timberline of southeast Tibet. Based on the sampling plot investigation and basal diameter structure analysis, this paper studied the distribution pattern of R. aganniphum var. schizopeplum population at the timberline of Sejila Mountains. With the increase of altitude, the population density of R. aganniphum var. schizopeplum increased, but the population height decreased. At the same altitudes, the population density on the shady slope was larger than that on the sunny slope, while the basal diameter was smaller. On the two slope directions, the distribution of the basal diameter classes of the population appeared as “∩” shape, i.e., middleaged individuals were more, while seedlings and saplings were relatively less. The intraspecific competition of R. aganniphum var. schizopeplum population was in the form of wave, being stronger on shady slope than on sunny slope, and existing self-thinning.

Effects of different forest restoration approaches on the soil quality in red soil region of Southern China.

WANG Yun, OUYANG Zhi-yun, ZHENG Hua, ZENG Jing, CHEN Fa-lin, ZHANG Kai

2013, 24(5):  1335-1340. 

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In 2008-2009, an investigation was conducted on the effects of three typical forest restoration approaches, i.e., naturally restored  secondary forest, artificially restored native species Pinus massoniana plantation (Masson pine plantation), and introduced species Pinus elliottii plantation (slash pine plantation), on the soil quality in red soil region of Southern China. The results showed that the soil moisture content, bulk density, particle composition, and the contents of total carbon (C), total nitrogen (N), total phosphorus (P), organic C, available N, available P, and available potassium (K) in natural secondary forest were all superior to those in artificial plantations. The soil physical, chemical, and microbial properties were integrated into a soil quality index, which was significantly higher (1.20±0.10) in natural secondary forest than in Masson pine plantation (0.59±0.03) and slash pine plantation (0.59±0.06). Our results suggested as compared with the restoration with native species P. massoniana and with introduced P. elliottii, natural restoration could be a better forest restoration approach to improve the soil quality in red soil region of Southern China.

Effects of exogenous Ca²⁺ on the seed germination of Koelreuteria paniculata in limestone area of Southwest China under drought stress.

CAI Xi-yue1,2,3, CHEN Xiao-de1,2,3, LI Chao-zheng1,2,3, LIU Cheng1,2,3

2013, 24(5):  1341-1346. 

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In this paper, different arid environments in the limestone area of Southwest China were simulated by using different concentrations (0%, 5%, 15%, 25%, and 30%) of PEG6000 (polyethylene glycol), and a gradient of exogenous Ca²⁺ (0, 15, 20, 25, and 30 mmol·L^-1 of CaCl₂) was installed to simulate the high calcium soil environments, aimed to study the effects of different concentration PEG6000, CaCl₂, and their interactions on the seed germination characteristics of Koelreuteria bipinnata, one of the preferred species in the ecological restoration in limestone area. Under the action of CaCl₂ alone, medium or low concentration exogenous Ca²⁺ had lesser effect on the seed germination parameters, but high concentration exogenous Ca²⁺ had inhibition effect on the seed germination. Medium or low concentration CaCl₂ could increase the seedling fresh biomass. When the PEG6000 concentration increased from 0% to 25%, the seed germination rate, germination potential, germination index, and vigor index showed a significant decreasing trend, and the seedling fresh biomass decreased remarkably. When certain concentration of exogenous Ca²⁺ was exerted to the drought treatment groups, medium or low concentration CaCl₂ improved the seed germination characteristics, which compensated the loss from drought stress to a certain degree. When the CaCl₂ concentration was up to 30 mmol·L^-1, the seeds were hard to germinate. Additionally, no seeds germinated under the condition of PEG with the concentration of 30%. It was suggested that applying definite concentration of exogenous Ca²⁺ could increase the seedling fresh biomass under PEG6000 stress, and make the seedlings more adapt to arid environment.

Uptake and accumulation characteristics of silicon and other nutritional elements in different age Phyllostachys praecox plants.

HUANG Zhang-ting1, JIANG Pei-kun1,2, SONG Zhao-liang1,2, MENG Ci-fu1, WU Jia-sen1,2

2013, 24(5):  1347-1353. 

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The samples of different age (1-4 years old) Phyllostachys praecox plants and their organs (leaf, branch, and culm) were collected from their main production area in Lin’an County, Zhejiang Province of East China to study the contents and the uptake and accumulation characteristics of silicon and other nutritional elements, as well as the interrelations between Si and other nutrient elements. In the P. praecox plants, the C content in aboveground part was in the order of culm>branch>leaf, whereas the Si, N, P, K, Ca, Mg, Al, Fe and Mn contents were in the order of leaf>branch>culm. Mn was mainly accumulated in leaf, while the other nine nutrient elements were mainly accumulated in the culm of 1-year old plants. The average Si content in the aboveground part of 3-4 year old plants was 13.66 g·kg^-1, suggesting that P. praecox belonged to Si accumulation plant. The leaf N, P, K, and Mg contents decreased, while the C, Al, and Mn contents increased with increasing plant age. The Si uptake by the aboveground part was mainly occurred in the second year (57.1%), while the N and K uptake was mainly in the first two years (67.7%-93.7%). Thereafter, the N and K flowed out from the aboveground part, with the outflow rates reached 19.1%-39.1% of the total accumulated amounts. The Si in P. praecox was significantly correlated with Ca, Al, and Mn, and negatively correlated with N, P, K, and Mg.

Effects of longterm rotation on the nutritional quality of wheat grain protein on dryland of Loess Plateau, Northwest China.

CAI Yan1,3, HAO Ming-de2

2013, 24(5):  1354-1360. 

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A long-term experiment was conducted on the dryland of Loess Plateau to study the effects of three typical rotation systems, including wheat-sainfoin rotation, wheatpea rotation, and wheat-maize rotation, on the nutritional quality of wheat grain protein. Rotation system and the cropping years of rotated plants affected the nutritional quality of wheat grain protein in varying degrees. As compared with continuous wheat cropping, wheat-sainfoin rotation made the nutritional quality of wheat grain protein relatively stable, and the essential amino acid content, amino acid score, amino acid ratio coefficient, chemical score, and amino acid index of the protein all relatively high, being able to be adopted as a cropping system to product high quality protein wheat in Loess Plateau. Under wheat-pea rotation, the nutritional quality of wheat grain protein after 1year pea cropping was relatively high, but the essential amino acid content of wheat grain protein after 2-year- pea cropping was relatively low, and several essential amino acid scores and chemical score of the grain protein were lower than those under continuous wheat cropping. Furthermore, the essential amino acid index was 12.2% lower than that under continuous wheat cropping. Therefore, wheat-pea rotation showed a relatively low nutritional quality of wheat grain protein. Under wheat-maize rotation, the nutritional quality of wheat grain protein was also relatively stable, but the crude protein and essential amino acid contents and amino acid balance level were lower than those under continuous wheat cropping.

Effects of supplemental irrigation based on the measurement of moisture content in different soil layers on the water consumption characteristics and grain yield of winter wheat.

YI Li-pan1, YU Zhen-wen1, ZHANG Yong-li1, WANG Dong1, SHI Yu1, ZHAO Jun-ye2

2013, 24(5):  1361-1366. 

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In 2010-2011, a field experiment with high-yielding winter wheat cultivar Jimai 22 was conducted to study the effects of supplemental irrigation based on the measurement of moisture content in different soil layers on the water consumption characteristics and grain yield of winter wheat. Four soil layers (0-20 cm, W₁; 0-40 cm, W₂; 0-60 cm, W3; and 0-140 cm, W₄) were designed to make the supplemental irrigation at wintering stage (target soil relative moisture content=75%), jointing stage (target soil relative moisture content=70%), and anthesis stage (target soil relative moisture content=70%), taking no irrigation (W₀) during the whole growth season as the control. At the wintering, jointing, and anthesis stages, the required irrigation amount followed the order of W₃ > W₂ > W₁. Treatment W₄ required smaller irrigation amount at wintering and jointing stages, but significantly higher one at anthesis stage than the other treatments. The proportion of the irrigation amount relative to the total water consumption over the entire growth season followed the sequence of W₄, W₃ > W₂ > W₁. By contrast, the proportion of soil water consumption relative to the total water consumption followed the trend of W₁ > W₂ > W₃ > W₄. With the increase of the test soil depths, the soil water utilization ratio decreased. The water consumption in 80-140 cm and 160-200 cm soil layers was significantly higher in W₂ than in W₃ and W₄. The required total irrigation amount was in the order of W₃ > W₄ > W₂ > W₁, the grain yield was in the order of W₂, W₃, W₄ > W₁ > W0, and the water use efficiency followed the order of W₂, W₄ > W₀, W₁ > W₃. To consider the irrigation amount, grain yield, and water use efficiency comprehensively, treatment W₂ under our experimental condition could be the optimal treatment, i.e., the required amount of supplemental irrigation based on the measurement of the moisture content in 0-40 cm soil layer should be feasible for the local winter wheat production.

Effects of watering and nitrogen fertilization on the growth, grain yield, and water- and nitrogen use efficiency of winter wheat.

LI Li1, HONG Jian-ping1, WANG Hong-ting2, XIE Ying-he1, ZHANG Lu1

2013, 24(5):  1367-1373. 

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A field experiment with splitplot design was conducted to study the effects of watering, nitrogen fertilization, and their interactions on the growth, grain yield, and water and nitrogen use efficiency of winter wheat. Four watering levels (0, 900, 1200, and 1500 m³·hm^-2) in main plots and five nitrogen fertilization levels (0, 90, 150, 210, and 270 kg N·hm^-2) in subplots were designed. The results showed that the grain yield, nitrogen absorption, nitrogen use efficiency, and nitrogen productive efficiency of winter wheat increased with increasing level of watering, but the nitrogen use efficiency and nitrogen productive efficiency decreased with increasing nitrogen fertilization level. The grain yield, nitrogen absorption, and nitrogen harvest index were increased with increasing nitrogen fertilization level when the nitrogen application rate was 0-150 kg N·hm^-2, but not further increased significantly when the nitrogen application rate exceeded 150 kg·hm^-2. With the increasing level of watering, the water consumption amount (WCA) and the total water use efficiency increased, while the proportion of precipitation and soil water supply to WCA as well as the irrigation water use efficiency decreased. With the increasing level of nitrogen fertilization, the proportion of precipitation and watering amount to WCA increased, that of soil water supply to WCA decreased, and the total water use efficiency and irrigation water use efficiency decreased after an initial increase, with no significant differences among the treatments of 150, 210, and 270 kg N·hm^-2. It was considered that under our experimental condition, 1500 m³·hm^-2  of watering amount plus 150 kg·hm^-2 of nitrogen fertilization could be the optimal combination for the high yielding and high efficiency.

 

Effects of different maize straw-returning modes on the soil respiration in a winter wheat field.

WANG Bing-wen, CHI Shu-yun, TIAN Shen-zhong, NING Tang-yuan, HAN Hui-fang, ZHAO Hong-xiang, LI Zeng-jia

2013, 24(5):  1374-1380. 

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By using static chamberTGC method, an in situ observation was conducted in a 10-year conservation tillage winter wheat field to study the effects of different maize strawreturning modes on the soil respiration. The soil respiration had a significant positive correlation with the stubble height of maize straw, and two peaks were observed in wheat growth period. Under no tillage and no strawreturning, the soil respiration was 72.5% of that under no tillage with all strawreturning, and the soil respiration under conventional tillage and no straw- returning was 76.5% of that under conventional tillage with all straw-returning. The soil respiration was significantly positively correlated with the soil temperature and soil organic carbon at 20 cm depth, but no significant correlation with the soil organic carbon at 40 cm depth. A correlation was also observed between the soil respiration and soil moisture. The diurnal soil respiration in the treatments of all straw-returning presented a single-peak curve, with the peak at 18:00. There was a similar variation trend of soil temperature and soil respiration at the depth of 20 cm. Among the treatments of different straw-returningamounts, straw-returning with the stubble of 1 m height could reduce the soil respiration significantly, being a reasonable straw-returning mode.

Changes of rice yield and quality in different accumulated temperature zones in Heilongjiang Province of Northeast China.

WANG Qiu-ju1,2, ZHANG Yu-long2, LIU Feng3, WANG Lian-min1, LI Ming-xian1

2013, 24(5):  1381-1386. 

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Field experiments were installed in different accumulated temperature zones in Heilongjiang Province to study the changes of the grain yield and quality of five major rice varieties with accumulated temperature. The rice yield changed with accumulated temperature in quadratic curve, and the correlation degree differed with the varieties. The panicle number and the grain number per panicle changed significantly in quadratic curve with accumulated temperature, while the 1000-grain mass had less correlation with accumulated temperature. The sterile spikelet rate of grain increased obviously from suitable accumulated temperature zone to low accumulated temperature zone, but had no obvious change from suitable accumulated temperature zone to high accumulated temperature zone. The rates of chalky and head milled rice also changed with accumulated temperature in quadratic curve, i.e., there were both the lowest and the highest values in suitable accumulated temperature zone. The protein and amylose contents of the grain as well as the taste varied little with accumulated temperature. According to the sensitivity to temperature, the test rice varieties were divided into sensitive, medium, and blunt types, with the optimal and allowable cultivation accumulated temperature limits being 300 ℃ and 420 ℃, 360 ℃ and 440 ℃, and 380 ℃ and 520 ℃, respectively. It would be very important to select the rice varieties with higher yield and better quality according to the local conditions, especially the accumulated temperature.

Short-term effects of different tillage modes combined with straw-returning on the soil labile organic carbon components in a farmland with rice-wheat double cropping.

YANG Min-fang1, ZHU Li-qun2, HAN Xin-zhong1, GU Ke-jun3, HU Nai-juan2, BIAN Xin-min1,2

2013, 24(5):  1387-1393. 

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A two-year (2009-2011) field experiment was conducted to study the effects of different tillage modes, straw-returning, and their interactions on the soil total organic carbon (TOC) and labile organic carbon (LOC) components (easily oxidizable organic carbon (EOC), water-soluble organic carbon (WSOC), and microbial biomass carbon (MBC)) at the soil depths of 0-7, 7-14, and 14-21 cm in a farmland with rice-wheat double cropping. In all treatments of straw-returning, the TOC and LOC contents in each soil layer were significantly higher than those without straw-returning. Under plowing tillage, the MBC content in 0-7 cm soil layer was significantly higher than that under rotary tillage, but the EOC content was in adverse. Rotary tillage made the TOC content in 7-14 cm soil layer being significantly higher, as compared with plowing tillage. The TOC, WSOC, and MBC contents in 14-21 cm soil layer under plowing tillage were significantly higher than those under rotary tillage. Plowing tillage combined with rice and wheat strawsreturning made the soil TOC content being higher than the other treatments.

Effects of soil compaction stress on the growth and nitrogen metabolism of cucumber roots.

WANG De-yu, SUN Yan, ZHENG Jun-xian, ZHAO Na, WANG Li-ying

2013, 24(5):  1394-1400. 

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Taking cucumber cultivar ‘Jinchun 4’ as test material, a pot experiment was conducted to study the effects of soil compaction stress on cucumber root growth, respiration rate, activity, and nitrogen metabolism at different development stages. Two treatment were installed, i.e., bulk density 1.25 g·cm^-3 (loose soil, CK) and 1.55 g·cm-3 (compacted soil). Under the stress of soil compaction, the total root length, root surface area, root forks, and root tips at different development stages decreased significantly, the root elongation growth and lateral root emergence were constrained remarkably, but the root radial growth was stimulated and the root average diameter was significantly increased. Meanwhile, both the root activity and the respiration rate decreased significantly, the root NO₃^-, free amino acids, and soluble protein contents had a large decrease, the root nitrate reductase, glutamine synthetase, and glutamate synthase  activities decreased significantly, whereas the root NH₄⁺ content had a significant increase. All the results indicated that under the stress of soil compaction, the uptake of nitrate by cucumber roots decreased, the nitrogen assimilation was inhibited, and the nitrogen metabolism was remarkably constrained.

Effects of exogenous spermidine on the nitrogen metabolism and main mineral elements contents of tomato seedlings under saline-alkali stress.

ZHANG Yi1,2,3, SHI Yu1,3, HU Xiao-hui1,2,3, ZOU Zhi-rong1,2,3, CAO Kai1,2,3, ZHANG Hao1,2,3

2013, 24(5):  1401-1408. 

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Taking two tomato cultivars Zhongza No.9 and Jinpengchaoguan as test objects, a hydroponic experiment was conducted to study the effects of exogenous spermidine (Spd) on the tomato seedling nitrogen metabolism and main mineral elements contents under saline-alkali stress. Under the stress, the seedling dry biomass decreased significantly, and the plant growth was inhibited. The activities of nitrate reductase (NR), glutamine synthetase (GS), and glutamate synthase (GOGAT) and the contents of nitrate nitrogen (NO₃^--N) and total N, K, Ca²⁺, and Mg²⁺ in leaves and roots decreased significantly, while the contents of ammonium nitrogen (NH₄⁺-N), and Na⁺ had a significant increase. The activity of glutamate dehydrogenase (GDH) in the leaves of the two cultivars and in the roots of Zhongza No.9 increased significantly, but that in the roots of Jinpengchaoguan had less change. The total P content in the leaves of the two cultivars decreased significantly, while that in the roots of Jinpengchaoguan and Zhongza No.9 had a significant increase and less change, respectively. Applying exogenous Spd increased the assimilation of NH₄⁺ by the plants through increasing the NR, GS and GOGAT activities, alleviated the nitrogen metabolic disturbance caused by the salinealkali stress, and further, promoted the absorption, release, or transportation of P, K, Ca, Mg, and Na in different organs, maintained a proper balance among the nutrients, and improved the plant salinealkali resistance. Zhongza No.9 was more sensitive to the salinealkali stress than Jinpengchaoguan, and the alleviation effect of exogenous Spd on the nitrogen metabolic disturbance and nutritional outofbalance of Zhongza No.9 was more obvious.

Alleviation effects of brassinolide on cucumber seedlings under NaCl stress.

LU Xiao-min1， YANG Wei2

2013, 24(5):  1409-1414. 

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This paper studied the effects of 2，4-epibrassinolide (EBR) on the photosynthesis and antioxidant system of cucumber seedling leaves under NaCl stress. As compared with the control, NaCl stress increased the leaf superoxide anion production rate, hydrogen peroxide content, malondialdehyde content, and cell membrane permeability while decreased the leaf net photosynthetic rate, stomatal conductance, transpiration rate, and intercellular CO₂ concentration significantly, and inhibited the seedlings growth significantly. Applying EBR could increase the activities of leaf superoxide dismutase, peroxidase, and catalase, decrease the leaf superoxide anion production rate, hydrogen peroxide content, malondialdehyde content, and cell membrane permeability, make the leaves keep a higher photosynthetic rate, and thus, promote the seedlings growth, being able to effectively alleviate the damage of NaCl stress.

Variations of arsenic species in the solution of arsenic-contaminated paddy soil under flooding and at different temperatures.

WANG Zhao1, CUI Jiang-hui1, CHEN Zheng2, LU Xiu-jun3,LIU Wen-ju1

2013, 24(5):  1415-1422. 

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Taking arsenic (As)-contaminated paddy soil as test object, and by using high performance liquid chromatography inductively coupled plasma-mass spectrometry (HPLC-ICPMS), this paper studied the variations of As species in soil solution when the soil was sterilized or nonsterilized and incubated at different temperatures (5, 27, and 50 ℃) under flooding. In the soil solution (pore water), only As^Ⅲ(arsenite), As^V (arsenate), and DMA^V (dimethylarsinic acid) were detected, but no  MMA^V (mono methylarsinic acid) was found. With the increasing time of flooding and at the test temperatures, arsenite became the predominant species, averagely accounting for 64%, followed by  As^V, with the proportion of 35%, and DMA^V, with the least proportion of 1%. Soil sterilization or nonsterilization had less effect on the concentrations of As^Ⅲ and DMA^V in the soil solution, but remarkably affected the reduction of As^V and the methylation of As^Ⅲ. The promotion effect of soil sterilization decreased gradually with the increasing time of flooding and incubation. At 50 ℃ and after flooded for 23 days, the DMA^V concentration in sterilized soil solution was the highest and up to 23.7 ng·mL^-1, indicating that some thermophilic microbes remained in sterilized soil became predominant species, and promoted the methylation of As^Ⅲ. In sum, the total arsenic concentration in nonsterilized soil at incubation temperature 27 ℃ and flooded for 23 days was relatively low (501 ng·mL^-1), and thus, in As-contaminated paddy rice planting areas, to adopt the water management mode of short cycle flooding-nonflooding could decrease the As level in soil solution as far as possible, and in the same time, save water resources and ensure yielding.

Effects of mulberry/soybean intercropping on the plant growth and rhizosphere soil microbial number and enzyme activities.

HU Ju-wei1, ZHU Wen-xu2, ZHANG Hui-hui1, XU Nan1, LI Xin1, YUE Bing-bing1, SUN Guang-yu1

2013, 24(5):  1423-1427. 

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A root separation experiment was conducted to investigate the plant growth and rhizosphere soil microbes and enzyme activities in a mulberry/soybean intercropping system. As compared with those in plastic barrier and nylon mesh barrier treatments, the plant height, leaf number, root length, root nodule number, and root/shoot ratio of mulberry and soybean in non-barrier treatment were significantly higher, and the soybean’s effective nodule number was larger. The available phosphorous content in the rhizosphere soils of mulberry and soybean in no barrier and nylon mesh barrier treatments was increased by 10.3% and 11.1%, and 5.1% and 4.6%, respectively, as compared with that in plastic barrier treatment. The microbial number, microbial diversity, and enzyme activities in the rhizosphere soils of mulberry and soybean were higher in the treatments of no barrier and nylon mesh barrier than in the treatment of plastic barrier. All the results indicated that there was an obvious interspecific synergistic effect between mulberry and soybean in the mulberry/soybean intercropping system.

Effects of intercropping Sedum plumbizincicola and Apium graceolens on the soil chemical and microbiological properties under the contamination of zinc and cadmium from sewage sludge application.

2013, 24(5):  1428-1434. 

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Taking the vegetable soil with zinc and cadmium contamination from a longterm sewage sludge application as the object, a pot experiment was conducted to study the remediation effect of Sedum plumbizincicola and Apium graceolens under continuous monoculture and intercropping. With the remediation time increased, both  S. plumbizincicola and  A. graceolens under monoculture grew poorly, but  S. plumbizincicola under intercropping grew well. Under intercropping, the soil organic matter, total N, extractable N, and total P contents decreased significantly while the soil extractable K content had a significant increase, the counts of soil bacteria and fungi increased by 7.9 and 18.4 times and 3.7 and 4.3 times, respectively, but the soil urease and catalase activities remained unchanged, as compared with those under A. graceolens and S. plumbizincicola monoculture. The BIOLOG ECO micro-plates also showed that the carbon sources utilization level and the functional diversity index of soil microbial communities were higher under intercropping than under monoculture, and the concentrations of soil zinc and cadmium under intercropping decreased by 5.8% and 50.0%, respectively, with the decrements being significantly higher than those under monoculture. It was suggested that soil microbial effect could be one of the important factors affecting plant growth.

 

Effects of host plants on the life table parameters of experimental populations of Aphis gossypii.

LI Yan-yan, ZHOU Xiao-rong, PANG Bao-ping, CHANG Jing

2013, 24(5):  1435-1438. 

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A comparative study was conducted on the life table parameters of Aphis gossypii  reared on five host plant species at (25±1) ℃ in laboratory. There existed significant differences in the durations of various developmental stages, adult longevity, mean offspring number per day, net reproductive rate, intrinsic rate of increase, finite rate of increase, mean generation time, and population doubling time for the A. gossypii populations reared on the host plants. For the aphids on Lagenaria siceraria var. turbinate, they needed the longest time (5.84 days) to complete one generation, but for those on the other four plants, no significant differences were observed, with the time needed ranged from 5.24 to 5.45 days. The adult longevity was the longest (20.04 days) on Cucumis sativus, but had no significant differences on the other four host plants, being from 14.76 to 16.03 days. The  populations’ survival curves on all test host plants were of Deevey Ⅰ, i.e., the death mainly occurred during late period. The survival rate on C. sativus was higher than those on the other four host plants. Based on the intrinsic rates of increase of A. gossypii, its host suitability was in the order of Cucumis melo var. saccharinus > Lagenaria siceraria var. turbinate > Cucurbita moschata var. melonaeformis > Cucumis sativus > Cucurbita pepo var. medullosa.

Effects of sediment on the early settlement stage of Sargassum horneri on rocky subtidal reefs.

BI Yuan-xin, ZHANG Shou-yu, WU Zu-li

2013, 24(5):  1439-1445. 

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By using sediment trap and suction pump to measure the relative sediment levels across different sites and water depths, and through the in situ measurements of Sargassum horneri density, this paper assessed the relationships between the distribution of S.horneri and the sediment levels and wave exposure on the rocky subtidal platforms around Gouqi Island, China. The laboratorybased experiments were also conducted to test the effects of different sediment levels on the attachment of S. horneri zygote and the survival rate of S. horneri germling after the attachment. S. horneri predominated at the sites with lesser sediment and wave exposure, but less distributed in the sites with high level sediment and waveexposure. At different water depths, the distribution of S. horneri was negatively correlated with the amount of sediment. A medium dusting (dry mass 10.47 mg·cm^-2, approximate 0.543 mm deep) of sediment on the plate reduced the percentage of S. horneri zygotes attached to the substratum by 4.4%, and a heavy dusting (dry mass 13.96 mg·cm^-2, approximate 0.724 mm deep) of sediment on the plate completely prevented the attachment. One week after the settlement of the zygotes, there were 24% of the germlings still survived when the dry mass sediment coverage was 13.96 mg·cm^-2. However, when the dry mass sediment coverage was up to 34.9 mg·cm^-2 (approximate 1.81 mm deep), 100% of the germlings died. Overall, the distribution of S. horneri was not only related to sediment level, but also restricted by wave exposure to some extent. Sediment level was a critical factor affecting the distribution of S. horneri, particularly at its zygote attachment stage.

 

Feeding ecology of Amblychaeturichthys hexanema in Jiaozhou Bay, China.

HAN Dong-yan, XUE Ying, JI Yu-peng, MA Qiu-yun

2013, 24(5):  1446-1452. 

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From February to November 2011, four seasonal bottom trawl surveys were conducted in the Jiaozhou Bay of China. A total of 624 Amblychaeturichthys hexanema individuals were collected to analyze their stomach contents, with the feeding ecology of  A. hexanema studied. The prey items of  A. hexanema included more than 40 species, among which, Alpheus japonicas, Philine kinglippini, and Leptochela gracilis were the dominant prey species. The diet composition of A. hexanema had an obvious seasonal variation, with the gastropods, fish, decapods, and microcrustacean being the most important prey items in spring, summer, autumn, and winter, respectively. This phenomenon could be mainly related to the seasonal variations in the species and biomass of the preys in Jiaozhou Bay. With the increase of predator size, the prey species of A. hexanema varied from small size copepod to larger sizes P. kinglippini, Raphidopus ciliates, and A. japonicas. The canonical correspondence analysis (CCA) showed that water temperature and salinity were the most important factors affecting the feeding of A. hexanema, followed by predator size and water pH.

Effects of temperature on the embryonic development and larval growth of Sepia lycidas. 

JIANG Xia-min, PENG Rui-bing, LUO Jiang, TANG Feng

2013, 24(5):  1453-1460. 

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A singlefactor experiment was conducted to study the effects of different temperature (15, 18, 21, 24, 27, 30, and 33 ℃) on the embryonic development and larval growth of Sepia lycidas, aimed to search for the optimum temperature for the development and growth of S. lycidas. The results showed that temperature had significant effects on the embryonic development and larval growth of S. lycidas (P<0.05). The suitable temperature for hatching ranged from 21 ℃ to 30 ℃, and the optimum temperature was 24 ℃. At the optimum temperature, the hatching rate was (93.3±2.9) %, incubation period was (24.33±0.58) d, hatching period was (6.00±1.00) d, completely absorked rate of yolk sac was (96.4±3.1) %, and newly hatched larvae mass was (0.258±0.007) g. The effective accumulated temperature model was N=284.42/(T-12.57). The suitable temperature for the larval survival and growth ranged from 21 ℃ to 30 ℃, and the optimum temperature was from 24 ℃ to 27 ℃.At the optimum
 temperature, the survival rate ranged from 70.0% to 73.3%, and the specific growth rate was from 2.4% to 3.8%.

Species composition and geographical distribution of threatened fishes in Yunnan Province of Southwest China.

ZHANG Qian, ZHONG Jin-xin

2013, 24(5):  1461-1467. 

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Based on the related published papers, and by using Geographic Information System (ArcGIS 9.3), this paper analyzed the species composition and geographical distribution of threatened fishes in Yunnan Province of Southwest China. There were 83 threatened species living in the Province, belonging to 5 orders, 13 families, and 47 genera. Cypriniformes was absolutely dominant, with 64 species, followed by Siluriformes, with 16 species. Cyprinidae fishes had 51 species, accounting for 79.7% of Cypriniformes. The most species of Cyprinid fishes were of Barbinae (14 species), Cyprininae (10 species), and Cultrinae (10 species). The threatened fishes could be divided into two zoogeographical regions, i.e., Tibetan Plateau region and Oriental region, and their species composition and geographical distribution were resulted from the historical evolution adapted to the related environments. Whatever in rivers and in lakes, the Cyprinid fishes were both absolutely dominant, occupying 36.1% and 31.3% of the total, respectively. The Cyprinid fishes in rivers were mostly of endangered species, while those in lakes were mostly of vulnerable species. The factors affecting the threatened fishes in the Province were discussed from the two aspects of geodynamic evolution and present situation.

Ecological security of wastewater treatment processes: A review.

YANG Sai, HUA Tao

2013, 24(5):  1468-1478. 

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Though the regular indicators of wastewater after treatment can meet the discharge requirements and reuse standards, it doesn’t mean the effluent is harmless. From the sustainable point of view, to ensure the ecological and human security, comprehensive toxicity should be considered when discharge standards are set up. In order to improve the ecological security of wastewater treatment processes, toxicity reduction should be considered when selecting and optimizing the treatment processes. This paper reviewed the researches on the ecological security of wastewater treatment processes, with the focus on the purposes of various treatment processes, including the processes for special wastewater treatment, wastewater reuse, and for the safety of receiving waters. Conventional biological treatment combined with advanced oxidation technologies can enhance the toxicity reduction on the base of pollutants removal, which is worthy of further study. For the process aimed at wastewater reuse, the integration of different process units can complement the advantages of both conventional pollutants removal and toxicity reduction. For the process aimed at ecological security of receiving waters, the emphasis should be put on the toxicity reduction optimization of process parameters and process unit selection. Some suggestions for the problems in the current research and future research directions were put forward.