Table of Content

18 June 2013, Volume 24 Issue 6

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Vegetation biomass allocation and its spatial distribution after 20 years ecological restoration in a dry-hot valley in Yuanmou, Yunnan Province of Southwest China.

LI Bin1, TANG Guo-yong1,2, LI Kun1,2, GAO Cheng-jie1, LIU Fang-yan1,2, WANG Xiao-fei1

2013, 24(6):  1479-1486. 

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By using layering harvest method, a comparative study was conducted on the biomass allocation and its spatial distribution of 20-year-old-Eucalyptus camaldulensis plantation, Leucaena leucocephala plantation, and E. camaldulensis-L. leucocephala plantation in Yuanmou dry-hot valley of Yunnan Province, Southwest China. The stand biomass in the mixed E. camaldulensis-L. leucocephala plantation (82.99 t·hm^-2) was between that of monoculture E. camaldulensis plantation (60.64 t·hm^-2) and L. leucocephala plantation (127.79 t·hm^-2). The individual tree biomass of E. camaldulensis in the mixed plantation (44.32 kg) was 49.8% higher than that in monoculture plantation (29.58 kg). The branch and leaf biomass of L. leucocephala (25.4%) in monoculture plantation was larger than that of E. camaldulensis (8.9%) in monoculture plantation, and the aboveground biomass distribution ratio (78.0%) of L. leucocephala (25.4%) was also higher than that of E. camaldulensis (73.4%). The roots of L. leucocephala in both monoculture and mixed plantations were mainly distributed in 0-40 cm soil layer, while those of E. camaldulensis in monoculture and mixed plantations were mainly found in 0-80 cm and 0-60 cm, respectively. The proportion of biomass allocated to roots including medium roots, small roots, and fine roots of L. leucocephala in mixed plantation was higher than that in monoculture plantation, but it was contrary for E. camaldulensis. It was suggested that introducing L. leucocephala in E. camaldulensis plantation promoted the growth of E. camaldulensis, especially for its aboveground biomass, and increased the amount of lateral roots in 0-20 cm soil layer, which had significance in soil and water conservation in the study area.

Effects of thinning on  fine-root morphology, biomass and N concentration of different branch orders of Chinese fir.

WANG Zu-hua, LI Rui-xia, GUAN Qing-wei

2013, 24(6):  1487-1493. 

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Taking a 25-year old Chinese fir (Cunninghamia lanceolata) plantation as the object, this paper studied the effects of thinning on the biomass, morphological traits, and nitrogen concentration of the first five orders roots. With the increase of root order (from the first to the fifth order), there was a significant increase in the fine-root biomass, diameter, and tissue density, and a significantly decrease in the specific root length (SRL), root length density (RLD), and root number (RN). Thinning increased the biomass, RLD, and RN of the first and second orders roots as well as the tissue density of the first, third, fourth, and fifth orders roots significantly, but had no effects on the SRL and nitrogen concentration of each order root. In contrast, thinning decreased the diameter of the first, third, and fourth orders roots significantly. The diameter of the second order roots was obviously smaller in surface (0-10 cm) soil than in subsurface (10-20 cm) soil, while the RLD of the first three orders roots and the RN and nitrogen concentration of the first two orders roots were larger in surface soil than in subsurface soil. The interaction of thinning and soil layer only decreased the diameter of the first two orders roots. It was suggested that the fine-root biomass and morphological traits of Chinese fir were closely related to the vegetation growth and regeneration after thinning.

Effects of thinning intensity on the seed bank and seedling growth of Quercus variabilis on the south slope of Qinling Mountains, Northwest China.

RAN Ran, ZHANG Wen-hui, ZHOU Jian-yun, HE Jing-feng

2013, 24(6):  1494-1500. 

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In August-November 2010 and August 2011, and taking the pure Quercus variabilis forests under closetonatural management of different thinning intensity (30%, 20%, and 10%) in Shangluo district of south slope of Qinling Mountains as the object, an investigation was conducted on the seed amount of seed bank, the survival rate and growth status of seedlings, and their relationships with environmental factors 4-5 years after thinning. As compared with the control, the seed amount in the seed bank of 10%, 20%, and 30% thinning plots increased by 2.0%, 21.1%, and 34.8%, respectively in the fourth year after thinning, and the 1-year-old seedlings amount increased by 28.5%, 99.7%, and 122.2%, respectively in the next year. The survival rate of the seedlings in the 10%, 20%, and 30% thinning plots was increased by 25.5%, 235.7%, and 480.0%, respectively in the fifth year after thinning. Thinning improved the light, temperature, soil moisture, and soil nutrient conditions in the forests, which promoted the height and new shoot growth and the leaf area index of each age seedlings. The three growth indices also increased with increasing thinning intensity. In the Q. variabilis forest with a canopy density of ≥0.85, the thinning intensity 30% (canopy density 0.6) was most conducive to the seed germination and seedling growth.

Temperature sensitivity of CO₂ fluxes from rhizosphere soil mineralization and root decomposition in Pinus massoniana and Castanopsis sclerophylla forests.

LIU Yu1, HU Xiao-fei1, CHEN Fu-sheng2, YUAN Ping-cheng2

2013, 24(6):  1501-1508. 

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Rhizospheric and non-rhizospheric soils and the absorption, transition, and storage roots were sampled from the midsubtropical Pinus massoniana and Castanopsis sclerophylla forests to study the CO₂ fluxes from soil mineralization and root decomposition in the forests. The samples were incubated in closed jars at 15 ℃, 25 ℃, 35 ℃, and 45 ℃, respectively, and alkali absorption method was applied to measure the CO₂ fluxes during 53 days incubation. For the two forests, the rhizospheric effect (ratio of rhizospheric to non-rhizospheric soil) on the CO₂ flux from soil mineralization across all incubation temperature ranged from 1.12 to 3.09, with a decreasing trend along incubation days. There was no significant difference in the CO₂ flux from soil mineralization between the two forests at 15 ℃, but the CO₂ flux was significantly higher in P. massoniana forest than in C. sclerophylla forest at 25 ℃ and 35 ℃, and in an opposite pattern at 45 ℃. At all incubation temperature, the CO₂ release from the absorption root decomposition was higher than that from the transition and storage roots decomposition, and was smaller in P. massoniana than in C. sclerophylla forest for all the root functional types. The Q₁₀ values of the CO₂ fluxes from the two forests were higher for soils (1.21-1.83) than for roots (0.96-1.36). No significant differences were observed in the Q₁₀ values of the CO₂ flux from soil mineralization between the two forests, but the Q₁₀ value of the CO₂ flux from root decomposition was significantly higher in P. massoniana than in C. sclerophylla forest. It was suggested that the increment of CO₂ flux from soil mineralization under global warming was far higher than that from root decomposition, and for P. massoniana than for C. sclerophylla forest. In subtropics of China, the adaptability of zonal climax community to global warming would be stronger than that of pioneer community.

Canopy interception of Pinus tabulaeformis plantation on Longzhong Loess Plateau, Northwest China: Characteristics and simulation.

FANG Shu-min1,2, ZHAO Chuan-yan2, JIAN Sheng-qi2, YU Kai3

2013, 24(6):  1509-1516. 

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Taking the Pinus tabulaeformis plantation in the Anjiagou catchment on Longzhong Loess Plateau as test object, an observation was made on the characteristics of throughfall, stemflow, interception, and canopy structure of P. tabulaeformi during its growth season (from May to September) in 2011. Based on the observed data, the revised Gash analytical model was adopted to simulate the canopy interception, aimed to understand the ecological hydrological processes of Pinus tabulaeformis plantation and related mechanisms. In the observation period, a total of 19 precipitation events were observed, with a total precipitation of 215.80 mm. The throughfall, stemflow, and canopy interception were 165.24 mm, 2.29 mm, and 48.27 mm, occupying 76.7%, 1.1%, and 22.4 % of the total precipitation, respectively. The simulated canopy interception was 41.24 mm, being 7.13 mm lower than the observed value and with a relative error of 14.7%. There were 33.8% and 60.0% of interception were evaporated from the canopy during and after precipitation, respectively. The revised Gash analytical model was highly sensitive to the canopy storage capacity, forest coverage, rainfall intensity, and evaporation, but less sensitive to the stemflow rate and stem water holding capacity.

CO₂  response process and its simulation of Prunus sibirica photosynthesis under different soil moisture conditions.

WU Qin, ZHANG Guang-can, PEI Bin, XU Zhi-qiang, ZHAO Yu, FANG Li-dong

2013, 24(6):  1517-1524. 

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Taking the two-year old potted Prunus sibirica seedlings as test materials, and using CIRAS-2 photosynthetic system, this paper studied the CO₂ response process of P. sibirica photosynthesis in semi-arid loess hilly region under eight soil moisture conditions. The CO₂ response data of P. sibirica were fitted and analyzed by rectangular hyperbola model, exponential equation, and modified rectangular hyperbola model. Meanwhile, the quantitative relationships between the photosynthesis and the soil moisture were discussed. The results showed that the CO₂ response process of P. sibirica photosynthesis had obvious response characteristics to the soil moisture threshold. The relative soil water content (RWC) required to maintain the higher photosynthetic rate (P_n) and carboxylation efficiency (CE) of P. sibirica was in the range of 46.3%-81.9%. In this RWC range, the photosynthesis did not appear obvious CO₂ saturated inhibition phenomenon. When the RWC exceeded this range, the photosynthetic capacity (P_{n max}), CE, and CO₂ saturation point (CSP) decreased evidently. Under different soil moisture conditions, there existed obvious differences among the three models in simulating the CO₂ response data of P. sibirica. When the RWC was in the range of 46.3%-81.9%, the CO₂ response process and the characteristic parameters such as CE, CO₂ compensation point (Γ), and photorespiration rate (R_p) could be well fitted by the three models, and the accuracy was in the order of modified rectangular hyperbola model > exponential equation > rectangular hyperbola model. When the RWC was too high or too low, namely, the RWC was ＞81.9% or ＜46.3%, only the modified rectangular hyperbola model could well fit the CO₂ response process and the characteristic parameters. It was suggested that when the RWC was from 46.3% to 81.9%, the photosynthetic efficiency of P. sibirica was higher, and, as compared with rectangular hyperbola model and exponential equation, modified rectangular hyperbola model  had more applicability to fit the CO₂ response data of P. sibirica photosynthesis under different soil moisture conditions.

Effects of nutrients on the seedlings root hair development and root growth of Poncirus trifoliata under hydroponics condition.

CAO Xiu, XIA Ren-xue, ZHANG De-jian, SHU Bo

2013, 24(6):  1525-1530. 

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Ahydroponics experiment was conducted to study the effects of nutrients (N, P, K, Ca, Mg, Fe， and Mn) deficiency on the length of primary root, the number of lateral roots, and the root hair density, length, and diameter on the primary root and lateral roots of Poncirus trifoliata seedlings. Under the deficiency of each test nutrient, root hair could generate, but was mainly concentrated on the root base and fewer on the root tip. The root hair density on lateral roots was significantly larger than that on primary root, but the root hair length was in adverse. The deficiency of each test nutrient had greater effects on the growth and development of root hairs, with the root hair density on primary root varied from 55.0 to 174.3 mm^-2. As compared with the control, Ca deficiency induced the significant increase of root hair density and length on primary root, P deficiency promoted the root hair density and length on the base and middle part of primary root and on the lateral roots significantly, Fe deficiency increased the root hair density but decreased the root hair length on the tip of primary root significantly, K deficiency significantly decreased  the root hair density, length, and diameter on primary root and lateral roots,  whereas Mg deficiency increased the root hair length of primary root significantly. In all treatments of nutrient deficiency, the primary root had the similar growth rate, but, with the exceptions of N and Mg deficiency, the lateral roots exhibited shedding and regeneration.

Effects of relative abundance of Quercus mongolica acorns on five tree species seed dispersal in Xiaoxing’an Mountains, Northeast China.

YU Fei1,3, SHI Xiao-xiao2, YI Xian-feng3,4, WANG De-xiang1

2013, 24(6):  1531-1535. 

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An investigation was conducted in a forest farm in the Xiaoxing’an Mountains in autumn, 2009 and 2010 to study the effects of Quercus mongolica acorn quantity and rodent density on the seed dispersal of five tree species (Juglans mandshurica, Pinus koraiensis, Corylus mandshurica, Corylus heterophylla, and Q. mongolica). In the farm, there was an annual change in rodent density. The total capture rate of small rodents in 2009 (31.0%) was significantly higher than that in 2010 (16.7%). The acorn quantity and relative seed abundance (per capita rodent) of Quercus mongolica in 2009 (6.2±2.1 acorns·m^-2 and 20.0, respectively) were significantly lower than those in 2010 (26.7±10.2 acorns·m^-2 and 160.0, respectively). In 2009, all the seeds of the five tree species except J. mandshurica were dispersed or eaten in situ, among which, the acorns of Q. mongolica were scatter-hoarded most, and their average dispersal distance was the furthest. In 2010, the seeds of J. mandshurica were scatter-hoarded most, and their average dispersal distance was the furthest. The relative seed abundance of Q. mongolica could be the key factor determining the seed dispersal of the other tree species in the study area.

Interannual variation patterns of  heavy metals concentrations in tree rings of Larix gmelinii near Xilin Lead-zinc Mine, Yichun of Northeast China.

HU Shen, WANG Xiao-chun, YANG Jin-yan

2013, 24(6):  1536-1544. 

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By using dendro-environmental methods, this paper measured and analyzed the variations of five heavy metals (Pb, Cd, Zn, Cu, and Mn) concentrations in the tree rings of Larix gmelinii near Xilin Leadzinc Mine, Yichun of Northeast China. Among the test heavy metals, the Mn concentration in the tree rings was the highest, while the Cd concentration was the lowest. The Cd, Zn, and Cu concentrations in the tree rings near the ground (0.3 m high from the ground, D_0.3) were significantly higher than those at breast height (1.3 m high from the ground, D_1.3), while the Pb and Mn concentrations at the two heights had less difference. In 1987-2010, the Pb concentration in the tree rings had a slight increase, but the Cd, Zn, Cu, and Mn concentrations presented a decreasing trend. The Cd concentration decreased most obviously, while the Zn, Cu, and Mn concentrations decreased after an initial increase. With the increase of tree ring width, the Pb concentration decreased, while the Cd, Zn, Cu, and Mn concentrations were in adverse. The relationships between the Pb and other four heavy metals concentrations in the tree rings near the ground and at breast height had definite differences. Near the ground, the Pb concentration showed a significant positive correlation with the other four heavy metals concentrations, but at breast height, less correlation was observed, and even, the Cd concentration decreased significantly with increasing Pb concentration. The variations of the heavy metals concentrations in the L. gmelinii tree rings could be affected by the production and mining activities of Xilin Lead-zinc Mine, and thus, it would be possible to use the Pb concentration in the tree rings to reconstruct the mining history of the study area. At present, the Pb concentration in the tailing wastes has polluted the surrounding environments near Xilin Lead-zinc Mine. Therefore, countermeasures should be adopted to manage the heavy metals in tailing wastes if the Mine would be continued to be mined.

Effects of temperature on CH₄ emission from subtropical common tree species leaves.

YANG Yan-hua1, YI Li-ming1, XIE Jin-sheng1, YANG Zhi-jie1,2, JIANG Jun1, XU Chao1, YANG Yu-sheng1,2

2013, 24(6):  1545-1550. 

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Laboratory incubation test was conducted to study the effects of temperature on the CH₄ emission from the leaves of subtropical common tree species Castanopsis carlesii, Schima superb, Cinnamomum chekiangense, Castsanopsis fabri, Cunninghamia lanceolata, and Citrus reticulata. Among the six tree species, only S. superb, C. reticulate, and C. fabri emitted CH₄ at 10 ℃. At above 20 ℃, all the six species emitted CH₄, and the average CH₄emission rate at above 30 ℃ (1.010 ng CH₄·g^-1DM·h^-1) was 2.96 times higher than that at 10-30 ℃ (0.255 ng CH₄·g^-1 DM·h^-1). Moreover, increasing temperature had much more effects on the CH₄ emission rate of C. reticulata and C. lanceolata than on that of the other four tree species. Incubation time affected the CH₄ emission rate of all test tree species significantly, suggesting that the effects of temperature stress on the CH₄ emission could be controlled by plant activity. Dry leaves could not emit CH₄ no matter the temperature was very high or low. It was suggested that high temperature stress had important effects on the CH₄ emission from subtropical tree leaves, and global warming could increase the CH₄ emission from plants.

Quality level assessment of lowly efficient Tamarix chinensis secondary shrubs in Laizhou Bay of Yellow River Delta.

XIA Jiang-bao1, LIU Yu-ting1, ZHU Jin-fang1,2, XU Jing-wei3, LU Zhao-hua1,2, LIU Jing-tao1, LIU Qing1

2013, 24(6):  1551-1558. 

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Taking the Tamarix chinensis secondary  shrubs in Laizhou Bay of Yellow River Delta as test objects, and by using synthetic factor method, this paper studied the main factors causing the lowly efficiency of T. chinensis secondary shrubs as well as the main parameters for the classification of lowly efficient T. chinensis secondary shrubs. A total of 24 indices including shrubs growth and soil physical and chemical properties were selected to determine the main affecting factors and parameters in evaluating and classifying the lowly efficient shrubs. There were no obvious correlations between the indices reflecting the shrubs growth and soil quality, and thus, only using shrub growth index to reflect the lowly efficiency level of T. chinensis was not enough, and it would be necessary to combine with soil quality factors to make a comprehensive evaluation. The principal factors reflecting the quality level of lowly efficient T. chinensis shrubs included soil salt content and moisture content, stand age, single tree’s aboveground stem, leaf biomass, and basal diameter, followed by soil density, porosity, and soil nutrient status. The lowly efficient T. chinensis shrubs in the Bay could be classified into five types, namely, shrub with growth potential, slightly low quality shrub, moderately lowly efficient shrub, moderately low quality and lowly efficient shrub, and seriously low quality and lowly efficient shrub. The main features, low efficiency causes, and management measures of these shrubs were discussed based on the mean cluster value.

 

Butterfly diversity and faunal characteristics on the south slope of Taibai Mountain, Shaanxi Province of Northwest China.

GAO Ke1, FANG Li-jun1，2, SHANG Su-qin1，3, ZHANG Ya-lin1

2013, 24(6):  1559-1564. 

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An investigation was conducted on the butterflies on the south slope of Taibai Mountain from April to October, 2009, with their diversity index, evenness index, dominance index, and species richness calculated and analyzed. A total of 126 species were recorded, belonging to 77 genera and 5 families. Nymphalidae had the highest diversity index (3.3621) and species richness (9.9363), and Pieridae had the highest dominance index (0.0573) and evenness index (0.8352). The genera and species were most abundant in June-August, the diversity index was the highest in July (3.4094), and the species richness was the highest in August (10.7). The biogeographic component analysis of 124 species (other 2 species were not identified) showed that the widely distributed species were most abundant (51 species), occupying 40.5% of the total, followed by Palaearctic species (41 species), occupying 32.5%, and Oriental species were the least (32 species), occupying 25.4%, which suggested that Taibai Mountain could be the transitional area of Palearctic and Oriental regions. The comparative analysis of the butterfly diversity and  faunal characteristics on the south and north slopes of Taibai Mountain showed that there were 85 shared species, and the similarity coefficient was 62.0%, indicating that the butterfly fauna had definite difference between the two slopes though they were geographically in proximity.

Prediction models for ground surface fuels moisture content of Larix gmelinii stand in Daxing’anling of China based on one-hour time step.

YU Hong-zhou, JIN Sen， DI Xue-ying

2013, 24(6):  1565-1571. 

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By using the equilibrium moisture content-time lag methods of Nelson and Simard and the meteorological element regression method, this paper studied the dynamics of the moisture content of ground surface fine dead fuels under a Larix gmelinii stand on the sunny slope in Daxing’anling with a time interval of one hour, established the corresponding prediction models, and analyzed the prediction errors under different understory densities. The results showed that the prediction methods of the fuels moisture content based on one-hour time step were applicable for the typical Larix gmelinii stand in Daxing’anling. The mean absolute error and the mean relative error of Simard method was 1.1% and 8.5%, respectively, being lower than those of Nelson method and meteorological element regression method, and close to those of similar studies. On the same slopes and slope positions, the fuel moisture content varied with different understory densities, and thus, it would be necessary to select the appropriate equilibrium moisture content model for specific regional stand and position, or establish the fuel moisture content model based on specific stand when the dynamics of fuel moisture content would be investigated with a time interval of one hour.

Effects of rice straw returning mode on rice grain yield and soil carbon pool management index in double rice-cropping system.

WU Jian-fu1, ZENG Yan-hua1,2,3, PAN Xiao-hua1, SHI Qing-hua1, LI Tao1, WANG Su-ying1

2013, 24(6):  1572-1578. 

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A 2-year field experiment was conducted to study the effects of different rice straw returning modes on the rice grain yield and soil carbon pool management index (CPMI) in a double rice cropping system. Four treatments were installed, including balanced mineral fertilization (NPK), NPK plus cut rice straw returning (SNPK), NPK plus incinerated rice straw returning (SINPK), and no fertilization (CK). In treatments SNPK and SINPK, the 2 years average grain yield of early rice and late rice was basically the same, and much higher than that in treatment NPK, with an increment of 5.7%-7.3%. As compared with treatments NPK and SINPK, treatment SNPK increased the grain yield of early rice significantly by 3.8%-8.8%, and enhanced the contents of various soil carbon forms and the soil CPMI, with the soil total organic carbon, active carbon, mineralized carbon contents, and the soil CPMI increased by 1.8%-2.0%, 5.9%-6.5%, 16.0%-41.6%, and 7.3%-7.8%, respectively. There was a significant parabolic correlation between soil CPMI and rice grain yield (r=0.999 and r= 0.980 in early and laterice season, respectively). Treatment SNPK also increased the grain yield, the contents of various soil carbon forms, and the soil CPMI in the next early rice season.

Optimum field observation data for simulating maize leaf area index.

MA Xue-yan, ZHOU Guang-sheng

2013, 24(6):  1579-1585. 

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Leaf area index is a key indicator of leaf area change of crop population, and also, an important parameter for studying crop photosynthesis, transpiration, and biomass formation, etc. How to establish an optimum leaf area index (LAI) dynamic model with the minimum field observation data is of great significance for accurately simulating crop growth and yield. Based on the field experiment data of various spring maize varieties from the Jinzhou Agricultural Ecosystem Research Station in Northeast China in 2005-2011, in combination with the universal maize LAI dynamic model, this paper discussed the optimum field observation data for accurately simulating the dynamics of maize LAI. It was suggested that for the accurate simulation of the dynamics of maize LAI, the field observation  should be no less than 3 years, with at least 4 times observation during the growth period each year. The proper four observation times during maize growth period were suggested as about 20 d after seedling emergence for the first observation, and monthly thereafter for the other three observations. This study could provide reference for conducting an effective observation on leaf area index and its dynamic modeling.

Effects of drought stress on the root growth and development and physiological characteristics of peanut.

DING Hong1, ZHANG Zhi-meng1, DAI Liang-xiang1, KANG Tao1,2, CI Dun-wei1, SONG Wen-wu1

2013, 24(6):  1586-1592. 

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Taking two peanut varieties Huayu 17 and Tangke 8 as test objects, a soil column culture experiment was conducted in a rainproof tank to study the peanut root morphological development and physiological characteristics at late growth stages under moderate drought and well-watered conditions. Tanke 8 had more developed root system and higher yield and drought coefficient, while Huayu 17 had poorer root adaptability to drought stress. For the two varieties, their root length density and root biomass were mainly distributed in 0-40 cm soil layer, whereas their root traits differed in the same soil layer. The total root length, total root surface area, and total root volume of Huayu 17 at each growth stage were smaller under drought stress than under well-balanced water treatment, while these root characteristics of Tangke 8 under drought stress only decreased at flowering-pegging stage. Drought stress increased the root biomass, surface area, and volume of the two varieties in 20-40 cm soil layer, but decreased these root traits in the soil layers below 40 cm. Under drought stress, the root activity of the two varieties in the soil layers below 40 cm at pod filling stage decreased, and the decrement was larger for Huayu 17. The differences in the root system development and physiological characteristics of the two varieties at late growth stages under drought stress suggested that the root system of the two varieties had different water absorption and utilization under drought stress.

 

Effects of different accumulated temperature on photosynthetic performances of spring maize varieties during grain-filling period.

CHEN Chuan-xiao1,2, DONG Zhi-qiang1, GAO Jiao1, XU Tian-jun1, JIAO Liu1, LU Lin1, ZHANG Feng-lu2

2013, 24(6):  1593-1600. 

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Taking cold-resistant maize variety Fengdan 3 and cold-sensitive maize variety Zhengdan 958 as test materials, field experiments were conducted in Ⅰ, Ⅱ, and Ⅲ accumulated temperature zones in Heilongjiang Province of Northeast China to study the effects of different accumulated temperature on the photosynthetic performances of different types of cold-resistant spring maize varieties during their grain-filling period. In the three accumulated temperature zones, the tasseling and maturing periods of Fengdan 3 and Zhengdan 958 were prolonged in the order of Ⅰ > Ⅱ > and Ⅲ, and the grain bulk density decreased in the same order. The RuBPCase and PEPCase activities of Fengda
n 3 and Zhengdan 958 leaves had different temperature sensitivity. For Fengdan 3, its leaf RuBPCase and PEPCase activities were high in early grain filling period (0-20 days after anthesis), and the variety could ripen in temperature-limited region. For Zhengdan 958, its leaf RuBPCase and PEPCase activities were high within 0-10 days and 40-60 days after anthesis but not sensitive to the active accumulated temperature during 10-40 days after anthesis, and the variety could not ripen in temperature-limited region. The photosynthetic rates of the two varieties were significantly positively correlated with the active accumulated temperature during 0-10 days and 30-40 days after anthesis. The effects of the accumulated temperature in the three zones on the photosynthetic performances were significant at both early and later grain filling stages. For the same varieties, the higher the active accumulated temperature in grain filling period, the higher the grain yield. Zhengdan 958 had higher yield than Fengdan 3.

Change characteristics of soil moisture and nutrients in rain-fed winter wheat field under different fertilization modes in Southern Shanxi of China during summer fallow period.

LI Ting-liang1, XIE Ying-he1, HONG Jian-ping1, FENG Qian1, SUN Cheng-hong2, WANG Zhi-wei3

2013, 24(6):  1601-1608. 

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In 2009-2011, a field experiment was conducted in a rain-fed winter wheat field in Southern Shanxi of China to study the effects of different fertilization modes on the change characteristics of soil moisture and nitrate-N contents in 0-200 cm layer and of soil available phosphorus (Oslen-P) and potassium contents in 0-40 cm layer during summer fallow period (from June to September). Three fertilization modes were installed, i.e., conventional fertilization (CF), recommended fertilization (RF), and ridge film furrow planting (RFFP) combined with straw mulch. The results showed that the rainfall in summer fallow period could complement the consumed water in 0-200 cm soil layer in dryland wheat field throughout the growth season, and more than 94% of the water storage was in 0-140 cm soil layer, with the fallow efficiency ranged from 6% to 27%. The rainfall in summer fallow period caused the soil nitrate N moving downward. 357-400 mm rainfall could make the soil nitrate N  leaching down to 100 cm soil layer, with the peak in 20-40 cm soil layer. Straw mulching or plastic film with straw mulch in summer fallow period could effectively increase the Oslen P and available K contents in 0-40 cm soil layer, and the accumulative increment in three summer fallow periods was 16-45% and 36-49%, respectively. Among the three modes, the binary coverage mode of RFFP plus furrow straw mulching had the best effect in maintaining soil water and fertility. The accumulative water storage and mineral N in 0-200 cm soil layer in three summer fallow periods were up to 215 mm and 90 kg·hm^-2, and the accumulative OslenP and available K contents in plough layer were increased by 2.7 mg·kg^-1and 83 mg·kg^-1, respectively, being significantly higher than those in treatments CF and RF. There were no significant differences in the change characteristics in the soil moisture and nutrients between treatments CF and RF.

Relationships of wheat leaf stomatal traits with wheat yield and drought-esistance.

WANG Shu-guang1, LI Zhong-qing2, JIA Shou-shan1, SUN Dai-zhen1, SHI Yu-gang1, FAN Hua1, LIANG Zeng-hao1, JING Rui-lian3

2013, 24(6):  1609-1614. 

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Taking the DH population of wheat cultivar Hanxuan10/Lumai14 as test object, and by the methods of correlation analysis and path analysis, this paper studied the relationships of the flag leaf stomatal density (SD), stomatal length and width (SL and SW), stomatal conductance (g_s), photosynthetic rate (P_n), and transpiration rate (T_r) on the 10th and 20th day after anthesis with the yield and the index of droughtresistance under the conditions of drought stress and normal irrigation. Under the two conditions, most of the test leaf traits on the 10th day after anthesis had less correlation with the yield and the index of droughtresistance, whereas the leaf traits on the 20th day after anthesis had significant positive correlations with thousand kernel weight  but less correlation with grain number per ear, grain yield per plant, and index of droughtresistance. Path analysis showed that g_s,P_n, and T_r were the main factors affecting the grain yield per plant (YPP) and the index of drought resistance (IDR), and the effects were stronger both in direct and in indirect ways. The direct and indirect effects of SD, SL, and SW on the YPP and IDR were lesser. Under both drought stress and normal irrigation, and on the 10th and 20th day after anthesis, there were significant correlations between SD and SL, and between SL and SW, g_s, P_n, and T_r, but the correlations of SD and SL with g_s, P_n, and T_r changed with water condition or growth stage. Therefore, it would be not always a good means to select the leaf stomatal density and size as the targets for breeding to improve the leaf stomatal conductance, photosynthetic rate, and transpiration rate, and further, to promote the yield.

Effects of applying tea seed meal and EDTA on the speciation transformation and phytoavailability of nickel and zinc in soil.

YU Bin， XIA Hui-long

2013, 24(6):  1615-1620. 

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A pot experiment with sugarcane was conducted to study the effects of applying tea seed meal and EDTA on the speciation transformation and phytoavailability of nickel (Ni) and zinc (Zn) in soil. With the increasing application rate of tea seed meal, the biomass of sugarcane root, stem， and leaf increased gradually, but no significant difference was observed in the stem and leaf biomass between EDTA treatments and the control. Applying tea seed meal and EDTA increased the acid-soluble Ni and Zn contents in soil, and promoted the bioconcentration and translocation of Ni and Zn in sugarcane. Meanwhile, the strengthening effect increased gradually with the increasing application rate of tea seed meal. As compared with EDTA, tea seed meal was more efficient in improving the accumulation of Ni and Zn in sugarcane, and thus, made the sugarcane remove more Ni and Zn from soil. The Ni and Zn contents in sugarcane stem and leaf had significant positive correlations with the application rate of tea seed meal, while the Ni and Zn contents in sugarcane root were significantly negatively correlated with the application rate of tea seed meal.

Effects of simulated acid rain on seed germination and seedling growth of different type corn (Zea mays).

ZHANG Hai-yan

2013, 24(6):  1621-1626. 

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Taking normal corn, waxy corn, pop corn, and sweet corn as test materials, this paper studied their seed germination and seedling growth under effects of simulated acid rain (pH 6.0, 5.0, 4.0, 3.0, 2.0, and 1.0). Simulated acid rain at pH 2.0-5.0 had no significant effects on the seed germination and seedling growth, but at pH 1.0, the germination rate of normal corn, waxy corn, pop corn, and sweet corn was 91.3%, 68.7%, 27.5%, and 11.7%, respectively. As compared with those at pH 6.0 (CK), the germination rate, germination index, vigor index, germination velocity, shoot height, root length, shoot and root dry mass, and the transformation rate of stored substances at pH 1.0 had significant decrease, and the average germination time extended apparently. At pH 1.0, the effects of acid rain were greater at seedling growth stage than at germination stage, and greater on underground part than on aboveground part. Due to the differences in gene type, normal corn and waxy corn had the strongest capability against acid rain, followed by pop corn, and sweet corn. It was suggested that corn could be categorized as an acid rain-tolerant crop, the injury threshold value of acid rain was likely between pH 1.0 and pH 2.0, and normal corn and waxy corn would be prioritized for planting in acid rain-stricken area.

Effects of biological organic fertilizer on microbial community’s metabolic activity in a soil planted with chestnut (Castanea mollissima).

2013, 24(6):  1627-1632. 

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 A field experiment was conducted in Zhashui County of Shaanxi Province, Northwest China in 2011 to study the effects of biological organic fertilizer on the microbial community’s metabolic activity in a soil planted with chestnut (Castanea mollissima). Three treatments were installed, i.e., control, compound fertilizer, and biological organic fertilizer. Soil samples were collected at harvest, and the metabolic activity was tested by Biolog method. In the treatment of biological organic fertilizer, the average well color development, Shannon evenness, richness, and McIntosh indices of microbial community were all significantly higher than the other two treatments. As compared with the control, applying biological organic fertilizer improved the ability of soil microbes in utilizing the carbon sources of carbohydrates and polymers, while applying compound fertilizer was in opposite. The principal component analysis demonstrated that there was an obvious difference in the soil microbial community among different treatments, mainly depending on the species of carbohydrates and amino acids.

Effects of adding straw carbon source to root knot nematode  diseased soil on soil microbial biomass and protozoa abundance.

ZHANG Si-hai1，2, LIAN Jian-hong2, CAO Zhi-ping3, ZHAO Li

2013, 24(6):  1633-1638. 

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A field experiment with successive planting of tomato was conducted to study the effects of adding different amounts of winter wheat straw (2.08 g·kg^-1, 1N; 4.16 g·kg^-1, 2N; and 8.32 g·kg^-1, 4N) to the soil seriously suffered from root knot nematode disease on the soil microbial biomass and protozoa abundance. Adding straw carbon source had significant effects on the contents of soil microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN) and the abundance of soil protozoa, which all decreased in the order of 4N > 2N > 1N > CK. The community structure of soil protozoa also changed significantly under straw addition. In the treatments with straw addition, the average proportion of fagellate, amoeba, and ciliates accounted for 36.0%, 59.5%, and 4.5% of the total protozoa, respectively. Under the same adding amounts of wheat straw, there was an increase in the soil MBC and MBN contents, MBC/MBN ratio, and protozoa abundance with increasing cultivation period.

Effects of different vegetation restoration patterns on the diversity of soil nitrogen-fixing microbes in Hulunbeier sandy land, Inner Mongolia of North China.

LI Gang1, WANG Li-juan1,2, LI Yu-jie1,3, QIAO Jiang1,3, ZHANG Hai-fang1, SONG Xiao-long1, YANG Dian-lin1

2013, 24(6):  1639-1646. 

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By using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and sequence analysis, this paper studied the nifH gene diversity and community structure of soil nitrogenfixing microbes in Hulunbeier sandy land of Inner Mongolia under four years management of five vegetation restoration modes, i.e., mixedplanting of Agropyron cristatum, Hedysarum fruticosum, Caragana korshinskii, and Elymus nutans (ACHE) and of Agropyron cristatum and Hedysarum fruticosum (AC), and monoplanting of Caragana korshinskii (UC), Agropyron cristatum (UA), and Hedysarum fruticosum (UH), taking the bare land as the control (CK). There existed significant differences in the community composition of nitrogenfixing microbes among the five vegetation
restoration patterns. The Shannon index of the nifH gene was the highest under ACHE, followed by under AC, UC, UA, and UH, and the lowest in CK. Except that UH and CK had less difference in the Shannon index, the other four vegetation restoration modes had a significantly higher Shannon index than CK (P<0.05). The phylogenetic analysis showed that the soil nitrogen-fixing microbes under UA, UH, and UC were mainly of cyanobacteria, but the soil nitrogen-fixing microbes under AC and ACHE changed obviously, mainly of proteobacteria, and also of cyanobacteria. The canonical correlation analysis showed that the soil total phosphorus, available phosphorus, total nitrogen, and nitrate nitrogen contents under the five vegetation restoration modes had significant effects on the nitrogen-fixing microbial communities, and there existed significant correlations among the soil total phosphorus, available phosphorus, total nitrogen, and nitrate nitrogen. It was suggested that the variations of the community composition of soil nitrogen-fixing microbes under the five vegetation restoration modes were resulted from the interactive and combined effects of the soil physical and chemical factors.

Exposure degree of important non-target arthropods to Cry2Aa in Bt rice fields.

ZHANG Qing-ling1,2, LI Yun-he1, HUA Hong-xia2, YANG Chang-ju2, WU Hong-jin1, PENG Yu-fa1

2013, 24(6):  1647-1651. 

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Based on the principle of “risk = hazard × exposure”, the selected representative non- target organisms in the assessment of the potential effects of insect-resistant genetically modified (GM) crops on non-target arthropods in laboratory are generally the arthropod species highly exposed to the insecticidal proteins expressed by the GM crops in farmland ecosystem. In order to understand the exposure degree of the important arthropod species to Cry proteins in Bt rice fields, and to select the appropriate nontarget arthropods in the risk assessment of insect-resistant GM crops, the enzyme-linked immunosorbent assay (ELISA) was conducted to measure the Cry2Aa protein concentration in the arthropods collected from the cry2Aa rice fields at different rice growth stages. The results showed that there was a significant difference in the Cry2Aa content protein concentration in different arthropod species. Some species did not contain Cry2Aa protein, while some species contained larger amounts of Cry2Aa protein. Relative to the arthropods colleted after rice anthesis, the arthropods colleted in rice anthesis contained relative higher concentrations of Cry2Aa protein, especially for the predacious arthropods. No Cry proteins were detected in parasitic arthropods. This study provided references for the laboratory assessment of the effects of GM rice on non-target arthropods.

Land use pattern of Dalian City, Liaoning Province of Northeast China based on CA-Markov model and multi-objective optimization.

HU Xue-li, XU Ling, ZHANG Shu-shen

2013, 24(6):  1652-1660. 

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Based on the land use/cover maps of 1990, 2000, and 2010, topographic factors, and geographic elements, a CA-Markov model consisting of Markov transition matrix, multicriteria evaluation, and cellular automata was developed to simulate the change trends of the future land use and landscape patterns of Dalian, Liaoning Province. The future land use pattern of Dalian was optimally allocated by the method of fuzzy multi-objective programming, based on the characters of land use structure, society, economy, and natural environment. The results indicated that in 1990-2010, the rapid development of Dalian showed the characteristics of the continued expansion of urban area and the reduction of cropland and woodland area. With the present speed of urban development, the landscape pattern and land use cover would have a great change, and the landscape fragmentation would be exacerbated. To optimize the land use structure could meet the demand of the future sustainable development of Dalian.

Relationships of wetland landscape fragmentation with climate change in middle reaches of Heihe River, China.

JIANG Peng-hui, ZHAO Rui-feng, ZHAO Hai-li, LU Li-peng, XIE Zuo-lun

2013, 24(6):  1661-1668. 

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Based on the 1975-2010 multi-temporal remotely sensed TM and ETM images and meteorological data, in combining with wavelet analysis, trend surface simulation, and interpolation method, this paper analyzed the meteorological elements’ spatial distribution and change characteristics in the middle reaches of Heihe River, and elucidated the process of wetland landscape fragmentation in the study area by using the landscape indices patch density (PD), mean patch size (MPS), and patch shape fragment index (FS). The relationships between the wetland landscape fragmentation and climate change were also approached through correlation analysis and multiple stepwise regression analysis. In 1975-2010, the overall distribution patterns of precipitation and temperature in the study area were low precipitation in high temperature regions and high precipitation in low temperature regions, and the main characteristics of climate change were the conversion from dry to wet and from cold to warm. In the whole study period, the wetland landscape fragmentation was mainly manifested in the decrease of MPS, with a decrement of 48.95 hm², and the increase of PD, with an increment of 0.006 ind·hm^-2.

Variation patterns of soil wall temperature and heat flux in sunken solar greenhouse.

HUANG Xue1, WANG Xiu-feng1,2,3, WEI Min1,2,4, HOU Jia-lin5, LIU Fu-sheng6, LI Qing-ming1,2,4, YANG Feng-juan1,2,3, SHI Qing-hua1,2,3

2013, 24(6):  1669-1676. 

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From December 2011 to March 2012, a consecutive test was conducted on the temperature and heat flux of different thickness of the soil backwall of sunken solar greenhouse in Shouguang of Shandong Province, East China, aimed to analyze the variation patterns of soil wall temperature and heat flux of the sunken solar greenhouse and to confirm the suitable wall thickness. In winter, the temperature and heat flux of the wall inner surface and outer surface varied over a wide range, which was in accordance with the variation trend of indoor and outdoor air temperature. Overall, the wall temperature decreased from the inner to the outer surface, and the layers of the inner wall with higher variation range of temperature and heat flux were more than those of the outer wall. The variation range of temperature and heat flux decreased gradually from the shallow layers to deep layers of the wall. In successive cloudy days, the temperature of each layer of inner wall decreased to different degrees, and the layers releasing heat to the indoor deepened constantly, whereas the heat in the layers of outer wall was mainly released to the outdoor. According to the variation patterns of temperature and heat flux in the wall, the wall from inside to outside could be divided into heat storage layer, transitional layer, and cold resistant layer, and their thickness was 0.8-1.0 m, 2.2-2.6 m, and 0.4-0.6 m, respectively, under the condition of the outer surface being covered. Without considering the transitional layer, the suitable thickness of the soil wall in Shouguang solar greenhouse would be 1.4-1.6 m.

Relationships between urbanization and water resource utilization in Dongting Lake District of South-central China.

LI Jing-zhi, ZHU Xiang, LI Jing-bao, XU Mei

2013, 24(6):  1677-1685. 

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By using analytic hierarchy process and entropy method, the evaluation index system and the response relationship model of comprehensive development level of urbanization and comprehensive development and utilization potential of water resources in Dongting Lake District were constructed, with the key affecting factors, their change characteristics, and response characteristics from 2001 to 2010 analyzed. During the study period, the Dongting Lake District was undergoing a rapid development of urbanization, and at a scale expansion stage. The economic and social development level was lagged behind the population and area increase, and the quality and efficiency of urbanization were still needed to be improved. With the advance of urbanization, the water consumption increased yearly, and the water resources utilization efficiency and management level improved steadily. However, the background condition of water resources and their development and utilization level were more affected by hydrological environment rather than urbanization. To a certain extent, the development of urbanization in 2001, 2002, 2005, 2006, 2007, 2009 was slowed down by the shortage of water resources. At present, Dongting Lake region was confronted with the dual task of improving the level and quality of urbanization, and hence, it would be necessary to reform the traditional epitaxial expansion of urbanization and to enhance the water resource support capability.

Annual changes of phytoplankton’s ecological features in Qinzhou Bay of South China.

WANG Di1, CHEN Pi-mao2, LU Jing-jing3, MA Yuan1

2013, 24(6):  1686-1692. 

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Four cruise surveys were conducted on the phytoplankton in Qinzhou Bay of South China in different seasons in 2008-2009. A total of 131 phytoplankton species were identified, among which, diatom (101 species) accounted for 30.0% of the total, followed by pyrrophyta (23 species), and other groups (7 species). Most of the phytoplankton was of eurytherm or warmwater species. The total species number and the diatom abundance were the smallest in spring, and increased successively in summer, autumn, and winter, being the highest in winter. The phytoplankton density varied from 232.28×10⁴ cell·m^-3 to 977.0×10⁴ cell·m^-3, with an average of about 558.57×10⁴ cell·m^-3. Temporally, the phytoplankton density was the highest in summer, followed by in spring, and the lowest in winter and autumn. Spatially, the phytoplankton density was increased from the inner bay to the open bay, and decreased from the open bay to outside the bay. In summer, the highest density area switched from the open bay to the bay’s entrance. The average Shannon diversity index was 3.18, and the average evenness index was 0.63, suggesting a high diversity of the phytoplankton community. The correlations of the phytoplankton density with the water temperature, salinity, dissolved inorganic phosphorus, and dissolved inorganic phosphorus  varied with seasons.

Active carbon from Thalia dealbata residues: Its preparation and  adsorption performance to crystal violet.

CHU Shu-yi1，2, YANG Min2, XIAO Ji-bo2, ZHANG Jun2, ZHU Yan-ping2,YAN Xiang-jun3， TIAN Guang-ming1

2013, 24(6):  1693-1698. 

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By using phosphoric acid as activation agent, active carbon was prepared from Thalia dealbata residues. The BET specific surface area of the active carbon was 1174.13 m²·g^-1, micropore area was 426.99 m²·g^-1, and average pore diameter was 3.23 nm. An investigation was made on the adsorption performances of the active carbon for crystal violet from aqueous solution under various conditions of pH, initial concentration of crystal violet, contact time, and contact temperature. It was shown that the adsorbed amount of crystal violet was less affected by solution pH, and the adsorption process could be divided into two stages, i.e., fast adsorption and slow adsorption, which followed the pseudosecondorder kinetics model. At the temperature 293, 303, and 313 K, the adsorption process was more accordance with Langmuir isotherm model, and the maximum adsorption capacity was 409.83, 425.53, and 438.59 mg·g^-1, respectively. In addition, the adsorption process was spontaneous and endothermic, and the randomness of crystal violet molecules increased.

Distribution characteristics and correlations of phosphorus in sediment and interstitial water of Nansi Lake, Shandong Province of East China in summer and winter.

LI Bao1, WANG Zhi-qi1,2, WANG Qian-suo1,2, CUAN Jing-bo1,2

2013, 24(6):  1699-1706. 

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By using cylindrical sediment sampler and Peeper’s interstitial water sampler, the intact sediment and interstitial water were collected from different zones of Nansi Lake in Shandong Province in summer and winter. The distribution characteristics of the sediment phosphorus forms and of the phosphate (PO₄^3-P) in interstitial water were analyzed, and their correlations were discussed. In the sediments of  Nansi Lake, phosphorus was richer, and had a significant spatial differentiation, with an overall decreasing trend from north to south, which was related to the seriously polluted Northern Nansi Lake near Jining City. Among the phosphorous forms, inorganic phosphorus (IP) had the highest concentration, accounting for 52.3%-87.2% and 60.6%-88.3% of the total phosphorus (TP) in summer and winter, respectively. The TP concentrations in 5 cm surface sediment of four sub-lakes were all higher in summer than in winter, which could be related to the human activities such as exuberant aquaculture, more chemical fertilizers application around lake, and frequent tourism activities, etc. in summer. In vertical direction, the PO₄^3-P concentration in interstitial water decreased after an initial increase in summer and winter, and was obviously higher in summer than in winter, suggesting that the phosphorous in sediment had a higher potential to release to the overlying water in summer. The organic phosphorus (OP) and IP in sediment had a significant correlation in summer but less correlation in winter, indicating that the transformation between sediment IP and OP was more active in summer than in winter. The iron and aluminum bound phosphorus (Fe/AlP) and IP in sediment were significantly positively correlated with the PO₄^3-P in interstitial water. In summer and winter, the average PO₄^3-P concentration in interstitial water collected by Peeper’s interstitial water sampler was about 20%-50% higher than that collected by the conventional centrifugal method, suggesting that using Peeper’s interstitial water sampler could be more precise.

Fish community structure and its relationships with environmental factors in Haizhou Bay and adjacent waters of East China in winter.

WANG Xiao-lin, XU Bin-duo, JI Yu-peng, REN Yi-ping

2013, 24(6):  1707-1714. 

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Based on the bottom trawl survey and environmental investigation data in December 2011, and by using species diversity indices and multielement analysis, this paper studied the species composition, species diversity, and spatial pattern of fish community as well as their relationships with environmental factors in Haizhou Bay and adjacent waters. A total of 60 fish species were captured, belonging to 51 genera, 34 families, and 10 orders, and mainly composed of warm temperature and warm water demersal fishes. The Margalef species richness index, Shannon diversity index, and Pielou evenness index ranged from 1.14 to 2.84, 1.08 to 2.64, and 0.41 to 0.83, respectively. Cluster analysis and nonmetric multidimensional scaling (MDS) analysis showed that the fish community could be spatially clustered into three groups. Group I was in the north of 35° N, group Ⅱ was in the inshore waters near bay-ead, and group III was in the south of 35° N.  ANOSIM analysis showed that there existed highly significant differences (R=0.45-0.91) in the fish species composition among the groups. The canonical correspondence analysis (CCA) indicated that the bottom water temperature, water depth, and sea surface salinity were the most important environmental variables affecting the spatial pattern of fish community in Haizhou Bay and adjacent waters in winter.

Influence of 175-m-impoundment in Three Gorges Reservoir Area on the food web energy sources of main commercial fishes in backwater area of Xiaojiang River.

LI Bin1,2, WANG Zhi-jian2, YUE Xing-jian2, WANG Yong-ming2, JIN Li1, ZHANG Yao-guang1

2013, 24(6):  1715-1721. 

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The impoundment in the Three Gorges Reservoir Area (TGRA) was first reached 175 m in 2010. To approach the influence of this impoundment on the food web energy sources of fishes in the tributaries of TRGA, an analysis was made on the food web energy sources of seven economically important fishes (Carassius auratus, Cyprinus carpio, Silurus asotus, Culter mongolicus mongolicus, Mystus macropterus, Pelteobagrus vachelli, and Pelteobagrus nitidus) in the backwater area of Xiaojiang River by using stable isotope method in combining with IsoSource Model. The results showed that before this impoundment (July 2010), microalgae were the main energy sources for the seven species. After this impoundment (December 2010), the contribution ratio of the microalgae decreased somewhat, while the relative contribution of terrestrial C4 plants had an obvious increase. Especially for crucian carp (C. auratus) and catfish (S. asotus), the contribution rate of the C4 plants reached 38-54% and 32-50%, respectively. After the impoundment, at least 30% of the energy resources of these two fishes were come from terrestrial C4 plants, suggesting that the impoundment in TGRA increased the contribution rate of exogenous terrestrial C4 plants as the energy sources of fishes.

Statistical characteristic analysis of soil PAHs in a coking contaminated site of China.

LIU Geng1,2, BI Ru-tian1, WANG Shi-jie2, WEI Wen-xia3, LI Fa-sheng2, GUO Guan-lin2

2013, 24(6):  1722-1728. 

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Statistical characteristic analysis of pollutants in contaminated sites can help identify the origin, generation, and spatial variation of different pollutants, and can reduce the uncertainty of site survey data. Taking a large and abandoned contaminated coking site of China as the object, 114 surface (0-50 cm) soil samples were collected, with the statistical and spatial characteristics of 16 priority PAHs (ΣPAHs) analyzed. The descriptive statistical analysis indicated that the ΣPAH levels varied significantly, and the data were severely skewed. The correlation matrix (CM) and principal component analysis (PCA) showed that the extracted first two principal components (PCs) could effectively represent the whole site pollution data. Four pollutants, i.e., Baa, Bbf&Bkf, Bap, and Inp, were selected for trend analysis and spatial local variance analysis. In the eastwest and north-south directions of the site, the pollution showed a low-high-low trend. The variation coefficient of pollution for the site was higher in the central, northwest, and southwest regions, while lower in the other regions.

Ecological vulnerability of coal mining area: A case study of Shengli Coalfield in Xilinguole of Inner Mongolia, China.

QUAN Zhan-jun1,2, LI Yuan3, LI Jun-sheng1, HAN Yu1, XIAO Neng-wen1, FU Meng-di1

2013, 24(6):  1729-1738. 

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In this paper, an ecological vulnerability evaluation index system for the Shengli Coalfield in Xilinguole of Inner Mongolia was established, which included 16 factors in ecological sensitivity, natural and social pressure, and ecological recovery capacity, respectively. Based on the expert scoring method and analytic hierarchy process (AHP), an ecological vulnerability model was built for the calculation of the regional ecological vulnerability by means of RS and GIS spatial analysis. An analysis of the relationships between land use and ecological vulnerability was also made, and the results were tested by spatial auto-correlation analysis. Overall, the ecological vulnerability of the study area was at medium-high level. The exploitation of four opencast areas in the Coalfield caused a significant increase of ecological vulnerability. Moreover, due to the effects of mine drained water and human activities, the 300-2000 m around the opencast areas was turning into higher ecologically fragile area. With  further exploitation, the whole Coalfield was evolved into moderate and heavy ecological vulnerability area, and the coal resources mining was a key factor in this process. The cluster analysis showed that the spatial distribution of the ecological vulnerability in the study area had reasonable clustering characteristics. To decrease the population density, control the grazing capacity of grassland, and regulate the ratios of construction land and cultivated land could be the optimal ways for resolving the natural and social pressure, and to increase the investment and improve the vegetation recovery coefficient could be the fundamental measures for decreasing the ecological vulnerability of the study area.

Dark respiration of terrestrial vegetations: A review.

SUN Jin-wei1,2, YUAN Feng-hui1，2, GUAN De-xin1, WU Jia-bing1

2013, 24(6):  1739-1746. 

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The source and sink effect of terrestrial plants is one of the hotspots in terrestrial ecosystem research under the background of global change. Dark respiration of terrestrial plants accounts for a large fraction of total net carbon balance, playing an important role in the research of carbon cycle under global climate change. However, there is little study on plant dark respiration. This paper summarized the physiological processes of plant dark respiration, measurement methods of the dark respiration, and the effects of plant biology and environmental factors on the dark respiration. The uncertainty of the dark respiration estimation was analyzed, and the future hotspots of related researches were pointed out.

Ecosystem services supply and consumption and their relationships with human well-being.

WANG Da-shang, ZHENG Hua, OUYANG Zhi-yun

2013, 24(6):  1747-1753. 

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Sustainable ecosystem services supply is the basis of regional sustainable development, and human beings can satisfy and improve their well-being through ecosystem services consumption. To understand the relationships between ecosystem services supply and consumption and human wellbeing is of vital importance for coordinating the relationships between the conservation of ecosystem services and the improvement of human well-being. This paper summarized the diversity, complexity, and regionality of ecosystem services supply, the diversity and indispensability of ecosystem services consumption, and the multi-dimension, regionality, and various evaluation indices of human well-being, analyzed the uncertainty and multi-scale correlations between ecosystem services supply and consumption, and elaborated the feedback and asynchronous relationships between ecosystem services and human well-being. Some further research directions for the relationships between ecosystem services supply and consumption and human well-being were recommended.

Applications of stable isotope techniques in the studies of soil collembolan: A review. 

WANG Min, XU Guo-liang

2013, 24(6):  1754-1760. 

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The development and application of stable isotope techniques is one of the most important progress in ecological methodologies in the 1990s. Many ecological processes are accompanied with the changes of stable isotopes ratio. According to these changes, the material circulation and energy flow of ecosystems can be followed. In recent years, many researchers introduced stable isotope techniques in soil ecology to study the soil carbon cycle and the trophic relationships between soil organisms, which greatly improved our understanding on belowground ecosystem. As for collembolan, one of the most important members of soil animals, its feeding habits and trophic position in soil ecosystem are little known. Stable isotope techniques provide a useful approach to study the food resources, trophic position, and trophic relationships of collembolan. This paper summarized the applications of stable isotope techniques in the studies of the feeding habits and trophic position of collembolan, and discussed the deficiencies and prospects of related researches.

 

Spatiotemporal distribution of negative air ion concentration in urban area and related affecting factors: A review. 

HUANG Xiang-hua1,2, WANG Jian1,2, ZENG Hong-da1,2, CHEN Guang-shui1,2, ZHONG Xian-fang1，2

2013, 24(6):  1761-1768. 

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Negative air ion (NAI) concentration is an important indicator comprehensively reflecting air quality, and has significance to human beings living environment. This paper summarized the spatiotemporal distribution features of urban NAI concentration, and discussed the causes of these features based on the characteristics of the environmental factors in urban area and their effects on the physical and chemical processes of NAI. The temporal distribution of NAI concentration is mainly controlled by the periodic variation of solar radiation, while the spatial distribution of NAI concentration along the urban-rural gradient is mainly affected by the urban aerosol distribution, underlying surface characters, and urban heat island effect. The high NAI concentration in urban green area is related to the vegetation life activities and soil radiation, while the higher NAI concentration near the water environment is attributed to the water molecules that participate in the generation of NAI through a variety of ways. The other environmental factors can also affect the generation, life span, component, translocation, and distribution of NAI to some extent. To increase the urban green space and atmospheric humidity and to maintain the soil natural attributes of underlying surface could be the effective ways to increase the urban NAI concentration and improve the urban air quality.

 

Evidence of long distance migration of diamondback moth (DBM) Plutella xylostella: A review.

XING Kun1,2, MA Chun-sen2, HAN Ju-cai1

2013, 24(6):  1769-1776. 

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As cruciferous plants have been cultivated northwards due to climate warming, diamondback moth (DBM) Plutella xylostella is becoming a major pest in North China. The long distance migration of DBM not only induces its sudden outbreak over extensive areas, but also leads to its insecticide resistance by the spread of resistant genes in large area. To elucidate the long distance migration of DBM is of significance for early warning and decisionmaking in integrated pest managements. So far, the migration of DBM has not yet been systematically investigated in China. Here, we reviewed the literatures about the long distance migration of DBM at home and abroad, and summarized the related evidence: 1) DBM cannot overwinter in cold regions such as northern Japan, western Canada, and northeast China, where the DBM outbreak is presumed from elsewhere by long distance migration, 2) DBM adults are captured from seas, mountain tops, sea islands, and sky, etc., and the collection of large quantity of DBM presents the powerful direct evidence of DBM long distance migration, 3) the sudden increase of DBM in fields is consistent with the meteorological conditions such as the presence of nocturnal temperature inversion layer and the front passage, suggesting that these meteorological conditions supply suitable backgrounds for the insect migration, 4) the target insect characters identified by vertical insect looking radar is consistent with the measured DBM characters in laboratory and the trapping data from fields, confirming the long distance migration of DBM, 5) the biological characteristics and genetic variations of different DBM populations have no correlations with geographic distance, suggesting the frequent gene flows among the populations in different positions, and 6) the flight test of DBM indicates its long distance flight capacity, and the decreasing fitness of host plants is probably one of the trigger factors for the migration of DBM. Some future research directions are prospected: the construction of track model for DBM long distance migration to clarify the DBM long distance migration pathways in China；  the further understanding on the physiological, biochemical, and ecological bases of DBM long distance migration； the strategies for the population insecticide resistance management based on the long distance migration of DBM.