Table of Content

10 August 2013, Volume 32 Issue 8

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Effects of nitrogen addition and precipitation change on soil methane and carbon dioxide fluxes.

LI Wei1,2, BAI Edith1**, LI Shan-long1,2, SUN Jian-fei1,2, PENG Bo1,2, JIANG Ping1

2013, 32(8):  1947-1958. 

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Increased nitrogen deposition and changed precipitation pattern are the two important factors of global change, while the in situ experiments studying how the two factors affect greenhouse gases CO₂ and CH₄ fluxes are still limited. Taking the temperate broadleaved Korean pine (Pinus koraiensis) forest in Changbai Mountains of Northeast China as the object, and by using static chambers, this paper studied the effects of nitrogen addition (50 kg N·hm^-2·a^-1) and changed precipitation regime (30% increase and decrease of precipitation) on the soil CO₂ and CH₄ fluxes. Nitrogen addition inhibited the soil CH₄ consumption, and even, converted the CH₄ consumption into CH₄ release. However, this inhibition effect only lasted for approximately 5 days. Nitrogen addition also affected the relationships between the CH₄ flux and environmental factors (soil temperature, pH, and clay content) to some extent. The changed precipitation regime had no significant effects on the CH₄ flux. Nitrogen addition decreased the CO₂ flux, with an average decrement of 27.4% after 4 years continuous nitrogen addition. It was predicted that the effects of longterm continuous nitrogen addition on the CO₂ flux would be increased with time, and reached the maximum after certain years of nitrogen addition. Oppositely, the effects of single time nitrogen addition would be decreased with time, and disappeared by the end of the 1month cycle. The inhibition effect of nitrogen addition on the CO₂ flux was negatively correlated with soil water filled pore space (WFPS) (P=0.022), and enhanced and extended at higher temperature. Nitrogen addition and precipitation change could possibly alter the temperature sensitivity of soil respiration. Our results indicated that the soil nitrogen in temperate forest in Changbai Mountains had not reached a threshold, and the future nitrogen deposition increase would inhibit the CO₂ release and CH₄ uptake. Overall, nitrogen addition would inhibit the soil carbon release.

Relationships of seeding Azadirachta indica plantations seed yield and quality with foliar nutrient contents in Yuanmou dryhot valley, China.

ZHENG Yi-xing, WU Jiang-chong, PENG Xing-min, ZHANG Yan-ping**

2013, 32(8):  1959-1966. 

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By using the foliar nutrient diagnosis methods such as critical concentration value approach (CCVA), graph diagnosis and recommendation integrated system (DRIS), and index DRIS, this paper studied the relationships between the seed yield and its azadirachtin content and the foliar nutrient contents of seeding Azadirachta indica plantations in Yuanmou dry-hot valley. There existed significant linear correlations between the nutrient contents of foliages collected in June and the seed yield. In high-yielding plantations, the optimal contents of foliar total N, total P, and total K were 15.09-22.68, 1.22-1.59, and 7.68-9.17 g·kg^-1, and the critical values were 15.09, 1.22, and 7.68 g·kg^-1, respectively. In low-yielding plantations, the nutrient diagnosis results from graph and index DRIS were identical, i.e., the nutrient requirement was P>N>K, which fitted with the background data of the nutrient contents in local soils. There were no correlations between the foliar nutrient contents and seed azadirachtin content, which was possibly due to the genetic factors of A. indica itself. Therefore, foliar nutrient diagnosis test could be not appropriate for measuring the seed azadirachtin content of A. indica seeding plantations.

Effects of climate change on China forest ecosystems: An assessment based on regional vegetation types.

NING You-liang1, WU Shui-rong1**, LI Zhi-yong1, LIU Shi-rong2, CHEN Shao-zhi1

2013, 32(8):  1967-1972. 

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Based on the literatures with the subject headings “Climate Change” and “Forest” collected from the CNKI and Google, and according to the regional vegetation types within China, the meta-analysis method was used in this paper to assess the effects of climate change on China forest ecosystems. Among the observed effects of climate change, those on the tree phenology, forest productivity, and forest fire of the regional vegetation types were similar, but definite differences were observed in the effects on the forest geographic distribution. As for the projected effects of climate change, those on the tree phenology, forest productivity, forest carbon storage, and forest fire of the regional vegetation types were similar, but there were some differences in the effects on the forest geographic distribution and forest structure. The main problems of the existing studies and the directions of future researches were also discussed.

Effects of copper stress on the expression of DNA mismatch repair genes in Arabidopsis thaliana plantlets.

SUN Xiao-xia1, SONG You-tao3, LI Zhao-ling2, LIU Wan2**, TAI Pei-dong2, LI Pei-jun2

2013, 32(8):  1973-1979. 

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By using semi-quantitative reverse transcriptionpolymerase chain reaction (RT-PCR), and with 18S rRNA as the internal standard gene, this paper studied the effects of copper (Cu) stress on the expression of DNA mismatch repair genes (MLH1, MSH2, MSH3, MSH6, and MSH7) in Arabidopsis thaliana plantlets, and, in combining with the morphological and physiological indices of the plantlets, the sensitive biomarkers of Cu stress were selected. The results showed that under Cu stress (0.5, 1.0, and 2.0 mg·L^-1) for 10 days, no significant changes were observed in the seed germination percentage, shoot fresh mass, and chlorophyll content, but the root length was obviously inhibited, and the shoot total soluble protein content and mismatch repair genes expression decreased with increasing concentration of Cu. An obvious dose-effect relationship existed between the Cu concentration and the above-mentioned indicators of A. thaliana plantlets. The results indicated that the change trend of the shoot total soluble protein content was similar to that of the mismatch repair genes expression, which were all sensitive to the Cu stress and could be served as the potential and useful biomarkers for the detection of genotoxic effects of Cu pollution on plants.

Allocation patterns of above- and below-ground biomass of Caragana microphylla in Horqin Sandy Land, North China.

NIU Cun-yang1,2, Alamusa1**, ZONG Qin2, LUO Yong-ming1, Toshio Oshid3, SUN Gui-fan4, LIU Qian4

2013, 32(8):  1980-1986. 

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Taking the 4 and 18-year-old artificial plantations and the natural stand of Caragana microphylla in Horqin Sandy Land as the objects, and through digging root system by layers, this paper investigated the features of C. microphylla root distribution in different vegetation zones, and studied the responses of C. microphylla in its biomass allocation, root/shoot ratio, and root distribution to dry environment. The C. microphylla tended to allocate more biomass to roots. Among the three vegetation zones, natural stand and 4 years old artificial plantation had the largest and the smallest proportion of belowground biomass, respectively. The root biomass decreased gradually with soil depth, and the roots were mainly distributed in the 0-100 cm soil layer. The biomass of the absorptive roots of 4 years old C. microphylla plantation was more distributed in surface soil layer, being significantly greater than that of 18 years old plantation and natural stand (P<0.05) in 0-50 cm soil layer. However, the 18 years old plantation and the natural stand had more absorptive root biomass in 50-100 cm soil layer. The conductive root biomass of natural stand in 50-100 cm soil layer was significantly greater than that of 4 and 18-year-old plantations. The relationships between the above and belowground biomass allocations of C. microphylla were characterized by allometry model.

Adaptive growth strategies of Leymus chinesis population in response to shading.

WANG Hong-yi1, WANG Zheng-wen2**

2013, 32(8):  1987-1993. 

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Since the 1950s, the shortwaved solar radiation that the earth received has been reduced by 2.7% every decade, and this phenomenon is called “global dimming”, which may impact plants and their inhabitant ecosystems. However, no consensus concerning such impacts has been reached. In this paper, different degrees (0, 30%, 50% and 70%) of shading were installed to simulate the global dimming effect to study the population density, morphological features (shoot height, leaf area, and heading rate), and photosynthetic physiology (stomatal conductance, photosynthetic rate, and transpiration rate) of Leymus chinensis in response to shading. Shading decreased the shoot density somewhat, but increased the shoot height obviously, enlarged the leaf area significantly, and promoted the heading rate. Shading also significantly reduced the PAR that L. chinensis received. Under 0, 30%, and 50% shading, the afternoon depression in stomatal conductance, photosynthetic rate, and transpiration rate occurred. Under 70% shading, the stomatal conductance, photosynthetic rate, and transpiration rate at 11:00-16:00 were higher than those in other shading treatments, and the afternoon depression of photosynthetic rate and transpiration rate did not occur. The absence of the afternoon depression of photosynthetic rate and transpiration rate under 70% shading could be one of the main reasons of the increased productivity of some vegetation types after being shaded or being exposed to global dimming. To more precisely predict the responses of various ecosystems to global dimming, it would be necessary to conduct more empirical studies about the responses of plants to shading in more regions, with more habitat types and more plant functional types, and at more growth stages, and do more model studies and meta-analyses to incorporate the empirical data.

Non-growth season’s greenhouse gases emission and its yearly contribution from alpine meadow on Tibetan Plateau of China.

WANG Guang-shuai1,2, YANG Xiao-xia1,2, REN Fei1,2, ZHANG Zhen-hua1, HE Jin-sheng1**

2013, 32(8):  1994-2001. 

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Alpine meadow is widely distributed on the Tibetan Plateau. The studies on the greenhouse gases (GHGs) flux in the alpine meadow are mostly carried out during growing season, but scarcely quantified during nongrowing season. By using static chamber technique and gas chromatography, this paper studied the characteristics of CO₂, CH₄, and N₂O fluxes in this alpine meadow during nongrowing season. The mean fluxes of CO₂, CH₄, and N₂O were 89.33 mg·m^-2·h^-1, -11.35 μg·m^-2·h^-1, and 8.02 μg·m^-2·h^-1, and the cumulative fluxes were 280.01 g·m^-2, -124.74 mg·m^-2, and 39.51 mg·m^-2, respectively. Therefore, this alpine meadow was performed as the sources of CO₂ and N₂O and the sink of CH₄ during nongrowing season. The cumulative CH₄, CO₂ and N₂O fluxes during nongrowing season contributed 13.33%, 53.47% and 62.67% of the total in a whole year. During freezethawing period (April, 2012), cumulative CH₄ flux was smaller, only contributing 4.5% of the total during non-growing season, whereas the cumulative CO₂ and N₂O fluxes were larger, contributing 25.8% and 20.8%, respectively. The CO₂ flux during nongrowing season had significant positive correlations with air temperature, soil temperature at the depths of 5 cm and 10 cm, and soil moisture at depth 5 cm. Our results showed that though the cumulative CH₄ flux during freezethawing period only occupied a smaller part of that during nongrowing season, the cumulative CH₄ and N₂O fluxes during nongrowing season contributed more than 50% of the total in a whole year, which should not be neglected in the estimation of the GHGs fluxes and their global warming potential in the alpine meadow on the Tibetan Plateau.

Effects of excessive nitrogen absorption on the dark respiration rate and relative growth rate of Kochia scoparia.

CAO Xun1,2, ZHENG Xin-jun1**, LI Yan1, TANG Li-song1

2013, 32(8):  2002-2007. 

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To better understand the effects of excessive nitrogen (N) absorption on plant growth, three N fertilization treatments were installed to measure the plant N content, dark respiration rate, biomass, and relative growth rate (RGR) of halophyte (Kochia scoparia) during its growth period. Under the conditions of excessive N absorption, the excessive N had minor effects on the dark respiration rate, resulting in the low N use efficiency during dark respiration. There was a highly linear correlation between mass-based dark respiration rate and RGR, and this correlation was consistent across different N treatments. An allometric relationship was observed between dark respiration rate and plant N content, and the relationship was correlated with N application rate, i.e., the higher the N application rate, the smaller the scaling exponent.

Effects of nitrogen fertilization and cutting on the photosynthesis, yield, and quality of Pennisetum purpureum cv. Guimu-1.

LIANG Zhi-xia1,2,3, SONG Tong-qing2,3, ZENG Fu-ping1,2,3**, PENG Wan-xia2,3, YANG Gai-ren1, TAN Qiu-jin1,2,3

2013, 32(8):  2008-2014. 

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A L₁₆ (4⁵) orthogonal experiment was conducted to study the photosynthesis, yield, and quality of Pennisetum purpureum cv. Guimu-1 in a karst region of Southwest China under effects of different nitrogen fertilization rates and cutting times and intensities. Nitrogen fertilization increased the chlorophyll a and b and total chlorophyll contents, net photosynthetic rate, yield, and plant nutrient contents significantly, with the best effect of 1000 kg·hm^-2·a^-1. Cutting times had significant effects on the net photosynthetic rate, chlorophyll content, and plant nutrient contents. After 2 or 3 times cutting, the photosynthesis improved significantly; after cutting 3 or 4 times per year, the nutritional quality of Guimu-1 was the best. Cutting intensity had significant effects on the crude protein content, but minor effects on the other nutrient contents and yield. The best effects were obtained when the cutting intensity was at the distance 5 cm or 20 cm from the roots. Based on the comprehensive analysis of the indices, the optimum scheme for high yield and good quality of Guimu-1 in the karst region was proposed as nitrogen application rate 1000 kg·hm^-2·a^-1, 3 times cutting per year, and cutting at the distance 5 cm or 20 cm from the roots.

Effects of submergence on the growth and photosynthetic characteristics of Rhizoma cyperi in hydrofluctuation belt of Three Gorges Reservoir area, Southwest China.

LIU Ze-bin1, CHENG Rui-mei1**, XIAO Wen-fa1, GUO Quan-shui1, WANG Xiao-rong2, FENG Xiao-hui3

2013, 32(8):  2015-2022. 

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In order to explore the effects of water level change in the hydro-fluctuation belt of the Three Gorges Reservoir area on the growth of Rhizoma cyperi seedlings, a simulation experiment was conducted to study the response mechanisms of the seedling’s photosynthetic physiology to different submerged environments induced by the water level change. Four treatments were installed, i.e., no submergence (CK), root submergence (T1), semi-plant-submergence (T2), and whole plant submergence (T3). After treated for 45 days, the plant basal diameter, stem height, and non-photochemical quenching in all treatments tended to be increased, illustrating that R. cyperi could adapt to different submerged environments. The leaf length, leaf width, and aboveground biomass in different submerged environments differed. As compared to CK, the leaf length, leaf width, and aboveground biomass in T2 had some increase, while those in T1 and T3 had some decrease. With the increasing time of submergence, the specific leaf area, net photosynthetic rate, stomatal conductance, transpiration rate, maximal photochemical efficiency, electron transfer rate, and photochemical quenching were significantly lower than those in CK. However, all the parameters in T1 and T2 were still maintained at a higher level, while those in T3 were declined to an extremely lower level. This study indicated that R. cyperi could well adapt to submerged environment (especially partially submerged environment), and thus, could be applied to the re-vegetation of the hydro-fluctuation belt in the Three Gorges Reservoir area, especially in the low altitude region (145-160 m) which had suffered from long-term water level fluctuation. The submergence-tolerance characteristics of R. cyperi also provided a basis for screening riparian plants in the hydro-fluctuation belt of the Three Gorges Reservoir area.

Plant functional traits of Carex and Potentilla around Beijing mountainous areas.

LI Dan**

2013, 32(8):  2023-2028. 

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Plant functional traits can effectively reflect the plant metabolism activities, biochemical components, and nutritional absorption. This paper analyzed the plant functional traits of Carex and Potentilla around Beijing mountainous areas, and the results showed that the plant height, leaf length, leaf width, flower length, specific leaf area (SLA), and leaf total nitrogen (TN) and total phosphorus (TP) contents had positive correlations with each other, and the leaf thickness and leaf weight had negative correlations with the other traits. Phylogenetic information affected the plant height, leaf length, and leaf TN content. With the increase of altitude, the plant height, leaf length, leaf width, flower length, SLA, and leaf TN and TP contents decreased, while the leaf thickness and leaf weight increased. Altitude and phylogenetic information had the same effects on the functional traits of Carex and Potentilla, only the relationships between SLA and phylogenetic information had differences.

Risk evaluation indicator system for exotic plant invasion in Hainan Island, South China.

PENG Zong-bo1,2, JIANG Ying1, JIANG Ju-sheng1**

2013, 32(8):  2029-2034. 

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Based on the demands of prevention, control, and management of biological invasion of exotic species in Hainan Island, an investigation was made on the species, distribution, and harm of invasive plants in the Island. According to our investigation, the invasion of exotic species in the Island was very serious. A total of about 160 exotic plants belonging to 38 families were found. A risk evaluation indicator system was established, which could be adapted to the local characteristics of ecological, economic, and social development. The indicator system comprised 5 firstclass indices, 12 second-class indices, and 42 third-class indices, and the weight of each index was determined by applying analytic hierarchy process (AHP) method. The risk of 50 exotic invasive plants was evaluated by using this indicator system, the levels of the invasion risks were determined, and the corresponding risk management strategies were put forward. The risk evaluation indicator system could be used as an important tool in early warning and decision management of biological invasion. In order to prevent the biological invasion and to guarantee ecological security, a rapid response system for Hainan biological invasion should be established based on the biological invasion risk assessment and management.

Effects of prolonged mechanical stimulation with different intensities on rice plant physiological characters.

LIANG Kai=ming1,2, ZHANG Jia-en1,2,3**, HUANG Zhao-xiang1, QUAN Guo-ming1,4, ZHAO Ben-liang1,2,3

2013, 32(8):  2035-2042. 

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A laboratory experiment was conducted to study the effects of mechanical stimulation on the physiological characters of rice plant. Mechanical stimulation decreased the permeability of rice leaf plasma membrane, but, with the increase of stimulation intensity and treatment time, the permeability presented an increasing trend. The leaf chlorophyll a (Chl-a) content was increased by mechanical stimulation treatments, while the leaf chlorophyll b (Chl-b) content presented a decreasing trend. Low intensity mechanical stimulation increased the activities of protective enzymes peroxidase (POD), superoxide dismutase (SOD), and polyphenol oxidase (PPO) in rice leaves. In mechanical stimulation treatments, the leaf 3indoleacetic acid (IAA) content was reduced with time, whereas the leaf abscisic acid (ABA) content and the root activity showed an opposite trend. These results indicated that mechanical stimulation could be one of the important reasons leading to the morphological and physiological variations of rice plant. The findings from this study could provide a theoretical basis to further study the effects and action mechanisms of mechanical stimulation on the rice plant growth in rice-duck farming system.

Cadmium accumulation in different eggplant cultivars and the effects of grafting on the cadmium accumulation characteristics.

QIN Qin1,4, LI Xue-mei3, TAI Pei-dong1**, LIU Wan1, FENG Qian5, DENG Xin1,4, MA Jun2,4

2013, 32(8):  2043-2048. 

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A hydroponic experiment was conducted to study the cadmium (Cd) accumulation in different eggplant cultivars (common Solanum melongena and wild S. torvum) and the effects of grafting on the Cd accumulation and transportation. 0.1 mg Cd·L^-1 was added to the nutrient solution for 7 days after 44 days of eggplant growth. The Cd accumulation in S. melongena was higher than that in S. torvum. The Cd concentrations in different parts of the eggplants ranked as root > leaf > stem, and the accumulated Cd in roots accounted for approximately 80.0% of the total. The Cd concentration accumulated in young leaves was higher than that in old leaves growing on the same stems. Grafting decreased the Cd accumulation in shoots significantly, and the Cd concentration in scions was significantly lower than that in rootstocks. As compared with S. melongena, grafting on S. torvum reduced the shoot Cd concentration by 48.4%, grafting on S. melongena reduced the shoot Cd concentration by 34.2%, while selfgrafting on S. torvum reduced the shoot Cd concentration by 88.5%. As compared with S. torvum, the shoot Cd concentration of the eggplants selfgrafted on S. torvum reduced by 58.0%. The decrease of the Cd accumulation in eggplant shoots due to grafting could be induced by the discrepancies between the phloem structure of rootstock and scion plants after grafting. It was speculated that phloem played an important role in the Cd transportation from root to shoot.

Maize emergence speed and its relationships with water and heat conditions in Northeast China and meteorological assessment of the maize emergence period.

MA Shu-qing1, WANG Qi2, YU Hai3, XU Li-ping3, ZHANG Tie-lin3, JI Ling-ling1**

2013, 32(8):  2049-2055. 

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In 2010-2011, a twofactor experiment of water stress and sowing date for spring maize (Zea mays) was conducted to reveal the effects of soil moisture and air temperature on the spring maize emergence speed in Northeast China, and to establish the corresponding models for assessing and predicting the maize emergence period. The maize emergence speed had close relationships with the soil moisture and air temperature. The maize emerged faster under the conditions of more sufficient soil moisture and higher air temperature, while delayed under dry weather and low temperature. Under the conditions of the average soil moisture (S) in 0-20 cm layer being 21%-25%, soil available water capacity (H) being 50-70 mm, and average air temperature (T) being 18-20 ℃, the maize emerged about 10 d after sowing; at the S was 18%-21%, H was 30-50 mm, and T was 16.5-18 ℃, the emergence was prolonged to about 18 d; while at the S was <18%, H was <30 mm, and T was temperature 16.5 ℃, the emergence was prolonged to 25 d, and even, no seedling appeared. The relationships between the interval days from seeding to emergence (D) and the S, H, and T were D=78.017-1.746S-1.642T or D=60.776-0.288H-1.937T. These indicators and models could be applied in the assessment and prediction of the maize emergence period, and in the guidance of drought-resisting activities and weather services.

Cloning and bioinformatic analysis of signal-degrading enzyme gene aiiA from marine bacterium ZD02.

DING Xian1**, SUN Wei-wen2, ZHANG Dian-chang1, WENG Xiong1, LIN Hei-zhe1, ZHOU Shi-ning2

2013, 32(8):  2056-2061. 

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By using a pair of degenerate primers designed according to the known conserved sequence of aiiA, the gene aiiA encoding the quorum sensing signal degrading enzyme (AiiA) in the genome of marine bacterium ZD02 was amplified by PCR, and the PCR products (ZD02 aiiA) were cloned, sequenced, and analyzed. The ZD02 aiiA was 753 bp (Genbank accession number: KC756214), containing an open reading frame (ORF) which encoded a polypeptide chain AiiA of 250 amino acids residues with a molecular weight of 28.1 kDa and an isoelectric point value of 4.78. A conservative domain (Lactamase-B) (34AA-235AA) in the sequence was identified, and the 3D structure of deduced AiiA protein was further predicted. This study would provide a foundation for the expression of the sequence and its bio-activity analysis.

Shrimp resource distribution and its relationships with environment in the Jiaojiang Estuary of East China in spring and autumn.

QI Hai-ming1,2, XU Zhao-li1**

2013, 32(8):  2062-2069. 

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Based on the survey data of fishery resources in the Jiaojiang Estuary in spring (April) and autumn (October), 2010, this paper analyzed the distribution patterns of the shrimps in the Estuary in spring and autumn and the effects of water temperature, salinity, and depth on these distribution patterns. In spring and autumn, the average weight density of the shrimps was 7.89 and 86.20 kg·km^-2, and the average number density was 11.04×10³ and 34.41×10³ ind·km^-2, respectively. In spring, the weight density was higher in the west than in the east area, but the number density was in opposite. In autumn, both the weight density and the number density were obviously higher in the east than in the west area. The shrimps in spring had the highest weight density at the coastal area of the Estuary, especially in the northwest area where the water was affected by the runoff of Jiaojiang River; whereas the shrimps in autumn had the highest weight density in the southeast area where the water was affected by the Taiwan Warm Current. The stepwise regression analysis showed that the shrimps weight density and number density were significantly correlated with surface water temperature (P_W = 0.004, P_N = 0.01), but less correlated with water salinity and depth. In spring, Acetes chinensis had the greatest contribution to the shrimp number density, and had greater contribution to the shrimp weight density, being the most dominant shrimp species. In autumn, Solenocera crassicornis had the highest contribution to both the weight density and the number density of the shrimps, being the most dominant species.

Changes of macrobenthos community and their relationships with environmental factors along cascading reservoirs of Xiangxi River Basin, China.

LI Bin1,2, SHEN Heng-lun1,2, ZHANG Min3, CAI Qing-hua1**, SHAO Mei-ling4

2013, 32(8):  2070-2076. 

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An investigation was made on the macrobenthos communities in three cascading reservoirs in Xiangxi River Basin in October, 2005 and 2011, respectively, aimed to explore the changes of the macrobenthos communities and their relationships with the environment. As compared with that in 2005, the macrobenthos community in the three reservoirs in 2011 changed to some extent. In Gudongkou Reservoir I, Oligochaeta was still dominant, and the total macrobenthos density increased. In Gudongkou Reservoir Ⅱ, the dominance degree of Chironomidae descended, while the total macrobenthos density ascended. Meanwhile, the relative abundance of Procladius sp. declined dramatically from 94.5% to 35.5%, while that of Limnodrilus hoffmeisteri increased to 36%. The macrobenthos community in Xiangxi Bay had great change. Since Chironomidae replaced Tubificidae as the absolutely preponderant species, the relative abundance of Chironomidae reached 89%, but the total macrobenthos density decreased. These changes were attributed to the drastic water level fluctuation of the ThreeGorges Reservoir. The canonical correspondence analysis (CCA) on the relationships between the macrobenthos community and environmental factors in the three reservoirs showed that Procladius sp. preferred the waters with higher turbidity, while Limnodrilus hoffmeisteri and Tubifex tubifex preferred the waters with higher water column stability and lower bottom water temperature.

Impacts of starvation on the juveniles of Chinese mitten crab Eriocheir sinensis.

HE Jie1,2, WANG Chun1,2, SHAO Lu-chang1,2, HONG Yu-hang1,2, LU Yi1,2, YANG Xiao-zhen1,2, CHENG Yong-xu1,2**

2013, 32(8):  2077-2084. 

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This paper studied the impacts of starvation on the morphology, behavior, survival, and physiology of juvenile Eriocheir sinensis at water temperature 26.2-28.4 ℃, and determined the point of reserve saturation (PRS) and the point of no return (PNR). Under starvation, the time the first death occurred (T₁) for the E. sinensis juveniles at stages Ⅰ, Ⅱ, and Ⅲ was 8.0, 14.0, and 20.3 d, the time the 50% mortality occurred (T₅₀) was 11.4, 16.0, and 25.5 d, and the time the 100% mortality occurred (T₁₀₀) was 15.0, 22.0, and 32.3 d, respectively. The ability of starvation resistance for stage Ⅲ juveniles was the highest, followed by stage Ⅱ, and stage Ⅰ juveniles. During starvation period, the moisture content of E. sinensis increased, dry weight decreased significantly, and the dry weight loss rate decreased gradually with the extension of time. Under the feeding strategy of presatiation, the molting rate of stage Ⅱ juveniles increased with the extension of feeding time, and the PRS₅₀ was 2.10 d. No significant difference was found in the molting duration between different treatment groups and continuous feeding group. However, if continuous feeding lasted less than 3 d, the weight of the juvenile crabs in each treatment couldn’t reach to that of the continuous feeding group. Under the feeding strategy of prestarvation, the molting rate of stage Ⅱ juveniles decreased with the extension of starvation time, the PNR₅₀ was 9.95±0.33 d, and the PNR₁₀₀ was 14 d. The time of molting cycle extended, and the gap was approximately equal to the initial starvation time. There was no extra feeding time taken to offset the lost energy during the starvation period. No significant difference was observed in the body weight after molting between treatment groups and control group (P> 0.05).

Induction velocity of juvenile grass carp, silver carp, and darkbarbel catfish.

BAI Yan-qin1, LU Bo1, LUO Jia1, LIANG Yuan-yuan1, LIU De-fu1, CHEN Qiu-wen1, SHI Xiao-tao1,2**

2013, 32(8):  2085-2089. 

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By using self-made test chamber and the method of increasing velocity, this paper studied the induction velocity of juvenile grass carp (Ctenopharyngodon idellus) (body length 964±3.12 cm, body weight 20.97±16.71 g), silver carp (Hypophthalmichthys molitrix) (body length 10.60±3.45 cm, body weight 24.37±18.61 g), and darkbarbel catfish (Pelteobagrus vachelli) (body length 11.54±1.46 cm, body weight 20.98±6.94 g) at water temperature 21±1 ℃. The induction velocity of the juvenile grass carp, silver carp, and darkbarbel catfish was (8.21±0.68), (6.74±0.84), and (33.11±3.06) cm·s^-1, and the relative induction velocity was (0.91±0.22), (0.67±0.15), and (2.9±0.29) BL·s^-1, respectively. No significant difference was observed in the induction velocity between juvenile grass carp and silver carp (P>0.05), but the induction velocity of juvenile darkbarbel catfish was four times higher than that of the juvenile grass carp and silver carp. It was suggested that the juvenile grass carp and silver carp were more sensitive to the water velocity than the juvenile darkbarbel catfish. This study could provide scientific reference for designing the fish way and determining the trawling speed.

Effects of planting two energy crops on soil faunal community in Guangxi of South China.

HU Li-le1, LOU Xue-dong1,2, LIU Wen-hui1, KANG Bing2, LI Jun-sheng1**

2013, 32(8):  2090-2096. 

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In this study, the energy crop effects of species types (cassava Manihot esculenta and sugarcane Saccharum officinarum), cropping patterns (intercropping and monoculture), and terrain selection (sloping land and flat land) on the soil fauna and corresponding soil environment quality were examined, taking the flat arable land planting with cassava as a reference for the cultivated land continuing operations in Wuming County, Guangxi Province. Planting sugarcane led to the significant decrease in the abundance and diversity of soil fauna and the corresponding soil biological quality, with the decrement of the soil biological quality reached 53% (P=0.032). Intercropping peanut (Arachis hypogaea) had no obvious effects on the abundance and diversity of soil fauna and the soil biological quality, but the biodiversity increased significantly, as compared to cassava monoculture. Terrain selection had obvious effects on the soil fauna. On sloping fields, the abundance of soil fauna, biodiversity, and corresponding biological quality were generally decreased. These results indicated that cassava could be more suitable for long-term cultivation than sugarcane. The negative impacts of cassava cultivation on the soil biodiversity and soil quality could be buffered through the optimization of cropping pattern and terrain selection. It could be predicted that cassava would be selected as a long-term prior energy crop in Guanxi.

Effects of suspended solid on the survival, growth, and antioxidant enzyme activities of Mactra veneriformis.

YANG Guo-jun1, SONG Lun2, WANG Nian-bin2**, LIU Qing-ming3, CHEN Wei-qiang4, CHEN Zhi-qiao1

2013, 32(8):  2097-2103. 

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A laboratory simulation experiment was conducted to investigate the effects of suspended solid on the survival, growth, and physiology of Mactra veneriformis. The M. veneriformis individuals were exposed to different concentrations of suspended solid (0 mg·L^-1 group A), 100 mg·L^-1 (group B), 1000 mg·L^-1 (group C), and 10000 mg·L^-1 (group D), and the changes of the superoxide dismutase (SOD) and catalase (CAT) activities in the visceral mass and gill filament of M. veneriformis were investigated. Under the stress of suspended solid, M. veneriformis appeared chronic toxic effect, with the survival and growth being inhibited to some extent. The gill SOD activity of the M. veneriformis exposed to 100 and 1000 mg·L^-1 of suspended solid produced an adaptive induced response, but that of the M. veneriformis exposed to 10000 mg·L^-1 of suspended solid was significantly inhibited first and induced then, as compared to the control group. The visceral SOD activity had less change with time and suspended solid concentration (P>0.05). The gill CAT activity of the M. veneriformis exposed to 1000 and 10000 mg·L^-1 of suspended solid was up-regulated first, returned to normal then, and increased again, while that of the M. veneriformis exposed to 100 mg·L^-1 of suspended solid was only upregulated significantly during the later period of the experiment. The visceral CAT activity had less change with time and suspended solid concentration. These findings showed that the visceral mass antioxidant system was not activated under suspended solid stress, but the gill filament antioxidant enzyme activity responded quickly to the stress, suggesting that the gill filament antioxidant system was more sensitive to suspended solid.

Secondary productivity of benthic macrofaunal community in intertidal zone of Lianzhou Bay, China.

HE Bin-yuan1,2**, LAI Ting-he1,2, WANG Xin1,2, PAN Liang-hao1,2, CAO Qing-xian1,2

2013, 32(8):  2104-2112. 

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A seasonal investigation was conducted on the dynamic changes of benthic macrofaunal community in the three types of intertidal habitats, i.e., bare flat, mangrove forest, and Cyperus malaccensis saltmarsh, in Lianzhou Bay in January, April, July, and October, 2011, and the Brey’s empirical formula was applied to estimate the secondary productivity of benthic macrofaunal community in the three habitats. A total 156 species belonging to 8 phyla of intertidal benthic macrofauna were collected, among which, 136, 85, and 29 species were recorded in bare flat, mangrove forest, and saltmarsh habitats, respectively. The average species abundance per sampling station was 9.5±4.8 species in bare flat, 9.5±3.9 species in mangrove forest, and 5.9±19 species in saltmarsh, respectively. In all the three habitats, the percentages of different categories to total species followed the same decreasing order of Mollusk > Arthropod > Annelid > Chordate > other categories. The community structure of the benthic macrofauna in saltmarsh had smaller change, with Ilyoplax ningpoensis significantly dominated. In mangrove forest and bare flat, the dominant species changed with the water salinity. In the intertidal zone of Lianzhou Bay, the average secondary productivity of the benthic macrofaunal community was 15.88 g·m^-2·a^-1, and that in bare flat, mangrove forest, and saltmarsh was 16.16 g·m^-2·a^-1, 997 g·m^-2·a^-1, and 3.88 g·m^-2·a^-1, respectively. The average P/B ratio in the intertidal zone was 0.70, and that in bare flat, mangrove forest, and saltmarsh was 0.70, 0.65, and 1.02, respectively. The annual secondary production in the intertidal zone was 14623 t (FM). Water salinity and vegetation type were the major factors affecting the community structure of the intertidal benthic macrofauna, and further, the spatial distribution of the secondary productivity of the benthic macrofauna in Lianzhou Bay.

Phylogeographic structure of Pheropsophus jessoensis (Insecta: Coleoptera: Carabidae) in Tsinling Mountains of China based on mtCoI gene analysis.

YIN Huan**

2013, 32(8):  2113-2119. 

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In order to understand the phylogeographic structure of Pheropsophus jessoensis Morawitz in the Tsinling Mountains, a fragment with 789 bp from the mtCoI gene was sequenced for the 184 P. jessoensis individuals from 25 geographical populations belonging to two geographic areas. A total of 55 polymorphic sites were found, and 67 haplotypes were identified. The haplotype diversity was high (H_d=0.9550), while the nucleotide diversity was relatively low (P_i=0.0049). The Kimura 2-parameter (K2P) genetic distance of the P. jessoensis between west Tsinling population and east Tsinling population or among the 25 populations was small, with the values ranged from 0.0026 to 0.0072. The analysis of molecular variance (AMOVA) and the nested clade phylogeographical analysis (NCPA) revealed the significant genetic subdivision among the individuals within populations, but there existed no remarkable phylogeographic structure between the eastern part and the western part of Tsinling Mountains. The NCPA showed certain geographical association of haplotypes. The results from mismatch distribution and neutrality tests suggested that the present complex genetic pattern of P. jessoensis in Tsinling Mountains was resulted from the restricted gene flow with isolation by distance, and from the sudden or contiguous range expansion. The demographic history analysis revealed that this species could have experienced a relatively recent population expansion occurring in the later Pleistocene (0.05-0.23 Ma). The climatic oscillations during this period might have affected the geographical isolation and genetic differentiation of P. jessoensis in this area.

Effects of chicken-grazing intensity and sampling time on soil nitrogen availability in sandy grassland.

SHI Sheng-nan1,2, YU Zhan-yuan1,3**, ZENG De-hui1,3, HAN Xing-guo1

2013, 32(8):  2120-2125. 

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A field experiment with five chicken-grazing intensities (0 feather·200 m^-2, CK; 10 feathers·200 m^-2, D₁; 10 feathers·400 m^-2, D₂; 10 feathers·600 m^-2, D₃; and 10 feathers·800 m^-2, D₄) was conducted in the Keerqin Sandy Land of China to study the effects of the grazing intensity and sampling time on the soil inorganic nitrogen concentration, potential net nitrogen mineralization and nitrification rates, and microbial biomass in sandy grassland. Compared with CK, treatments D₁ and D₂ increased the soil potential net nitrogen mineralization and nitrification rates in August and October significantly, while treatments D₃ and D₄ had little effects on the soil nitrate nitrogen concentration and the soil potential net nitrogen mineralization and nitrification rates. Chickengrazing increased the soil nitrate nitrogen concentration and the soil potential net nitrogen mineralization and nitrification rates significantly, but less affected the soil ammonium nitrogen concentration. Sampling time had significant effects on the soil inorganic nitrogen concentration and the soil potential net nitrogen mineralization and nitrification rates, but the effects of the interaction between grazing intensity and sampling time were not significant. Chickengrazing had little effects on the soil microbial biomass C, N, and C/N. In conclusion, chicken-grazing could enhance the soil nitrogen supplying capability, which had an uptrend with the increase of grazing intensity. In this study, the optimum grazing intensity was 250-500 feathers·hm^-2.

Concentrations of soil rare earth elements and their accumulation characteristics in plants in recovered mining wastelands in Fujian Province, South China.

LI Xiao-fei1,2, CHEN Zhi-biao1,2**, CHEN Zhi-qiang1,2

2013, 32(8):  2126-2132. 

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Based on filed sampling and laboratory analysis, this paper studied the concentration, distribution, and migration of rare earth elements (REEs) in the soils and dominant plants in recovered mining wastelands in Changting County of Fujian Province. Due to the serious destruction of the soils, their nutrient contents were lower, but the REEs concentrations ranged from 507.40 to 841.37 mg·kg^-1, being higher than those of the control. The REEs in the soils were mainly in exchangeable form, accounting for 61%-98% of total. The soil REEs were transformed from single exchangeable form to a variety of fractions, and the concentration of organic fractions increased significantly. The REEs concentrations in plant root, stem, and leaf were 40.27-98601, 5.14-206.58, and 6.81-2364.51 mg·kg^-1, respectively. Except that the REEs concentrations in Dicranopteris pedata organs were in the order of leaf > stem > root, those in the other plants organs were in the order of root > leaf > stem. According to the REEs concentrations in shoot and root, the plants could be classified into two types. Dicranopteris pedata was accumulator plant, whereas Eucalyptus spp., Paspalum wettsteinii, Schima superba, and Camellia'sasanqua were rootcompartment plants.

Spatial heterogeneity of surface soil trace elements in a small catchment in Karst peak-cluster depression area of South China.

GAO Peng1,2,3, FU Tong-gang1,2,3, WANG Ke-lin1,2**, CHEN Hong-song1,2, ZENG Fu-ping1,2

2013, 32(8):  2133-2139. 

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Based on grid (80 mx80 m) sampling and by using the methods of classical statistics and geostatistics, an investigation was conducted on the spatial heterogeneity of trace elements (Pb, Cr, Ni, Cu, Zn, and B) in 163 surface soil (0-20 cm) samples in a small catchment in a typical Karst cluster-peak depression area of South China. There was a great difference in the concentrations of the soil trace elements. Their average concentrations were in the order of Zn>Cr>Ni>Pb>B>Cu, and the average variation coefficients were in the sequence of Ni>Cu>Zn>Pb>B>Cr. Except that the Cr had a medium spatial autocorrelation with longer range and a better spatial continuum, the other five trace elements had a stronger spatial autocorrelation with shorter range and a stronger spatial dependence. The similar Kriging contour maps indicated that the distribution patterns of the six trace elements were almost similar, i.e., higher in the east and lower in the north and south, and higher in depression and lower on slope. It was suggested that human disturbances and natural conditions (vegetation, bare rock rate, slope, and aspect) were the primary factors affecting the spatial patterns of the soil trace elements in small catchments in Karst peak-cluster depression regions.

Ecological risk assessment of mercury in soils and waters in Guizhou Province of Southwest China.

LI Qiang1,2, ZHANG Rui-qing3, GUO Fei2, MO Ce-hui1, LIAO Hai-qing2 **

2013, 32(8):  2140-2147. 

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This paper analyzed the spatial distribution of mercury (Hg) in the soils and surface waters in Guizhou Province. The geo-accumulation index and potential ecological risk index were applied to assess the pollution degree and the ecological risk of total mercury (THg) in soils, and the single factor method and safety threshold method were employed to evaluate the THg pollution degree and the ecological risks of reactive mercury (RHg) and methylmercury (MeHg) in surface waters, respectively. The results showed that in the soils close to mercury-related mines and factories, there was a higher THg pollution. Of the 23 soil samples from the mercuryrelated mines and factories, the extreme, severe, and moderately severe THg pollution occupied 78.26%, 13.04%, and 8.70% of the total samples, respectively. Meanwhile, the potential ecological risk of THg in the soils was extremely high. In the other areas, soil THg pollution was moderate, and the potential ecological risk was acceptable. The THg pollution in the surface waters close to mercury mines, lead-zinc mines, and organic chemistry factories was serious, but the ecological risk to aquatic organisms was negligible due to the low concentrations of RHg and MeHg.

Pollution characteristics and risk assessment of heavy metals in the sediments of Nansha River in Beijing.

ZHU Guang-xu1,2, GUO Qing-jun1**, CHEN Tong-bin1, Marc Peters1, YANG Jun-xing1, ZHANG Han-zhi1,2, WEI Rong-fei1,2, WANG Chun-yu1,2

2013, 32(8):  2148-2153. 

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Nansha River is an important river for drainage and landscape in the north of Haidian District, Beijing. In order to have an overall understanding on the pollution characteristics of heavy metals in the sediment of Nansha River, the surface sediment samples were collected, and the concentrations and speciations of the heavy metals were analyzed. Based on the single factor index method, Hakanson comprehensive pollution index method, and potential ecological risk index method, the ecological risk of the heavy metals in the sediment was evaluated. The results showed that the heavy metals in the surface sediment of Nansha River had homogeneity, and the pollution degree of the heavy metals followed the order of Cr>Cd>Zn>Cu>Pb>Ni. Based on the ecological risk index evaluation, the ecological risk of the heavy metals was in the order Cd>Pb>Cu≈Cr>Ni≈Zn, and only Cd showed higher potential ecological risk. The comprehensive potential ecological risk index showed that Nansha River was predominantly at a low ecological risk level, except the section near the Jingzang Highway Bridge, which showed a high risk level. The analysis on the speciation of the heavy metals showed that weak acid soluble Cd had a high concentration and high transference ability, and was most likely to harm the biological environment directly. Pb and Zn and Cu and Ni had a moderate potential risk for the environment, and Cr had a little environmental hazard. These results could be used as a valuable database for the pollution management of Nansha River.

Variation characteristics of different-level precipitation in Ningxia of Southwest China in 1962-2011. 

LI Fei, ZHANG Ming-jun**, LI Xiao-fei, WANG Bao-long, WANG Sheng-jie, WANG Qiong

2013, 32(8):  2154-2162. 

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Based on the daily precipitation data from 9 meteorological stations in Ningxia in 1962-2011, and by using linear trend method, correlation analysis, Hurst trend analysis method, and IDW spatial interpolation method, this paper analyzed the variation characteristics of different levels precipitation, precipitation days, and precipitation intensity, aimed to understand the structural characteristics of different levels precipitation in Ningxia. Overall, the annual precipitation and the precipitations days showed a decreasing trend, while the annual precipitation intensity had a slight increase. In the future, the annual precipitation would be reversely persistent, while the precipitation days and precipitation intensity would be persistent. Spatially, due to the effects of different factors, the annual precipitation, precipitation days, and precipitation intensity decreased from southeast to northwest, and the spatial pattern of the precipitation and precipitation days was in consistency. Temporally, the precipitation in summer was abundant, precipitation days were more, and precipitation intensity was large, with the largest precipitation intensity of rainstorm. In winter, the precipitation was short, precipitation days were less, and precipitation intensity was small. The climate change trend analysis of different levels precipitation events on different time scales showed that the annual precipitation and precipitation days presented a decreasing trend, while the annual precipitation intensity, as affected by the light rain and storm rain in winter, summer and autumn, showed a slight increase.

A comprehensive analysis of landscape pattern dynamic change based on multi-methods: A case study of Tieling City, Liaoning Province of Northeast China.

SUN Feng-yun1,2, LIU Miao1**, HU Yuan-man1, LI Jun-ying3, LI Chun-lin1,2, CHEN Tan1,2

2013, 32(8):  2163-2171. 

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Landscape dynamics is one of the core areas in landscape ecology study, and also, the basis of relevant ecological and environmental researches. In this paper, the changes of the landscape pattern in Tieling City of Liaoning Province in 2002-2011 were comprehensively studied by using traditional spatial statistical analysis, transition matrix, landscape metrics, landscape dynamic index, and Kappa coefficient series method based on 3S technology. During the study period, the landscape pattern in the City changed in a certain degree. The upland area increased substantially, while the paddy field area reduced markedly. The landscapes of different categories kept changing. Overall, the shape of the landscape patches tended to be more complex. The landscape pattern became heterogeneous, and the landscape fragmentation tended to be intensified. Human activities affected the landscape pattern obviously. The comprehensive landscape dynamic index from 2002 to 2007 was significantly higher than that from 2007 to 2011, which showed a slowdown trend of landscape dynamics. The results of Kappa index series showed that the landscape pattern change was gradually transformed from the change of landscape categories into the change of position. It was suggested that a combined application of multi-methods could reflect the dynamic change of landscape pattern more comprehensively and effectively.

Remote sensing monitoring of drought in Turkmenistan oasis based on temperature/vegetation drought index.

ZHANG Zhe, DING Jian-li**, YAN Xue-ying, LI Xin, WANG Gang

2013, 32(8):  2172-2178. 

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Drought stress is an important issue in the agricultural production in central Asia. Selecting the typical MurghabTejen oasis in Turkmenistan as the study area, and by using two MODIS images and the two TM images in the same time, the land surface temperature (LST)/normalized difference vegetation index (NDVI) characteristic space was established, and two kinds of temperaturevegetation drought index (TVDI), i.e., TVDI-TM and TVDI-MODIS, were calculated from the LST/NDVI of different sensor images in 2001 and 2011. The Landsat TM data with higher resolution were used to verify the results of the MODIS inversion data. The absolute error of the TVDITM and TVDI-MODIS was 0.0178 and 0.0228, the RMSE was 0.0226 and 0.0279, and the correlation coefficient was 0.949 and 0.922, respectively, indicating that TVDI could effectively reflect regional soil drought conditions. In the oasis, arid region occupied more than 60% of the total, and drought was becoming more serious from the center to the outer oasis. In the past ten years, the area of low soil moisture in the oasis presented an expanding trend, the mist and normal moisture area decreased by 5.32%, and the drought and severe drought area increased by 14%. Overall, the drought situation was aggravated. Therefore, using the TVDI of MODIS image could effectively monitor the droughts in central Asia.

Structural characteristics of plant-animal mutualistic networks and related affecting factors.

LUO Fang, PAN Yang, LU Chang-hu**

2013, 32(8):  2179-2185. 

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The mutually beneficial interactions between plants and pollinators or seed dispersers have a significant consequence in the maintenance of biodiversity. The mutualistic interactions often involve dozens or even hundreds of species that form interdependently complex networks. Recent improvements in network analysis provide suitable means for the researches on the structure of the complex ecological networks. The mutualistic networks have the following characteristics: (1) with the structural characteristic of nestedness, which introduces functional redundancy, (2) with asymmetry in the numbers and strengths of interactions, which facilitates the maintenance of biodiversity, and (3) with the characteristic of modularity. The species between modules interact with each other more loosely than those within modules. Of the factors affecting plantanimal mutualistic networks, habitat fragmentation and invasive species are the two especially obvious factors. Habitat fragmentation hampers the interaction of mutualism, reducing the potential of plant regeneration, while invasive species are mainly represented as alien plant invasion, competing with native plants for the mutualistic interactions with animals. In contrast with native plants, alien plants are interrelated with native generalists more easily. The plantanimal mutualistic interactions in communities can be changed with time and space. Accordingly, how and why these changes happened should be further approached in the future.

Impacts of alien species invasion on the South China Sea ecosystem and related control strategies. 

LU Qin-yan1,2, LIU Yong1, LI Chun-hou1**, WEI Xiao-lan1,3, LIU Yong1,2

2013, 32(8):  2186-2193. 

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Alien species invasion is generally regarded as the second serious threat following habitat destruction to marine ecosystem. This paper elaborated the biological and ecological characters of marine alien species in the South China Sea and the impacts of these species invasion on the South China Sea ecosystem, and put forward the corresponding control strategies. There were totally 35 alien species in the South China Sea, most of which were accidentally introduced species. Among the alien species, alien algae were dominant (16 species, 45.7% of the total), followed by fouling animals (11 species, 31.4%), alien microorganisms (5 species, 14.3%), and intertidal plants (3 species, 8.6%). The alien species invasion weakened the community structure and reduced the biodiversity, altered the genetic diversity and decreased the genetic variation, caused diseases outbreak, and aggravated the marine ecological disasters of the South China Sea ecosystem. The above-mentioned analyses on the characters of marine alien species in the South China Sea and on the impacts of these species invasion on the South China Sea ecosystem could provide basic data for the further research of alien species invasion in the South China Sea, whereas the suggested control strategies could help the regional administrations to better protect the marine ecosystem of the South China Sea.

Methods for studying water cycle and water sources in arid regions based on SPAC system.

SHOU Wen-ai1,2, HU Fei-ong1,2, Alamusa1, LIU Zhi-in1**

2013, 32(8):  2194-2202. 

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Soil-plant-atmosphere continuum (SPAC) is the core in studying plant water use and water cycle. To study the water transportation process of SPAC is of significance for the vegetation restoration in arid regions. From the aspects of soil moisture and plant transpiration, this paper summarized the study methods of soil moisture, mainly thermal inertia method, neutron probe method, and time domain reflectometry, and the study methods of plant transpiration at foliage scale, single wood scale, stand scale, and regional scale. The applications of stable isotope method in the study of plant water sources were also highlighted.

Interactions between fine particulate matter (PM_2.5) and vegetation: A review.

ZHAO Chen-xi, WANG Yu-jie**, WANG Yun-qi, ZHANG Hui-lan

2013, 32(8):  2203-2210. 

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Due to its small size and inertia tendency of sedimentation, fine particulate matter (PM_2.5) seriously pollutes the environment, while vegetation can alleviate the pollution from particulate matters to a certain extent. Based on the previous studies on the sedimentation mechanisms of PM_2.5, this paper analyzed the interactions between PM2.5 and vegetation. Through blockage and adsorption, vegetation can positively remove atmospheric particulates, whereas the retention of excessive particulates can negatively affect plant growth. However, the positive effect of vegetation on atmospheric particulates is overweighed the negative effect. This paper elaborated the effects of vegetation crown, stem, and blade on the removal of PM_2.5 at the scales of forest stand (environment features), individual tree (tree species characteristics), and blade sample (types and distribution of particulates), and with the considerations of environmental factors (meteorological and aerodynamical elements, atmospheric particle concentration, and plant phenology), air chamber experiment, and characteristics of particulates retained by blade. It was suggested that in the further researches, quantitative measurement should be preferred, with the focuses on the comparative analysis and systematic study about the PM_2.5 removal capability of different kinds of vegetation and on the determination of dominant tree species for the prevention of atmospheric PM_2.5 pollution in a certain place.

River health assessment based on different biological indicators: A review.

ZHOU Shang-bo1,2, YUAN Xing-zhong1,2**, LIU Hong1,2, ZHANG Yue-wei1,2, REN Hai-qing1,2

2013, 32(8):  2211-2219. 

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In order to comprehensively and objectively reflect the impacts of human disturbances on river ecosystems, various countries and regions have set up a series of river health assessment methods based on the ecological responses of fish, diatom, and macroinvertebrates to the human disturbances. Among these assessment methods, the methods based on fish still pay attention to the application and perfection of the index of biotic integrity, those based on diatom have a wider application, and the methods based on macroinvertebrates are still at the leading place. As for the construction of indicator systems, in addition to the evaluation at the levels of community structure and function, the evaluation based on biological taxonomy (family, genera and species) is made. At present, the multivariate assessments of the ecological responses of aquatic organisms to human disturbances are the most common assessment methods, but the methods tend to lack consideration of information redundancy among the various indicators. The longterm use of the indicator systems should be further studied.

Construction methods of nature reserve system: Research progress.

GUO Zi-liang1, LI Xiao-yu2, CUI Guo-fa1**

2013, 32(8):  2220-2228. 

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To establish a scientific nature reserve system is a hot topic in the research field of nature reserve protection under the issues of more and more serious wildlife habitat loss and habitat fragmentation. This paper summarized the research progress in the construction of nature reserve system, and introduced the related construction methods, including conservation gap analysis, conservation prioritization analysis, and ecoregion conservation planning analysis, as well as the methods of habitat corridor design. The advantages and disadvantages and the suitable application conditions of these methods were analyzed, and the future research directions were put forward to provide some references for the study and practice in the construction of nature reserve system and to promote the development of nature reserve.

Research advances and trends in forest ecosystem services value evaluation.

ZHAO Jin-long, WANG Luo-xin, HAN Hai-rong**, KANG Feng-feng, ZHANG Yan-lei

2013, 32(8):  2229-2237. 

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As the main body of terrestrial ecosystem, forest ecosystem plays an important role in global ecosystem. The valuation of forest ecosystem services integrates different aspects of several subjects, and has become one of the hotspots in present ecological economics and environmental economics study. How to evaluate forest ecosystem services value and to establish a globally unified and feasible evaluation standard and index system become the urgent issues in the present time. However, it is difficult to accurately evaluate the ecosystem services value because of the complexity of ecosystem and the limitations of value research. This paper described the concept of forest ecosystem services, reviewed the research progress of forest ecosystem services value evaluation at home and abroad, and listed some important research workers and events in the history of the evaluation. In addition, the evaluation methods and the concrete calculation methods for the forest ecosystem services value based on the market theory of the actual market approach, substitution market approach, and virtual market approach were introduced in detail. In order to effectively solve the problems in ecosystem services dynamic evaluation, this paper also analyzed the advantages and disadvantages of some abroad ecological models, including InVEST, MIMES, CITYgreen, SoIVES, and GUMBO. Finally, on the basis of summarizing the current evaluation methods, the directions for future forest ecosystem services value evaluation were put forward, i.e., modeling of evaluation, precision of evaluation, processes and formation mechanisms, and conversion rate of functions to services.

Fruit ecology: Its concepts, research advances, and research perspectives.

FANG Wei-wei1,2, YU Shun-li1**

2013, 32(8):  2238-2244. 

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This paper introduced the concepts and main research contents of fruit ecology, summarized the related research advances, analyzed the shortcomings and gaps of the extant researches, and pointed out the future research perspectives. So far, some advances have been made in the correlativity between seed and fruit, fruit color and environment, fruit chemical components and environment, and fruit physical properties and geographic distribution pattern, and the coevolution between fruits and frugivores. However, following scientific issues need a further focus in the future: 1) the spatial differentiation patterns and their mechanisms of fruit physical traits such as mass spectrum and seed number per fruit, 2) the spatial variations and their mechanisms of fruit chemical components, and 3) the large scale geographical distribution patterns of fruit type composition modes and fruit type diversity and their environmental adaptation explanation, and the coevolution between fruit spread and frugivores.