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    10 October 2018, Volume 37 Issue 10
    The influence of stand factors on species diversity of herb layer in Zhangbei poplar plantations.
    ZHU Yuan-jun, YANG Xiao-hui, SHI Zhong-jie, LIU Yan-shu, ZHANG Xiao
    2018, 37(10):  2869-2879. 
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    Understanding the influence of stand factors on species diversity of herb layer in forest plantations is of great significance for forest tending and rational management. In this study, we investigated six stand factors (i.e., stand death rate, average tree height, average branch height, average diameter at breast height, average crown width, and stand density) and community characteristics of herb layer in Zhangbei poplar plantations. The species diversity indices of herb layer were calculated to analyze the changes in stand structure and species diversity of herb layer with changes of stand factors. The results showed that 44 species of vascular plants in herb layer were found, belonging to 38 genera of 17 families. The top three families with the most species were Compositae, Leguminosae and Gramineae. Xerophytes were the dominant ecological water type of plants, with a total of 25 species accounting for 56.82% of all species. Hemicryptophyte, a total of 27 species, was the dominant life form in herb layer, which accounted for 61.36% of the total species. The species richness index, Shannon index and Pielou index varied among different plots, with species richness index having the largest coefficient of variation (CV). Simpson index did not vary among different plots, with a minimal CV. There were significant differences in the stand factors among various plots, among which the degree of variation of stand death rate was the highest, and the variation degree of average diameter at breast height was the lowest. The main stand factors affecting species richness index of herb layer were stand death rate, average branch height, average diameter at breast height and stand density. The main stand factors affecting the Shannon index were stand death rate, average tree height, average diameter at breast height and stand density. Stand factors had no effects on Simpson index and Pielou index. Appropriate regulation of stand density and mixture of poplar with conifer species would be beneficial to the maintenance of species diversity of herb layer in Zhangbei poplar plantations.
    Temporal changes of vegetation characteristics during the long-term grazing exclusion in Horqin Sandy Land.
    LV Peng, ZUO Xiao-an, YUE Xi-yuan, ZHANG Jing, ZHAO Sheng-long, CHENG Qing-ping
    2018, 37(10):  2880-2888. 
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    To reveal the variation of vegetation characteristics during the enclosure restoration of degraded vegetation in Horqin Sandy Land, we investigated the vegetation characteristics in mobile dune, semi-fixed dune, fixed dune, and sandy grassland after grazing exclusion, in midAugust of 2011, 2013 and 2015. The results showed that during 2011-2015, the dominance of dominant species Agriophyllum squarrosum in mobile dunes was gradually decreased, while that of the dominant species Artemisia halodendrom in semi-fixed dunes undulately decreased and that of therophytes increased. The dominance of therophytes was decreased and the perennials increased in fixed dunes and grasslands. Along with enclosure restoration, vegetation cover, species richness, litter biomass, aboveground biomass and belowground biomass were significantly increased. During 2011-2015, the mean litter biomass in the four habitats and the vegetation coverage in semi-fixed dunes were significantly increased, while species richness and aboveground biomass were changed undulately and there was no significant difference in the belowground biomass among the three years. Vegetaion coverage, aboveground biomass, litter biomass, belowground biomass and total plant biomass were positively related to species richness during the enclosure restoration. Changes of plant community composition and dominant species reflected a positive succession of plant community and complication of community structure, which could be predicted by a positive linear model between species diversity and biomass.
    Rainfall redistribution and canopy leaching in pure stands of Pinus massonianaand Castanopsis hystrixin Guangxi, China.
    LEI Li-qun, NONG You, CHEN Lin, WEI Ju-ling, HE Yuan, LIANG Yong-ke
    2018, 37(10):  2889-2895. 
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    The differences of rainfall redistribution and canopy leaching between the pure stands of Pinus massoniana and Castanopsis hystrix were compared to provide hydrological data for the transformations of coniferous plantations in southern subtropical China. In Guangxi Youyiguan Forest Ecosystem Research Station, a combination of field testing and laboratory analysis was used to measure rainfall, throughfall, and stemflow by 30 understory tipping bucket rain gauges from January to December in 2016. We analyzed the chemistry compositions in samples from ten rainfall events occurred during July to December. The results showed that precipitation was 1070.2 mm during study period. The throughfall reached 823.0 and 693.2 mm in pure stands of P. massoniana and C. hystrix, accounting for 76.9% and 64.8% of the precipitation, respectively. Moreover, the stemflow was 3.2 and 9.9 mm for both stands, being 0.3% and 0.9% of the precipitation, respectively. The canopy interceptions were 244.0 and 367.1 mm, accounting for 22.8% and 34.3% of the precipitation, respectively. Our results suggested that there were differences in the rainfall redistribution between the two pure stands, with C. hystrix stand having better ability of canopy interception than P. massonianastand. The amount of canopy leaching for K+, Mg2+, Na+ and Ca2+ in C. hystrix stand was 17.53 kg·hm-2, which was 0.7 times of the P. massoniana stand. However, the acid buffering capacity of C. hystrixstand was 1.6 times of the P. massoniana stand. Compared with the P. massoniana pure stand, the C. hystrix pure stand was more effective to prevent canopy nutrient leaching and adapt to the acid deposition.
    Effects of soil nutrient heterogeneity and interspecific competition on growth and reproductive traits of Spartina alterniflora and Phragmites australis.
    GUAN Yu-ting, QIN Tian-jian, NIU Yu-xin, NING Lei, LI Hong-li, YU Fei-hai
    2018, 37(10):  2896-2904. 
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    Soil nutrient heterogeneity is ubiquitous in natural ecosystems, which affects the growth and reproduction of clonal plants. Relatively little is known about the interactive effect of soil nutrient heterogeneity and competition on the growth and reproduction of invasive and native plants. In a greenhouse experiment, we grew an invasive clonal species Spartina alterniflora and a native one Phragmites australis in either monoculture or mixture in both homogeneous and heterogeneous soil nutrient conditions. In the monoculture, each pot was grown with six ramets of each species, and in mixture each pot was planted with three ramets of both species. The amount of soil nutrients in each pot was exactly the same in the homogeneous and heterogeneous treatments. Soil nutrient heterogeneity significantly decreased the number of leaves of S. alterniflora, but increasedinternode length and rhizome length of P. australis. Competition increased leaf number, ramet number, internode length, rhizome number, and rhizome length of S. alterniflora, but decreased aboveground biomass, leaf mass and stem mass of P. australis.There were interactive effects of soil nutrient heterogeneity and competition on number of leaves, stem mass and internode length of S. alterniflora, but not on any of the growth characters of P. australis. These findings suggest that soil nutrient heterogeneity can alter the competition between S. alternifloraand P. australis.
    Photosynthetic characteristics of oil peony Paeonia ostii under different intercropping patterns and their relationships with environmental factors.
    YANG Yu-zhen, ZHANG Zhi-hao, LI Juan
    2018, 37(10):  2905-2912. 
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    To explore the efficient cultivation of Paeonia ostii, a main cultivar of oil peony, and improve the efficiency of land and light utilization, we measured the microclimate of P. ostii monoculture (CK) and its intercropping systems with Carica papaya, Toona sinensis, and Juglans regiarespectively, and analyzed the photosynthetic characteristics (Pn) of P. ostii, the relationship between Pn and main eco-physiological factors, and differences among chlorophyll content and fluorescence parameters under the four cropping systems. The results showed that there were significant differences of microclimate among the four cropping patterns in June. Bimodal curves were presented in monoculture and P. ostii-C. papaya intercropping system, while unimodal curves were presented in P. ostii-T. sinensis and P. ostii-J. regia intercropping systems. The highest daily mean value of Pn was observed in P. ostii-J. regiaintercropping system, while the lowest value was in P. ostii-C. papayaintercropping system. The daily mean value of stomatal conductance (Gs) in P. ostii-C. papaya intercropping system was the lowest. The daily mean values of Gs and transpiration rate (Tr) in P. ostii-T. sinensis intercropping system were the highest, while the water use efficiency (WUE) was the lowest in this system. Results from the correlation analysis and multiple stepwise regression analysis showed that eco-physiological factors affectingPn varied among intercropping patterns. Moreover, intercropping patterns also increased the chlorophyll content, Fm, Fv/Fm,ΦPSⅡ, ETR and NPQ ofP. ostiileaves. Therefore, intercropping patterns, especiallyP. ostii-T. sinensis and P. ostii-J. regia intercropping, could guarantee normal photosynthetic production of oil peony and improve the utilization efficiency of land and light and increased biomass per unit land area, with generalized value of application.
    Effects of soil nutrients on leaf N, P and N∶P stoichiometry in Poyang Lake wetlands.
    ZHONG Xin-zi, WU Qin, CUI Hao, FENG Zhe, HU Qi-wu
    2018, 37(10):  2913-2919. 
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    To examine the effects of soil nutrients on leaf nitrogen (N), and phosphorus (P), and N∶P stoichiometry in Poyang Lake wetlands, we collected leaf and rhizospheric soil samples and analyzed N and P concentrations. Results showed that leaf N concentration ranged from 0.44 to 3.02 g·kg-1, with an average of 21.71±8.99 g·kg-1. Leaf P concentration varied from 0.44 to 3.02 g·kg-1, with an average of 1.38±0.53 g·kg-1. The mean of foliar N∶P ratio was 17.19±8.23, suggesting that P, rather than N availability, mainly limited plant growth in Poyang Lake wetlands. Moreover, leaf N and P concentrations were more sensitive to changes in soil P availability rather than soil N availability. Leaf N∶P stoichiometry was well constrained in Poyang Lake wetlands, in that variation in soil N and P did not alter foliar N∶P. In addition, the signi ficantly positive correlations between leaf N and P concentrations were found in various soil nutrient environments. The relationship between N and P in leaves did not shift with the changes of soil nutrients.
    Effects of exponential fertilization on biomass and nitrogen accumulation of Carya illinoensis seedlings.
    WANG Yi-ming, LI Rui-rui, ZHANG Hui, JU Chang-hua, PEI Wen-ming, HU Fei, WAN Fu-xu
    2018, 37(10):  2920-2926. 
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    An exponential fertilization experiment was conducted with six N application levels (0 (CK), 100, 200, 400, 600, 800 mg·seedling-1) to examine the effects of N application levels on the growth and N accumulation of pecan (Carya illinoensis) seedlings. The objective of this study was to reveal the N demand and determine the optimal N application amount for pecan seedlings. Results showed that the stem biomass, leaf biomass, and total biomass of pecan seedlings increased as fertilization levels increased from 0 to 600 mg·seedling-1 and then decreased with the levels increased from 600 to 800 mg·seedling-1. The maximum values of these three variables were 2.30, 4.39 and 9.33 g·seedling-1, being 2.30, 4.99 and 2.17 times as high as that of the CK respectively. Root biomass decreased with the increases of N supply. For exponential fertilization treatments, the N concentration increased by 79%-640% in roots, 101%-352% in stems, and 43%-103% in leaves with N content increasing 184%-666% in roots, 240%-935% in stems, and 402%-823% in leaves. The N content and total biomass of pecan seedlings increased as the N fertilization increased from 0 to 600 mg·seedling-1 and then decreased with the fertilization levels  from 600 to 800 mg·seedling-1. The N concentration of pecan seedlings increased with the increases of N supply. We concluded that 600 mg·seedling-1 would be the optimal N application level for pecan seedlings in greenhouse.
    Effects of arbuscular mycorrhizal fungi on the growth of afforestation seedlings in a rocky desertification area.
    ZHANG Zhong-feng, ZHANG Jin-chi, ZHOU Long-wu, XU Guang-ping, LI Yan-qiong
    2018, 37(10):  2927-2934. 
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    The rocky desertification ecosystem in Southwest China is characterized by ecologically fragile environment, in that the surface soil is poor and dry, vegetation degradation is severe, and vegetation recovery is difficult. The survival rate of local afforestation seedlings is low, with poor resistance for stresses. To improve the survival rate and growth of afforestation seedlings, we used mixed mycorrhizal inoculum of Glomus versiforme and Rhizophagus intraradices to inoculate Delavaya toxocarpa, Dalbergia odorifera, Toona sinensis, Camptotheca acuminata, and Zenia insignis and cultivated mycorrhizal seedlings. A transplanting afforestation experiment was conducted in the rocky desertification land by using the mycorrhizal inoculated seedlings. The effects of arbuscular mycorrhizal fungi inoculation on the survival rate and growth of afforestation seedlings under field conditions were investigated. The mycorrhizal infection rates of the inoculated seedlings of five species ranged from 48.5% to 69.5% after one year transplantation, being higher than that of the uninoculated ones. The survival rate, preservation rate, plant height, and base diameter of the five inoculated species increased by 8.9%-14.9%, 11.5%-22.6%, 14.4%-44.6%, and 7.6%-31.7%, respectively, compared with the uninoculated plants. The inoculation of mycorrhizal fungi promoted nutrient absorption of the seedlings. In particular, the phosphorus content in the inoculated treatments was significantly higher than that of the uninoculated ones. Furthermore, the biomass of the inoculated seedlings was significantly higher than that of the uninoculated ones. Among the five species, mycorrhizal dependence was the highest for T. sinensis (up to 26.0%) and the lowest for Z. insignis (9.1%). These results suggested that the inoculation of arbuscular mycorrhizal fungi could promote the growth of afforestation seedlings and increase their survival rate under field conditions; this method has good potential for application in vegetation restoration in rocky desertification areas.
    Biomass distribution and architecture of roots in Pinus densiflora and Pinus sylvestris var.mongolica in Horqin sandy land.
    MENG Peng, ZHANG Bai-xi, WANG Man
    2018, 37(10):  2935-2941. 
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    Pinus densiflora has been introduced to the southern Horqin Sandy Land, China for 50 years. However, little is known about its growth performance, especially for root biomass distribution and architecture characteristics. The growth characteristics of P. densiflora were compared with the same aged P. sylvestris var.mongolica(40 years old). The biomass distribution of different diameter sizes of roots was sampled by the method of layered and full excavation. Meanwhile, root length, root link number as well as average link length were measured, and fractal dimension and fractal abundance were calculated. Growth and biomass of P. densiflorawere greater than those of P. sylvestris var. mongolica. The root biomass of P. densiflora was 1.96 times as much as that of P. sylvestris var.mongolica, and the fine root (≤0.2 cm in diameter) biomass of the former was 4.76 times as much as that of the latter. Root biomass occupied 29.0% of the total biomass for P. densiflora. Its fine root biomass represented only 1.1% of total root biomass, but fine root length accounted for 44.3% of  total root length. Root biomass occupied 25.6% of the total biomass forP. sylvestris var. mongolica. Its fine root biomass represented 0.4% of total root biomass, but fine root length accounted for only 28.8% of its total root length. In terms of root vertical distribution, fine roots of P. densiflora were distributed in the range of 0-180 cm soil, and fine root biomass in the range of 40-180 cm represented 65.2% of total fine root biomass. Almost all the fine roots (99.2%) of P. sylvestris var.mongolica were distributed in the range of 0-100 cm. Fine root biomass in 0-40 cm soil layer accounted for 63.4% of the total. Although there was no significant difference in root average link length between the two species, the link number of fine roots and parts of middle roots (0.2-2.0 cm) for P. densiflora were significantly higher than that forP. sylvestrisvar. mongolica. The fractal dimension of root system for P. densiflora was 1.548±0.251, which was 1.2 times as much as that of P. sylvestris var.mongolica (1.293±0.190). Furthermore, its fractal abundance was 1.3 times as high as of P. sylvestris var.mongolica. Compared with P. sylvestris var.mongolica, root system of P. densiflora has more branches, more complex topology, and stronger absorption ability, which help it make use of deeper soil water and nutrient.
    Effects of anthropogenic disturbance on species diversity and soil physicochemical properties of Symplocos sumuntia secondary forest in Bifengxia.
    YAO Jun-yu, QI Jin-qiu, ZHANG Liu-hua, WANG Mei-zhen, LI Ting-ting, ZHANG Xiao-yue, HAO Jian-feng
    2018, 37(10):  2942-2950. 
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    Anthropogenic disturbance is an important driving factor in restoring the degraded systems. The objective of this study is to explore the effects of anthropogenic disturbance on vegetationsoil systems in Symplocos sumuntia secondary forests under three disturbance intensities (slight, moderate, and intensive) in Bifengxia. Plant species composition and diversity (richness index, Simpson index, Shannon index, and Pielou evenness index) in disturbed communities were measured, and the variation of soil properties and their correlation with diversity were evaluated. The results showed that a total of 132 vascular plant species were recorded, belonging to 99 genera and 56 families. Species density and composition showed significant difference among the three communities. With the increases of disturbance intensity, species number in the tree and herb layers decreased, while that of the shrub layer first increased and then decreased. The species diversity of tree layer significantly varied across different intensities of disturbance (P<0.01), decreasing with the increase of the disturbance intensity. No significant difference in species diversity of shrub and herb layers were observed, and their diversity levels were the highest under the moderate disturbance intensity, indicating that disturbance affected mostly the species diversity of the tree layer. The moderate intensity of disturbance enhanced the species diversity in the understory, but was not beneficial to tree species diversity. Disturbance had significant effects on soil moisture, organic matter, and available K contents (P<0.05). Except for soil total P, pH, and bulk density, other soil physicochemical properties (total N, total K, available P, available K, organic matter and soil moisture contents) were the highest in the moderate disturbance, indicating that the moderate intensity of disturbance could improve soil physicochemical properties. Furthermore, there were correlations between soil environmental factors and plant diversity, with the correlations between soil available K, organic matter, available P, and species diversity of community being significant. Our results indicated that the moderate intensity of disturbance could increase species diversity in the understory and improve the soil physicochemical property. Thus, moderate intensity of disturbance was beneficial to the community assembly and ecological restoration of S. sumuntia secondary forest.
    Effects of fertilization regimes on nitrogen leaching and maize yield in Hetao Irrigation Area.
    CHANG Fei, GAO Fan-shen, HONG Mei, WU Yan, LI Yan-qin
    2018, 37(10):  2951-2958. 
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    To understand the impacts of different fertilization regimes on the risk of nitrogen leaching and thus to provide scientific reference for the control of non-point source pollution of chemical fertilizers in basic croplands of Hetao, we monitored the nitrogen leaching of salinized fluvoaquic soil in the growing season of maize in Hetao Irrigation District for two consecutive years by in situ leakage meter method. There were five treatments, including no fertilization (NF), farmer conventional fertilization (CK), conventional fertilization by farmers + bentonite (B), conventional fertilization by farmers + biochar (C), and conventional fertilization by farmers + organic fertilizer (F). The results showed that the total amount of leaching water under treatments B and C decreased by 16.4% and 15.9%, respectively, compared to CK treatment. In contrast, the amount of leaching water was relatively higher under treatment F. For nitrogen leaching, nitrate and ammonium concentrations peaked after the second irrigation. The peak values of treatments B and C were relatively lower and that of treatment F was slightly higher. Except for the NF treatment, the treatment B was lowest in cumulative inorganic nitrogen loss with an average of 65 kg·hm-2, being 41.3% lower than that of CK. The amounts of nitrogen loss were 73.4 kg·hm-2 and 96.4 kg·hm-2 under treatments C and F, espectively, which decreased by 33.7% and 12.9%, respectively, compared to CK. Leaching volume of total nitrogen and total dissolved nitrogen in leaching water following the pattern: NF <B <C <F <CK. The apparent leaching rates of treatments B, C and F (averaged 15.3%, 16.5% and 18.5%, respectively) were lower than that under CK (25.5%). The yield of maize under treatments F, B and C increased by 9.8%, 8.4%, and 6.6%, respectively, compared to CK (P<0.05). All fertilization treatments enhanced maize production during the two years. The amount of nitrogen leaching loss was greater under treatment F. Bentonite and biochar addition effectively inhibited the leaching loss of nitrogen and increased nitrogen fertilizer utilization rate, which would contribute to reducing the non-point source pollution of chemical fertilizers in Hetao Irrigation Area. In conclusion, treatment B is more feasible for application, followed by treatment C.
    Effects of nitrogen application rate and seedlings per hole on yield and nitrogen use efficiency of double-season early hybrid rice.
    DUAN Li-cheng, LV Wei-sheng, FANG Jia-hai, ZENG Yong-jun, SHI Qing-hua, PAN Xiao-hua, CAI Hai-sheng, WU Zi-ming
    2018, 37(10):  2959-2967. 
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    To provide theoretical basis for high yield and benefit of doubleseason early hybrid rice, we examined the effects of nitrogen (N) application rate and the number of transplanting seedlings per hole on the yield, yield components, and nitrogen use efficiency of doubleseason early hybrid rice. The experiment used a completely randomized block design, including five N application levels (0, 120, 150, 180 and 210 kg·hm-2, expressed as N0, N1, N2, N3 and N4 respectively) and three levels of seedlings per hole (2, 3 and 4 seedlings per hole, expressed as M1, M2 and M3 respectively). We investigated the dry matter, leaf area index, grain yield and its components, N uptake, N use efficiency in the mature period of rice. The results showed that both N application rate and seedlings per hole had significant effects on doubleseason early rice yield. Rice yield had a significantly positive correlation with panicle number and grain number per spike, and a significantly negative correlation with seed setting rate and 1000-grain weight. With the increases of N application rate, total N accumulation in rice increased, but the N agronomic efficiency, N partial factor productivity, N internal efficiency and N harvest index decreased. The absorption and utilization efficiency of N fertilizer and yield increased at first and decreased later with the increases of N application rate. With the increases of seedlings per hole, the agronomic efficiency of N decreased. A proper amount of seedlings could increase the total dry matter and yield to improve the N use efficiency. Compared with other treatments, the combination of 180 kg·hm-2 of N application rate and 3-4 seedlings of per hole could get higher yield and N use efficiency. Suitable amount of N application and seedlings per hole could produce a significant increase in effective panicle number, yield and total N accumulation. Nitrogen fertilization rate was recommended as 180 kg·hm-2 for the early rice with the transplanting density of 3-4 seedlings per hole.
    Functional guild composition and diversity of insect communities in Mingcui Lake wetland.
    HE Yun-chuan, YANG Gui-jun, WANG Xin-pu
    2018, 37(10):  2968-2975. 
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    To clarify the changes of functional guild structure and diversity of insect community in Mingcui Lake wetland, an investigation was conducted by sweep net and fall trap from May to October in 2016. In total, 11780 individuals of insects were sampled, belonging to 271 species, 81 families and 11 orders. They were classified into four subcommunities and eight functional guilds according to feeding habits. The temporal variations of species diversity, functional guild and subcommunity were analyzed. The results showed that piercing sucking insects, neutral insects and parasitic insects were the dominant guilds, accounting for 35.02%, 32.67% and 13.51% of the total individuals, respectively. The dominant insect species belonged to Chironomids, which accounted for 20.44% of the total abundance. In different seasons, the relative richness of phytophagous and neutral insects was generally higher than that of parasitic and predatory insects. The abundance of dominant groups in different functional guilds varied greatly with seasons. The relative stability of insect communities exhibited fluctuations among different months, but the seasonal succession of insect community was distinct.
    Community structure of ichthyoplankton and its relationship with environmental factors in Laizhou Bay.
    YANG Yan-yan, GAO Yan-jie, WANG Jian-ping, XU Bing-qing, SUN Chun-xiao
    2018, 37(10):  2976-2984. 
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    On the basis of four trawl investigations with large plankton net on 20 stations in Laizhou Bay in May and August of both 2014 and 2015, we examined the community structure of ichthyoplankton, including species composition, quantity distribution, and dominant species, as well as its correlation with environmental factors. The results showed that a total of 22 ichthyoplankton taxa were collected during the four voyages. Except for the one un-identified taxon and another one identified to the family level, the remaining 20 taxa belonged to 20 genera, 16 families, and 8 orders. Dominant taxa showed substantial seasonal changes. Results from the multivariate analysis of the correlation between the quantity distribution of ichthyoplankton and environmental factors showed that salinity had a significant influence on the number of eggs and temperature had an obvious effect on the number of larvae. The number of larvae was significantly correlated with dissolved oxygen (DO), nitrite, inorganic nitrogen and activated phosphate contents (P<0.05), ammonia nitrogen (NH3-N) and chlorophyll-a contents (P<0.01). The density of copepods had a significant positive correlation with the number of eggs (r=0.479,P=0.032), but had a significant negative correlation with the number of larvae (r=-0.510,P=0.022).
    Killing effect of “Miefeiling” on alien Nile tilapia in ornamental aquaculture.
    GU Dang-en, YU Fan-dong, YANG Ye-xin, MA Guang-ming, HU Yin-chang, MU Xi-dong, XU Meng, LIU Chao, LUO Du, WEI Hui
    2018, 37(10):  2985-2988. 
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    Nile tilapia (Oreochromis niloticus) can cause a series of economic problems in aquaculture ponds due to its competition with other species and negative impacts on their growth and breeding. To test the killing effect of “Miefeiling” on O. niloticus and to provide scientific guide for its application, we conducted an experiment by applying 0.16 mg·L-1“Miefeiling” twice to control Nile tilapia in a big ornamental aquaculture pond. We found that the application of 0.16 mg·L-1“Miefeiling” had significant effects on the removal of Nile tilapia, with a removal rate of >99% but without any side effects on the breeding species. Our results give first evidence that “Miefeiling” can effectively remove the Nile tilapia in the pond and thus provide new insight to control tilapia species in ornamental aquaculture and to manage invasive fish species in the field.
    The aggressive behavioral patterns maintaining social rank in captive male forest musk deer (Moschus berezovskii).
    ZHAO Yu-jiao, CAI Yong-hua, CHENG Jian-guo, FU Wen-long, HAN Hong-jin, QIAO Jia-lun, MENG Xiu-xiang
    2018, 37(10):  2989-2994. 
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    To understand the aggression pattern maintaining social rank in captive male forest musk deer, we observed conflicting behaviors (i.e. defending, chasing, displacing, attacking, and threatening) among 14 captive males by behavioral sampling from June 1 to July 28 in 2016, at the Maerkang Musk Deer Breed Center, Sichuan Province of China. The relationships between their social rank and initiating or received conflicting behaviors and expression intensities were analyzed. We found that they had stable social hierarchical structure. The following behaviors were considered “aggressive”: chasing, displacing, attacking, and threatening. As the initiators of conflict behaviors, males performed both defending and aggressive behaviors. The frequencies of defending (7.71±2.18, n=14) were significantly higher than those of aggressive behaviors: chasing (1.29±0.50, n=14) (P<0.05), displacing (1.36±0.57, n=14) (P<0.05), attacking (0.21±0.15,n=14) (P<0.05) and threatening (1.29±0.77, n=14) (P<0.05). There was a significantly negative relationship between frequencies of defending behaviors and social ranks (P<0.05). Aggressive behavior types that males of different ranks initiated were different. Males with high-rank expressed both high-intensity (chasing and attacking) and low-intensity (displacing and threatening) aggressive behaviors. Low-ranked males did not express highintensity aggressive behaviors, but only exhibited displacing behaviors. As the receivers of conflict behaviors, the frequencies of displacing (1.43±0.532,n=14) that male received were significantly higher than those of attacking (0.29±0.12, n=14) (P<0.05) and threatening (0.36±0.16, n=14, P<0.05). Although the frequencies of aggressive behaviors of mediumranked males(5.50±1.50,n=2) were higher than those of low-ranked (4.60±2.08, n=5) and high-ranked individuals (1.14±0.55, n=7), the difference was not statistically significant (all P>0.05). In conclusion, male forest musk deer mainly showed low-intensity aggressive behaviors to maintain social rank. The initiators of conflict behaviors were the individuals that occupied higher rank and expressed more high-intensity aggressive behaviors.
    Behavioral rhythm of captive Chrysolophus amherstiae in summer and autumn.
    ZHAO Yun-lin, WANG Shuang-ye, DUAN Chou-cang, JIANG Wei-xing, XU Zheng-gang
    2018, 37(10):  2995-3000. 
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    To understand behavioral rhythms of captive Chrysolophus amherstiae in summer and autumn, we monitored the behavior of six captive individuals in Hunan Wild Animal Rescue and Breeding Center in June, September, and October, 2016 by instantaneous scanning. We analyzed behavioral time allocation in summer and autumn. Based on their functions, sixteen types of behavior observed were classified into five categories, including exercise, resting, feeding, cleanup, and alert, with exercise being most frequently occurred. In summer, fluctuation of resting was the most tremendous, while proportion of exercise was the highest in most time periods. Compared with summer, the tendencies of five categories in autumn were smooth and distinct; however, exercise was also the most frequent and resting showed the most fluctuations. Alert was less prominent, with low proportion. The results in this study were similar to that of previous studies on time allocation in their reproductive cycles of C. amherstiae. Exercise and resting were the two kinds of behavior with the highest frequency for captive C. amherstiae. The difference between our finding and previous ones was that the proportion of cleanup increased obviously in this study.
    Root-associated fungi diversity of eight orchid species in Liaoning, China.
    JIANG Yu-ling, MIAO Qing, CHEN Xu-hui, QU Bo
    2018, 37(10):  3001-3009. 
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    The existence of orchids strongly depends on their associated mycorrhizal fungi. The research of orchid mycorrhizal fungi (OMF) provides important reference for the conservation of orchids. Here, we took eight species of orchid with extremely small populations in Liaoning as examples to study the fungi diversity of orchids using nextgeneration sequencing technique. The results showed that Amitostigma gracile,Platanthera chlorantha,Goodyera repens and Oreorchis patens preferred to associate with Ceratobasidiaceae. Liparis makinoana preferred to associate with Tulasnellaceae. Cephalanthera longibracteatawas mainly associated with Thelephoraceae and Sebacinaceae.Spiranthes sinensiswas not only associated with Rhizoctonia, but also with Sebacinaceae. Meanwhile, different S. sinensisindividuals growing in the same habitat may choose differentOMF, and different species of orchid growing in the same place may associate with distinct OMF, indicating that the composition of OMF in the roots of orchids may not be completely controlled by orchids. However, the selection of main OMF may still depend on the orchids themselves. Most of the fungi existing in the roots of orchids were non-mycorrhizal fungi, while the abundance of OMF was usually much lower, which may be related to the rarity of orchids in Liaoning, China.
    Effects of grass-planting on soil bacterial community composition of apple orchard in Longdong arid region.
    QIAN Ya-li, LIANG Zhi-ting, CAO Quan, YANG Xian-long, SHEN Yu-ying, WANG Xian-zhi
    2018, 37(10):  3010-3017. 
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    To examine the impacts of grass-planting on soil bacterial diversity in apple orchard, high-throughput sequencing technology was used to analyze bacterial community and composition of specific bacteria genera in top soil (0-10 cm) in a 13-year-old Qinguan apple orchard under planting different grass species including orchard grass (Dactylis glomerata), white clover (Trifolium repens) and alfalfa (Medicago sativa) in Longdong arid region, Gansu. The results showed that the top three phyla with highest relative abundance were Proteobacteria (48%-52%), Bacteroidetes (14%-19%) and Acidobacteria (10%-17%) under the three grassplanting models. Compared to the control, the relative abundance of Betaproteobacteria increased by 19%-38%,Flavobacteriia by 31%-65%, Lysobacter by 37%-93% and Phenylobacterium by 45%-52% respectively under different grass-planting patterns. Clostridium, which promotes soil nitrogen accumulation, was observed only in the orchard grass treatment. Nannocystis, favoring organically rich environments, existed only in the white clover treatment. Bacillus, which has a strong association with plant nitrogen fixation, mainly occurred in the soil where white clover and alfalfa were cultivated. Our results suggested that soil bacteria diversity increased under grass-planting in the apple orchard. Grass-planting can promote the occurrence of specific beneficial bacteria in the soil and thus play a role in regulating soil microenvironment.
    Microbial community structure and its relationship to heavy metals in Shenzhen and Hong Kong mangrove sediments.
    DING Su-li, ZHANG Qi-jiong, DONG Jun, CHEN Zong-wei, CHEN Si
    2018, 37(10):  3018-3030. 
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    To explore the effects of heavy metals to microbial community structures of mangrove sediment, surface and rhizosphere sediment samples were collected from Futian National Reserve, Shenzhen Bay Mangrove Park, Baguang Mangrove Reserve, and Mai Po Reserve. The contents of Cr, Ni, Cu, Zn and Pb were analyzed, with the pollution levels of which being evaluated by Pollution Load Index (PLI). Microbial assemblages were profiled using 16S rRNA highthroughput sequencing and OTUs data were analyzed using cluster analysis, α diversity analysis (Shannon Index), and Spearman correlation analysis. There were significant differences in heavy metal contents among different sampling sites. Mai Po Reserve had the most severe pollution of heavy metals, with PLI of 1.51 in mud flat and 1.38 in mangrove forest. The other three sampling sites were less polluted, with PLI of 0.45 in Futian Reserve, 0.31 in Shenzhen Bay Mangrove Park, and 0.21 in Baguang Reserve. The four sites had no significant differences in microbial community structure, with predominance of Proteobackteria, Chloroflexi, Actinobacteria, Bacteroidetes, and Firmicutes at phylum level, as well as Gammaproteobacteria, Alphaproteobacteria, Deltaproteobacteria, Anaerolineae, Betaproteobacteria at class level. Multivariate analyses revealed that there were no statistically significant correlations between metal pollutions and microbial community structure across different sites. Results from Spearman correlation analyses indicated that heavy metal contents influenced the within habitat diversity of some phylum and class such as phylum BRC1 and class Epsilonproteobacteria.
    Research on soil microbial functional genes in alpine meadow based on GeoChip technique.
    LU Hui, ZHAO Heng, SHENG Yu-yu, CONG Wei, WANG Xiu-lei, LI Di-qiang, ZHANG Yu-guang
    2018, 37(10):  3031-3037. 
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    Soil microorganisms, an essential component of terrestrial ecosystems, play important roles in driving biogeochemical processes and maintaining ecosystem function. Studying soil microbial functional genes and their impact factors of alpine meadow in Qinghai-Tibet Plateau would help us understand the functional metabolic potential of soil microorganisms and provide valuable information for predicting the response of Qinghai-Tibet Plateau to global changes. Here, soil microbial functional genes in alpine swamp meadow and alpine meadow at QinghaiTibet Plateau were analyzed using a functional gene array technique (GeoChip 4.0). A total of 45818 functional genes were detected in two meadows, involving 16 key microbialmediated biological processes. The results of Detrended Correspondence Analysis (DCA) and dissimilarity test showed significant differences in the microbial community structure between two types of meadow. All key carbon and nitrogen metabolism processes mediated by microorganisms were detected, among which, alpine swamp meadow had higher gene abundance and metabolic potential involved in carbon degradation and nitrogen cycling than alpine meadow, though soil organic carbon and total nitrogen contents of two types of meadow were relatively stable. The results of Canonical Correspondence Analysis (CCA) showed that soil pH and moisture were the main factors shaping the structure of microbial functional genes. In summary, our results will help us understand the impacts of environmental changes on the structure and function of alpine grasslands and provide scientific reference for their conservation and management.
    Litterfall production and its relationships with climatic factors in Chinese natural forests.
    YUAN Fang, HUANG Li, WEI Yu-jie, QIAN Shen-hua, ZHAO Liang, YANG Yong-chuan
    2018, 37(10):  3038-3046. 
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    Litterfall plays an important role in nutrient cycling and energy flow in terrestrial ecosystems. We collected 532 literatures published in 1970-2017 that studied forest litterfall, extracted 373 data points, and established a database of litterfall in natural forests in China. The production, composition and seasonal dynamics of the litterfall were analyzed, and their relationships with temperature and precipitation were examined at the national scale. The results showed that mean annual litterfall production of the natural forests in China was (5.33±2.87) t·hm-2. With respect to litterfall production at the national scale, the rank of forest types was: rainforest > evergreen broadleaved forest > broadleaved and coniferous mixed forest > deciduous broadleaved forest > coniferous forest. Across different climatic zones, litterfall production of subtropical broad leaved forest and broadleaved and coniferous mixed forest were significantly higher than that in the temperate zone. There were no significant differences in litterfall production between tropical coniferous forests and temperate coniferous forests. In all the forests, leaf was the main component of litterfall, which accounted for 67.49%±9.75% of the total. The contribution of branch, reproductive organ, and other components was 16.45%±7.30%, 8.16%±5.18% and 7.88%±5.72%, respectively. Among them, the proportion of leaf of the deciduous broadleaved forest was the highest, accounting for 75.07%±9.92%. There were no significant differences in leaf litter among the other forest types. The seasonal dynamics of the litterfall in Chinese natural forests as a whole showed a bimodal pattern, with peaks occurring in April and October. When separated by forest types, rain forest and deciduous broadleaved forest showed a unimodal pattern, broadleaved and coniferous mixed forest showed a bimodal pattern, and evergreen broadleaved forest and coniferous forest showed a multimodal pattern. At the national scale, litterfall production was positively correlated with mean annual temperature and mean annual precipitation. The responses of forest litter production to hydrothermal factors were different among different climatic zones. In the temperate areas, litterfall production was positively correlated with mean annual temperature and mean annual precipitation, while in the subtropical areas, litterfall production was positively correlated with mean annual temperature, and there was no significant correlation between litterfall production and mean annual precipitation. In the tropical areas, litterfall production was negatively correlated with mean annual temperature but had no significant correlation with mean annual precipitation. This study provides implications for the studies of nutrient cycling in forest ecosystems and data support for the studies of carbon cycling in the context of global climate change.
    Effects of N and P fertilization on soil labile organic carbon fractions in Cunninghamia lanceolata plantations in mid-subtropics.
    YU You-zhi, WANG Qing-kui, YU Xiao-jun, ZHENG Wen-hui
    2018, 37(10):  3053-3060. 
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    To understand the effects of nitrogen (N) and phosphate (P) fertilization on different fractions of labile soil organic carbon (SOC) in mid-subtropical forests, an experiment was conducted in Cunninghamia lanceolata plantations with treatments of N (200 kg N·hm-2·a-1),P (50 kg P·hm-2·a-1), NP (200 kg N·hm-2·a-1 plus 50 kg P·hm-2·a-1) and the control without fertilization (CK). Different fractions of labile SOC were measured after five years of fertilization. Fertilization had no significant effects on SOC concentration. In comparison with CK, the microbial biomass carbon was decreased by 34.6% and 45.8% in N and NP treatments respectively. Nitrogen fertilization decreased the WSOC concentration. Furthermore, the HWC concentration was significantly increased by 31.5% in N treatment. MBC/SOC decreased by 48.4% in NP treatment. The POC/SOC significantly increased by 24.3% in NP fertilized plots compared with N fertilized plots. HWC was significantly positively correlated to nitrate and available P concentrations.
    C∶N∶P stoichiometry of Pinus tabuliformis leaf and soil in two mixed stands in western Liaoning Province.
    ZHANG Teng-zi, LI Ya-nan, HAN Fei-yan, ZHANG Song-zhu, ZHOU Yong-bin
    2018, 37(10):  3061-3067. 
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    To evaluate the effects of mixed stands on nutrient limitation for Pinus tabuliformis growth,P. tabuliformis-Quercus mongolica and P. tabuliformis-Platycladus orientalis mixed stands in western Liaoning Province were selected and pure P. tabuliformis stand was taken as control. The concentrations of C, N, and P of P. tabuliformisleaves and soil were measured, and stoichiometric characteristics were analyzed. Results showed that P. tabuliformis-Q. mongolica mixed stand had a better capacity of improving soil fertility. P. tabuliformis-Q. mongolicamixed stand significantly increased soil C, N, and P concentrations, and significantly decreased C∶N and C∶P ratios of soil, leading to a higher N and P availability. The effects of P. tabuliformis-P. orientalis mixed stand on soil C∶N∶P stoichiometry were similar to that of P. tabuliformis-Q. mongolicamixed stand, but without statistical significance. N∶P ratio of P. tabuliformis leaf in themonoculture stands was higher than 16, while that under P. tabuliformis-Q. mongolicamixed stand and P. tabuliformis-P. orientalis mixed stand decreased to 14.88 and 14.02, respectively, indicating that the growth ofP. tabuliformisin monoculture was limited by P, which was improved by mixed stands. Foliar P concentration was not altered by both mixed stands; however, N concentration of leaf was decreased. Foliar C∶N and C∶P ratios were significantly associated with foliar N concentration, indicating that P. tabuliformis changed the stoichiometric characteristics of leaf due to that mixing stand improved soil P supply and N use efficiency.
    Effects of plant diversity on nitrogen removal and nitrous oxide emission in simulated constructed wetlands.
    YU Chen-chen, LUO Bin, TANG Yu-li, CHEN Yu-chu, ZHOU Shi-rong, CHANG Jie, GE Ying
    2018, 37(10):  3068-3076. 
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    To understand the effects of plant diversity on ecosystem functioning in constructed wetlands which were used for treating wastewater with a high nitrogen concentration, a microcosm experiment with simulating constructed wetlands was conducted. Three common plants (Juncus effusus, Rumex japonicus,and Phalaris arundinacea) were selected to establish the monocultures of the three species and a threespecies mixture. At the intermediate stage (with hydraulic retention time of four days) and the late stage (eight days) after wastewater was supplied, nitrous oxide (N2O) emission and the effluent nitrogen concentration in each microcosm were measured. Results showed that N2O emission from the mixtures was lower than the average value of three monocultures in the intermediate stage but not in the late stage. The average N2O emission from monocultures in the intermediate stage was higher than that in the late stage, but it was not the case in the mixture. The nitrogen removal efficiency from the mixture was lower than that averaged across the three monocultures in the intermediate stage, but not in the late stage. In the intermediate stage, the average nitrogen removal efficiency from the monoculture of P. arundinacea was higher than that from the other monocultures or the mixtures, but not in the late stage. Our results suggest that the N2O emission from the mixtures was lower than that from the monocultures but it was contrary for nitrogen removal efficiency.
    Effects of copper and lead ion stress on the characteristics of extracellular polymeric substances of highly efficient PAHs degrading fungus, Mucor mucedo.
    CHEN Xiang, JIA Chun-yun, GONG Zong-qiang, TANG Rui, ZHANG Zuo-jin, LI Xin-yan
    2018, 37(10):  3077-3085. 
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    The functions of extracellular polymeric substances (EPS) on microbial degradation of PAHs and the remediation of heavy metal polluted soil have been widely examined, but the mechanism of heavy metal stressing on the characteristics of EPS is not clear. In this study, the highly efficient PAHsdegrading fungus, Mucor mucedo, was cultured under the stresses of copper and lead ions, and their EPS characteristics were evaluated. Results showed that as the concentration of stressful metal ions increased from 0 to 80 mg·L-1, M. mucedo EPS production (TOC), polysaccharide concentration (PS), protein concentration (PN), surface tension, emulsification index and Zeta potential (absolute value) gradually increased, with corresponding maximum values being 706.4 mg·L-1, 1.035 mg·L-1, 0.907 mg·L-1, 57.63 mN·m-1, 44.5%, and -26.21 mV, respectively. Except for emulsification index, M. mucedo EPS production, PS, PN, surface tension and Zeta potential (absolute value) decreased when the concentration of metal ions was over 80 mg·L-1. Moreover, the physicochemical properties of EPS varied more obviously under Cu2+ stress than those under Pb2+ stress. The production, PS, PN, surface tension, emulsification index and Zeta potential (absolute value) of M. mucedo EPS could be enhanced under the copper and lead ion stress.
    Protein response of bacterial enzymes involved in degradation during BaP degradation.
    ZANG Shu-yan, SHAN Hua-xu, YAO Shu-hua, DANG Lu-yi, HU Jing-xian, LUO Xiao-chen
    2018, 37(10):  3086-3091. 
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    The protein response of bacterial enzymes involved in degradation of benzo(a)pyrene (BaP) by three bacteria (BZSY-1, BZSY-2 for Bacillus, BZSY-3 for Zooloea sp.) were examined under different conditions. The relationships between the degradation rate and enzyme activity were analyzed. Four enzymes (C12O, C23O, CAT and PPO) were detected upon using different concentrations of BaP. Among the four enzymes, the activity of C23O was the highest and that of PPO was the lowest. The activity of CAT was not correlated with the concentration of BaP. 〖After adding sodium succinate (co-metabolites), the activities of C12O and C23O were enhanced, whereas that of CAT was not changed, and the activity of PPO was still lower. Compared with the control, the activities of C12O, C23O and PPO were not affected when the concentration of TW80 was less than or equal to 1000 μg·mL-1. When the concentration of TW80 was greater than 2000 μg·mL-1, the activities of these three enzymes were inhibited by various degrees. Compared with BZSY-1, both BZSY-2 and BZSY-3 had higher BaP degradation rates and higher activities of the corresponding enzymes (especially C12O and C23O), which further supported the notion that the microbial degradation of BaP is an enzymatic reaction. C12O and C23O are the two key BaPdegrading enzymes in the three bacteria.
    Analysis on water supply of Hani Rice Terrace wetland based on stable hydrogen and oxygen isotopes.
    LIU Cheng-Jing, JIAO Yuan-Mei, LIU Xin, LIU Zhi-Lin, DING Ying-Ping
    2018, 37(10):  3092-3099. 
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    The development and maintenance of wetland ecosystems are controlled by hydrological processes, especially the stability of water supply. To ascertain the temporalspatial stability of water sources and water supply relations of the Hani Rice Terraces, we collected the monthly samples of terrace water, rainfall, and groundwater in different altitudes during the growing season of rice from May to October in 2015 (rainy season). We analyzed the hydrogen and oxygen stable isotopes of water as well as meteorological data in the study area. The results showed that, during the rice growth stages, the δ18O of rainfall had obvious amount effects of rainfall, with a correlation coefficient of -0.94. The δ18O altitude gradient of groundwater was -0.1‰/100 m, while the isotopic effect of terrace water was not significant. Rainfall and groundwater were the main water sources of terraces in the whole growing season. In the early stage of rainy season (from May to June), the main water sources of terraces were the previous terrace water and rainfall. In the mid-rainy season (from July to August), the main water source was rainfall. At the end of the rainy season (from September to October), groundwater became the main water source. During the whole growing season of rice, large part water supply of rice terraces was from rainfall and small part was from groundwater, with rainfall and groundwater supply of rice terraces distributed spatially as a watersupply mosaic. In summary, owing to the water supply of the three temporal periods and the spatial rainfall-groundwater mosaic characteristics, the Hani Rice Terraces keep stable and last for thousands of years.
    Seasonal and spatial variation of nitrogen and phosphorus concentrations in Liuxi River in Guangzhou.
    ZHUO Quan-long, LIN Luo-min, WANG Jin, HUANG Xiao-lan, TANG Que-hui, WEI Gui-feng
    2018, 37(10):  3100-3109. 
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    Liuxi River, across the Tropic of Cancer, is a typical river in transition between tropics and subtropics. To understand the seasonal and spatial variation of nutrient concentrations in the river, eight investigations on water quality were carried out at 20 sites covering the whole river from February 2015 to February 2017. We analyzed the seasonal dynamics and spatial distribution of N and P concentrations and the potential affecting factors by multivariate statistical methods. The concentrations of TN and TP ranged from 0.29 to 11.88 mg·L-1 and 0.01 to 0.59 mg·L-1, respectively. TN concentration in the dry season was higher than that in the flood season, regulated by rainfall and affected by river dilution. TP concentration in the flood season was higher than that in the dry season, which was regulated by rainfall and significantly affected by exogenous input. Seasonal variations of TN and TP were similar in the dry season, but different in the flood season. Spatial variations of NO3--N and TN concentrations were similar, which could be divided into three distinct sections: the mid-value section of upstream of Liuxihe Reservoir, the low-value section from downstream of the Liuxihe Reservoir to the Jiekou Bridge, and the high-value section of downstream of Jiekou Bridge. Nutrient retention in two large reservoirs located in the upstream was one of the main factors accounting for the spatial difference. The concentrations of NH4+-N and TP increased from upstream to downstream. The concentrations of N and P were significantly higher in the third-order stream than in the first and second-order streams, which were significantly correlated with the land use types. The high proportion of building land, open land and cultivated land increased the concentrations of TP, NH4+-N and NO3--N, while the increased proportion in forest land contributed to soil and water conservation and reduced the concentrations of N and P in the river. Therefore, the regulation of upstream reservoirs and the increase of forest land in downstream urban areas are helpful to improve the water quality of Liuxi River.
    Responses of net primary productivity of natural vegetation to climate change in the Shiyang River basin.
    ZHANG Xue-lei, WANG Yi-cheng, XIAO Wei-hua, YANG Rui-xiang, WANG Yan, ZHU Li-shan
    2018, 37(10):  3110-3118. 
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    Net primary productivity (NPP) of the mountainous area in upper reaches and oasis areas in middle and lower reaches of Shiyang River basin was estimated using the Thornthwaite Memorial model. The spatial and temporal dynamics of NPP were analyzed by Sen’s slope method. Based on the sensitivity analysis, the contributions of main climate factors to NPP were estimated. The response of NPP to climate change was analyzed by setting four different climate scenarios. Subsequently, the changes of NPP in future were predicted. The results showed that climate had a tendency to be warm and wet from 1981 to 2015, with increasing NPP in the study area. The spatial heterogeneity of change trend of NPP was not significant, but the spatial heterogeneity of change magnitude was strong, with NPP increasing from the upper reaches to the lower reaches. NPP was mainly affected by precipitation, relative humidity, and net radiation. The “warm and wet” climate was beneficial to the vegetation growth, while the “cold and dry” climate was unfavorable to the vegetation growth. The changes in NPP depend on precipitation, with temperature affecting the amplitude of such changes. The NPP in Shiyang River basin is predicted to increase by 5.71%-7.83% in 2050.
    Spatiotemporal variation and ecosystem service value assessment of green space system in Zhejiang Province, China.
    LIU Rui-qing, LI Jia-lin, HE Gai-li, FENG Bai-xiang, HUANG Ri-peng, TIAN Peng, WANG Li-jia
    2018, 37(10):  3119-3129. 
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    The analysis of temporal and spatial variation and ecosystem service value assessment of green space system is of great significance to the optimization of green space system landscape pattern in large scale and to regional economic development and environmental management. Based on the theory of landscape ecology and the modified evaluation method of ecosystem service value, we analyzed the temporal and spatial variation of green space system and ecosystem service value (ESV) in Zhejiang Province from 1990 to 2015. There were substantial temporal and spatial changes of landscapes in the green space system. Forest land, as the main landscape type, increased first and then decreased. The transformation between green space landscapes and other land use types was characterized by obvious periodicity and directivity, with the landscape tending to be fragmented and heterogeneous. The overall ESV of green space system in Zhejiang Province continued to decline, with an average annual change rate of -0.62%. The ESV was dominated by the region with high ecological service value, and the proportion of extremely high ecological service value area was the smallest. In the first five years (1990-1995), the areas with high, extremely high, and low ESV increased, while the extremely low and middle grade areas showed a decrease trend. Afterwards, in addition to the sharp decrease of the extremely high ecological service value area, all the other grades tended to increase steadily and were extended to the mountain. The high ecological service value zones were gradually replaced by low grade zones. The ESV of all cities in Zhejiang Province had significant spatial differentiation, with the highest ESV being in Lishui, followed by Hangzhou. The overall trend of ESV of the cities was decreasing, with the rate of such decrease being decreased. The decrease rate increased after 2010, indicating that the green space system was not properly protected and managed during its development and utilization. Therefore, we should pay more attention to the environmental protection, seeking a balance between economic development and environmental protection.
    Techniques for substrate amelioration and revegetation of iron mine wasteland in northern China.
    ZHANG Hong-ling, SUN Li-na, MA Guo-feng, LI Tian-jiao, ZHENG Xue-hao
    2018, 37(10):  3130-3136. 
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    Due to the large hardness of wall rock of iron ores in northern China, the site condition of the iron mine dumps is bad. The silty and sand contents in such iron mine dumps are about 99%. Water and nutrition holding capacity is poor. The contents of N, P and K are low. By adding artificial substrates, which were made up of municipal sewage sludge, fly ash and clay, the physicochemical properties of iron mine wasteland would be improved. The results showed that total N concentration in artificial substrate was 4.37-6.60 g·kg-1, and the available P and K concentrations were at the high fertility level. Moreover, concentrations of heavy metals (Zn, Ni, Cr, Mn and Hg) in the substrates were low. Robinia pseudoacacia and Amorpha fruticosa were planted in fishscale pits on the slope of dump. After two years, trees grew well, many herbaceous plants appeared, and the vegetation coverage increased. Heavy metals were enriched in plant roots, which were less and less transferred to the aboveground parts over time. Soil fertility and nutrient supplementation were the key to revegetation in the iron mine dumps after 2-3 years.
    Grain size effect of karst mountainous urban landscape pattern indices in the central Guizhou: A case study of Anshun City.
    REN Mei, WANG Zhi-jie, WANG Zhi-tai, ZENG Yu-jing, HE Li-ying
    2018, 37(10):  3137-3145. 
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    The influence of landscape pattern on ecological processes is scale-dependent. Reasonable determination of the scale is the key for studying landscape pattern and ecological process. Taking Anshun, a typical karst mountainous city in the central Guizhou, as the research object, we analyzed the spatial grain effect of landscape pattern at the levels of type and landscape with GIS and RS technology, to reveal the variation of different landscape pattern indices with the increases of grain size. Furthermore, we explored the optimal spatial grain size for the landscape ecological study in karst mountainous city. Spatial grain size significantly affected the landscape pattern indices except for Simpson’s diversity index (SIDI), Simpson’s evenness index (SIEI) and total area (TA). The responses of each index with increasing grain size could be divided into types of monotone decreasing, monotone increasing, fluctuating decline, and basic stability. Most of the landscape pattern indices had obvious inflection point at 20 or 100 m, with a “critical threshold”. For Anshun central planning area, the optimal scale range of landscape pattern analysis was 5 to 20 m, with the appropriate grain size being 20 m. Mountain green space occupied the dominant position in the karst mountainous urban green space system, and class area (CA), total edge (TE), edge density (ED) and the other four landscape pattern metrics had similar grain size response curves. In conclusion, the suitable granularity of urban landscape ecological research in karst mountain areas based on high-resolution images was 20 m.
    Evolution and reconstruction of industrial ecosystems of mining cities in the traditional industrial area of northeastern China: A case study of Dashiqiao in Liaoning Province.
    HUANG Yu-pu, LU Cheng-peng, XIAO Xiao, XING Ran, REN Wan-xia, XUE Bing
    2018, 37(10):  3146-3154. 
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    Based on the theories of evolutionary economic geography and industrial ecology, we mapped the evolutionary process and characteristics of magnesium industry, and established the structure and function model of magnesium industry ecosystem with Dashiqiao City of Liaoning Province as a case. The evolution of magnesium industry system in Dashiqiao was divided into five phases: initial phase, fast phase, mature phase, transitional phase, and optimizing phase. Each phase presented different evolutionary characteristics due to diverse influencing factors. From the perspective of industrial ecology, the structural model of magnesium industry ecosystem in Dashiqiao included five subsystems: primary industrial subsystem, resource and environment subsystem, exogenous industrial subsystem, symbiosis industrial subsystem, and industrial innovation subsystem. The five subsystems interacted with each other and formed a network through systematic coupling and multilevel utilization of material and energy. This structure is similar to a general ecosystem, both of which have the characteristics of isomorphism and difference. Regulating the evolutionary path and process of magnesium industry ecosystem can maximize ecological, economic and social benefits and further promote the construction of ecological civilization of magnesium industry in Dashiqiao.
    Watershed ecosystem management of river and lake based on supply and demand coupling mechanism.
    JIANG Bo, CAI Jin-zhou, YANG Meng-fei, WANG Xiao-yuan
    2018, 37(10):  3155-3162. 
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    A comprehensive understanding of the coupling mechanism between ecosystem services supply and demand at the watershed scale is an important pathway for coordinating the contradiction between the development and protection of water resources of stakeholders across different scales in the watershed and promotes the ecological protection and top-level design of ecological civilization. Here, we mainly focused on three issues: connotation and scale-related characteristics of ecosystem services supply and demand; coupling mechanisms between ecosystem services supply and demand; major factors affecting coupling mechanism of ecosystem services supply and demand and research methods on connecting ecosystem services supply to demand for guiding ecosystem management. Scientific and technology support, financial mechanism, and monitoring platform are key to maintain the integrity and naturalness of river and lake ecosystems, improve river and lake ecosystem services supply, coordinate the spatial coupling between river and lake ecosystem services supply and demand, and promote the harmonious development between socioeconomic development and ecosystem protection. In the future, we should strengthen the accumulation of primary data and construction of ecologicalproduction functions to improve the scientific and reasonable prediction of ecosystem services supply and demand, providing scientific basis for the formulation of management measures such as ecological compensation.
    Estimation of the hyperspectral inversion of reed chlorophyll under Hyalopterus pruniattack.
    DOU Zhi-guo, CUI Li-juan, WU Gao-jie, LI Jing, PAN Xu, CAI Zhang-jie, LEI Yin-ru, LI Wei
    2018, 37(10):  3163-3170. 
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    Chlorophyll content is an important indicator for the stress state of reeds. Phragmites australis affected by Hyalopterus pruni were selected as research objects. The reflectance spectra of leaves were recorded by an ASD FieldSpec 4 portable ground object spectrometer and the chlorophyll contents (SPAD readings) were measured using a SPAD-502 Plus Chlorophyll Meter. Univariate linear regression and partial least squares (PLS) regression were used to analyze the relationships between the spectral reflectance and the chlorophyll content of the leaves. We established two models, a full wave band spectrum model and a red-edge position regression model, to estimate the chlorophyll content of the reeds. The results showed that the reflectance of healthy reed leaves was higher than that of the leaves suffered by pests. The correlation of chlorophyll content with hyperspectrum was different between the two types of leaves, especially in the spectral range of 1400-2500 nm. The full wave band hyperspectral estimation model had high accuracy, with the determination coefficient of healthy leaves regression model being 0.965, the mean square root error (RMSE) being 0.813, and the predicted deviation ratio (RPD) being 3.940. The determination coefficient of pest-bearing leaves regression model was 0.966, RMSE being 0.989, and RPD being 3.855. The crossvalidation and offsitevalidation results further demonstrated that full-wave band hyperspectral data inversion could estimate the relative chlorophyll content of reeds suffered by H. pruni, indicating that it was feasible to use full wave band hyperspectral data to estimate the relative chlorophyll content of vegetation suffered by pests.
    Multiscale landscape ecological risk assessment in ecologically fragile regions: A case study in Gaoqu Town in Mizhi County, Shaanxi Province.
    MA Sheng, LIANG Xiao-ying, LIU Di, DUAN Ning, CHEN Hai
    2018, 37(10):  3171-3178. 
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    As one of the core concepts in landscape ecology, the multiscale synthesis is an essential part in landscape ecological risk assessment. In this study, we analyzed the effects of landscape pattern at different spatial grains of 30, 60, 90, 120, 150, and 180 m in Gaoqu Town of Mizhi County, Shaanxi Province, with eight landscape pattern indices. We established a landscape ecological risk assessment model based on landscape pattern. Landscape ecological risk indices at quadrat scale, administrative scale and ecological scale were calculated and spatially interpolated. The most suitable scale was selected base on the overlay analysis of the landscape ecological risk distribution results. A typical village was used to verify the results. Our results showed that 120 m was the most suitable spatial grain. The accuracy of landscape ecological risk spatial distribution at quadrat scale decreased with the increases of spatial grain. The results of landscape ecological risk distribution varied greatly across different scales. The overlapping area between the quadrat scale and ecological scale was the largest, accounting for 32.14% of the total. Landscape ecological risk distribution at the ecological scale matched the actual situation of study area. Therefore, ecological scale would be the most suitable scale for analyzing the landscape ecological risk in this area.