Table of Content

10 October 2015, Volume 34 Issue 10

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Effects of forest gap on microbial biomass during litter decomposition of Toona ciliata in Pinus massoniana plantations.

ZHANG Ming-jin1,2,3,CHEN Liang-hua1,2,3, ZHANG Dan-ju1,2,3, ZHANG Yan1,2,3, LIU Hua1,2,3, LI Xun1,2,3, YANG Wan-qin1,2,3, ZHANG Jian1,2,3**

2015, 34(10):  2691-2698. 

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To understand the effects of forest gap on microbial biomass in the process of leaf litter decomposition, seven gap sizes (G1: 100 m², G2: 225 m², G3: 400 m², G4: 625 m², G5: 900 m², G6: 1225 m², G7: 1600 m²) were created in a 42-year-old Pinus massoniana plantation, and uncut pure stand was used as a control. We investigated the dynamics of microbial biomass C (MBC), N (MBN) and MBC/MBN in the process of leaf litter decomposition of Toona ciliata after 30, 90, and 180 days of incubation, and compared the differences of such parameters between the center and edge of the gaps. Our results showed that: (1) the gap size significantly affected MBN, MBC and MBC/MBN. Overall, the microbial biomass in small and moderate forest gaps (G1-G5) was higher than that in large forest gaps. (2) There was no significant difference in MBC, MBN and MBC/MBN between the center and the edge of each size of gap. (3) Decomposition time exhibited very sig〖HJ*3〗nificant effects on MBC, MBN and MBC/MBN. After 90 days of incubation, MBC and MBC/MBN were the highest, whereas MBN was the lowest. (4) MBC showed a very close correlation with both temperature and water content, while MBN and MBC/MBN were related to temperature significantly. Taken together, our results indicated that the alteration of soil temperature and moisture due to the formation of forest gaps significantly affected the microbial biomass in the process of T. ciliata litter decomposition, the small and moderate gaps (G1-G5) could significantly increase microbial biomass, and the variation of MBC showed an opposite trend to MBN along with decomposition time.

Influence of long-term nitrogen fertilization and precipitation reduction on rhizospheric phosphorus concentration of Pinus koraiensis and Quercus mongolica.

YANG Jian-hua1,2, WANG Fang1,2, ZHANG Jun-hui1**, YUE Lin-yan1,2, ZHU Bao-kun3, GENG Shi-cong1,2, WANG Xiu-xiu4, HAN Shi-jie1

2015, 34(10):  2699-2704. 

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Understanding changes in soil phosphorus concentration is critical to predict the influence of longterm environmental change on forest ecosystems. By measuring total phosphorus and available phosphorus concentrations in rhizospheric soil of Pinus koraiensis and Quercus mongolica in the sixthyear nitrogen and precipitation manipulation experiment, we intended to study the influence of longterm nitrogen deposition and precipitation variation. The results showed that longterm nitrogen fertilization significantly increased the total phosphorus concentration in rhizospheric soil by 7.4%-10.9%, and the influence of tree species on total phosphorus concentration in rhizospheric soil was not significant. Longterm nitrogen fertilization significantly increased the available phosphorus concentration in rhizospheric soil of P. koraiensis and Q. mongolica by 25.1% and 32.4%, respectively. The available phosphorus concentration in rhizospheric soil of Q. mongolica was 31.8%-84.1% higher than that of P. koraiensis. The reduction in precipitation had no significant effects on both total phosphorus and available phosphorus concentrations in rhizospheric soil.

 

Carbon storage in mixed Schima superba Gardn. et Champ. -Cyclobalanpsis glauca (Thunb.) Oerst. young plantations at different stand ages.

CHENG Cai-fang1, LU Ai-yun3, LI Zheng-cai1**, ZHOU Jun-gang2, WU Ya-cong1, ZHAO Zhi-xia1, SUN Jiao-jiao2

2015, 34(10):  2705-2710. 

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Seven and 11-year-old mixed Schima superba Gardn. et Champ. - Cyclobalanpsis glauca (Thunb.) Oerst. plantations (SC) transformed from shrub, and the reserved shrub were chosen to study their dynamic changes in carbon storage. The results showed that the carbon storage in the three types of vegetation and in the soils followed the ascending order of shrub < 7-year-old SC < 11-year-old SC. The vegetation carbon storage in 7 and 11-year-old SC had significant increment of 5.49 and 23.64 t·hm^-2, as compared with shrub (P<0.05). Vegetation carbon storage in 11-year-old SC was 18.15 t·hm^-2 larger than that in 7-year-old SC. Soil carbon storage in 7 and 11-year-old SC was 12.56 and 30.99 t·hm^-2, being much higher than that in shrub soil. Soil carbon storage in 11-year-old SC was 18.43 t·hm^-2 more than that in 7-year-old SC, with significant difference in each soil layer of 0-50 cm depth. The total ecosystem carbon storage of shrub, 7 and 11-year old SC was 54.11, 72.16 and 108.74 t·hm^-2, respectively. The annual increment of total carbon storage in 7 and 11yearold SC was 2.58 and 4.97 t·hm-2·a-1 compared with shrub, respectively. The carbon storage of evergreen broadleaved young plantations transformed from shrub has increased significantly; however, long-term effect of stand age on carbon accumulation needs to be further studied.

Comparative study on the response of deciduous and evergreen shrubs to nitrogen and phosphorus input in Hani Peatland of Changbai Mountains.

LIU Chao1, BU Zhao-jun1**, MA Jin-ze1, YUAN Min1, FENG Lu1,2， LIU Sha-sha1

2015, 34(10):  2711-2719. 

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It is not clear how the shrubs in peatlands respond to nitrogen deposition and phosphorus input, which could impact ecosystem processes. Our objective was to investigate the effects of different levels of nitrogen and phosphorus addition on three deciduous shrubs and three evergreen shrubs in Hani Peatland of Changbai Mountains through six years of simulation experiment. The responses of deciduous shrubs (with reduced abundance and coverage and increased height) and evergreen shrubs (with reduced abundance, coverage, and importance value) to nitrogen addition were different, while their responses to phosphorus addition was similar. Interspecific difference existed at species level. Nitrogen addition inhibited the growth of Potentilla fruticosa and Vaccinium uliginosum, and decreased their abundance and coverage. Meanwhile, nitrogen a ddition facilitated the growth of Betula ovalifolia, and height, coverage and importance value increased. Among the evergreen shrubs, nitrogen addition only decreased the abundance and importance value of Chamaedaphne calyculata but had no effect on Ledum palustre and R. parvifolium. Phosphorus addition relieved nutrient limitation of these shrubs and increased the coverage of B. ovalifolia, the height and importance value of R. parvifolium and the abundance of C. calyculata. Interactive effects of nitrogen and phosphorus addition were observed for deciduous shrubs. When little or no nitrogen was amended, phosphorus addition had no effects on the height or importance value of deciduous shrubs. Under the condition of high nitrogen addition rate, phosphorus addition increased the height and importance value of deciduous shrubs. This result indicated that only addition of nitrogen and phosphorus at a certain ratio can promote the growth of shrubs. Our study suggests that nitrogen and phosphorus addition can affect shrub performance and change the competitive balance between the two types of shrubs. B. ovalifolia may obtain growth advantage and restrain the growth of other shrubs, which will have a profound impact on vegetation pattern in peatlands.

Community phylogenetic structural characteristics of various secondary forests in mountainous eastern Yunnan.

DING Hong-bo, WU Zhao-lu**, LU Dong-peng, WU Qiu-jun, SHAN Meng-ying, BAI Hao-tian, LUO Kang

2015, 34(10):  2720-2726. 

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Phylogenetic structure has been used to explore the mechanisms of community composition, but little attention has been paid to the phylogenetic structure of plant communities undergoing strong human disturbance. Based on data from 205 species in four kinds of community in 39 quadrats on mountains of eastern Yunnan, we analyzed the community phylogenetic structure to discover the community assembly mechanism during forest restoration. The results indicated that: (1) Pinus armandii forest, Alnus ferdinandicoburgii forest and secondary evergreen broadleaved forest developed under different restoration ways were all phylogenetically clustered, suggesting the dominance of habitat filtering. (2) Herbaceous plants growing in Pyracantha fortuneana shrubs at early stage of recovery were phylogenetically random at large scale, which might be the result of habitat filtering and competitive exclusion. (3) The legacy effects of previous stages or interference (such as farming, logging) might remain, which made the new community phylogenetic structure more clustered under the effects of habitat filtering. (4) Plant community phylogenetic structures of differing lifeforms were different, indicating that the dominant factors affecting plant community assembly varied according to lifeform.

Differences of tradeoff relationship among root forks and link length in Reaumuria soongorica on slopes of different aspects.

ZHENG Hui-ling, ZHAO Cheng-zhang**, DUAN Bei-bei, FENG Wei, XU Ting, HAN Ling

2015, 34(10):  2727-2732. 

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Tradeoff is the basis of life history strategy theory. Elucidation of the tradeoff between root forks and link length is important for understanding the phenotypic plasticity of plants under different habitat conditions. By using the ArcGISestablished regional digital elevation model (DEM), this paper studied the tradeoff relationship between root forks and link length of Reaumuria soongorica at different slope aspects in a desert grassland on the northern slope of Qilian Mountains, Northwest China with the method of whole root system excavation. The results showed that the plant community density, cover, height and soil moisture content displayed a pattern of gradual increase, and the height, rootshoot ratio and root link length of R. soongorica displayed a pattern of gradual decrease, while the specific root length and root forks increased gradually with the slope aspect turned from south to west, east and north. The relationship between root forks and link length varied with the slope aspect: there was a highly significant negative correlation between the root forks and link length at north slope and south slope (P<0.01), whereas the correlation reached a significant level at the east slope and west slope (P<0.05). There was a tradeoff in resource allocation between the root forks and link length. The resource allocation mode in roots by reasonable tradeoff between root forks and link length with changes in slope aspect of habitat reflected the mechanism of biomass allocation and the adaptation strategy of R. soongorica populations under conditions of multiple competitions for resources in diverse habitats.

Distribution pattern of riparian vegetation along Donghe River, a tributary of the Three Gorges Reservoir area.

SUN Rong**, DENG Wei-qiong, LI Xiu-ming

2015, 34(10):  2733-2741. 

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Using the methods of TWINSPAN and DCCA, this paper studied the spatial distribution of the plant communities in Donghe River, in terms of the interactions between plant species and communities and environmental factors. The results showed that the riparian plant communities were classified into 15 types including 4 forest types and 11 shrub and grassland types. Elevation and human disturbance played a dominant role in spatial distribution of the riparian plant communities. Plant communities had a significant altitudinal pattern. Along longitudinal and lateral gradients of the river, plant communities presented a fragmentation pattern. The composition and types reflected that the riparian plant communities were typical secondary plant ones.

Carbon sequestration and oxygen release capabilities of six garden tree species in Dalian.

ZHANG Na1,2, ZHANG Wei3, CHEN Wei1**, HE Xing-yuan1, WANG Xue-yan1,2

2015, 34(10):  2742-2748. 

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In this study, photosynthetic physiological indices of six garden tree species in Dalian were measured with LI-6400 photosynthesis system in different seasons. The responses of photosynthesis to different light intensities were also calculated. The results showed that the capacity of carbon sequestration and oxygen release per unit of leaf area was the strongest in summer for all the six species. The capabilities of daily carbon sequestration and oxygen release per unit of leaf area were in order of Sophora japonica var. pendula > Albizia julibrissin > Zelkova serrata > Quercus dentata > Platanus acerifolia > Pterocarya stenoptera; in terms of per individual plant, such capabilities were in order of P. acerifolia > Q. dentate > A. julibrissin > Z. serrata > P. stenoptera > S. japonica var. pendula. Stomatal conductance, intercellular CO₂ concentration, transpiration rate and light irradiance were key factors affecting the net photosynthetic rate. According to the photosynthetic lightresponse curve data, P. acerifolia and A. julibrissin had better environmental adaptability. Therefore, we recommend that P. acerifolia and A. julibrissin should be as the priority tree species and Q. dentate and S. japonica be used as tree species for high carbon sequestration and oxygen release in Dalian.

Adaptive mechanisms of seven psammophytes in an arid desert margin in Shapotou area, China.

ZHU Rui-qing**, ZHANG Zhi-shan, LIU Li-chao, HUI Rong, ZHANG Hao, BAO Jing-ting

2015, 34(10):  2749-2756. 

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Studies on plant adaptation strategy in extreme habitats from arid desert areas help to reveal the mechanism of plant community succession, predict ecosystem stability and succession orientation, as well as provide theoretical grounds for sandbinding engineering and revegetation. In this paper, we investigated the adaptation strategies of seven dominant plant species in different communities in a transitional zone of shiftingfixed dunes. The pioneer annual, Agriophyllum squarrosum, was found to possess a high transpiration rate (T_r), high peak of water use efficiency (WUE), with WUE peak occurring at relatively low soil moisture, while the intrusive species, Eragrostis poaeoides, behaved in conservative water use characteristics (low T_r, low WUE peak, with WUE peak occurring at relatively high soil moisture). For the seven species, we defined three types of water use characteristics: lavish water use (including Agriophyllum squarrosum, Hedysarum scoparium, Artemisia ordosica, Salsola ruthenica), moderate water use (Corispermum mongolicum), and conservative water use (Bassia dasyphylla, E. poaeoides). Species coverage of all the dominant species including shrubs and herbs was significantly negatively correlated with their diurnal transpiration under the conditions of rhizosphere moisture (R²=0.94, P<0.01). The results indicate that both the water use characteristics of different species and the distribution of soil moisture are the two major factors mediating the dominance of plant species in the community, soil water balance and succession processes in arid desertoasis ecosystems. Soil physicochemical properties play an important role in the fixed and semifixed dunes, while soil moisture effects are more important in shifting and semishifting dunes.

Effects of elevated O₃ concentration on chemical composition of leaf litter of Ginkgo biloba.

SU Li-li1, FU Wei1,2, XU Sheng1, HE Xing-yuan1**, CHEN Wei1, ZHAO Yi1, HUANG Yan-qing1

2015, 34(10):  2757-2763. 

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Concentrations of ozone (O₃) near ground level in the northern hemisphere have increased substantially in the past few decades. Currently, the effects of elevated O₃ concentration on the litter of woody plants were poorly investigated, particularly in China. In order to reveal the effects of elevated O₃ concentration on the chemical composition of leaf litter of G. biloba and forecast subsequent decomposition, an experiment was conducted to study the variations of the chemical composition in leaf litter of G. biloba exposed to elevated O₃ concentrations (80 and 120 nmol·mol^-1) during two successive growing seasons (2012-2013) in open top chambers (OTCs). The results showed that elevated O₃ significantly increased N and K contents, while significantly reduced the content of total phenolics and the ratios of C/N and lignin/N. The contents of C, P, and lignin and the ratio of C/P of leaf litter from the elevated O₃ treatments were not significantly different from those of the control. Elevated O₃  (120 nmol·mol^-1) significantly decreased the content of soluble sugar by 38%. The content of condensed tannins significantly increased by 343% under 80 nmol·mol^-1 O₃, while no significant change was found under 120 nmol·mol^-1 O₃ compared to the control. Different O₃ concentrations caused different changes in chemical composition of leaf litter of G. biloba. We inferred that such variations of litter chemical composition might affect the decomposition of leaf litter and material cycling (especially C) in forest ecosystems in O₃polluted areas.

Effects of simulated acid rain on ecophysiological characteristics of Melia azedarach.

LIAO Yuan-lin1, CAI Shi-zhen1**, YE Chong2, LIU Mei-song1, XU Xiao-ming1, TAO Rui1

2015, 34(10):  2764-2770. 

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A pot experiment was conducted with 1-year-old Melia azedarach as material. Simulated acid rain of four pH levels (5.6 (CK), 4.5, 3.5 and 2.5) was sprayed on leaves every two days, and the chlorophyll (Chl) content, soluble protein content, cell membrane permeability, MDA content, antioxidant enzyme activity of leaves were investigated after 20, 40 and 60 days of treatment. The results showed that with the extension of treatment time, the soluble protein content decreased firstly and increased afterward at pH 4.5 with a greatest increase of 10.3%, while it decreased at pH 3.5 and pH 2.5 with a sharpest drop of 42.9%. The plasma membrane permeability and MDA content significantly increased up to 84.6% and 145.5%, respectively. SOD activity increased at pH 4.5, while it first increased and then decreased at pH 3.5 and decreased at pH 2.5, with a greatest increase of 47.9% and a sharpest drop of 20.9%. CAT activity appeared in a dropping trend after an initial increase at pH 4.5, and it decreased at pH 3.5 and pH 2.5, with a greatest increase of 23.0% and a sharpest drop of 27.0%. POD activity increased at pH 4.5 and pH 3.5, and decreased at pH 2.5, with a greatest increase of 47.1% and a sharpest drop of 17.6%. Chla, Chlb and Chl decreased with sharpest drops of 39.0%, 37.0% and 38.3%, respectively. Combining the findings on leaf shape, abscission rate and plant height increment, it was found that leaves turned yellow and abscission rate increased significantly at pH 3.5 (P<0.05), while leaves deformed severely and plant height decreased significantly at pH 2.5 (P<0.05). Thus, the threshold of M. azedarach to resist acid rain is about pH 3.5.

Assessment of soil quality of different plant communities in the Karst mountains of Pingguo County, Guangxi.

OU Zhi-yang1,2,3**, SHEN Wen-hui1,2,3, PANG Shi-long1,2,3, PENG Yu-hua1,2,3, TAN Yi-bo1,2,3, HE Qin-fei1,2,3

2015, 34(10):  2771-2777. 

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Evaluating soil quality in Karst mountains is important to vegetation restoration and desertification control in the rocky region. Based on the analyses of soil fertility characteristics, canonical correspondence analysis (CCA) was used in conjunction with factor analysis to quantitatively assess the soil fertility of scrub, shrub, Lysidice rhodostegia forest, and Excentrodendron hsienmu forest in the Karst mountains of Pingguo County, southwest Guangxi. The results indicated that along with the restoration of vegetation, soil bulk density decreased while soil porosity and soil waterholding capacity increased. Of the four communities, the scrublands had the highest soil pH. Soil organic matter, total nitrogen, and available nitrogen concentrations in L. rhodostegia and E. hsienmu forests were significantly higher than in the scrublands and shrublands. However, soil total phosphorus, total potassium, and available potassium concentrations in the scrublands and shrublands were significantly higher than in the two forests. Soil available phosphorus and exchangeable calcium concentrations showed no detectible differences among the four plant communities. Our results suggested that CCA was effective for screening the soil fertility assessment index, and the integrated assessment scores of soil quality of the four communities were in the order of: L. rhodostegia forest (0.41) > E. hsienmu forest (0.27) > scrub (-0.20) > shrub (-0.44). Lower plant productivity and nutrient accumulation were the primary factors resulting in poor soil quality in the scrublands and shrublands.

 

Piosphere effect on soil seed bank in desert steppe.

LIAN Zhong-min1,2, XU Ting3, XU Wen-xuan1, WU ke1,2, YANG Wei-kang1**, David BLANK1

2015, 34(10):  2778-2784. 

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In grasslands, livestock often concentrate in the vicinity of water point due to watering demands, which generates piosphere. We set 6 sampling distances (50, 100, 200, 400, 800 and 1200 m) from an artificial water point in the Junggar Basin, Xinjiang, and collected soil samples to investigate the soil seed bank. Our analysis showed that there were 17 species belonging to 8 families in the soil seed bank. The species were mainly from Compositae and Chenopodiaceae. The numbers of annual herbs and perennial herbs were 10 and 7 respectively. The soil seed bank density was 211.5-362.5 seeds·m^-2, and the lowest density of soil seed bank was found in the closest vicinity of the water point (50 m), while the highest was observed in the farthest area (1200 m). The species number of the soil seed bank significantly decreased (P<0.01) with distance from water point; the percentage of the annual herbs increased, while the percentage of the perennial herbs decreased. The similarity indexes of the soil seed bank between every two adjacent sampling points were 0.70-0.84, displaying small spatial heterogeneity. The Shannon, Margalef and Pielou indexes of soil seed bank decreased with distance from water point. These results suggested that the number of plant species in soil seed bank was increased by piosphere effect. Consequently, the number of constructive species seeds decreased, while the number of ephemeral and ephemeroid plant seeds increased.

Effects of flooding condition and mesh size on leaf litter decomposition of the dominant species, Carex atrofusca, in an alpine swamp meadow in Tibetan Plateau.

YU Qin, WU Jie, LIANG De-fei, ZHANG Jing-ran, LI Zhun, ZHANG Shi-ting**

2015, 34(10):  2785-2791. 

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In May 2013, standing leaf litter of the dominant species Carex atrofusca was collected in an alpine swamp meadow in Tibetan Plateau. In early June, we set up three decomposition zones, including longtime flooding, periodic flooding and no flooding. The litterbag method was used, with different mesh sizes \[big mesh (4.5 mm), medium mesh (2.0 mm) and small mesh (0.1 mm)\]. Our objective was to study the effects of flooding condition and mesh size on early litter decomposition in an alpine swamp meadow. The results showed that longterm flooding significantly inhibited the decomposition of litter, and there was no significant difference in litter decomposition under periodic flooding and no flooding. Mesh size affected significantly litter decomposition, and big mesh exhibited the highest litter mass loss, followed by medium, and small mesh size. In the early period of litter decomposition, litter was characterized by nitrogen and phosphorus enrichment, irrespective of any treatment. Flooding condition affected significantly nitrogen and phosphorus enrichment. Mesh size influenced significantly nitrogen enrichment, but not phosphorus enrichment. A significant interaction of flooding conditions with mesh size was found for nitrogen enrichment, but not for phosphorus enrichment. Mesh size could reflect effects of different soil biota on litter decomposition. Therefore, our results indicated that flooding condition and soil biota had important influences on carbon, nitrogen and phosphorus cycling, and thus ecosystem functioning of alpine swamp meadow in Tibetan Plateau.

Soil organic carbon mineralization and its relation with salinity in coastal wetland of Liaohe estuary.

XIAO Ying, YANG Ji-song**

2015, 34(10):  2792-2798. 

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Coastal wetland soils with different salinity in Liaohe estuary were collected and an airtight incubation experiment was conducted to study the characteristics of organic carbon mineralization and its relationship with the salinity. The results showed that the mean values of electric conductibility (EC_1:5) of soil were different among the sampling sites. The cumulative carbon mineralization amounts of top soil (0-10 cm) and subsoil (10-20 cm) were 6.54 g C·kg^-1 and 2.79 g C·kg^-1 for 74d incubation, respectively. According to the first order kinetic, the mean values of mineralization potentials (C₀) were 14.5 g C·kg^-1 for top soil and 3.84 g C·kg^-1 for subsoil, respectively, and the corresponding values of mineralization constants (k) were 0.009 and 0.017 d^-1. The C₀ value of top soil was significantly higher than that of subsoil and they were both significantly different among the sampling sites. There were significant positive relationships between the C₀ values and EC_1:5, soil organic carbon (SOC), total nitrogen (TN), Ca²⁺, Mg²⁺ and Cl^- contents in soil. However, a negative correlation was found between the k values and these properties of the soil. The results of stepwise regression showed that the C₀ value was mainly regulated by the contents of Cl^- and SOC, but the k value was mainly regulated by the SOC content. The results indicated that the soil organic carbon mineralization of the coastal wetland was controlled by a combined effect of soil salinity and organic carbon content.

Decomposition dynamics of organic carbon in Spartina alterniflora litter in developing salt marshes.

WU Ya-ping, WANG Guo-xiang, LIU Jin-e**, YU Pei-pei, XU Jie

2015, 34(10):  2799-2806. 

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In order to characterize the decomposition patterns of total organic carbon (TOC), recalcitrant organic carbon (RC) and labile organic carbon (LC) in Spartina alterniflora litter, we buried litterbags at S. alterniflora salt marshes of 3-year-old (SAF2011), 5-year-old (SAF2009), 11-year-old (SAF2003), 25-year-old (SAF1989) and S. alterniflora-Suaeda salsa salt marsh (SAF-SS) along the Xinyanggang coastal wetland in Yancheng, the largest S. alterniflora salt marsh in China. The results showed that: (1) During the oneyear decomposition, the TOC remaining percentage, RC remaining percentage and LC remaining percentage decreased monthly. The RC remaining percentage was higher than the LC remaining percentage, and the remaining percentages of TOC, RC and LC increased with the developmental duration of salt marsh. (2) The organic carbon decomposition rates differed seasonally. The higher decomposition rates of TOC, RC and LC occurred in August, January and June respectively, whereas the lower decomposition rates of TOC and LC occurred in October and February respectively, and the lower decomposition rates of RC were observed in December and February. The decomposition rate of LC was higher than that of RC, while the TOC and LC decomposition rates decreased with the developmental duration of salt marsh. The RC decomposition rates were higher in SAF2011 than in the other salt marshes. (3) After litter decomposition, the ratio of RC to TOC increased, while the ratio of LC to TOC decreased. (4) The annual TOC decomposition rates were 0.3167, 0.2632, 0.2608, 0.2583 and 0.2380 g·g^-1 for SAF1989, SAF2003, SAF2009, SAF2011 and SAFSS, respectively. These findings suggest that the development duration of salt marsh can affect decomposition processes of organic carbon in litter.

Effect of wetlands on reducing atmospheric fine particles PM_2.5 in Beijing.

KANG Xiao-ming1，2，3, CUI Li-juan1，2，3**, ZHAO Xin-sheng1，2，3, LI Wei1，2，3, ZHANG Man-yin1，2，3, WEI Yuan-yun1，2，3, LEI Yin-ru1，2，3, MA Mu-yuan1，2，3

2015, 34(10):  2807-2813. 

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Based on field observation and remote sensing data, this research investigated the function of wetlands in reducing the concentration of atmospheric fine particles PM_2.5 in Beijing. The results indicated that wetlands could reduce the PM_2.5 concentration significantly. For example, the concentration of PM_2.5 around Cuihu Lake wetland (P<0.05) was remarkably lower than that nearby bare land. Wetland reduced PM_2.5 in surrounding air by 17% averagely, and the peak reduction could reach 50%. The results also demonstrated the reduction effect of lake and reservoir was larger than that of river (P<0.05). The distribution of PM_2.5 in Beijing showed a spatial pattern of northwest < southeast and suburb region < downtown. It is necessary to appropriately select wetland types especially lake and reservoir wetlands and properly allocate plants in wetlands in future wetland construction, so that wetlands can play roles in humidifying and changing the flow field, thus achieving the goals of improving meteorological conditions, reducing atmospheric fine particles, and relieving haze in urban area. This research provides scientific guidance for wetlands conservation, planning and distribution in Beijing, as well as for making policies of PM_2.5 pollution control.

 

Volatile chemical cue for Dastarcus helophoroides (Coleoptera: Bothrideridae) discriminating the larval frass of Anoplophora glabripennis (Coleoptera: Cerambycidae) larvae feeding on different host tree species.

WEI Jian-rong1**, SU Zhi2, DONG Li-jun1

2015, 34(10):  2814-2820. 

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Anoplophora glabripennis is a destructive woodborer attacking many deciduous hardwood tree species, especially in northern China. Dastarcus helophoroides parasitizes larvae and pupae of A. glabripennis. Olfactory response of one population of D. helophoroides to larval frass of A. glabripennis from six different host tree species in the genera Populus, Salix, Ulmus and Acer were different, and the larval frass from Acer negundo was not attractive to the population of D. helophoroides. In order to explore the reason that different larval frass of A. glabripennis from different host tree species have different attractive capacities to D. helophoroides, frass volatiles were extracted by solidphase microextraction (SPME) and analyzed by gas chromatographymass spectrometry (GC-MS). The monoterpenes released from frass were extracted by Porapak Q and quantified by gas chromatography. Results showed that terpenes were the major components, and their release amounts differed significantly among the tree species. Among all compounds, ()α-copaene was the only compound that was at a trace level in the larval frass from A. negundo but detectable in the larval frass from the other five tree species. Further Ytube bioassays indicated that ()α-copaene could attract D. helophoroides adults at a low release rate. Therefore, ()α-copaene might serve as the kairomone for D. helophoroides discriminating the larval frass of their hosts feeding on different host tree species.

Relationship between protein content and resistance of tree species factitiously infected by Hyphantria cunea (Lepidoptera: Arctiidae).

WANG Qiu-fen1,2**, HU Qi-meng1,2, LIN Ya-jie1, YU Wen-xing1, LIU Ting-ting1, BAI Hui-cong1, LIN Sheng-nan1

2015, 34(10):  2821-2826. 

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In September 2014, an experiment of factitious infection by Hyphantria cunea (Drury) (Lepidoptera: Arctiidae) was done in 3-year-old woodland of target garden greening tree species, namely Fraxinus chinensis Rosb., Platanus orientalis L., Morus alba L., Ailanthus altissima (Mill.) Swingle, Populus tomentosa Carr., Toona sinensis (A. Juss.) Roem in Langfang, Hebei. The larvae of H. cunea were reared on leaves of the target species under laboratory conditions. Leaf consumption and changes of soluble protein content before and after factitious infection by H. cunea were measured. The results indicated that the order of leaf consumption by H. cunea was arranged as M. Alba > Pl. orientalis > A. altissima > F. chinensis > P. tomentosa > T. sinensis. The soluble protein content ascended firstly and then descended in target species M. alba, Pl. orientalis, A. altissima and F. Chinensis with low resistance to H. cunea, but it descended firstly in P. tomentosa with high resistance to H. cunea after 2, 4, 6, 8, 10 days of feeding, respectively; but these protein contents on day 10 were lower than that before feeding by H. cunea and of the control. The results demonstrated that the effect of H. cunea on protein contents of target species varied with the extent of tree species tolerance to the moths. The resistance of trees to H. cunea was insignificantly correlated with protein content.

Relative fitness of propargiteresistant strain of Tetranychus cinnabarinus (Boisduval)(Acari: Tetranychidae).

LUO Yan-jie1, YANG Zhen-guo1, WANG Dan2, XIE Dao-yan1, DING Wei2**

2015, 34(10):  2827-2832. 

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To identify the relative fitness of propargiteresistant strain of Tetranychus cinnabarinus, a propargiteresistant strain (PRR34) was established after 34generation selection of the susceptible strain (SS) by using propargite. The differences in development, reproduction, and population parameters between these two strains were analyzed by comparing experimental population life table. The result showed that after 34generation, the resistance ratio of PRR34 increased to 37.78fold. Compared with SS, the hatching rate of eggs, duration of development stages, and generation time of PRR34 showed no difference, but its preoviposition period significantly increased by 37.07%, the fecundity of single female decreased by 14.61%, and the ratio of female/male (♀/♂) increased by 23.38%. The survival curve was determined as Deevey I according to Weibull distribution, and the parameter c for SS and PRR34 were 2.04 and 2.38, respectively. The population tendency index, intrinsic rate of increase (r_m), and net reproduction rate (R₀) were 123.78, 0.24 and 25.34 for SS, and 111.91, 0.26 and 28.99 for PRR34, respectively. Besides, the relative fitness of PRR34 was 1.14, which showed advantage over SS. In conclusion, compared with SS, the fecundity of single female of PRR34 decreased, but its female ratio and population fitness increased, which may result in the expansion of the resistant strain population and the increase of difficulty for pest control.

Effect of herbivore’s gut passage on seed germination of legume: A metaanalysis.

YANG Jie-jing, Narkes WALI, LU Yan-ping, ZHAO Gang, REN Ai-tian, LU Wei-hua**

2015, 34(10):  2833-2842. 

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In this paper, we combined metaanalysis with APGIII system to analyze the effect of herbivore’s gut passage on seed germination of 70 plant species to search for patterns that predict the circumstances in which germination of seeds is enhanced, inhibited, or not affected by endozoochorous seed dispersal. The results showed that the overall effect of animal digestion on seed germination percentage of 70 plant species was slightly negative (OR=0.89, OR95%=0.61-1.28). Based on genetic relationship, we divided all plant species into seven groups to analyze the OR of germination. Gut treatment enhanced the seed germination of group 1 (including Acacia, Mimosa, Leucaena, Ceratonia and Prosopis) significantly, while inhibited that of group 4 (including Cajanus, Calopogonium, Neonotonia, Lablab, Lespedeza and Centrosemo) significantly. We further divided group 3 and group 5 into three subgroups to analyze the effects of gut treatment on seed germination, and the result showed that animal digestion promoted the seed germination of Medicago and inhibited the seed germination of Stylosanthes significantly. The seed germination of Trifolium was inhibited, but the difference was not significant. Among the 25 species of Trifolieae, the germination of intermediatesized seeds was promoted after endozoochorous dispersal, but the germination of small and big seeds was inhibited. The germination rate of digested seeds from the other 45 species was negatively correlated with seed weight, but the correlation was not significant.

Oviposition selection behavior of four sympatric shootboring noctuids.

ZHANG Qin1, HUANG Ji-yu2, SHU Jin-ping1**, CHEN Wen-qiang3, WANG Hao-jie1, WU Hong1

2015, 34(10):  2843-2847. 

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To explore the sympatric speciation of four dominant shootboring noctuids, Sapporia repetita, Oligia vulgaris, Apamea apameoides and Kumasia kumaso, the oviposition behaviors of the four hootboring noctuids were observed in lab conditions using Phyllostachys heteroclada, Roegneria kamoji and Carex breviculmis as host plants. The results showed that the host preference in oviposition was significantly different among the four hootboring noctuids (P<0.01). A. apameoides and O. vulgaris only choose R. kamoji to lay eggs. All four noctuids selected their oviposition sites on different parts of the same plant, with most sites on the leaf surface, sheath and root of R. kamoji. A. apameoides and O. vulgaris spawned more eggs than the other two noctuids. Meanwhile, the oviposition time of the four noctuids was different. Kumasia kumaso was the ovipositionearliest moth and its spawning process lasted for 10 days. The oviposition time for the other three species was in sequence of S. repetita > O. vulgaris > A. apameoides. The results indicated that the four shootboring noctuids used temporal and spatial isolation mechanisms to avoid fierce interspecific competition for the development of their offsprings.

 

Bed-site habitat use of Burmese python (Python bivittatus) during early reintroduction in Hainan Yinggeling National Nature Reserve.

DUAN Yu-bao1,2，3, LIU Lei4, HUANG Yun-long1, MI Hong-xu4, RONG Ke1, MA Jian-zhang1**

2015, 34(10):  2848-2854. 

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Habitat use of seven Burmese pythons was analyzed using radio track, GPS position, quadrat investigation and resource selection functions in Hainan Yinggeling National Nature Reserve from March to June in 2014. A total of 80 utilized quadrats and 75 random quadrats were measured. The results showed that the habitats that the Burmese pythons occupied during early release stages tended to be shrub and grassland. The habitats were characterized as lower elevation, sunny slope, lower forest canopy density, environmental temperature (27.19±2.44) ℃, higher illumination intensity, far from the disturbance and close to the water. Resource selection function on habitat use of Burmese python was expressed as: logit(p)=-0.21 - 2.77 × environmental temperature -2.20 × slope + 1.44 × illumination intensity + 1.21 × vegetation type -1.19 × forest canopy density. In this model, habitat use of Burmese python was negatively correlated with environmental temperature, slope and forest canopy density, and positively related to illumination intensity and vegetation type. According to the fitted resource selection function, habitat use probability of Burmese python was expressed as P=elogit(P)/\[1+elogit(P)\], and the accuracy rate of this model was 90.7% (R²=0.843). The main factors affecting habitat use of the Burmese pythons during early reintroduction included environmental temperature, illumination intensity and vegetation type.


 

Autumn nocturnal bedsite selection by freeranging and rewilding populations of Milu (Elaphurus davidianus) in Shishou County of Hubei Province, China.

LI Chi1, YANG Dao-de1**, ZHANG Yu-ming2, SONG Yu-cheng1, LI Peng-fei2

2015, 34(10):  2855-2860. 

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Bedsite selection is the result of wild animals’ preferences for different habitats and anthropogenic interference, and is a key measure of behavioral adaptation of wild animals to ecological environments. In this study, we investigated nocturnal bedsite selection of the Milu (Elaphurus davidianus; Père David’s deer) to provide information for the conservation and management of this species. From September to November 2014 (autumn), we used track observations and direct observations to assess nocturnal bedsite selection of a population of freeranging Milu in the Hubei Shishou Milu National Nature Reserve, and a second population of Milu that escaped the reserve in 1998 and have since been living wild in Sanheyuan, Shishou County, Hubei Province, China. For each population (freeranging and re-wilding), we monitored 61 bedsite plots and 61 control plots. Both populations mainly selected bedsites on grasslands within forests that provided highly hidden spots, high herbage coverage and abundant foods, and that were less windy and closer to shelter (reed and woods); however, re-wilding Milu preferred sites farther from roads and human settlements. A stepwise discriminant analysis showed there existed overlap and separation characters in bedsites between the freeranging and rewilding populations. The Fisher discriminant function parameterized with the variables ‘distance to road’ and ‘distance to human settlement’ could discriminate the bedsites of the two populations with 87.5% accuracy, suggesting that these two factors appear to distinguish the bedsites of freeranging and rewilding Milu. The characteristics of bedsites selected by freeranging and re-wilding Milu were broadly similar, most likely as a consequence of the ecological similarities of these two populations. Differences in bedsites selected by the two populations are likely due to the differences in anthropogenic interference they experienced. On the basis of our findings, we suggested that implementing direct management of the Sanheyuan area by getting land ownership, enlarging fenced areas and retaining vegetation that provides cover for animals would benefit the conservation of Milu in this region.

Comparison of nest site selection of Orthotomus sutorius and O. cucullatus.

HUANG Qiu-li1, WANG Long-wu1,2, YANG Can-chao1, LIANG Wei1**

2015, 34(10):  2861-2865. 

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Nest site selection and nest characteristics of Common Tailorbird (Orthotomus sutorius) and Mountain Tailorbird (O. cuculatus) in Nonggang, Guangxi, Southwest China, were compared in the breeding season from March to June 2013-2014. A total of 64 nests of O. sutorius and 47 nests of O. cuculatus were found. Among them, 60 nests (93.7%) of O. sutorius were located in the forest nearby village, while 44 nests (93.6%) of O. cuculatus were found in the forest at the mountain foot and far from village. The principal component analysis indicated that the main factors for nest site selection by O. sutorius were height of nesting trees, distance to forest and altitude, whilst the main factors for O. cuculatus included height of nesting trees, visibility around nest and distance to mountain. Linear discrimination analysis showed that distance to mountain plays the most important role in nest site selection for the two tailorbird species.

Sexual reproductive characteristics of Zostera marina L. in Shuangdao Bay.

LI Le-le, ZHENG Feng-ying**, LIU Xue-qin, JIN Yan-mei, HAN Xiao-di

2015, 34(10):  2866-2872. 

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We studied sexual reproductive characteristics of a population of eelgrass (Zostera marina L.) in Shuangdao Bay, Weihai, China. At population scale, reproductive shoots were first observed in late March or early April. Initial anthesis occurred in early May, and seed release peaked in late June. Senescent reproductive shoots were detached around early July and the fertile season ended in late July. The phenophases of this species were closely correlated with water temperature and 15 ℃ was required for initial anthesis. At individual scale, the maximum numbers of reproductive branch and rhipidium were recorded in the initial appearance of reproductive shoots, and they were 4.4 and 4.9 per shoot, respectively. The maximum number of spathes per shoot (18.6) and the maximum height of reproductive shoots (96.2 cm) were observed during the initial seed release with a mean abortion rate of 40%. The average mature seed production of eelgrass was 44.8 per shoot. The maximum density of reproductive shoot (64 shoots·m^-2) was found in initial anthesis. The reproductive shoot ratio was only 12.6%. The vegetative shoot density and total population density decreased more than 40% in reproductive season. The biomass of reproductive shoots was the largest (27.9 g·m^-2) in the initial appearance of visible fruit and the mean biomass allocation percentages of underground, vegetative shoots and reproductive shoots were 38.4%, 52.4% and 9.2% respectively. The mature seed production of eelgrass was 1859 seeds·m^-2.

Accumulation characteristics of lead and cadmium in vegetables and their effects on the growth of vegetables.

ZHANG Bing-chun1,2**, WANG Lei1,2, FAN Li-xia1,2, CHEN Lu1,2, MAO Jiang-sheng1,2

2015, 34(10):  2873-2878. 

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A pot experiment was conducted with a soil originally contaminated with different concentrations of lead and cadmium, to determine the accumulation characteristics of lead and cadmium in 8 kinds of vegetable species and their effects on the growth of vegetables. The purposes of this study were to discover the relationship of lead and cadmium concentrations in vegetables and soil and to find the safety thresholds of lead and cadmium concentrations in soil for the eight vegetables. The results indicated that the cabbage and baby bokchoi grew well and their growth weren’t inhibited, while the growth of other species was inhibited to varying degrees with the increase of lead and cadmium concentration. The degree of growth inhibition of vegetables was in the descending order of celery, lettuce, daucus carrot, cowpea, pepper, tomato, cabbage and baby bokchoi, which was in accordance with their capacity of lead and cadmium accumulation. There were significant linear correlations between lead, cadmium concentrations of celery and soil (R²=0.923, 0.956). The critical values of lead in soil for different vegetables were in order of: leaf vegetables (cabbage, baby bokchoi) > root vegetables (lettuce, carrot) > beans (cowpea) > celery and pepper. The critical value of lead in soil wasn’t fixed for tomato. The critical values of cadmium in soil were the same for the 8 vegetables.

Derivation of freshwater quality criteria by multi-index for pyrethroids in China.

CHEN Lang1,2,3, SONG Yu-fang1**, ZHANG Wei-dong4, ZHANG Wei5, YANG Hai-rong3, ZHAO Yu3, HAN Xue3, LI Zhao-li3, WANG Shao-ye3

2015, 34(10):  2879-2892. 

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Based on the US EPA framework, together with the data obtained using ECOTOX and CNKI database on the acute toxicity of 3 typical pyrethroid pesticides and the responses of biomarker parameters, the present research identified their criteria maximum concentration (CMC) and criteria continuous concentration (CCC) of China national water quality criteria as 7.5 and 0.9 ng·L^-1 for deltamethrin, 110 and 19 ng·L^-1 for cypermethrin, and 21 and 3.5 ng·L^-1 for fenvalerate, respectively. Biomarkers, such as SOD, CAT, AchE, MDA, GSH, DNA/RNA contents could reflect the ecotoxicological effect of the pollutants from various perspectives on multilevels, which could help predict the ecological risk of the pollutants more precisely. The present research provides scientific support for setting the national water quality criteria and controlling the risk of pyrethroid pesticides in China.

Effect of stocking density on water quality in Sinonovacula constricta culture system.

LI Li, LIU Nan, LI Dong-ming, GUO Kai, ZHAO Wen**

2015, 34(10):  2893-2899. 

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According to the practical stocking density of Sinonovacula constricta from the experiment ponds in Donggang, Liaoning Province, stocking density was set up at 0, 30, 60, 90 or 120 ind·m^-2. Effect of S. constricta stocking density on water quality in S. constricta culture system in the laboratory was studied by experimental ecology methods. The results indicated that the stocking density of S. constricta had significant effects on the concentrations of DO, NO₃^--N, NO₂^--N, PO₄^3--P and TP (P<0.01) but not NH₄⁺-N (P>0.05). The concentrations of DO, NO₃^--N and NO₂^--N decreased with the increase of the stocking density, while PO₄^3--P and TP concentrations increased with the increase of the stocking density. The higher density of S. constricta (90 and 120 ind·m^-2) improved the cycle and regeneration of P in sediment and the utilization of N in water, which could help to control the concentrations of NO₂^--N and NH₄⁺-N in the culture period. Based on this study, the stocking density of S. constricta ranging from 90 to 120 ind·m^-2 is feasible in the culture ponds, but we need pay more attention on water quality management during the culture period.

 

Integrated risk assessment of flood disasters in southern China.

WEN Quan-pei1,2, HUO Zhi-guo1**, ZHOU Yue-hua2, CHE qin3, XIAO Jing-jing4, HUANG Da-peng5

2015, 34(10):  2900-2906. 

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Based on the data of meteorological disaster losses of flood disasters in 12 southern China provinces (municipalities) during 2004-2012, the proportions of the affected area, the affected population and direct economic losses were derived to develop an integrated index of relative flood disaster and flood risk assessment model to assess the flood risk in southern China using grey association and normal information diffusion methods. The three indicators abovementioned eliminated the effect of multiple cropping, population dynamics, rising prices and regional scale restriction. Results showed that the integrated index of relative flood disaster could reveal the variation of flood damage in different provinces of southern China for each year, and the coefficients of correlation between the integrated index of relative flood disaster and the actual flood damage in each province were above 0.7 (P<0.05). Most of flood disasters were small and mediumscale ones. The occurrence probabilities of largescale disaster in Jiangxi, Hubei, Sichuan and Chongqing were much bigger than those in other provinces. By excluding the influence of tropical cycloneinduced flood disasters, the value of the integrated relative flood risk was higher in interior areas than in coastal areas. Flood risk in Hubei Province was the highest in interior areas and the risk in Jiangsu Province was the lowest in coastal areas. This study solved the problems in risk quantification and the comparability of integrated relative disaster grades in different regions, and provided a scientific basis for prevention countermeasures and insurance policymaking of regional flood disasters.

Analysis of vegetation degradation and its driving factors in Shaanxi Province.

LI Deng-ke**, FAN Jian-zhong, QUAN Wen-ting

2015, 34(10):  2907-2913. 

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Based on the MODIS NDVI data of 250m resolution during the period of 2000-2013, the mixed pixel decomposition model was employed to calculate vegetation coverage and evaluate vegetation degradation situation in Shaanxi Province, in order to analyze the main factors causing the degradation of vegetation and to provide a basis for ecological construction and the planning of urban construction. The results showed that: 1) The degradation areas of vegetation in Shaanxi Province were mainly distributed in the Guanzhong urban agglomeration, especially in Xi’an City and the desert belt in the north of Yulin City. Xi’an City was the city with the greatest vegetation degradation area, followed by Yulin City, and Ankang City had the least area. 2) The vegetation was mainly improved or not significantly changed, accounting for 48.03% and 49.10% of the total land area, respectively. The vegetation degradation area was smaller, accounting for 2.87% of the total land area, of which the areas of mild, moderate and severe degradation accounted for 1.39%, 0.56% and 0.92% of the total land area, respectively. 3) Vegetation degradation occurred mainly in the farmland, accounting for 54.36% of the total degradation area. 4) The relationship between the vegetation degradation area and newly increased built area reached a significant level, indicating that the continuous development of urbanization came with the occupation of the farmland, forest and grassland with high degrees of vegetation coverage, thus directly leading to the degradation of vegetation. Therefore, attention should be paid on green space landscape construction in urban planning. Some vegetation in the desert region of the north of Yulin City continued to degrade, and desertification control should be continuously maintained.

Review on forest ecosystem services assessment based on big data.

SONG Qing-feng, NIU Xiang, WANG Bing**

2015, 34(10):  2914-2921. 

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Compared with traditional data, perception, acquisition, processing and expression of big data has been faced with enormous challenges. As forest ecosystem is the main body of terrestrial ecosystem, forest ecosystem services play an extremely important role in the global ecosystem. Forest ecosystem services assessment has entered the period of big data after the period of small data and surface big data. Forest ecosystem services assessment based on the longterm monitoring data from forest ecological stations could obtain more detailed information from the big data, and thus the multiscale evaluation could be carried out. At the same time, the random error brought by selection of small sample data could be avoided to make the evaluation results more reliable. So longterm monitoring data from forest ecological stations provide supports for forest resources protection and sustainable development.

Contemporary research advances on carbon emissions by forest fires and future prospects.

CHANG Yu1**, HUANG Wen-tao1, HU Yuan-man1, LI Yue-hui1, BU Ren-cang1, LIU Yong-yao2

2015, 34(10):  2922-2929. 

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Forest fire is an important natural disturbance in forest ecosystems. It releases the carbon sequestrated by forest ecosystems into atmosphere directly or indirectly, affecting carbon budget and carbon balance of forest ecosystems. Therefore, accurate estimate of carbon emissions by forest fires has great significance for scientifically making effective forest fire management decisions, enhancing the carbon sink effect of forest ecosystems, and mitigating the rate of climatic change. In this paper, we illustrated the most recent advances on carbon emissions by forest fires with regard to the following four aspects: 1) forest fire emitted gases containing carbon. 2) factors affecting carbon emissions by forest fires. 3) the models used to estimate carbon emissions by forest fires. 4) the estimation of carbon emissions by forest fires. Based on the issues and problems existing in current researches on carbon emissions by forest fires, future research directions were proposed, including 1) inventory and measurement of burn efficiencies of forest fuels; 2) establishment of spatial database for forest fuel load and fire burn severity; 3) estimate of indirect carbon emissions by forest fires; 4) estimate of carbon emissions by forest fires on the conditions of climatic change.

Advances and prospects in research of measurement and modeling methods of hydraulic redistribution of plant roots.

YU Teng-fei1,2,3**, FENG Qi1,2,3, SI Jian-hua1,2,3, ZHANG Xiao-you1,2, ZHAO Chun-yan1

2015, 34(10):  2930-2936. 

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Hydraulic redistribution (HR) is a passive movement process of water between different soil parts via plant root systems, driven by water potential gradients in the rootsoil interface. Now, HR has been observed in approximately 120 species that involve in a wide variety of ecosystems and a wide range of life forms. Empirical and modeling estimates of the average amount of water moved by HR span nearly two orders of magnitude, from 0.04 to 1.3 mm·d^-1 in the empirical literature, and from 0.1 to 3.23 mm·d^-1 in the modeling literature. The applicative techniques of HR measurements include soil moisture, isotopic labeling and sap flow methods. Each of the measurement techniques of HR has defects and uncertainty about test results, due to the lack of the comparison of the various methods. The soil connection model of HR has been widely applied, but other models, including the physical processesbased big root model, mesoscale moisture dynamic model and dynamic root profile model, have not been promoted for their complex structures and numerous parameters. In the future, quantifying the magnitude and understanding the mechanism of HR are still the difficulties of this subject.

Research progress on the molecular regulation mechanism of anthocyanin biosynthesis pathway.

LI Ying1,2, GAO Zhen-rui1,2, ZHANG Chi1,2, LI Nan1,2, LIU Chen1**

2015, 34(10):  2937-2942. 

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Anthocyanin is a natural watersoluble pigment which widely exists in plants. Flower color is determined by the inherited characteristics and regulatory mechanism of anthocyanin biosynthesis pathway. In recent years, the anthocyanin biosynthesis pathway has been revealed clearly. The structural genes in anthocyanin biosynthesis pathway are mainly regulated by some transcription factors at transcription levels. Recent researches show that some important transcription factors that regulate the structure genes in anthocyanins metabolic pathway mainly include WD40 repeat proteins, bHLH proteins and R2R3 MYB proteins. The combinations and interactions between these transcription factors determine the expression of structure genes. In this review, the molecular mechanism of anthocyanin biosynthesis is discussed. Transcription factors form trimer complex and combine with the promoter of structural genes to regulate its expression. We also summarize the application of the molecular mechanisms
 in flower color modification and anthocyanin content improvement.

Status, problems and countermeasures in biological control of Pomacea canaliculata. 

GUO Jing1, ZHANG Jia-en1,2,3**

2015, 34(10):  2943-2950. 

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Golden apple snail, Pomacea canaliculata L., is a cosmopolitan harmful alien invasive species listed by the World Conservation Union. It was introduced to China more than 30 years ago and has been widely distributed in southern China, and caused incalculable economic losses and ecological harms. In order to effectively control the snails in environmentfriendly ways, natural enemy resources of golden apple snails were summarized in this paper. Eight categories of the natural enemies were grouped into Gastropoda, Clitellata, Insecta, Malacostraca, Actinopterygii, Reptilia, Aves, and Mammalia. Meanwhile, the existing problems in biological control of the snails were also pointed out from the aspects of introduction, development and application of natural enemies and the defense strategies of P. canaliculata to its enemies. Finally, some perspectives on future research in the selection of natural enemies of P. canaliculata were put forward, including origin and parasite natural enemies, microbes, biocontrol plants, local economic animals, with an attempt to provide references for biological controlling of P. canaliculata by using the abundant biological resources in China.

Noninvasive microtest technique and its application in environmental science.

JI Dan-dan1,2, WEI Shu-he1**, WANG Si-qi1,2

2015, 34(10):  2951-2955. 

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Noninvasive microtest technique (NMT) is mainly controlled by a computer to measure the voltage at two points around the sample using selective microelectrodes. The mobile rates of ions or molecules can be obtained through a calibration curve, Nernst equation and Fick first diffusion law formula conversion based on the obtained voltage values. This technology shows some superiority such as keeping sample intact, higher distinguishability in time and space and determining several points at the same time, which can be used to realtime determine molecular or ion flow in organisms. This paper introduced the principle and characteristics of NMT used in environmental science. The applications of NMT in phytoremediation, plant resistance to soil salinization and biological monitoring in water were reviewed. Some shortages and perspectives of NMT in environmental science were also discussed.

Monitoring indicators and methods for lake wetland ecosystem services.

JIANG Bo1，2, Christina P. WONG3, CHEN Yuan-yuan1, OUYANG Zhi-yun1**

2015, 34(10):  2956-2964. 

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Lake wetlands provide humans with a great diversity of ecosystem services which are necessary for maintaining basic human needs and sustaining development in China. However, lake wetland resources nationwide are under great exploitation and utilization, which are significantly impairing the capacity of lake wetlands to provide the diversity of ecosystem services necessary to support human wellbeing. Implementing dynamic lake wetland ecosystem services monitoring can help minimize ecosystem services doublecounting and promote ecosystem services management practices. In this paper, we identified the necessary requirements for lake wetland ecosystem services monitoring and then analyzed the principles and perspectives for selecting monitoring indicators to measure lake wetland ecosystem services. We present a  set of ecosystem services monitoring indicators (including final ecosystem services and relevant ecosystem characteristics) to advance dynamic ecosystem services valuation, tradeoffs analyses, and the creation of ecological production functions in China. Final ecosystem services are biophysical outcomes which are of obvious and clear relevance to human wellbeing. Ecosystem characteristics are attributes of ecosystems measured as ecosystem structures, processes, and functions. Provisioning and cultural services are often final services while most regulating (i.e., ecosystem functions) and supporting services (i.e., ecosystem processes) are intermediate services. In order to overcome the significant challenge in credible evaluation of regulating and cultural services, and doublecounting in valuing regulating services, we propose scientists focus on establishing a lake wetland monitoring program to measure final ecosystem service indicators and relevant ecosystem characteristics metrics as a first step. We also discuss how to combine macromonitoring and local monitoring methods to monitor lake wetland ecosystem services across multiple scales. Our study is important to help acquire the necessary data to create ecological production functions to improve efforts on economic valuation by revealing the dynamic change of ecosystem services, and to effectively quantify the tradeoffs among different stakeholders. Monitoring programs are critical to moving lake wetland ecosystem services from scientific theory into management practices.

Bacterial diversity in the breeding environment of Takifugu rubripes revealed by MiSeq sequencing.

ZHAO Xiao-wei, DING Jun**, DOU Yan, WANG Meng-ge, CHANG Ya-qing

2015, 34(10):  2965-2970. 

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Microorganisms play an important role in matter cycle and energy flow in aquaculture environment. Studies on microorganism diversity in aquaculture environment not only lay the foundation of disease control but also explore new microorganism resources. In this study, Illumina Miseq was used to analyze the structure characters of microbiome living in Dalian Takifugu rubripesculturing water indoors, water inlet point outdoors and bottom sludge respectively. For the three samples, 27164, 41146 and 30474 effective sequences were selected and utilized to perform bacterial diversity analysis. The results disclosed great bacterial diversities in the Takifugu rubripes aquaculture environment. Furthermore, the richness and diversity indices in the sediment samples were higher than that in the water samples. In total, 33 phyla were identified. In addition to Chloroflexi, Bacteroidetes, Planctomycetes, Cyanophyta, Acidobacteria, Proteobacteria, Fusobacterium, Verrucomicrobia, Firmicutes and Actinobacteria that have often been reported, other 23 phyla rarely reported were detected too. Although there were differences in microbial composition between these three samples, Proteobacteria and Bacteroidetes (68.33%-93.37%) were the dominant groups in all samples. This study reveals the bacterial diversity and abundance in Dalian Takifugu rubripes culturing environment, compares the bacterial community structures and provides guidance for healthy aquaculture of Takifugu rubripes.

The application of RS and GIS technology in meso-scale landscape classification and cartography: A case study in Longquanyi District of Chengdu.

OU Ding-hua1, XIA Jian-guo1**, ZHANG Li2, OU Xiao-fang3, ZHAO Zhi4

2015, 34(10):  2971-2982. 

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In order to understand the local application of RS and GIS in classifying landscape and cartography, data of Landsat-8 OLI images and ASTER GDEM were used to landscape classification and cartography in Longquanyi District, Chengdu. The results showed that, ISODATA remote sensing image unsupervised classification method could automatically classify the types of landscape in the study area. The method could not only reduce the effects of manmade subjective judgments in the traditional classification, but also distinguish small scale landform types such as the valley and shallow hill to ensure the continuity and gradual changes of surface morphology. Compared with C5.0 and MLC, QUEST showed the higher overall classification accuracy, Kappa coefficient, average user accuracy, and average mapping accuracy of classification. Moreover, the average misclassification error and average omission error showed the order as QUEST < C5.0 < MLC, indicating that the QUEST decision tree classification method is the best in classifying land use/cover type in the study area. In addition, the combination with ArcGIS spatial analysis, map compilation technology and Python programming displayed much strong practicability, since the combined method could overcome the limitation of GIS platform general function and then improve the mapping efficiency. The Longquanyi District was divided into 18 kinds of landscape types. The landscape distribution characters were consistent with the actual regional landscape pattern. The results here suggest that the integrated application of QUEST remote sensing image decision tree classification, GIS spatial analysis and map compilation, Python programming technique take multiple landscape ecological classification indexes into consideration, and efficiently realize the landscape type classification and cartography in the study area. RS and GIS technology showed strong popularization and application values in mesoscale landscape classification and cartography.