Table of Content

10 January 2014, Volume 33 Issue 1

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The response of soil seed bank to clipping and grazing in a Stipa krylovii steppe, Inner Mongolia.

LI Yuan-heng1, HAN Guo-dong1**, WANG Zheng-wen2, BAI Wen-ming3, ZHAO Meng-li1

2014, 33(1):  1-9. 

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The seed bank is a potential plant community and indicates orientation of plant community succession. Since the grazing ban policy was implemented, grassland utilization has been shifted from free grazing to hay-making. In this study, we assessed the impacts of clipping and grazing on soil seed bank composition (density, functional and species composition) and its similarity with aboveground vegetation. We established four different clipping treatments: no clipping control (CK), clipping at 15 cm high (M₁₅), at 5 cm high (M₅) and free grazing (GR) in a typical Stipa kryloviidominated steppe in Inner Mongolia. The seed bank was sampled with cutting ring and TTC method was used for testing seed viability. Viable seeds were counted and the Sorensen’s similarity between the species composition of soil seed bank and above ground vegetation was calculated. The results showed that soil seed bank density ranged from 6245.0±1351.9 to 8155.9±909.1 seeds per square meter across all treatments. The CK had a higher soil seed bank density than M₁₅. Of all the functional groups, perennial forbs had the highest soil seed bank density and accounted for around 55%-60% of the total seed bank density. Annual forbs accounted for 36%-43% of the soil seed bank density and showed significantly a higher seed density at GR than at M₁₅. From the individual species level, the seed density of Stipa krylovii and Allium bidentatum was significantly affected by clipping and grazing. Sorensen’s similarity index for CK, GR, M₅ and M₁₅ was 0.55, 0.58, 0.48 and 0.60, respectively. Our experiments indicated that seed bank in the Inner Mongolia typical steppe was highly sensitive to free grazing and clipping. Both clipping and grazing reduced the soil seed bank density, and thus were predicted to retard the restoration of the degraded Stipa krylovii natural steppe.

Responses of spatial pattern of aboveground biomass of natural grassland to terrain at different scales in northern slope of Qilian Mountains.

HOU Zhao-jiang, ZHAO Cheng-zhang**, DONG Xiao-gang, LI Yu, ZHANG Qian, MA Xiao-li

2014, 33(1):  10-15. 

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Spatial pattern of aboveground biomass of grassland community reflects spatial heterogeneity of resource allocation caused by terrain difference. Community survey method and generalized additive model (GAM) were used to study the response characteristics of community’s aboveground biomass spatial pattern at hill and hillslope scales in natural grassland of the northern slope of Qilian Mountains. The results showed that at the hill scale, terrain factors had definite effects on the aboveground biomass of community, with the sequence of elevation > slope of aspect (SOA) ≈ slope of slope (SOS) ≈ slope. When reducing hill scale to hillslope scale by aspect, the aboveground biomass of grassland community would be most affected by SOA in east and west aspects, and by elevation and SOS in south and north aspects. On east slope, community’s aboveground biomass firstly decreased then increased in SOA gradient, and vice versa in west slope. On south slope, it increased with elevation. On north slope, it firstly kept stable then decreased in SOS gradient. Our study suggested that the spatial pattern of aboveground biomass of grassland community was obviously scaledependent at hill and hillslope scales.

Point pattern analysis of ex-situ population of Taxus wallichiana var. mairei. 

LI Wei, WANG Rui-xue, ZHANG Guang-fu**, PAN Chen

2014, 33(1):  16-22. 

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Taxus wallichiana var. mairei, a rare and endangered species, ranks as the first class on the List of the Important Wild Plants for Conservation in China (first passel). By applying Ripley’s point pattern analysis, we examined the spatial distribution patterns and the associations among different age-classes of T. wallichiana var. mairei ex-situ population from the western foothills of Zijin Mountain to elucidate its spatial distribution characteristics. The results showed that individuals of ageclass I presented a random distribution at small spatial scales (1-4 m) and large scales (10-15 m), but with an obvious clumped distribution at medium scales (4-10 m). At all scales, individuals of age-class Ⅱ performed an evident clumped distribution. However, individuals of age-class Ⅲ had a random distribution. Overall, the ex-situ population presented a clumped distribution. The spatial association of individuals between age-classes I and Ⅱ had a significantly positive correlation both at small spatial scales (1-4 m) and large scales (10-15 m), whereas there was no significant correlation at the rest of scales. Individuals of age-class I had a negative correlation with those of ageclass Ⅲ at the spatial scales of 6-13 m, but they did not have an obvious correlation at the rest of scales. In contrast, age-class Ⅱ had no obvious correlation with age-class Ⅲ at all scales. Considering that most young individuals mainly presented clumped distribution and that the intraspecific association of this ex-situ population was similar to that of wild population, all efforts that can minimize human disturbance and protect suitable habitats of the secondary forest near the mother trees in Zijin Mountain should be made to increase the population size and distribution area.

 

Effect of storage and temperature on seed germination of 12 shrub species from the eastern Qinghai-Tibet Plateau.

CUI Xian-liang, LUO Ya-ting, BI Ting-ju, JIANG Hong-zhong, LUO Yin-ling**

2014, 33(1):  23-32. 

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Germination of 12 shrub species from eastern Qinghai-Tibet Plateau was tested at four constant temperatures (10, 15, 20, and 25 ℃) and one alternating temperature (5/25 ℃) under two storage conditions (outdoor burial and indoor dry storage).The relationships between seed germination and storage condition, seed size and habitat were also tested. The results indicted that, the seeds stored indoors had the highest germination percentage and fastest germination rate at 5/25 ℃. The seeds buried outdoors had highest germination percentage at 10 ℃ and 5/25 ℃, the fastest germination rate at 5/25 ℃, the lowest germination rate at 10 ℃, and the lowest germination percentage at 25℃. The mean germination rate of the studied species was increased with increasing temperature. The germination percentage and germination rate of the seeds buried outdoors at 10, 15, 20, 25 ℃ were higher than those of the seeds stored indoors. However, an opposite result was found at 5/25 ℃. For the seeds stored indoors, there were significant negative correlations between germination percentage, germination rate and seed size at 5/25 ℃. For the seeds buried outdoors, there were significant negative correlations between germination percentage or rate and seed size at 10 ℃ and 5/25 ℃, and there also were significant negative correlations between germination rate and seed size at 20 ℃, but no relationships between germination percentage or rate and seed size at other temperatures. The seeds from the southern slope boscage had high germination percentages and germination rates at all the five temperatures regardless of storage condition, with the highest and lowest germination percentages observed at 5/25 and 15 ℃, respectively. The seeds from the northern slope boscage had the highest germination percentages at 5/25 ℃ regardless of storage condition, and the germination percentage decreased with the increase of temperature, regardless of storage condition. We concluded that temperature fluctuation benefited seed germination. The effect of storage condition on seed germination showed strong temperature dependence and the relationship between seed germination and seed size and habitat also varied with culture temperature and storage condition.

Structural characteristics and influencing factors of phytoplankton community in the middle and lower reaches of Hanjiang River during spring season.

PAN Xiao-jie**, ZHU Ai-min, ZHENG Zhi-wei, QIAO Ye, ZHOU Qing, ZHOU Lian-feng, ZHOU Xi

2014, 33(1):  33-40. 

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Diatom bloom occurs frequently in the middle and lower reaches of Hanjiang River during spring season. In this paper, we investigated the
 characteristics of phytoplankton community structure at different bloom stages and analyzed the major physical and chemical factors influencing water bloom. During the spring bloom season, 64 phytoplankton species (including varieties) belonging to 48 genera and 6 phyla were identified in Hanjiang River. The largest proportion was the species of diatom (23 species, 18 genera), which accounted for 44.12%-51.28% of the total phytoplankton species at different sampling sites. The second was the species of Chlorophyta (22 species, 16 genera), which accounted for 28.21%-35.14% of the total species. Only 2-3 species from either Cyanophyta or Cryptophyta were found at each sampling site during this season. Species of Chrysophyta and Dinophyta were the least. The absolutely dominant species in this period were found to be Cyclotella sp. (Bacillariophyta). In the early and middle stages of the bloom season, Cyclotella sp. was the predominant component of phytoplankton while other species of Bacillariophyta, Cyanophyta and Cryptophyta co-dominated in the late stage. During the bloom season, the phytoplankton population density could reach to 2.34×10⁷ cells·L^-1, while the density of Cyclotella sp. could reach up to 2.06×10⁷ cells·L^-1, accounting for 88% of the total phytoplankton density. Several diversity indices of the phytoplankton were also calculated. The Margalef index had no significant difference in space and time. The Shannon index was lower in the middle stage of the bloom season than in the early and the late stages. On the contrary, the trend of BergerParker index and Simpson’s index were the opposite. Redundancy analysis (RDA) on phytoplankton and environmental factors in Hanjiang River revealed that the total density phytoplankton was closely related to phosphate (PO₄^3--P), dissolved oxygen (DO) and total phosphorus (TP), and negatively related to nitrate (NO₃^--N), temperature and transparence.

Characteristics of plants during early restoration stage of abandoned riparian croplands in Liaohe River reserve.

XIA Hui-juan1,2,3, ZHANG Yuan2,3, ZHANG Wen-li1, KONG Wei-jing2,3**, YAO Yi-han2,3

2014, 33(1):  41-47. 

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Riparian vegetation on abandoned croplands after 3-year natural rehabilitation was surveyed with line transect method in Liaohe River reserve, and species composition and factors affecting biodiversity were investigated. Results showed that there were 51 species on 8 sampling sites, and the dominant species were herbs (49 species). The 51 species belonged to 46 genera and 21 families, and Compositae and Gramineae had the most species. The vegetation was mainly composed of singlespecies families, singlegenus families and single-species genera. There were a few species with high frequency and coverage, and Conyza canadensis and Artemisia capillaris as pioneer species in the community succession had the highest appearance frequency. The herbaceous species were mainly mesophytic and annual, and the weeds accounted for a larger proportion of total herbaceous species, indicating that species composition at an early restoration stage on abandoned riparian croplands was affected mainly by human activities rather than the river processes. The species diversity decreased from upstream to downstream. Correlation analysis on environmental factors indicated that Simpson diversity index, Shannon index and Pielou evenness index had positive correlations with altitude and distance from the estuary, and negative correlations with distance from the confluence of eastern and western Liaohe River and sinuosity. While Patrick richness index had negative correlations with the width between levees, and had no correlations with other factors.

Biomass structure and growth of reproductive ramets of Setaria viridis (L.) Beauv and S. glauca (L.) Beauv.

JIA Feng-qin1**, ZHANG Na1, Nuermaimaiti1, Nasenbate1, LAI Zhuo-yan2

2014, 33(1):  48-52. 

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Biomass structure and growth of reproductive ramets of Setaria viridis (L.) Beauv and S. glauca (L.) Beauv were compared in the field. Biomass of reproductive ramets had large variation between populations within each species. Coefficients of variation in biomass constituents were low, being 11.11%-22.77% in Setaria viridis and 12.41%-26.82% in Setaria glauca, respectively. Biomass of reproductive ramets increased in a power function with increasing plant height and total biomass, and they showed a similar allometric power growth pattern. The coefficients of determination R² of fitted equations were between 55% and 71% in Setaria viridis and between 62% and 81% in Setaria glauca. Plant height was the only parameter that had a significant difference between species. Reproductive allocation and sheath biomass allocation showed significant differences. The results demonstrated that, for both species under the same environment, biomass component and growth can be similar or different both within and between species, which is controlled by the interaction between environmental and genetic factors.

Effect of elevated O₃ concentration on epidermis stomata and tissue structure of leaves of Ligustrum obtusifolium Sieb.

LI Mei1,2, XU Sheng2**, ZHANG Heng-qing1, HE Xing-yuan2, CHEN Wei2, ZHAO Yi2, LI Bo2

2014, 33(1):  53-58. 

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An experiment was conducted to study the characters of epidermis stomata and leaf tissue structure of Ligustrum obtusifolium seedlings exposed to elevated O₃ concentration (160 nmol·mol^-1) for 136 days in open top chamber (OTC). The results showed that elevated O₃ decreased the stomatal length, width, perimeter and area in adaxial leaves of L. obtusifolium by 12.9%, 8.4%, 8.2%, and 15.0%, respectively, while decreased by 16.8%, 9.8%, 13.3%, and 23.6%, respectively in abaxial leaves. The stomatal aperture decreased by 69.2% in adaxial leaves (P <0.05), and decreased by 39.3% in abaxial leaves (P <0.05). The elevated O₃ concentration did not have significant effect on stomatal density (P >0.05). Under elevated O₃, the thickness of palisade tissue and thickness ratio of palisade tissue to spongy tissue in adaxial leaves increased by 10.2% and 28.9%, respectively, and increased by 7.3% and 295% in abaxial leaves, respectively (P <0.01). The thickness of spongy tissue decreased by 15.1% in adaxial leaves, and decreased by 16.8% in abaxial leaves (P<0.01). The thickness of upper and lower epidermis increased by 18.9% and 23.1% in adaxial leaves, respectively, and increased by 11.5% and 16.0% in abaxial leaves (P<0.05). The leaf thickness increased slightly (P>0.05). These results provided new evidence for the research in the effects of elevated O₃ on leaf tissue structure and function of urban plants under the background of global climate change.

The introduction of kenaf (Hibiscus cannabinus L.) hybrids on saline-alkali land in North Henan.

ZHANG Xin1, DONG Na1, LIU Ming-jiu1, PAN Zi-liang2**

2014, 33(1):  59-64. 

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In order to screen out the high-yielding kenaf hybrids which are suitable for growing on saline-alkali land in North Henan, taking H318 as a control, we compared 11 traits of six pairs hybrids F₁ and F₂ of kenaf and analyzed the competitive advantages of each trait, the difference and correlations between F₁ and F₂ generations, as well as the fading rates of the generation F₂ relative to F₁. The results showed that significant differences existed in the competitive advantage of each trait among combinations of F₁ and/or F₂ generations. The heterosis of F₂ generations declined significantly, but the heterosis in a few combinations could be exploited. Moreover, there were highly significant positive correlations in fiber thickness, dried rate of fresh fiber and fiber rate of fresh stem between F₁ and F₂ generations. For harvesting the whole stem of kenaf, the F₁ of combination F3A/992 and the F₂ of combination F3A/R7 were the best, but for harvesting the fiber of kenaf, the F₁ of combination P3A/R1 and the F₂ of combination P3A/992 were the best.

The causes of Anemone rivularis seed dormancy and the methods for breaking dormancy.

YU Xiao-jun1**, XU Chang-lin1, WANG Fang2, JING Yuan-yuan1, DUAN Chun-hua1, WANG Gen1, SHENG Fang1

2014, 33(1):  65-70. 

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In order to clarify the dormancy mechanisms of Anemone rivularis seed and find better methods for breaking seed dormancy to provide a basis for cultivation for medicinal plants of A. rivularis, the efficacy of a series of treatments on seed germination and dormancybreaking of A. rivularis were assessed when compared with the untreated achene (CK). Soaking for 3-5 h with 40-50 g·L^-1 NaOH solution failed to break the dormancy of A. rivularis achenes. After 2 months of storage, the percentages of germination of the achenes with the head or the entire seedcase being removed were 3.3% and 6.2% (P>0.05), respectively, when cultivated without light but 38.7% and 76.0% (P<0.05), respectively, when cultivated with light. Cutting off the bottom of the achene made no difference, irrespective of cultivation with or without light. The germination of A. rivularis seed after partial seedcase removal (from 1/5 to 1/4) reached 62.7% and was significantly higher than that of CK (P<0.05). The germination of A. rivularis seed after seedcase puncture treatment was also significantly improved by 19.3% (P<0.05) but was less effective than that when the seedcase was totally or partially removed (P<0.05). There was no significant allelopathic effect of aqueous extract liquid of A. rivularis seedcase on the seed germination of A. rivularis. Soaking in GA₃ solution with concentration of 10-30 g·L^-1 for 10 h did not improve the germination of A. rivularis achene. The highest germination percentage of the A. rivularis seed was found at temperature alternating between 25 and 15 ℃ (with durations 8 and 16 h, respectively). There was no seed germination at temperature alternating between 15 and 5 ℃  or 10 and 5 ℃. Our results suggest that seedcase blocks the light, causing the dormancy of A. rivularis seed. Removing the seedcase could break the seed dormancy of A. rivularis effectively. However, some seeds still remain dormant after the seedcase is removed. Therefore, the dormancy type of A. rivularis seed (achene) is combinational (physical dormancy + physiological dormancy).

Ecological thresholds of Suadea heteroptera under gradients of soil salinity and moisture in Daling River estuarine wetland.

WANG Bai, HAN Jia-bo**, ZHOU Zun-chun, DONG Ying, GUAN Xiao-yan, JIANG Bei

2014, 33(1):  71-75. 

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Based on the significant correlation of biomass with density, height and weight of Suadea heteroptera, the biomass was selected as a biological index for analyzing the distribution pattern of S. heteroptera population under different soil physicochemical conditions. Quadratic nonlinear regression of the biomass of S. heteroptera to soil moisture and salinity was fitted very well, suggesting that the distribution of S. heteroptera population was affected by soil salinity and moisture. The ecological thresholds of soil moister and salinity for S. heteroptera in the Daling River estuary were analyzed by Gaussian Model. The results indicated that the optimum soil salinity for the growth of S. heteroptera was 12.14 g·kg^-1, with the ecological threshold of 5.02-19.26 g·kg^-1 and the optimum ecological threshold of 8.58-15.70 g·kg^-1. The optimum soil moisture was 59.82% with the ecological threshold of 22.02%-97.62% and the optimum ecological threshold of 40.92%-78.72%. These results provided basic references for habitat protection and vegetation restoration of S. heteroptera in the estuarine wetland.

Effects of salt-alkali mixed stresses on seed germination of the halophyte Chenopodium glaucum L.

Gulnar Yasin, YANG Rui-rui, ZENG You-ling**

2014, 33(1):  76-82. 

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Chenopodium glaucum belonging to Chenopodiaceae is an annual economic halophyte which is widely distributed in the light saline and alkaline region, Xinjiang. We investigated the interactive effects of salt-alkali mixed stresses on its seed germination, germination recovery and growth phenotype of germinated seedlings. Seed germination percentage was significantly reduced with increasing salinity and pH and seed germination rate was also descent with increasing pH at a given salt concentration. Salinity and pH were also found to be the major factors influencing the growth phenotype of germinated seedlings of C. glaucum under the abovementioned corresponding treatments. Ungerminated seeds germinated well after being transferred to distilled water, with the final germination percentage being more than 90%, indicating that a certain degree of mixed salt-alkali stresses had almost no inhibitory influence on seed germination potential of C. glaucum, and the germination recovery percentage increased with increasing salt concentration. The two-way ANOVA analysis indicated that the seed germination of C. glaucum was significantly affected by salinity, pH and their interactions and salt was a decisive factor, and pH was a lesser one. In a word, the seed germination rate and growth phenotype of germinated seedlings of this species were inhibited by salinity and pH.

Effects of atmospheric CO₂ concentrations and N application levels on the growth, N uptake and utilization of oilseed rape during vegetative stage.

WANG Xiao-juan1,2, WANG Wen-ming1, ZHANG Zhen-hua1, ZHANG Li1, YANG Chun1, SONG Hai-xing1**, GUAN Chun-yun3

2014, 33(1):  83-88. 

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Dry biomass and changes of nitrogen (N) uptake and utilization in oilseed rape during vegetative growth stage at two levels of CO₂ (natural: 400 μmol·mol^-1, elevated: 700 μmol·mol^-1) and two levels of N application (normal: 15 mmol·L^-1, limited: 5 mmol·L^-1) were studied in a sand culture experiment. Results showed that plant height, basal diameter and dry biomass were increased under the elevated CO₂ concentration, and the increment of either basal diameter or dry biomass at the normal N level was higher than that at the limited N level, but the increased degree of plant height and root dry weight showed an opposite pattern. Regardless of the N application levels, root volume, total active absorption area were increased under the elevated CO₂ concentration, but number of the first lateral root was only increased at the normal N level, root length was only increased at the limited N level. N content in organs of oilseed rape was declined under the elevated CO₂ concentration, and the declined degree of N contents in leaves and roots was significantly higher than that of stems. Under the elevated CO₂ concentration, accumulation amount of N in roots, stems and leaves were increased at the normal N level, only increased in stems at the limited N level, and decreased in roots and leaves. N uptake efficiency, N use efficiency (NUE) and N efficiency were increased under the elevated CO₂ concentration, and increased degree at the normal N level was higher than at the limited N level, and the response of NUE to N application levels was more obvious.

Exogenous nitric oxide and hydrogen peroxide regulate the acclimation of chicory (Cichorium intybus) to salt stress.

GU Wen-ying1, MO Ping-hua2, YANG Jiang-shan4, ZHAO Guo-qi1, GAO Hong-wen3**

2014, 33(1):  89-97. 

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Chicory (Cichorium intybus) seedlings were employed to study the impacts of exogenous nitric oxide (NO) donor (sodium nitroprusside (SNP), 0.1 mmol·L^-1) or hydrogen peroxide (H₂O₂, 0.5 mmol·L^-1) on their growth, antioxidant enzyme activities and stress protein expression under salt stress (210 mmol·L^-1 of NaCl). The results showed that root length and fresh weight of chicory seedlings were obviously decreased under salt stress compared with the control, whereas the content of malondialdehyde (MDA) sig
nificantly increased (P<0.05). In addition, isoenzyme analysis showed that the activities of superoxide dismutase (SOD) and catalase (CAT) were weakened while peroxidase (POD) activity obviously increased under salt stress. The data from qPCR analysis suggested that the relative quantity of HSP 90 mRNA and CiDHN1 mRNA increased under salt stress, but the data from ELISA indicated that only the content of CiDHN1 gradually increased in a timedependent manner (2-48 h). Compared with the single salt stress, the inhibition on root length and fresh weight of plants induced by salt stress was apparently alleviated by SNP pretreatment, with a dramatic decline of MDA content, an obvious rise in activities of SOD, POD and CAT and an increase in numbers of SOD and POD isoenzymes. Moreover, qPCR analysis indicated that SNP pretreatment further increased the relative quantity of HSP 90 mRNA and CiDHN1 mRNA, and the contents of HSP 90 and CiDHN1 in chicory seedlings. The effects of H₂O₂ pretreatment were similar to those of SNP pretreatment. These data suggested that both of SNP and H₂O₂ were involved in alleviating adverse effects of salt stress on chicory seedlings by increasing antioxidant enzyme activities and stress protein expression.

Effect of sugarcane-sweet corn intercropping on yield, quality and economic benefit of sugarcane.

LI Zhi-xian1,2, YANG Wen-ting1,3, WANG Jian-wu1**

2014, 33(1):  98-104. 

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A field experiment was conducted in the Experiment Station Farm of South China Agricultural University located in Guangzhou China to investigate the effect of sugarcane planting patterns (sugarcane monoculture, sugarcane-sweet corn 1∶1 intercropping, and sugarcanesweet corn 2∶1 intercropping) and different N input levels (300,  525 kg·hm^-2) on yield, total biomass dynamic, quality and economic benefit of sugarcane. Results showed that the economic benefit of sugarcanesweet corn intercropping with the low N level was 52.67% to 20.59% (sugarcane-sweet corn 1∶1 to 2∶1 intercropping) higher than that of sugarcane monoculture, and the land equivalent ratio (LER) of which was higher than 1. The LER of sugarcane-sweet corn 1∶1 intercropping system was 31.5% higher than that of sugarcane-sweet corn 2∶1 intercropping system. Meanwhile, the economic benefit and the LER of sugarcane-sweet corn 1∶1 intercropping system with the high N level were 26.25% and 36.00% higher than that of sugarcane monoculture respectively, but the sugarcane-sweet corn 2∶1 intercropping system with the high N level had no advantages compared with the sugarcane monoculture. In the sugarcanesweet corn intercropping system, the yield of intercropped sugarcane was 9.72%-33.17% lower than that of monoculture because the eigenvectors such as maximum growth rate (v_m), theoretical maximum (w_m) and the fastest growth day (t_m) of the dynamic accumulation model of intercropped sugarcane were more uncoordinated than those of monoculture. However, the yield of intercropped sweet corn was 14.10%-24.43% higher than that of monoculture. Compared with sugarcane monoculture, sugarcane-sweet corn intercropping patterns had no significant effect on sugarcane quality. Therefore, it is feasible to apply sugarcane-sweet corn intercropping to realize high quality and high efficiency planting of sugarcane, and the sugarcane-sweet corn 1∶1 intercropping is the optimum intercropping pattern.

Agro-geological background characteristics of light-sweet flavor style of flue-cured tobacco in Wumeng tobacco-growing area of Guizhou.

LIU Chao1, ZHAI Xin2, XU Zi-cheng1**, CHEN Xue2, HUANG Hua-gang2, HU Wei2, NIU Li-li1

2014, 33(1):  105-111. 

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We collected samples of soil and tobacco leaves from 109 field sites in Wumeng tobacco-growing area in Guizhou Province, and identified the agro-geological background characteristics of light-sweet flavor style of flue-cured tobacco in terms of soil parent rock, parent material source, soil type and nutrition, and landform. The results indicate that carbonate and clastic sedimentary rocks are mainly the soil parent rocks for the typical light-sweet flavor style, carbonate sedimentary rocks for the light-sweet flavor style, and carbonate and clay sedimentary rocks for the weak light-sweet flavor style. Although the sources and compositions of parent materials that affect the formation of fluecured tobacco styles are different, they are all characterized as slope sediments. Yellow brown soil and sand land can improve the light-sweet flavor of flue-cured tobacco, and the contents of organic matter, available nitrogen, total potassium, watersoluble chlorine in the soil for the typical light-sweet flavor style are low, while the available potassium content is the highest. Furthermore, the high-middle mountain landform is mainly responsible for the typical light-sweet flavor style, the shares of high-middle and middle mountain landform are equivalent for the light-sweet flavor style, and the middle mountain landform is for the weak light-sweet flavor style.

Temporal patterns and environmental controls of sap flow in Artemisia ordosica.

LI Si-jing, ZHA Tian-shan, QIN Shu-gao, QIAN Duo, JIA Xin**

2014, 33(1):  112-118. 

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Sap flow in Artemisia ordosica, together with environmental variables, were continuously measured in situ from July to October 2012. Results showed that weather conditions exerted a strong control over the diurnal pattern of sap flow. The daily maximum sap flow rates were 107.81, 79.40, and 4.34 g·cm^-2·h^-1 on sunny, cloudy and rainy days, respectively. Sap flow showed pronounced seasonal variations, with the maximum occurring in July and the minimum in October. During drought periods, daily sap flow rate increased with soil water content, with that measured at 30 cm depth having the highest explanatory power. Under higher soil water conditions, daily sap flow rate showed a strong correlation with micrometeorological factors. Based on correlation analyses, these factors were ranked as follows in terms of the magnitude of their effects on sap flow: vapor pressure deficit > solar radiation > average air temperature > relative humidity.

Removal of pollutants in reservoir by typical hydrophytes: A laboratory simulation study.

SONG Hong1,2, WANG Kong-hai3, CHEN Wei1**, HE Xing-yuan1, LIU Zhou-li1, HUANG Yan-qing1, YU Shuai1,2

2014, 33(1):  119-124. 

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An experiment was conducted to study the removal of  total nitrogen (TN), ammonium nitrogen (NH₄⁺-N), nitrate nitrogen (NO₃^--N) and  total phosphorus (TP) by three hydrophyte plant species, Iris sanguinea, Acorus calamus, and Iris pseudacorus. The eutrophicated water in laboratory was prepared according to the eutrophication status of Dahuofang Reservoir and its tributary inflow. The results showed that after 28 days growing in the water, the removal rates on the four pollutants were 78.1%, 73.1%, 84.8% and 90.3% by I. sanguinea, 73.4%, 90.7%, 63.1% and 89.1% by A. calamus, and 83.9%, 77.3%, 75.0% and 93.8% by I. pseudacorus, respectively. The removal efficiencies on four pollutants by the three plants showed similar variations: From initial high rate to gradually lower rate. Removal effect was obvious for NO₃^--N during the whole experiment while more obvious for TN and NH₄⁺-N during the first 14 days, and more obvious for TP during the first 21 days.

Floral composition and distribution characteristics of polypores in Northeast China.

LI Jing-wen, WEI Yu-lian**

2014, 33(1):  125-131. 

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Polypores are the most important group of wood-inhabiting fungi. Most of these fungi can decompose cellulose, hemicellulose, and lignin in the plant cell walls, and therefore play a key role in nutrient recycling in forest ecosystems. Based on 16 years of field investigation and laboratory analyses, 304 polypore species were found and they belong to 93 genera, 14 families, and 7 orders. The dominant family is the Polyporaceae, accounting for 33.2% of all polypore species in the studied area, and the dominant genera are Phellinus, Postia and Antrodia. The majority of the polypores are the north temperate element and cosmopolitan element, showing a distinct north temperate character in floral composition. 23 threatened polypores were found and 11 of them grow on single tree species. This suggested that they need some special substrates for their growth. So the most important method for polypore conservation is to keep natural forests without disturbance. Most of the polypores are saprophytic species, and the white rot species are dominant. The percentage of brown rot polypores is 23.8% of all polypores in Northeast China, which is higher than the mean level in the world. Among these brown rot species, 80% of them were found on gymnosperm wood, suggesting that the brown rot polypores are very important for nutrient cycling in coniferous forests in Northeast China.

Comparison of understory bird communities in evergreen broadleaved forests of Daweishan and Jizushan, Yunnan, China.

SU Dong-dong1,2, WU Zhao-lu1, GAO Jian-yun1,2, LUO Kang1, WANG Xin-cai2, ZOU Fa-sheng2**

2014, 33(1):  132-140. 

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The understory birds in Xishuangbanna, Yunnan is characterized of higher species richness and lower species density compared to South China, where the Greycheeked Fulvetta (Alcippe morrisonia) is the most dominant species. To explore whether characteristics of understory birds in other areas of Yunnan are the same as in Xishuangbanna, and assess how topography impacts the understory bird community, we sampled birds in the evergreen broadleaved forests of Daweishan, southeast Yunnan and Jizushan, northwest Yunnan using mist nets from November 2011 to September 2012. The two sites are on the east of Red River Fault Zone. A total of 735 individuals from 52 species, 13 families and 3 orders were captured within 5614 net hours at Daweishan, and a total of 413 individuals from 45 species, 15 families and 2 orders were captured within 4731 net hours at Jizushan. Our results showed that species diversities of Daweishan and Jizushan communities were lower than that of monsoon evergreen broadleaved forest of Mengyang, Xishuangbanna; dominant species, especially the grey-cheeked fulvetta, accounted for a higher proportion in Daweishan and Jizushan than in Mengyang; as regard to resident species, Daweishan and Jizushan communities had high similarity but were quite different from Mengyang community; more migratory individuals were caught in Daweishan and Jizushan communities than in Mengyang community. We concluded that Red River Fault Zone had a significant impact on the understory bird community compositions by a comprehensive analysis of natural geography of Daweishan, Jizushan and Mengyang, as well as their bird community compositions.

Effects of land use/land cover change (LUCC) on habitats of Tibetan wild donkey in Aerjin Mountain National Nature Reserve. 

SU Xu-kun1, DONG Shi-kui1**, LIU Shi-liang1, LIU Ying-hui2, SHI Jian-bin1, WU Yu1, ZHANG Xiang3, XU Dong-hua3

2014, 33(1):  141-148. 

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Aerjin Mountain National Nature Reserve is one of the major refuges for Tibetan wild donkey in Qinghai-Tibetan Plateau. Understanding the effects of land use/land cover change (LUCC) on potential habitats of Tibetan wild donkey is the foundation to keep the survival and development of Tibetan wild donkey in the future. Based on the niche theory, we developed a GIS-based niche model to examine the impacts of LUCC on different kinds of suitable habitats for Tibetan wild donkey in 1985 when Aerjin Mountain National Nature Reserve was established and 2000 by using GIS and Analytic Hierarchy Process (AHP). The results suggested that highly and moderately suitable habitats were not obviously changed by LUCC. The highly suitable habitats were mostly located in the vicinities of Kardun inspection station and the corridor along Aerjin Mountain in the northeast of reserve. The moderately suitable habitats were mostly located around the highly suitable habitats. Between 1985 and 2000, the areas of highly and moderately suitable habitats increased slightly. The increased areas of highly suitable habitat were mainly came from those of moderately suitable habitats. Lowly suitable and unsuitable habitats were the main sources for increased moderately suitable habitats. The areas of lowly suitable habitats decreased sharply, changing into those of unsuitable habitats. The unsuitable habitats expanded continuously. The changing tendency of different habitats showed that the habitat patterns became more concentrating as the highly suitable and unsuitable habitats.

Observations of grooming and trophallaxis in a Chinese subterranean termite, Reticulitermes aculabialis Tsai et Hwang (Isoptera: Rhinotermitidae).

XING Lian-xi**, YIN Ling-fang, KONG Xiao-hong, LIU Ming-hua, WANG Kai, SU Xiao-hong

2014, 33(1):  149-154. 

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In order to understand the behaviors of grooming and trophallaxis in termite and apply the related knowledge to the control of termite, the grooming and trophallaxis of the Chinese subterranean termite, Reticulitermes aculabialis, were qualitatively observed and quantitatively measured. The results showed that grooming behaviors were performed mainly by 4-instar and above workers. Although 4-6 instar nymphs could also take part in grooming, they were less active than those of 4-instar and above workers. Grooming usually occupied a proportion of 1.6% time in all ordinary behaviors during 24 hours and, the frequency and session length of grooming would increase whenever the body surface was contaminated with other materials, including dye or fungus spores. The session length of grooming could account for up to 6.5% when termites were contaminated by dye. Workers were the most active castes in trophallaxis and, all the other castes could receive foods from workers. The transfer of dyed food from donors to recipients among 6-instar and above workers were measured in six days. The results showed that 5.86% of dyed food was transferred from donors to recipients in 24 hours, and the amounts of dyed food in the guts of donors and recipients were almost same in 48 hours. Afterwards, dyed food in both donors and recipients reduced over time, continually with less being kept in recipients than in donors during the experimental period. These results suggested that the pattern of distribution of materials via trophallaxis in R. aculabialis was trophallactic cascade.

Effects of auditory sense on locating preys by wolf spider (Pardosa pseudoannulata).

WANG Bo1,2, HUANG Ting1, ZHU Ling-ji2, LI Wen-ting2, LI Yong-min2, YAN Heng-mei1**

2014, 33(1):  155-158. 

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The sensitivity of Pardosa pseudoannulata to the sound and silence sources of Drosophila wings was compared in the laboratory. At close distances, the selection index of the P. pseudoannulata for the sound source was significantly higher than that for the silence source. However, when the distance was increased to 15 cm, no significant difference was found in the selection index. The residence time also showed a similar change. Within 12 cm, the residence time of the P. pseudoannulata on the sound source side was longer than 50% of the total observation time, and significantly higher than that on the silence side. As the distance increased, the sensitivity of the P. pseudoannulata to the sound decreased, and the residence time became insignificantly different. Therefore, the closer the distance to the sound source, the higher the sensitivity of P. pseudoannulata was to the sound. In addition, the distance between sound sources showed a clear correlation with the successful positioning of the prey. P. pseudoannulata can locate their prey by relying on hearing from a certain distance. Moreover, the gender of P. pseudoannulata is a factor in the sensitivity of the auditory sensor. Female P. pseudoannulata is more sensitive to the sound of Drosophila wings and exhibits a higher selection index.

Predicting occurrence degree of rice planthoppers in Guangxi Province based on BP artificial neural network method.

HE Yan1, HE Hui2**, MENG Cui-li1, XIE Mao-chang3, LONG Meng-ling3, LI Yu-hong1

2014, 33(1):  159-168. 

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Based on data of occurrence degree of rice planthoppers from 45 agricultural pest monitoring stations in Guangxi Province during 1988 to 2012 as well as data of meteorological factors and atmospheric circulation characteristics during 1987 to 2012, three zones with different occurrence degrees of early rice planthoppers were divided: east Guangxi, southwest Guangxi, and northwest Guangxi. Occurrence degree of early rice planthoppers was predicted in each zone by fuzzy cluster analysis, and BP neural network. The results showed that the occurrence degree of rice planthoppers was closely correlated with meteorological factors and atmospheric general circulation in Guangxi. High temperature, frequent rainy days, high humidity and insufficient sunshine in winter and spring seasons were beneficial to the occurrence of rice planthoppers, and subtropical high, IndiaBurma trough and southwest airflow also affected the occurrence degree of rice planthoppers. Original predictive factors for the occurrence degree of early rice planthoppers in each zone were selected from the meteorological factors in winter and spring seasons and the atmospheric circulation characteristics to build comprehensive predictors using EOF decomposition method, and then prediction models for the occurrence degree of rice planthoppers were established in each zone. The crosstest showed that the average absolute fitting error was lower in BP neural network model than in step regression by 0.07 in east Guangxi, 0.1 in southwest Guangxi, and 0.02 in northwest Guangxi. The prediction using independentsamples in 2011 to 2012 showed that the mean predicted absolute errors were 0.42 for BP neural network model and 0.5 for step regression, indicating that the nonlinear correlation between rice planthoppers and meteorological factors is better predicted by BP neural network model.

Accumulation of phenolic acids in the monocultured strawberry soils and their effect on soil nematodes.

LI He-qin1,2, LIU Qi-zhi1**, ZHANG Lin-lin1, WANG Yu-ling1, ZHANG Hang1, BAI Peng-hua1, LUAN Xiao-bing1

2014, 33(1):  169-175. 

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The accumulation of phenolic acids in monocultured strawberry soils and their effect on the numbers of total nematodes and bacterial-feeding nematodes were investigated. The effects of exogenous phenolic acids on the numbers of total nematodes and bacterial-feeding nematodes were also examined. With the increase of continuous cropping years, the content of phenolic acids in the soils increased while the numbers of total nematodes and bacterial-feeding nematodes decreased, with the lowest numbers being obtained in the monocultured strawberry soil continuously cropped for 5 years. There was a negative correlation between the content of phenolic acids and the numbers of total nematodes or bacterial-feeding nematodes. The numbers of total nematodes and bacterial-feeding nematodes increased when the addition of phydroxybenzoic acid or pcoumaric acid into soil not in monoculture was below 200 μg·g^-1 but decreased when the addition was above 200 μg·g^-1. A similar pattern was also observed in cinnamic acid test with a different threshold of 100 μg·g^-1. Numbers of total nematodes and bacterialfeeding nematodes decreased when a concentration of higher than 100 μg·g-1 of ferulic acid was added into soil. Numbers of total nematodes and bacterialfeeding nematodes decreased with the increase in concentration of mixed phenolic acids.

Impacts of Flaveria bidentis invasion on ground-dwelling soil animal community in different habitats.

LIU Ning1,2, FU Wei-dong1**, ZHANG Guo-liang1, LIU Yu-sheng2, LU Ai-Ling3

2014, 33(1):  176-183. 

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An investigation was conducted to understand the impacts of Flaveria bidentis invasion on ground-dwelling soil animal community in three different habitats (forestland, uncultivated land, and ditch). Pitfall trap was used to investigate grounddwelling soil animals every two weeks from April 26 to September 17 in 2012. A total of 439515 individuals were collected in three habitats, belonging to 3 phyla, 7 classes, and 21 orders, among which Formicidae was the dominant taxa in the community, and the relative abundance of other taxa was smaller. As the result demonstrated, F. bidentis could provide habitats for Formicidae, Isopoda, Gryllidae and Araneae which like shady and moist environment, thereby had an effect on the community structure and diversity of ground-dwelling soil animal community. Such impact, mainly related to growth conditions of F. bidentis, was weaker in forestland habitat but stronger in uncultivated land habitat and ditch habitat, and became more obvious during the season of growth peak for F. bidentis. In conclusion, the microclimate of three habitats might be changed and the ground-dwelling soil animal community structure was affected after the invasion of Flaveria bidentis, which increased ground-dwelling soil animal diversity.

Community structure of macrozoobenthos and bioassessment of water quality in Lake Nansi.

SHU Feng-yue**, ZHANG Cheng-de, ZHANG Chao, DONG Long-xiang, GAO Ran, FAN Xi-ying

2014, 33(1):  184-189. 

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A seasonal investigation of macrozoobenthos in Lake Nansi was carried out during April to December, 2010. Altogether 36 benthic taxa, including 5 annelids, 10 molluscs, 15 arthropods, and 6 other animals, were identified. Among them, Limnodrilus hoffmeisteri, Bellamya purificata, Alocinma longicornis and Propsilocerusi akamusi were dominant, accounting for 88.1% of the total number. Density and biomass of macrozoobenthos were 1119 ind·m^-2 and 83.23 g·m^-2, respectively. Species richness, dominant species and standing crops varied significantly in different seasons, and also in different areas. Water quality was assessed using Shannon index, Margalef index and Hilsenhoff biotic index. It was shown that Lake Nansi was moderately polluted in general during the sampling period; water quality in spring and winter was slightly better than that in summer and autumn. In terms of the four lake regions, Lake Nanyang and Lake Zhaoyang were heavily polluted, Lake Dushan was moderately to heavily polluted, and Lake Weishan was
moderately polluted.

Secondary productivity of macrobenthos in Laizhou Bay, East China.

LI Shao-wen1, LI Fan1**, ZHANG Ying1, LIU Yuan-jin1, XU Zong-fa1, ZHENG Liang2

2014, 33(1):  190-197. 

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A four-cruise investigation was conducted on macrobenthos at 20 sampling locations in Laizhou Bay, East China in 2011. A total of 177 macrobenthic species were recorded, of which, polychaete, mollusk, and arthropod were dominant. Brey’s empirical formula was used to analyze the abundance, biomass, secondary productivity, and P/B ratio of the macrobenthos in Laizhou Bay. The results showed that the annual mean abundance was 3057.69 ind·m^-2, mean biomass in ash-free dry mass (AFDW) was 3.45 g·m^-2, mean secondary productivity in AFDW was 5.60 g·m^-2·a^-1, and the mean P/B ratio was 1.59 a^-1. Correlation analysis indicated that the secondary productivity was impacted by the chlorophyll-a concentration in water as well as the biomass and abundance. Species of small size, short life-cycle and rapid metabolism were dominant in the macrobenthic community composition. An estimate of the annual mean secondary productivity of the macrobenthos in Laizhou Bay was 3.48×10⁴ t for AFDW and 1.93×10⁵ t for wet mass.

The temporal and spatial change of the oasis in Ganzhou District, Zhangye City of Gansu Province in the recent five decades.

XIE Yao-wen**, MI Pei-feng, TIAN Fei

2014, 33(1):  198-205. 

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The intervention of human activities on the oasis natural environment has caused a series of ecological and environmental problems. Combined with fieldwork verification, distribution of the oasis in Ganzhou District was extracted by 13 images which were acquired between 1963 and 2009 in this paper. To get the temporal and spatial change of the oasis, the single dynamic degree and bidirectional dynamic degree of the oasis were calculated. Additionally, 13 vector data about the distribution of the oasis were overlaid and landscape indices of oasis were analyzed successively. The development of oasis in Ganzhou District showed a trend of expansion in recent 50 years. Taking the year 1986 as a cutoff point, oasis development could be divided into two stages which were “wave expansion” in the early stage and “stable expansion” in the late stage. The main phenomenon of oasis change showed body stability and peripheral expansion; the secondary phenomenon was internal partial withdrawal and scattered wave. The stable oases were mainly distributed along the Heihe River and around the residential areas of the towns, while oases in fluctuation and atrophy were distributed at the periphery of stable oasis.

Spatiotemporal distribution of rainfall erosivity in Sichuan Province based on geostatistics.

CHEN Dong-dong1,2**, CHENG Lu3, LI Xiao-wei4, LI Jin-jian2

2014, 33(1):  206-213. 

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Based on the daily rainfall data of 147 meteorological stations in Sichuan Province during 1961-2012, we analyzed the statistical characteristics of rainfall erosivity by SPSS and ArcGIS, and proposed an appropriate interpolate method. The characteristics of spatial and temporal distributions of rainfall erosivity in Sichuan Province were then analyzed. Results showed that the rainfall erosivity variation was moderate. The ordinary Kriging interpolation method with spherical model could well represent the rainfall erosivity. The rainfall erosivity was relatively high in the basin and Panxi areas, and relatively low in the western Sichuan plateau. The rainfall erosivity gradually decreased from east to west. The tendency rate of the rainfall erosivity for last 52 years presented an ‘increase-decreaseincrease’ feature from east to west. The concentration degree of annual rainfall erosivity was relatively high and showed belt distribution characteristics of ‘low-high-low-high’ from east to west. The high-value areas were mainly distributed in the central and western basin and the western part of western Sichuan Plateau. The intra-annual distribution of the rainfall erosivity presented a bimodal pattern at 12 typical stations, which could be divided into high-value period, median-value period and low-value period. The occurrence of erosion was concentrated in the period from 8th to 19th semi-month, which accounted for 95%-99% of the total annual rainfall erosivity. Therefore, the development of large-scale civil projects should try to avoid the high incidence season of rainfall erosion according to the characteristics of spatial and temporal distribution of rainfall erosivity in Sichuan. Cross slope cultivation is recommended for slope farmland in order to reduce soil erosion.

Assessment of regional ecological risk in coastal zone of Shandong Province. 

WU Li1,2, HOU Xi-yong1**, DI Xiang-hong1,2

2014, 33(1):  214-220. 

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Base on land use maps in 2000, 2005 and 2010 of the coastal areas of Shandong Province and land use maps in 2020 and 2030 simulated by the Spatial-Markov model, ecological risk index was built based on landscape pattern indices. In specific, the study area was divided into 811 units with a size of 10 km×10 km. The ecological risk index in 811 units in 2000, 2005, 2010, 2020 and 2030 was calculated. Results showed that under current development scenario, areas converted from low to high ecological risk grade and from high to low ecological risk grade from 2020 to 2030 would be higher than those from 2000 to 2010. Area with high ecological risk would increase significantly in the future, i.e., ecological risk in coastal zones of Shandong Province would aggravate if the land use change trend in the past decade lasts in the future. The ecological risk showed significant positive spatial autocorrelation from 2000 to 2030. The “hot spot” areas of ecological risk were mainly distributed in the northern coastal area of Binzhou, the eastern coastal area of Dongying, the hilly area in the southern part of Weifang and Yantai, and coastal area of Qingdao. Some suggestions were put forward. Firstly, regional cooperation should be strengthened to prevent the ecological risk. Secondly, measures of risk management should be reinforced in “hot spot” areas where high ecological risk values cluster. Moreover, adjustments of regional land use patterns should be promoted, rationally planning land use in future.

Research advances in plant phenological responses to urban heat island.

CAI Hong-yan1, YANG Xiao-huan1**, ZHANG Shu-wen2

2014, 33(1):  221-228. 

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Local microclimate changes caused by urban heat island (UHI) have increasingly impacted the patterns, processes and functions of ecosystems. Plant phenology is a sensitive and easily observed biological indicator to detect these impacts, and its responses to UHI have become hotspots in the fields of urban ecology and global climate change. This paper reviewed related researches in recent years. It points out that there are three major ways to obtain urban phenology, that is, field observation, phenology modeling and remote sensing monitoring. Through cooperating with the public and employing photos and multi-resolution images, we can enrich the phenology data. Due to the impacts of UHI, spring phenology in urban area has been earlier than the surrounding rural area; however, the impact mechanism is still controversial. At temporal scale, spring phenology has advanced and autumn phenology has delayed induced by urban warming. Urban warming is caused by UHI and climate warming, and how to quantitatively discern their contributions is difficult. In addition, biological factors (e.g. plant functional types and exotic plants) and geographical location have affected the plant phenological responses to UHI. Thus, this paper proposes that future researches need to eliminate the interference factors, and enhance the researches in response mechanisms.

Key procedures of pressure-volume technique in plant water physiology.

YANG Liu, SUN Hui-zhen**

2014, 33(1):  229-234. 

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Classic pressure-volume (PV) technique measures water potential and relative water content of plant tissues during the whole process from water saturation to turgor loss and establishes their relationships. Based on these relationships, PV technique has been used to derive such plant water relation parameters as osmotic potential at turgor loss, osmotic potential at full turgor, relative water content at turgor loss, bulk modulus of elasticity, which are difficult to obtain with substitute methods. Because these parameters are strongly associated with plant resistance to drought, the technique will play an important role in understanding physiological mechanisms of droughtinduced tree mortality. However, there are still some inconsistent procedures in its implementing process, such as prerehydration, parameter measurement and calculations. This paper reviews the application of the PV technique by focusing on these inconsistent issues and provides suggestions on appropriate use of the technique in studies of plant water relations.

Current status and development ideas of the comprehensive disaster prevention and reduction standardization in China.

HU Jun-feng, ZHANG Bao-jun**, FAN Yi-da, YANG Si-quan

2014, 33(1):  235-241. 

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This paper summarizes the progress of China’s comprehensive disaster prevention and reduction standardization from the aspects of organization construction, planning and standards revision, and analyzes the main problems in standardization of disaster prevention and reduction. Through the analysis of future requirements, the paper builds the framework of standard system of comprehensive disaster prevention and reduction, and puts forward the development ideas in standardization of disaster prevention and reduction in the future. This review has important theoretical value and practical significance to promote normalization, scientification and standardization of  disaster prevention and reduction.


 

Two methods of estimating biomass and productivity for Cinnamonum camphora at individual scale.

GAO Kai, HU Yong-hong, LENG Han-bing, MENG Chao, QIN Jun**

2014, 33(1):  242-248. 

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The classic harvest method is most reliable to estimate forest biomass and net primary productivity (NPP) but not suitable in an urban green area due to its high heterogeneity. Therefore, a nondestructive method based on gas exchange measurements for estimating photosynthetic carbon sequestration was used to establish apparent characteristics and biomass and NPP models for Cinnamomum camphora, which is the most abundant greening species in Shanghai. The results showed that annual net primary productivity (ANPP) of individual trees based on the harvest method was 23%±4% of aboveground biomass (AVB), AVB=1.37D_2.15 (D: Crown, R²=0.97, P<0.01), ANPP =0.32D_2.13 (D: Crown, R²=0.97, P<0.01). The estimated biomass or ANPP based on the gas exchange method was tightly colse to that based on the harvest method with an accuracy rate of 87.3%. The system and environmental errors were the main sources of the difference between the two methods. When tuning the relevant correction factors, the gas exchange method could be applied to estimate carbon sink of urban greening with highprecision remote sensing monitoring without destruction.

An improved procedure for glomalin-related soil protein measurement in subtropical forest.

ZHANG Jing1,2,3, TANG Xu-li1,3**, ZHENG Ke-ju1,2,3, TONG Lin1,2,3, CHEN Hong-feng1

2014, 33(1):  248-258. 

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Glomalin as a recalcitrant glycoprotein produced by arbuscular mycorrhizal fungi is proved to improve soil structure, fix heavy metals in soils, and be a substantial contributor to soil carbon. At present, glomalin cannot be directly purified but can be quantified by measuring the content of glomalin-related soil protein (GRSP) in soil. Currently no standard procedure for GRSP measurement is available for all terrestrial ecosystems because of the non-specific nature of GRSP measurement. To investigate the possible influences of extraction time, centrifugal force, and centrifugal force before colorimetric test on GRSP measurement, we carried out a comparative study using latosolic red soils collected from a subtropical forest.  Higher centrifugal force extracted more easily extractable GRSP (EE-GRSP) for a given centrifuge time. Under 10 minutes of extraction, EEGRSP extracted with centrifugal force at 10000×g was 1.15-1.82 times more than at 5000×g, but the effect of centrifugal force on T-GRSP was not significantly different at α=0.05 level. Extending centrifugal time increased EE-GRSP concentration for a given centrifugal force. With the centrifugal force at 5000×g, EE-GRSP content increased significantly with the increase of centrifugation time from 10 minutes to 15 minutes. Centrifugation of the supernate with higher centrifugal force (≥10000×g) before colorimetric test significantly influenced the measurement of GRSP. The T-GRSP value reached 97.7%-99.8% of the theoretical maximum after 6 times of repeated extraction. Based on this study, the procedure for GRSP measurement for latosolic red soils in subtropical forests is recommended as centrifugation of soil solution at 10000×g for 10 minutes, and centrifugation of the supernate at 10000×g before colorimetric test.

The vulnerability assessment of grassland livestock industry to drought: A case study in pasture of Xilingol, Inner Mongolia.

ZHOU Li-guang1, DU Feng-lian2**, ZHANG Xue-feng1, ZHANG Cun-hou3

2014, 33(1):  259-268. 

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The vulnerability assessment is of great importance in the research of climate adaptation, especially for those climate sensitive areas and industries. This paper adopts the participating assessment and action impact matrix to identify the key vulnerability factors. Then we build up the indicator classes of vulnerability assessment employing the analytic hierarchy process methodology. With the assessment model, we calculate the vulnerability index, which reveals the vulnerability of grassland livestock industry to drought in Xilingol, Inner Mongolia. Drought is the most critical climate hazard, inciting serious and vast impact on grassland livestock industry. Drought has detrimental impacts on herdsmen’s livelihood because it deteriorates the supplies of grass, livestock, and water in pastoral areas. Unfortunately, the effect of drought on human being’s health is always ignored by stakeholders. The areas with poor husbandry infrastructure and intense climatic fluctuation are more vulnerable to climate change. The improving adaptive capacity is mainly responsible for the reduction of the vulnerability of grassland livestock industry to climate change at both spatial and temporal scales. The promotion of adaptive capacity is prior to the reductions of both sensitivity and exposure in terms of adaptation strategies to climate change. The promotion of adaptive capacity aims to guarantee herdsmen’s livelihood through increasing herdsmen’s economic income, improving the husbandry infrastructure, and enhancing the capacity of supplementary feeding.