Table of Content

10 November 2013, Volume 32 Issue 11

Previous Issue    Next Issue

Effects of fire on soil properties and nutrient availability in a Dahurian larch forest in Great Xing’an Mountains of Northeast China.

KONG Jian-jian1,2,3, YANG Jian1**

2013, 32(11):  2837-2843. 

Asbtract ( 1805 )   PDF (618KB) ( 579 )  

Fire is a major disturbance in boreal forest ecosystems, affecting not only forest productivity and species diversity but also biogeochemical processes. In this study, we investigated the effects of fire (one year after fire) on soil physicochemical properties, microbial biomass and nutrients (N, P, and K) availability in a boreal Dahurian larch forest that was burned in year 2010 at the Huzhong Natural Reserve in the Great Xing’an Mountains of Northeast China. Our results showed that fire significantly decreased soil moisture, organic matter depth, dissolved organic carbon content, total C∶N ratio and microbial biomass in burned plots, but increased soil pH significantly, as compared with the control plots. However, no significant differences were observed in these soil properties between different fire intensities. After light and heavy fires, the soil N availability was significantly higher than the control, but less difference was found between the two fire intensities. Soil P availability was also significantly higher after fire, and there existed significant difference between the two fire intensities. Fire showed no significant effects on soil K availability.

Effects of elevated temperature and doubled CO₂ concentration on soil dissolved organic carbon and nitrogen in a subalpine coniferous forest of western Sichuan, Southwest China. 

LIU Fu-rong1,2, WANG Hong-mei1,2, ZHANG Yong-mei1**

2013, 32(11):  2844-2849. 

Asbtract ( 1538 )   PDF (553KB) ( 400 )  

By using a fully automated microclimate-controlled artificial climate simulation system, this paper studied the effects of elevated temperate (ET) and doubled CO₂ concentration (EC) on the soil dissolved organic matter in a subalpine coniferous forest of western Sichuan. ET, EC, and their interaction (ETC) increased the soil dissolved organic carbon (DOC) content, with the increment being in the order of EC > ET > ETC > CK. The effects of ET, EC, and ETC on the soil DOC was greater in 0-15 cm than in 15-30 cm layer. The soil dissolved organic nitrogen (DON) content had the similar variation pattern to the soil DOC. There was no significant difference in the soil DOC/DON between different layers. ET decreased the soil DOC/DON significantly. The soil DOC and DON contents had significant positive correlations with the ultraviolet absorbency value at 254 nm (UVA_{254 nm}), indicating that UVA_{254 nm}  could be used to speculate the soil DOC and DON contents in subalpine coniferous forest of western Sichuan.

Responses of plant and soil C∶N∶P stoichiometry to N addition in a desert steppe of Ningxia, Northwest China.

HUANG Ju-ying1**, LAI Rong-sheng2, YU Hai-long2, CHEN Wei-min1

2013, 32(11):  2850-2856. 

Asbtract ( 1743 )   PDF (794KB) ( 426 )  

To study the effects of nitrogen (N) addition on the plant and soil C∶N∶P stoichiometry is of significance in understanding the responses of ecosystem biogeochemical cycling to elevated N deposition. In this paper, a field experiment was conducted in a desert steppe of Ningxia to study the effects of N addition on C and N concentrations in green leaves of Agropyron cristatum, Stipa capillata, Lespedeza potanimill, and Cynanchum komarovii, and C, N and P concentrations in soil, with the relationships between the N limitation related plant and soil stoichiometry analyzed. The results showed that with the increasing amount of N addition, the community aboveground biomass and species individual biomass all decreased after an initial increase. The C concentration in the green leaves of the four species had no obvious variation pattern, the N concentration in the green leaves of the four species except A. cristatum had a significant increase, while the C∶N ratio in the green leaves of L. potanimil and C. komarovii decreased significantly. The soil total N content increased significantly, while the other soil indices had no significant responses to N addition. The individual biomass of C. komarovii had positive correlations with soil N and N∶P ratio, the N concentration in green leaves of A. cristatum and C. komarovii was positively correlated with soil N, while the C∶N ratios in the green leaves of S. capillata and C. komarovii were negatively correlated with soil total N. Our results indicated that shortterm N addition had little effects on the soil C∶N∶P stoichiometry but relieved the N limitation of plant growth in desert grassland to a certain extent, and thus, increased the N uptake by green leaves, promoted the biomass accumulation of plant, and improved the leaf litter decomposition quality. These species-specific responses not only reflect flexible adaptation to environment change, but also mean that long-term elevated N deposition may change the structure of desert steppe ecosystem.

Distribution patterns of vegetation and soil carbon and nitrogen density in an alpine forb meadow under short-term grazing gradient.

WU Qi-hua1,3, LI Hong-qin1,2, ZHANG Fa-wei1,2, LIU Xiao-qin1,3, MAO Shao-juan1,3, LI Ying-nian1,2**

2013, 32(11):  2857-2864. 

Asbtract ( 1667 )   PDF (623KB) ( 236 )  

In order to obtain the equilibrium mode of grassland carbon sequestration and grazing management to provide a scientific basis for carbon sequestration management of grassland ecosystem, this paper studied the vegetation and soil carbon and nitrogen density under a short-term grazing gradient in an alpine forb meadow ecosystem on the northeastern QinghaiTibetan Plateau, China. Under the grazing gradient, the existing total vegetation carbon storage decreased with increasing grazing intensity, i.e., no grazing (SCK) > light grazing (SL) > moderate grazing (SM) > heavy grazing (SH). The annual net primary carbon production was in the order of SM >SL >SH > SCK, indicating that moderate grazing could promote vegetation carbon storage, while overgrazing or no grazing was in reverse. In the soil layers of 0-40 cm, the total organic carbon density and total nitrogen density had the same variation pattern, i.e., SCK > SH> SM > SL. However, in topsoil (0-10 cm), the organic carbon density was in the order of SH > SM > SL > SCK, while the total nitrogen density was of SH > SCK > SM > SL. In 10-20 cm, 20-30 cm, and 30-40 cm soil layers, both the organic carbon density and the total nitrogen density declined in the order of SCK > SH > SL > SM. A slight difference was observed in the soil carbon and nitrogen density between 0-10 cm and 10-40 cm layers, indicating that shortterm grazing had different effects on the soil carbon and nitrogen between surface layer and deeper layers. Under the grazing gradient, soil C/N in different layers of 0-40 cm had somewhat difference. Overall, the soil C/N under the grazing gradient except CK was suitable for microbial mineralization. Regression analysis showed that under the grazing gradient, soil carbon density in all layers was positively correlated with soil nitrogen density (P<0.01).

Denitrification potential of Cyperus malaccensis marsh soil in Minjiang River estuary of East China.

LIU Rong-fang1, ZHANG Lin-hai1,2, LIN Xiao1,2, MOU Xiao-jie3, ZENG Cong-sheng1,2**

2013, 32(11):  2865-2870. 

Asbtract ( 1498 )   PDF (568KB) ( 290 )  

By using submerged anaerobic incubation method, this paper studied the soil denitrification rate, denitrification ratio (denitrifying activity) and its contribution to the soil nitrogen loss in Cyperus malaccensis marsh in the Minjiang River estuary of East China. The denitrification rate in different soil layers varied with incubation time in firstorder exponential decay model (R²≥0.90), and was the maximum in 5-10 cm soil layer. The denitrifying activity in different soil layers increased gradually over time, and was the highest (93.92%) in 5-10 cm soil layer. The nitrogen loss rate in different soil layers was in accordance with the denitrification rate and denitrifying activity. The contribution rate of denitrification to the nitrogen loss was higher in upper soil layers than in deeper soil layers. The differences in the denitrification rate and denitrifying activity in each soil layer were related to the soil physical and chemical properties, being positively correlated with soil pH and the contents of soil clay, organic matter, NO₃^--N, and WHC, but negatively correlated with soil sand content.

Effects of stand density on nutrient cycling rate and use efficiency of Pinus elliottii plantation.

XIAO Xing-cui1, LI Zhi-hui1**, TANG Zuo-jun2,3, ZENG qin1, WANG Hai-feng3

2013, 32(11):  2871-2880. 

Asbtract ( 1417 )   PDF (685KB) ( 359 )  

This paper studied the nutrient content, accumulation, allocation, and cycling characteristics as well as their relationships with stand density in a 11-year-old Pinus elliottii plantation with five stand densities (1667, 2000, 2400, 3330, and 3900 trees·hm^-2) in northern Hunan of China, aimed to improve the nutrient use efficiency of Pinus elliottii plantation and maintain the long-term productivity of the forest land. In the stands, there existed great differences in the nutrient content among different organs, which was decreased in the order of leaf > branch  > trunk  > root > bark. The nutrient accumulation in individual tree decreased with the increase of stand density. The accumulated amounts of N, P, K, Ca, and Mg in the stands were 1542.3-2073.7 kg·hm^-2, among which, arbor layer accounted for 70.3%-77.4%. The nutrient uptake, retention, and return of the stands were 167.5-203.1, 110.3-155.0, and 48.1-58.8 kg·hm^-2·a^-1, respectively. The nutrient uptake and retention of the high density stands (3330 and 3900 trees·hm^-2) were significantly higher than those of the two lower density stands. The nutrient return was slightly decreased with the increase of stand density. Overall, with the increase of stand density, the nutrient turnover became longer, the nutrient cycling rate decreased, and the nutrient use efficiency increased. This study could provide theoretical and practical bases for developing the silvicultural measures, including stand density regulation, understory vegetation, and litter management, of Pinus elliottii plantations in northern Hunan of China.

Carbon storage and distribution pattern in main economic fruit forest ecosystems in Shanghai, East China.

GUO Xue-yan1, CAI Ting1, DUAN Xiu-wen1, HAN Yu-jie2, HUANG Dan2, DA Liang-jun1,3,4**

2013, 32(11):  2881-2885. 

Asbtract ( 1905 )   PDF (455KB) ( 376 )  

As an important part of commercial forest, economic fruit forest occupies nearly onefifth of Shanghai’s total forest land area, playing an important role in the evaluation of carbon sink of forest ecosystems in Shanghai. Taking the peach orchard and citrus orchard ecosystems with large distribution areas in Shanghai as the objects, and based on the biomass investigation, the biomass and net productivity equations for the two main tree species in the orchard ecosystems were established, and the carbon storage in the vegetation layers and soil as well as the annual net carbon sequestration in tree layer was calculated. There was a good fitting effect of the established equations on the basal diameter of the two main tree species (R²>0.9). In the peach orchard and citrus orchard ecosystems, the carbon storage was averagely 118.31 and 86.31 t·hm^-2, and the annual net productivity was averagely 4.87 and 6.51 t·hm^-2·a^-1, respectively. Among the carbon storage in the peach orchard and citrus orchard ecosystems, tree layer accounted for 13.4% and 27.3%, herb layer accounted for 1.0% and 1.3%, and soil accounted for 85.6% and 71.4%, respectively.

Analysis of ecological economic benefits in the planting and breeding model under rice ridge cultivation.

ZHENG Hua-bin1,2, CHEN Can1,2, WANG Xiao-qing3, SHE Wei1,2, LIAO Xiao-lan2,4, LIU Xiao-yan3, FU Zhi-qiang1,2, HUANG Huang1,2**

2013, 32(11):  2886-2892. 

Asbtract ( 1747 )   PDF (648KB) ( 254 )  

Water saving and high-value is one of development directions of the ecological planting and breeding model in the future. In this paper, rice yield, economic benefits and the process of water movement in the planting and breeding model under rice ridge cultivation were studied with the method of farmers’ planting and breeding and field survey. The result showed that, compared with rice mono-planting model (CK), the rice yield of rice-mallard complex ecosystem under rice ridge cultivation (RM), rice-turtle complex ecosystem under rice ridge cultivation (RT) increased by 9.4% and 18.0%, respectively, and net income, output/input ratio, labor productivity, cost-benefits ratio in the RM and RT increased by 4.2 and 14.4 times, 32.6% and 8.9%, 3.4 and 4.3 times, 245.0% and 24.6%, respectively, which ensured increasing food production and farmer’s income. The planting and breeding model under rice ridge cultivation changed the pathway of water movement. The quantity of water loss via transpiration in the planting and breeding model under rice ridge cultivation was 16% higher than CK. Our results suggest that the planting and breeding model under rice ridge cultivation can increase water use efficiency.

Relationships between the factors reflecting ecological health function of urban forests.

GUO Er-guo1,2,3,4, WANG Cheng1，2**, QIE Guang-fa1,2, CAI Yu3

2013, 32(11):  2893-2903. 

Asbtract ( 1631 )   PDF (1258KB) ( 453 )  

A 24-hour seasonal observation was conducted on the 4 factors reflecting urban forest ecological heath function (decreasing atmospheric particulate matters (PMs), declining airborne microbes, increasing aeroanions, and increasing biogenic volatile organic compounds (BVOCs)) in three typical urban forests in West Mountain of Beijing, and an analysis was made on the interrelationships between these factors, aimed to understand the ecological health function of urban forest. There existed close relationships between these four factors. The four sizes of atmospheric PMs had significant positive relationships each other, among which, PM_2.5 and PM_1.0 had the highest correlation, followed by total suspended particulate (TSP) and PM₁₀. The larger the difference in particulate size, the weaker the correlation was. The airborne bacteria were significantly positively correlated with the PMs, especially with the TSP. The aeroanions had a negative relationship with the PMs, and this relationship became stronger when the particulate size increased. The aeroanions had inhibitory effect on the airborne microbes, and this effect was more obvious on bacteria than on fungi. In Platycladus orientalis and Cotinus coggygria forests, BVOCs played definite roles in inhibiting airborne microbes and increasing aeroanions, and also, had definite association with PMs, but these effects varied with the components of BVOCs.

Effects of different soil moisture and air temperature regimes on the growth characteristics and grain yield of maize in Northeast China.

LIU Dan1, ZHANG Jia-hua1，2**, MENG Fan-chao1, HAO Cui1, ZHOU Zheng-ming1, LI Hui3, ZHANG Hua4, WANG Kai4

2013, 32(11):  2904-2910. 

Asbtract ( 1788 )   PDF (1461KB) ( 356 )  

It is an indisputable fact that climate change has affected crop growth and development. In order to predict the possible effects of future climate change on C4 plant maize and to test the simulated results of crop model, an infrared temperatureincreasing simulation experiment was conducted in Jinzhou of Liaoning Province, Northeast China. With the applications of free air temperatureincreasing system and water control devices, different soil moisture and air temperature gradients were installed to simulate the effects of climate change on maize growth. The results showed that increasing temperature alone decreased the plant height by 6.5%, while increasing both temperature and soil moisture had little effects on the plant height. Increasing temperature decreased the leaf area by 13.8%, while increasing soil moisture had little effect. Both increasing temperature and increasing soil moisture were unfavorable to the dry matter accumulation, but the difference with the control was not significant. Increasing temperature had positive effects on the leaf distribution coefficient, but increasing soil moisture was in reverse. Increasing both temperature and soil moisture had no obvious effects on the leaf distribution coefficient. Increasing temperature decreased the grain yield by 40%, mainly due to the decrease of ear length, ear diameter, rows per ear, and full grain number and the increase of shriveled grain number.

Responses of water use efficiency of rain-fed maize to environmental factors in sub-humid area of Liaoning, Northeast China.

MI Na1, JI Rui-peng1, ZHANG Yu-shu1**, ZHANG Shu-jie1, CAI Fu1, ZHAO Xian-li1, LIANG Tao2, WANG Yang3

2013, 32(11):  2911-2919. 

Asbtract ( 1450 )   PDF (927KB) ( 251 )  

Water use efficiency (WUE) can reflect the coupling status of carbon and water cycles, and is an effective integral trait for assessing the responses of terrestrial vegetations to climate change. In this paper, a moisture control experiment in Jinzhou during 2008-2009 and a field crop trial in Chaoyang during 1990-2010 were conducted, respectively, aimed to examine the instantaneous responses of maize leaf WUE (WUE_l) to the changes of photosynthetically available radiation, leaf surface CO₂ concentration, air temperature and soil humidity as well as the variation characteristics of the WUE at grain yield level (WUE_g) with air temperature and precipitation. The results showed that with the increase of leaf surface CO₂ concentration from 350 to 800 μmol·mol^-1, the leaf photosynthesis increased, while the stomatal conductance and evaportranspiration (ET) decreased, resulting in the increase of WUE_l. The increase of ambient temperature from 26 to 40 ℃ and of soil moisture content from 12% to 26% made the increment of leaf transpiration rate (T_r) be larger than that of net photosynthesis (P_n), causing a significant reduction of WUE_l. The analysis of the effects of ET on the grain yield over the 20 years of monitoring showed that there was a significant quadraticcurve relationship between the WUE_g and ET. When the ET was 400-450 mm, the grain yield and WUE_g were the maximum, and the ET in the growth season was the optimal economical evapotranspiration. No obvious relationship was observed between the mean air temperature from sowing to maturing stage, suggesting that the WUE_g of maize in the study areas was mainly affected by soil moisture condition, but less affected by air temperature.

Niche characteristics of dominant species in forest vegetation in Guandi Mountain, Shanxi of China.

MAO Kong1, ZHANG Yin-bo1, ZHANG Feng1,2**

2013, 32(11):  2920-2925. 

Asbtract ( 1920 )   PDF (451KB) ( 321 )  

Based on the field survey, and by using Shannon index and Pianka index, a quantitative analysis was made on the niche characteristics of 26 dominant species, including 6 tree species, 6 shrub species, and 14 herb species, in the forest vegetation in Pangquangou National Nature Reserve in the middle of Lüliang Mountains, west of Shanxi. In the tree layer, Betula platyphylla had the widest niche breadth; in the shrub layer, the niche breadth of Spiraea pubescens was the widest. Among the 26 dominant species, Carex lanceolata in herb layer had the widest niche breadth, suggesting its strong adaptability to environment factors and the advantages in competition with the other species. There was a significant positive correlation between the species niche breadth and the species frequency (P<0.01). The niche overlapping among the 26 dominant species occurred generally, but the overlapping degree was lower, suggesting the less strong competition between species. The correlation between the niche overlapping and niche breadth was not positively significant (P>0.05).

Relationship between exogenous juglone and soil microbial population in a Manchurian walnut plantation.

SUN Yue-zhi1, YANG Li-xue2**, WANG Dong-liang2

2013, 32(11):  2926-2930. 

Asbtract ( 1680 )   PDF (520KB) ( 255 )  

A laboratory experiment with the soil samples collected from a pure Manchurian walnut plantation was conducted under juglone addition and soil sterilization to study the interactions between added juglone and soil microbes. After soil sterilization, the decomposition rate of added juglone decreased obviously. On the 5th day of incubation, only a few of the added juglone (6.07% of the total) was found in unsterilized soil, and the remained juglone in sterilized soil occupied 42.92% of the total. After juglone addition, the total quantity of soil PLFAs decreased significantly, and the growth of soil gram-positive bacteria, gram-negative bacteria, fungi, and actinomycetes was all inhibited. This study demonstrated that soil microbes facilitated juglone decomposition, while juglone had inhibitory effects on the growth of soil microbes.

Effects of land use type on the abundance of bacteria, crenarchaea, and ammonia-oxidizing archaea in black soil. 

WANG Ying1,2, ZHANG Zhi-ming2, LI Xiao-hui2, YAN Jun2, HAN Xiao-zeng1,2**

2013, 32(11):  2931-2936. 

Asbtract ( 1581 )   PDF (557KB) ( 461 )  

Taking a long-term experiment in the black soil area of Northeast China as the platform, this paper studied the abundance of soil bacteria, crenarchaea, and ammoniaoxidizng archaea in grassland, cropland (soybean, corn, and wheat), and bare land by targeting the 16S rRNA gene and amoA gene with real-time PCR approaches, aimed to evaluate the functions of main microbial groups in soil ecosystem under different land use types. The results showed that the abundance of soil bacteria, crenarchaea, and ammonia-oxidizing archaea was significantly higher in grassland than in cropland and bare land, but had no significant difference in different crop lands. As compared with that in bare land, soybean land, corn land, and wheat land, the abundance of bacteria, crenarchaea, and ammonia-oxidizing archaea in grassland was increased by 62.7%, 29.0%, 41.1% and 18.8%, 34.4%, 30.7%, 37.6% and 33.7%, and 28.6%, 42.6%, 44.4% and 53.6%, respectively. The abundance of soil bacteria had significant positive correlations with soil pH (r=0.935, P<0.01) and organic carbon content (r=0.887, P<0.05), that of soil crenarchaea was significantly positively correlated with soil pH (r=0.845,P<0.05), whereas the abundance of soil ammonia-oxidizing archaea had no significant correlations with soil pH and organic carbon content.

Flowering phenology features of the rare desert plant Ammodendron argenteum. 

LI Zhi-cheng1, LI Jin1**, LU Hai-ying1, CAO Man-hang2

2013, 32(11):  2937-2943. 

Asbtract ( 1742 )   PDF (709KB) ( 320 )  

Based upon the data collected through field work, the paper attempts to probe into the flowering phenological and reproductive features of natural populations of Ammodendron argenteum from the following perspectives such as first flowering date, relative flowering intensity and flowering synchrony. The results indicate that the flowering period of test populations is from middle May to early June, and the flowering span of the population, individual, inflorescence and single flowering is approximately 20-22 d, 19-21 d, 14-19 d and 7-11 d, respectively. The flowering amplitude of individual and inflorescence shows a single peak, which shares high similarity from year to year. The individual has better flowering synchrony, relative flowering intensity distributed in narrow range, and there isn’t significant difference of first flowering date and relative flowering intensity from year to year, while there exists significant difference among other phenological indexes (P<0.05). Correlation analysis shows that both flower number and flowering duration have significant negative correlations with first flowering date (P<0.05), and there is not significant correlation between fruit number and first flowering date, inflorescence duration, flower number (P>0.05). Temperature is the main factor affecting flowering phenology of A. argenteum populations. Both mass-flowering pattern and the phenomenon of more flower and fewer fruit could be regarded as reproductive strategies of the species to adapt to the harsh habitat.

Effects of different long-term fertilization modes on weed community and early rice yield.

CHENG Chuan-peng1,2, CUI Bai-hui1,2, TANG Lei-lei1,2, TAO Yong1, PAN Jun-feng1,4, CHEN Fang1,3**

2013, 32(11):  2944-2952. 

Asbtract ( 1802 )   PDF (674KB) ( 323 )  

To understand the effects of different long-term fertilization modes on the weed community and early rice yield in ricericefallowing system in Southern China, an investigation was conducted on the weed density, aboveground biomass, canopy light transmittance, and rice yield components in a 28-year experimental field, and a measurement was made on the soil available nutrient contents and the N, P, and K contents and absorption rates in weeds and early rice plant. Different fertilization modes changed the soil nutrient status, leading to a significant difference in the weed community and rice yield. In the treatments of chemical N, P, and K fertilization and its combination with organic fertilization, the weed community density was relatively small, and the weed species diversity was relatively low, but the weeds grew well, and their aboveground biomass was high. The significant increase of soil available nutrients in the two treatments promoted the early rice growth and increased the rice yield significantly, and made the early rice have much stronger competitive capability, which decreased the light capture by weeds and restrained the weed growth.

 

Effects of AM fungi and simulated nitrogen deposition on the growth and biomass accumulation of Solidago canadensis seedlings.

YANG Jian-yu, WANG Yan-hong**， WEN Guo-sheng, YI Li-ta

2013, 32(11):  2953-2958. 

Asbtract ( 2007 )   PDF (614KB) ( 343 )  

Solidago canadensis, a notorious invasive weed species highly dependent on AM fungi (AMF), has been spreading rapidly in eastern China. At present, nitrogen deposition has become one of the most concerned environmental issues, but few studies have focused on the effects of AMF and nitrogen deposition on the growth of S. canadensis. In this paper, a greenhouse pot culture experiment was conducted to study the effects of inoculating AMF on the growth and biomass accumulation of S. canadensis seedlings under different nitrogen application levels. Inoculating AMF had significant positive effects on the leaf number, biomass accumulation, and AMF colonization rate of seedlings. Also, with the extension of the treatment period, the promotion effects of AMF on the plant height and leaf number were increasing. However, both nitrogen deposition and the interaction between AMF and nitrogen deposition had no significant effects on the seedlings’ growth. Different nitrogen application levels had definite influence on the effects of AMF. It was suggested that AMF had significant promotion effects on the invasion of S. canadensis, and the variation of exogenous nitrogen supply level determined the degree of host plant benefit derived from AMF.

Effects of simulated warming on the growth and reproduction investment of invasive plant Plantago virginica. 

ZHANG Wan-ling1,2, XIAO Yi-an1,2,3**, YAN Xiao-hong1, ZHANG Si-si1, HUANG Hai-qun1,2, LIU Bao-bing1

2013, 32(11):  2959-2965. 

Asbtract ( 1700 )   PDF (561KB) ( 330 )  

By using open-top chamber (OTC), this paper studied the effects of simulated warming on the growth and reproduction investment of invasive plant Plantago virginica during its growth season in 2012, with the plant height, root length, leaf number, length, and width, inflorescence number and length, biomass allocation pattern, and reproduction traits investigated. As compared with the control, simulated warming increased the plant height of P. virginica significantly by 38%, but decreased the root length. The leaf number of P. virginica in OTC group increased at its early growth stage, but reduced to less than that of the control at medium growth stage. The leaf length and width and the inflorescence number and length in OTC group increased significantly. Simulated warming increased the total biomass and aboveground biomass while decreased the leaf biomass, but no significant differences were observed between the OTC and CK groups. The root biomass and rootshoot ratio in OTC group decreased significantly. Simulated warming had little effects on the inflorescence number and spikelet biomass, but increased the inflorescence number, total flower number, inflorescence biomass, and peduncle biomass significantly by 17%, 21%, 18%, and 26%, respectively, with the reproduction investment ratio increased by 11%, as compared with the control. There were no significant differences in the seed setting rate and seed size between the OTC and CK groups, but the seed number in the OTC group increased significantly while the thousandkernel weight had a significant decrease. In sum, simulated warming could significantly promote the growth of P. virginica, improve its assimilation products allocated to reproductive organs, increase the numbers of flower and seed, and thus, enhance the reproduction capacity and invasiveness of the invasive plant P. virginica.

Effects of rainfall harvesting in ridges and furrows on root distribution patterns of oat in semiarid area of Gansu, Northwest China.

LI Fu-chun1, REN Xiang1, WANG Qi1**, ZHANG En-he2, HUO Hai-li1, WANG He-ling3

2013, 32(11):  2966-2972. 

Asbtract ( 1465 )   PDF (604KB) ( 256 )  

In order to understand the root distribution patterns of oat under rainfall harvesting in ridges and furrows, a field experiment with completely randomized design was conducted in the Dingxi semiarid loess hilly region of Gansu, Northwest China to study the effects of different mulching materials (plastic film and soil crust) and different ratios of furrow to ridge (60∶30, 60∶45, and 60∶60 cm) on the root physiological characteristic parameters (dry weight, length, surface area, and volume) of oat. It was observed that the test root physiological characteristic parameters decreased with increasing soil depth. Under rainfall harvesting in ridges and furrows, the percentage of root dry weight in 0-10 cm, 10-20 cm, and 20-30 cm soil layers to the total root dry weight in 0-30 cm soil layer was 61%-66%, 22%-25%, and 11%-14%, respectively. The ratio of root dry weight in the sides of furrows to that in the middle part of furrows in treatments SR₃₀ (30 cm width ridges compacted with soil), SR₄₅ (45 cm width ridges compacted with soil), SR60 (60 cm width ridges compacted with soil), MR₃₀ (30 cm width ridges covered with plastic film), MR₄₅ (45 cm width ridges covered with plastic film), and MR₆₀ (60 cm width ridges covered with plastic film) was 1.2, 1.5, 2.0, 1.1, 1.3, and 1.3, respectively. The test root physiological characteristic parameters were obviously higher in the sides of furrows than that in the middle part of furrows, indicating that the plants growing in the sides of furrows were likely to produce more grains. In most cases, the root physiological characteristic parameters increased with the increasing waterharvested ridge width, and were in the order of traditional planting > ridges covered with plastic film planting > ridges compacted with soil planting. When the ratio of furrow to ridge was 60∶37 cm, the root dry weight in the ridges compacted with soil planting was the minimum; and when the ratio of furrow to ridge was 60∶27 cm, the root dry weight in the ridges covered with plastic film planting was the minimum.

Chlorophyll-a and phaeophorbidea contents in the sediments of mangroves in Dongzhai Bay of Hainan Province, South China.

LIU Jun-ling1,2**, HUANG Bo1,2

2013, 32(11):  2973-2977. 

Asbtract ( 1718 )   PDF (1403KB) ( 259 )  

A seasonal investigation was conducted on the chlorophyll-a (Chl-a) and phaeophorbidea (Pha-a) contents in the sediments of mangroves in Dongzhai Bay of Hainan Province from September, 2010 to June, 2011. There was an obvious difference in the horizontal distribution of chl-a and pha-a in the sediments between different sampling points. The chl-a content was 1.59-6.82 μg·g^-1, with an average of 2.98 μg·g^-1, and decreased with increasing sediment depth, being 1.59-6.82, 0.70-5.93, and 0.60-4.49 μg·g^-1 in 0-2,  2-5, and 5-8 cm layers, respectively. The average chl-a contents in different sampling points had the similar seasonal variation pattern, with the highest chla content in 0-2 cm layer in September (6.82 μg·g^-1), and in 2-5 and 5-8 cm layers in June (5.93 and 4.49 μg·g^-1, respectively). The pha-a in the sediments had the similar distribution trend to chl-a. The pha-a content was 1.81-14.22 μg·g^-1, being the highest (14.22 μg·g^-1) at E station in June, 2011.

Effects of pruning on the growth and photosynthetic physiology of Eucalyptus urophylla × E. grandis.

REN Shi-qi1,2,3,4, CHEN Jian-bo1,3,4, ZHOU Wei1,3,4, LU Cui-xiang1,3,4, GUO Dong-qiang1,3,4, DENG Zi-yu1,3,4, XIANG Dong-yun1,3,4**, XIAO Wen-fa2

2013, 32(11):  2978-2984. 

Asbtract ( 1680 )   PDF (895KB) ( 299 )  

With a splitplot experimental design, this paper studied the effects of different pruning intensities (no pruning, CK; light pruning, cutting 25% of whole canopy; moderate pruning, cutting 33.3% of whole canopy; and heavy pruning, cutting 50% of whole canopy) on the growth and photosynthetic physiology of Eucalyptus urophylla × E. grandis. Pruning intensity had no significant effects on the diameter at breast height, tree height, and single tree volume. In the main plots, the diameter at breast height under heavy pruning was almost the same as that of CK, and was larger than that under light pruning and moderate pruning. The tree height in all treatments was basically the same, and the single tree volume had the same variation trend as the diameter at breast height. Heavy pruning had the best promotion effect on the tree growth in the 1st pruning practice. After carrying out the 2nd pruning practice, the tree growth under heavy pruning-heavy pruning, heavy pruning-no pruning, and no pruning-no pruning was slightly better than that in other treatments. Under the four pruning intensities, the net photosynthetic rate had the same variation trend as the tree growth rate, being mainly affected by instantaneous carboxylation efficiency. The transpiration rate was not changed with pruning intensity. The water use efficiency had the same variation trend as the tree growth rate, and the variation was mainly induced by the difference of net photosynthetic rate. Considering the water use efficiency, maximum growth, and length of wood without knot, it was suggested that the heavy pruning-heavy pruning could be the best manual pruning mode for the cultivation of E. urophylla×E. grandis.

Comparison of leaf construction cost between invasive plant Flaveria bidentis and its five co-occuring plants. 

TU Chen-yang1,2, HUANGFU Chao-he1,2, JIANG Na1,2, GAO Shang-bin1,2, YANG Dian-lin1,2**

2013, 32(11):  2985-2991. 

Asbtract ( 1769 )   PDF (668KB) ( 405 )  

Leaf construction cost (CC) is an important indicator in measuring the energy demand for plant leaf construction, and reflects the energy utilization strategy of plant leaf. Lower leaf CC has been hypothesized to give invasive plants a growth advantage through efficient energy utilization. In this paper, the invasive plant Flaveria bidentis and its cooccuring native plants Xanthium sibiricum, Amaranthus retroflexus, Setaira viridis, Chenopodium glaucum, and Vigna radiata were selected as the objects to compare their differences in leaf CC and related characteristics. The construction cost per unit leaf mass (CC_mass) of F. bidentis was significantly lower than that of the five cooccuring native plants, being 76.6% of the average CC_mass of the native plants. Likewise, the construction cost per unit leaf area (CC_area) of F. bidentis was significantly lower than that of the native plants except S. viridis, being 74.4% of the average CC_area of the native plants. The leaf carbon and nitrogen concentrations of F. bidentis were significantly lower than those of the cooccuring plants. The leaf ash content of F. bidentis was significantly higher than that of X. sibiricum, A. retroflexus, S. viridis, and V. radiate, but had less difference with that of C. glaucum; while the leaf ashfree calorific value of F. bidentis was significantly lower than that of the native plants except C. glaucum. For all test plants, their leaf CC_mass was significantly positively correlated with their leaf carbon concentration and leaf ashfree calorific value, but negatively correlated with the leaf ash content. As compared with that of the cooccuring plants, the lower leaf CC of F. bidentis could be one of the reasons causing the successful invasion of this invasive plant.

Clonal growth characteristics of Zostera marina L.

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

2013, 32(11):  2997-3003. 

Asbtract ( 1421 )   PDF (507KB) ( 292 )  

The study on the clonal growth characteristics of Zostera marina L. in Shuangdao Bay of Weihai, East China showed that in the clonal fragments of the Z. marina, only three connected ramet generations were observed. The Z. marina was found to have a phalanx clonal architecture, with spacer length and internodal length being 3.85 cm and 0.92 cm, respectively. From August, 2010 to March, 2011, the total length of the rhizomes of each clonal fragment elongated by 20.39 cm, and a total of 22.17 nodes and 5.41 ramets were produced, suggesting the limited clonal expansion. As compared with daughter and granddaughter ramets, mother ramets had higher biomass and node number, longer rhizome, and bigger size. The clonal fragment allocated the largest proportion of total net production and total biomass to leaves due to the resource and energy requirements from the leaf-replacing growth type of Z. marina. Mother ramets allocated the similar proportion of biomass to leaves, rhizomes, and roots, whereas daughter and granddaughter ramets allocated their most amounts of biomass resources to leaves. The different patterns of biomass allocation for mother and daughter (and granddaughter) ramets could reflect the functional specialization of ramets. Our results implied that it was more feasible to transplant healthy Z. marina ramets in Chinese northern sea area in autumn.

Drift frequency and distance of transgenic phyA maize pollen.

ZHAO Zong-chao, GUO Wei-wei, SU Ying, CHEN Fa-jun**

2013, 32(11):  3004-3009. 

Asbtract ( 1544 )   PDF (663KB) ( 200 )  

By using pollen staining technology, this paper studied the drift frequency and distance of transgenic phyA maize pollen. The risk probability of the pollen drift differed in different directions, and decreased with the increasing distance from the central planting area of transgenic phyA maize. The pollen drift risk probability was the maximum (65.6%-82.5%) at the place of 1 m distance from the central planting area of transgenic phyA maize, which was significantly greater than that (21.8%) at the place of 3 m distance from the central planting area. At the places of above 5 m distance from the central planting area, the pollen drift risk probability was less than 8.7%. Due to the different weather conditions of sampling dates, the pollen drift distance was somewhat different, and the maximum distance of pollen drift could be 35 m from the central planting area of transgenic phyA maize.

Temporal dynamics of fresh corn rust in Guangzhou.

TIAN Yao-jia, ZHAO Shou-guang**, ZHANG Jing, HUANG Liang-hua, CHEN Hong-di, WANG Qiu-yan

2013, 32(11):  3010-3014. 

Asbtract ( 1347 )   PDF (537KB) ( 247 )  

A field investigation was conducted to monitor occurrence dynamics of fresh corn rust, with sampling method of five-spot from August to December, 2012. In addition, the relationship between corn rust and corn growth period was also analyzed. The results showed that occurrence of rust increased with corn growing. The disease appeared from middle of September (seedling stage of fresh corn), and reached up to 90% in December. Fresh corn was sensitive to rust at flowering stages, at which damage of the disease increased rapidly, and both disease incidence and severity were significantly higher than that at seedling or jointing stages. Our study also indicated that rust made serious damage on fresh corn of autumn planting. Therefore, control measurement to the disease should be advanced, especially at corn flowering period.

Niches and following performance evaluation of arthropod populations under the barks of dead pine trees caused by Bursaphelenchus xylophilus.

CAO Dan-dan1, JI Bao-zhong1**, LIU Shu-wen2, CHEN Xiao-ming1, ZHANG Xin-wei1, YANG Jin-jin1, LIU Jia-jia1

2013, 32(11):  3015-3021. 

Asbtract ( 1509 )   PDF (481KB) ( 280 )  

By using the indices of relative dominance, Levins niche width and Pianka niche overlap, a field investigation was conducted to study the population composition and niches of arthropods under the barks of dead pine trees caused by Bursaphelenchus xylophilus in Zijin Mountain, Nanjing,  China. The populations of the arthropods under the barks of the dead pine trees belonged to 27 species, 17 families, 7 orders and 3 classes, among which, the dominant species were of Poduridae, Staphylinidae, Muscidae, and Scolytidae, the abundant species were of Cheyletidae and Cerambycidae, the common species were of Bethylidae, Bothrideridae, Braconidae and Curculionidae, and the rare species were of Formicidae, Nitidulidae, Thripidae, Histeridae, Labiduridae, Elateridae and Cleridae. The Staphylinidae species had the broadest niche width.
The values of temporal, spatial and temporalspatial niche overlapa and of niche similarity proportion between Staphylinidae and Scolytidae, Cerambycidae were higher than those between Staphylinidae and other species. This suggested that there existed the highest spatial and temporal encountering probabilities and the most obvious following performance between the Staphylinidae species and the main boring insects such as the species of Scolytidae and Cerambycidae. This study could have important theoretical and practical significance for developing the new methods for controlling the boring insects by using the entomopathogens carried by carrier insects.

Spatial pattern of male and female Oedaleus asiaticus in the upper reaches of Heihe River, western China.

ZHA Gao-de, ZHAO Cheng-zhang**, ZHANG Jun-xia, YIN Cui-qin, DANG Jing-jing, YANG Quan

2013, 32(11):  3022-3028. 

Asbtract ( 1587 )   PDF (687KB) ( 223 )  

It is important to study how male and female grasshoppers respond to topographyinduced environmental changes and to identify dominant topographic factors that affect the spatial distribution. The spatial heterogeneity pattern of male and female grasshoppers responding to terrain reflects the resource co-evolution mechanism that grasshoppers adapt to the diversity of habitats. Through field survey from July to August, 2009, by using the GIS and S-PLUS, we developed a GAM model for Oedaleus asiaticus in the upper reaches of Heihe River on the northern slope of Qilian Mountain. The topographic indices included elevation, direction, slope, position, profile and plane. The results showed that the structure and D₂ values of models were different for male and female, so was the model stability in modeling, indicating their differences in response to the gradients of topographic indices. The gradient analysis in this model showed that male and female were distributed in a wide range of environments, in different gradients of elevation, direction, slope, position, profile and plan, in all land positions. However, this did not mean that the distribution of male and female was equally affected by each factor, or had a uniform distribution probability in the whole environmental range. The GAM modeling results indicated that the distribution of male and female were mainly controlled by the elevation, but the upper limit of elevation for distribution of the female grasshopper was higher than that of the male. On the regional distribution, there was higher abundance of the female in the whole region, but they were mainly located in the region with profile less than 0, and the male mainly concentrated in the south and southwest slopes. The heterogeneity attribute of O. asiaticus in selecting habitats made the spatial pattern of male and female in the same terrain obviously different.

 

Diversity and seasonal distribution pattern of True Bug (Heteroptera) assemblages in Kunyu Mountains of China. 

ZHU Yan-peng1，2, LIANG Jun1,3**, NI Yang1, MA Lin1,4, ZHANG Xing-yao1,3

2013, 32(11):  3029-3036. 

Asbtract ( 1529 )   PDF (1220KB) ( 296 )  

In May-September, 2011, a field survey was conducted to study the diversity and seasonal distribution pattern of True Bug (Heteroptera) population in Kunyu Mountains of China. By using the improved ground surface insect flight interception traps, a total of 519 True Bug specimens belonging to 30 species and 8 families were collected from 40 standard plots. Among the collected specimens, Pentatomidae had the largest number of species (13 species), whereas Reduviidae had the largest number of individuals. The comparative analysis on the species composition and diversity of True Bug in Pinus thunbergii forest, P. densiflora forest, Larix kaempferi/Cunninghamia lanceolata forest, coniferbroadleaf forest, and broadleaf forest in the Mountains showed that the diversity of True Bug was the lowest in L. kaempferi/C. lanceolata forest, and the species composition in this forest was not similar to that in the other four forests. The canonical correspondence analysis (CCA) showed that the most important factors affecting the spatial distribution of True Bug were elevation and stand density. The seasonal distribution pattern of the True Bug in the Kunyu Mountains could be classified into four types, i.e., typeⅠ (appeared throughout the sampling periods, n=8), typeⅡ (only appeared in early sampling period, n=9), type Ⅲ (only appeared in medium sampling period, n=6), and type Ⅳ (only appeared in mediumlate sampling period, n=7). The abundance of the True Bug presented a singlepeak distribution pattern, with the largest individual number in mid and late July and the smallest one in late September. The species richness had a similar seasonal variation trend to the abundance, being the highest in mid and late July, but also higher in the early sampling period.

Dynamic patterns of available and abandoned holes under rodent pest control.

LIU Han-wu1**, WANG Rong-xin2, ZHOU Hua-kun3, ZHANG Feng-qin1, LI Qiu-ying1

2013, 32(11):  3037-3042. 

Asbtract ( 1357 )   PDF (564KB) ( 211 )  

Rodent pests often cause large damage to economy and ecology. However, as a member of many ecosystems, rodents are beneficial to other species. Some birds live in the rodents abandoned holes, and thus, the quantity of abandoned holes reflects the dynamics of these bird populations. In rodent pest control, rodents should not be exterminated thoroughly, because it would damage the species that benefit from rodents. In this paper, mathematical models were used to study the dynamic patterns of the quantities of the abandoned and available holes and their ratios, with the effects of rodent pest control measures and intensities on the changes of the rodent available and abandoned holes quantities analyzed. The quantity of available holes represented the population density of rodent pests, while the quantity of abandoned holes (sometimes both the available and the abandoned holes) represented the life conditions of the species that benefit from rodent pests. It was shown that under any control measures, the quantity of available holes was decreased, while that of abandoned holes was increased or decreased, depending on the control intensity and the population parameters of rodent species. The ratio of the abandoned holes to the available holes was unchanged under comprehensive control, decreased under contraception control, and increased under other control measures.

Correlation of prolactin receptor with litter size of Striped Hamster (Cricetulus barabensis).

XUE Hui-liang, WANG Dong-kuan, XU Jin-hui, XU Lai-xiang**

2013, 32(11):  3043-3047. 

Asbtract ( 1315 )   PDF (617KB) ( 178 )  

Striped Hamster (Cricetulus barabensis) is one of the main functional groups in the regulation of cropland ecosystems. Litter size is one of the main factors affecting the population fluctuation of Striped Hamster, and prolactin receptor (PRLR) is the main effective gene controlling the litter size of animals. However, how the PRLR works on the population fluctuation of Striped Hamster is still unclear. In this study, ninety Striped Hamster individuals with the records of litter size were taken as the test materials to detect the SNP of the 5′ end of PRLR, analyze the haplotype structure, and examine the expression quantity of PRLR in ovaries during the oestrum, aimed to understand the correlations of the haplotype structure of the 5′ end of PRLR and the expression quantity of PRLR in ovaries during the oestrum with the litter size. A total of 3 polymorphic loci and 5 haplotypes (H1, H2, H3, H4, and H5) were detected in the 5′ end of the PRLR. Among the 5 halotypes structure, there existed significant difference in the litter size. Except between H1 and H2 and between H4 and H5, the expression quantity in the PRLR in ovaries during the oestrum had significant difference among the other haplotypes, and this expression quantity was significantly positively correlated with litter size (r= 0.982). Therefore, the polymorphic loci detected in the 5′ end of PRLR significantly affected the litter size, which could provide theoretical basis at molecular level for the effective control of Striped Hamster population.

Artificial incubation and snakelet captive breeding of Mangshan pitviper (Protobothrops mangshanensis).

CHEN Si-kan1, YANG Dao-de1**, YANG Wen-cai2, CHEN Yuan-hui3

2013, 32(11):  3048-3053. 

Asbtract ( 3308 )   PDF (993KB) ( 386 )  

Mangshan pitviper (Protobothrops mangshanensis, formerly Zhaoermia manshanensis) is the largest pitviper in China, and a critically endangered snake species only found in the Nanling Mountains of China. The wild P. mangshanensis population is extremely rare, and needs to be urgently protected. To save this rare and endangered species and to establish a captive breeding population, nine P. mangshanensis fresh eggs (34-38 mm × 50-66 mm in size and 31-40 g in weight) were collected from the Hunan Mangshan National Nature Reserve on July 8th, 2011, and transferred to the Hunan Jingxiangyuan Snakes Breeding Limited Company in Changde City of Hunan Province on the next day to carry out artificial incubation. By using vermiculite as the incubation substrate, nine snakelets were successively hatched from September 1st to September 2nd, 2011. The average total length and average weight of the nine newly hatched snakenets were （38.17±0.98） mm and （27.37±2.15） g, respectively. During the captive breeding of snakelets, a feeding experiment was conducted to determine the diet of P. mangshanensis under captive condition. It was observed that the newly hatched snakenets had very low initiative to prey, and thus, were fed artificially. After artificial feeding, the snakelets could prey on small mice independently, and grew faster. Up to April 13th, 2012, the average weight of five snakelets increased by 15.74 g, with an increment of 55.57%, and the average total length increased by 16.02 cm, with an increment of 26.65%. The snakelets were nonhibernation fed by using aircondition to control the temperature of the breeding room, and using wet sponge and thin moss soil to control the humidity. The survival rate of the overwintered snakelets was 83.33%. This study could provide references to the captive breeding of P. mangshanensis.

Community structure and diversity of macrobenthos in southern intertidal zone of Yellow River Delta, China.

LENG Yu1,2, LIU Yi-ting1,2, LIU Shuang1,2, ZHANG Hong-liang1,2, ZHANG Ai-jun1,2, LIU Xu-dong1, 2**

2013, 32(11):  3054-3062. 

Asbtract ( 1636 )   PDF (833KB) ( 424 )  

In May and August, 2004-2010, an investigation was conducted on the macrobenthos diversity in the southern intertidal zone of the Yellow River Delta. A total of 89 macrobenthos species were collected, most of which were polychaetes, crustacean, and mollusks, accounting for 34.8%, 29.2% and 27.0% of the total, respectively. Helice tientsinensis and Macrophthalmus japonicas were the dominant species in high tidal zone, while Potamocorbula laevis, Bullacta exarata, Umbonium thomasi, and Mactra veseriformis were dominated in mid and low tidal zones. The average Shannon index, Margalef index, and Pielou evenness index were 146, 115, and 0.66, respectively, and the Shannon index and Pielou index showed an upward trend. The species distribution had an obvious difference in different tidal zones, but less difference among years, which was also shown by cluster analysis. Due to the changes of habitat conditions since 2005 when the dams were established, the bioresources in the high tide zone increased obviously. As compared with historical data, the composition of dominant species in the study area in 2004-2010 was relatively stable, but the polychaetes occupied larger proportion, which was related to the human activities and the eco-environment change.

Effects of morphological traits on body mass of Phoxinus lagowskii Dybowskii.

ZHANG Yong-quan1, BAI Qing-li1, GUO Wen-xue1, FENG Cheng-cheng1,2, YIN Jia-sheng1**

2013, 32(11):  3063-3068. 

Asbtract ( 1458 )   PDF (429KB) ( 197 )  

By using correlation analysis, path analysis, and multiple linear regression method, this paper studied the effects of the morphological traits of 1 and 2 years old Phoxinus lagowskii Dybowski individuals on their body mass, aimed to provide reference for selecting the indicators of P. lagowskii growth. For the 1 year old P. lagowskii individuals, the correlation coefficients of body mass with total length, body length, body height, and caudal peduncle depth were 0.953, 0.958, 0.951, and 0.948, respectively (P<0.01), and the path coefficients also reached very significant level (P<0.01). The strongest determinant on body mass was body length, followed by total length, body height, and caudal peduncle depth. The high correlation index of the four morphological traits and the body mass (0.954) suggested that the selected traits were the main morphological traits affecting the body mass. The related multiple regression equation was Y =-12.375+2.255X₂+4.683X₃+4.722X₈-1.162X₁, where Y is body weight, and the X₁, X₂, X₃ and X₈ are total length, body length, body height, and caudal peduncle depth, respectively. For the 2 years old P. lagowskii individuals, total length and caudal peduncle depth were the independent variables that significantly affected body mass, with the correlation coefficient being 0.939 and 0.846, respectively (P<0.01). The path coefficients also reached very significant level (P<0.01). The strongest determinant on body mass was body length, followed by body height. Judged from the high correlation index (0.912), these two morphological traits affected the body mass significantly. The related multiple regression equation was Y= -188.444+11.416X₂+16.304X₃.

Otolith characteristics and age determination of Poropuntius huangchuchieni (Tchang, 1962) in Lancang River.

DING Cheng-zhi1,2, CHEN Yi-feng1**, YAO Jing-long1, HE De-kui1

2013, 32(11):  3069-3073. 

Asbtract ( 2027 )   PDF (1003KB) ( 328 )  

Poropuntius huangchuchieni is an endemic fish and an important component of local fisheries in Lancang River. In this study, samplings collected from Buyuan River, a tributary of Lancang River, were aged using a suite of calcified structures including scales, dorsal fin and otoliths. The patterns of sectioned otoliths can be divided into two types: some otoliths recorded as interpretable annuli could be recognized; in other cases, no pattern of alternating zones of opaque and translucent bands, but the daily increment on otoliths can be used to age these fishes. According to the microincrements of sectioned otolith of currentyear individuals, the age of these fishes were 135 to 348 days, and the birthday of P. huangchuchieni was December to June, mainly in January-April. Marginal increment analysis of sectioned otoliths showed that the annuli were formed between April and June each year. The formation of annuli was related with the water temperature and the water level. The opaque band formed between April and June, which was corresponding to the highest temperature and the relatively high water level. The translucent bands formed in seasons with lower water temperature and lower water level. The ages of all samplings ranged from age 1 to 6 for females and age 1 to 5 for males.

Change trend of wheat water requirement and related affecting factors in Hedong region of Gansu Province, Northwest China in recent 50 Years.

YANG Qi, ZHANG Bo**, YIN Hai-xia, ZHAO Yi-fei, LI Xiao-ya

2013, 32(11):  3074-3081. 

Asbtract ( 1447 )   PDF (811KB) ( 302 )  

Based on the last 50 years meteorological data from 10 stations (including five stations for winter wheat and five for spring wheat) in Hedong region of Gansu Province, and by using FAO-recommended Penman-Monteith model, the water requirement and water deficiency of winter wheat and spring wheat in the study region were calculated. Meanwhile, by using MannKendall method to analyze the variation trends of the water requirement and water deficiency, the major meteorological factors affecting the variations of wheat water requirement were obtained by correlation analysis. The future trends of the wheat water requirement were forecasted by the method of rescaled range analysis. In the study region, the water requirement of winter wheat in Huanxian had a slight decrease, while that in Kongdong, Tianshui, Wudou, and Xifeng presented an increasing trend. The water requirement of spring wheat in Jingtai decreased, while that in Lintao, Linxia, Minxian, and Yuzhong exhibited an increasing trend. The water deficiency of winter wheat in the study region all showed an increasing trend, with a rate of 7.32-25.19 mm·10 a^-1. The water deficiency of spring wheat in Jingtai showed a decreasing trend, with a rate of 20.81 mm·10 a^-1, while that in Lintao, Linxia, Minxian, and Yuzhong showed an increasing trend, with a rate 0.42-20.4 mm·10 a^-1. The major meteorological factors affecting the water requirement of winter wheat were the mean daily air temperature and wind speed, while those
affecting the water requirement of spring wheat were the mean daily temperature, relative humidity, and wind speed.

Sexual size dimorphism of amphibians and reptiles: A review.

LIAO Hao-hong1,2, XU Feng1, YANG Wei-kang1**

2013, 32(11):  3082-3093. 

Asbtract ( 1741 )   PDF (612KB) ( 678 )  

Differences in body shape and size, as well as differences in body coloration between male and female of same species are called as sexual dimorphism (SD). Sexual difference in body size or in other words, sexual size dimorphism (SSD), attracts a lot of attention of researchers. SSD is a common phenomenon for animals, which reflects the different adaptation of male and female under the selection pressure of the environment. There are three main hypotheses for the causes of SSD, i.e., sexual selection pressure, fecundity selection pressure, and ecological niche divergence. SSD is a very common phenomenon for amphibians and reptiles. Due to the lifelong growth, the individual sexual size dimorphism of amphibians and reptiles is the result of the comprehensive effects of various factors. Therefore, amphibians and reptiles are the ideal models for studying the evolution of sexual dimorphism, being researched widely and deeply. This paper reviewed the research progress on the SSD of amphibians and reptiles, with the focuses on the definitions, patterns, and evolution mechanisms of SSD. Aiming at the present status and existing problems in our related researches, some suggestions for the further research of the SSD of amphibians and reptiles were proposed.

Regulation of micro-ecological environment in freshwater aquaculture pond: A review.

FAN Li-min1,2, XU Pao1,2, WU Wei1,2, QU Jian-hong1, QIU Li-ping1, CHEN Jia-zhang1,2**

2013, 32(11):  3094-3100. 

Asbtract ( 1507 )   PDF (652KB) ( 505 )  

The deterioration of micro-ecological environment induced by intensive culture has been thought to be the main reasons of the problems in non-point source pollution, aquatic product security, and fish diseases in freshwater aquaculture pond. From the three aspects of micro-ecological environment (plankton community, bacterial community, and abiotic environment), this paper reviewed the research progress and existing problems in the water quality control technologies of freshwater aquaculture ponds. There were two prominent issues, i.e., 1) the lack of effective control measures in the absence of phytoplankton downward pressure control makes the regulation of plankton community exist short board, and 2) it still could not make precise regulation on the bacterial community due to the lack of defining characteristic bacterial flora in healthy pond ecosystem and the limitation of related technologies. The three aspects of the micro-ecological environment in freshwater aquaculture pond were interrelated and interacted. Though the regulation of abiotic environment was the key element, the other two elements were also the controlling targets. It was suggested that a systematic control should be carried out on the intensively managed freshwater aquaculture pond.

Improvement of key techniques of contingent valuation method in estimating environmental resource value. 

HU Xi-sheng1, HONG Wei2, WU Cheng-zhen2,3**, QIU Rong-zu1

2013, 32(11):  3101-3108. 

Asbtract ( 1588 )   PDF (523KB) ( 636 )  

Contingent valuation method (CVM), owing to its flexibility, wide applicability, and mighty data resources, has become one of the most widely used techniques in estimating environmental resource value. However, due to the short time of CVM being introduced to China, it is lack of a set of applicable principles to guide the empirical studies in China, leading to a lot of problems and controversies concerning CVM, such as the validity and reliability of the estimate results. It is believed that CVM is still a promising method to estimate environmental resource value under the premise of extremely careful and proper conduction of the survey, including questionnaire design, survey execution, and data processing. From the three key steps of questionnaire design, implement, and statistic analysis, and from the aspects of core estimate issue, initial bid, totality and sample, survey way, statistic method of willing to pay (WTP), regression model of the factors affecting WTP, and validity and reliability of CVM, this paper analyzed the key techniques of using CVM to improve the estimation of environmental resource value. The possible biases existing in CVM were summarized from the valuation method itself, questionnaire details, implementing process, and data statistics, and the corresponding solutions were proposed.

Representative time periods for measuring daily soil respiration in Ebinur Lake area, Xinjiang of Northwest China.

QIN Lu1,2, LU Guang-hui1,2**, HE Xue-min1,2, YANG Jian-jun1,2, HE Jing1,2, ZHANG Yan1,2

2013, 32(11):  3109-3116. 

Asbtract ( 1865 )   PDF (724KB) ( 300 )  

To select proper time periods at daily scale to measure soil respiration and take the measured average value to represent the daily average soil respiration can make the shortterm observed data be effectively applied in the estimation of soil respiration at yearly scale. By using 64-days diurnal observation data of soil respiration rate (R_s) under different vegetation types in Ebinur Lake area in 2007-2012, the representative time periods for measuring the R_s were selected, and the effectiveness was estimated. The selected representative time periods for measuring the R_s in freezing period, thawing period, and growth period were 9:00-13:00, 12:00-16:00, and 8:00-12:00, respectively. The differences between the average R_s values of representative time periods and of 24 hours in freezing period, thawing period, and growth period were 0.030, 0.004, and 0.039 μmol·m^-2·s^-1, and the relative differences were 1.94%, 0.86%, and 1.76%, respectively. Overlaying the R_s in representative time periods to yearly scale could represent the yearly soil carbon flux in Ebinur Lake area (R²=0.972). Our results could provide data support for the selection of the measurement time periods of soil respiration in temperate arid area, and also, provide theoretical basis for the objective evaluation of soil respiration in arid area.

Individual size of moss-epiphytic diatoms in response to water level change in peatland.

ZHAO Hai-yan1, CHEN Xu1**, BU Zhao-jun2, YANG Kuo2

2013, 32(11):  2992-2996. 

Asbtract ( 2786 )   PDF (1022KB) ( 438 )  

Moss-epiphytic diatom is one of the important microbial groups in peatland. The population composition of the diatom in peatland is quite sensitive to water level change, but little is known about the relationships between the diatom morphology and the peatland water level change. In this paper, two dominant species of mossepiphytic diatom (Eunotia steineckei and E. paludosa var. paludosa) were taken as the objects, with their individual lengths measured under microscope. The Pearson correlation analysis on the relationships between the average diatom individual length and the peatland environmental factors (e.g., water table, water content, pH, conductivity, and total phosphorus and nitrogen contents) revealed that the average individual length of the two diatom species had highly significant negative correlations with the changes of water table, and positive correlations with the peatland water content. Except that the individual length of E. steineckei was significantly negatively correlated with water pH, the individual length of the two diatom species had little correlations with the other environmental factors, indicating that the individual length of the two diatom species was mainly affected by the peatland water level change. The diatoms at their vegetative reproduction stage had a successive diminution in cell size, but the cell size was restored at sexual reproduction stage via the gamete production and anxosporulation. Peatland water level change could regulate the diatom reproduction pattern, and then, affect the diatom individual morphology. This study demonstrated that the individual length of moss-epiphytic diatom could be used as a sensitive indicator reflecting the water level change of peatland.