Table of Content

18 February 2013, Volume 24 Issue 2

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Short-term death dynamics of trees in natural secondary poplar-birch forest in Changbai Mountains of Northeast China.

ZHANG Zhao-chen1,2, HAO Zhan-qing1, YE Ji1, LIN Fei1,2, YUAN Zuo-qiang1, XING Ding-liang1,2, SHI Shuai1,2, WANG Xu-gao1

2013, 24(2):  303-310. 

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Taking the 5 hm² sampling plot in the natural secondary poplar-birch forest in Changbai Mountains as test object, and based on the two census data in 2005 and 2010, an analysis was made on the main tree species composition and quantity, size class distribution of dead individuals, and regeneration characteristics of the main tree species in different habitat types of the plot in 2005-2010. In the five years, the species number of the individuals with DBH≥1 cm increased from 46 to 47, among which, 3 species were newly appeared, and 2 species were disappeared. The number of the individuals changed from 16509 to 15027, among which, 2150 individuals died, accounting for 13% of the whole individuals in 2005, and 668 individuals were newly increased. The basal area of the trees increased from 28.79 m²·m^-2 to 30.55 m²·m^-2, with that of 41 species increased while that of 6 species decreased. The decrease of the basal area of Betula platyphylla and Populus davidiana accounted for 72.3% of the total decrease. Small individuals had higher mortality, as compared with large ones, and the mortality of the individuals with DBH<5 cm occupied 65% of the total. B. platyphylla and P. davidiana contributed most in the dead individuals with large DBH. No difference was observed in the tree mortality among different habitat types, but the mortality of the individuals with different size classes showed greater variation.

Forest carbon storage, carbon density, and their distribution characteristics in Linzhi area of Tibet, China.

GE Li-wen1, PAN Gang2, REN De-zhi2, DU Yu-jie1, ZHENG Xiang-lei3

2013, 24(2):  319-325. 

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According to the 6th Second Class Forest Resource Inventory data in Linzhi area of Tibet, and by using the volume source biomass method and averagebiomass computing method, in combining with the molecular formula carbon rate of different tree species, this paper estimated the carbon storage and carbon density of different standing forests and their components in the area, and analyzed the spatial distribution patterns of the carbon storage and carbon density. In 2004, the forest carbon storage in the area was 2.43×10⁸ t, and the average forest carbon density was 76.01 t·hm^-2. The carbon storage followed the sequence of standing forest > shrub forest > open forest > scattered trees > bamboo forest > fourside trees. Standing forests had a carbon storage 251×10⁵-1.27×10⁸ t, accounting for 92.0% of the total forest carbon storage in the area. The average carbon density of various standing forests was 103.16 t·hm^-2, and fir forest had the highest carbon storage and carbon density. From the view of regional distribution, the forest carbon storage presented a trend of increased from northwest to southeast, whereas the forest carbon density tended to be increased from southwest to northeast. The carbon storage of the standing forests was mainly consisted by mature and overmatured forests, and the carbon density of overmatured forests was the highest among all the age classes’ forests. The forest carbon storage in Linzhi area would be increased with the increase of overmatured forests, but tended to be decreased with the death and decomposition of overmatured forests.

Priority conservation regions of threatened plants in Northeast China.

CAO Wei, WU Yu-yang, LI Yan, CONG Xin-xin

2013, 24(2):  326-330. 

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Based on the identification of the threatened plants in Northeast China and the priority conservation value of plants, the priority conservation regions of the threatened plants in Northeast China were determined. In the study area, there were 60 species of threatened plants, belonging to 42 genera and 25 families. In the 219 counties (or cities) of Northeast China, 119 counties (or cities) had the distribution of threatened plants. The Antu County in Jilin Province had the most species (42) of threatened plants. A total of 16 counties (cities) such as the Antu County of Jilin Province and the Huanren Manchu Autonomous County of Liaoning Province, etc. were identified as the priority conservation regions of the threatened plants in Northeast China. According to the priority conservation value, five priority conservation regions of threatened plants in Northeast China were divided, including Changbai Mountain conservation region, East Liaoning conservation region, South Liaoning conservation region, Zhangguangcai Mountain conservation region, and Xiaoxing’an Mountain conservation region. The main threatened plants in each priority conservation region were also analyzed.

Vertical distribution of fuels in Pinus yunnanensis forest and related affecting factors.

WANG San, NIU Shu-kui, LI De, WANG Jing-hua, CHEN Feng, SUN Wu

2013, 24(2):  331-337. 

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In order to understand the effects of fuel loadings spatial distribution on forest fire kinds and behaviors, the canopy fuels and floor fuels of Pinups yunnanensis forests with different canopy density, diameter at breast height (DBH), tree height, and stand age and at different altitude, slope grade, position, and aspect in Southwest China were taken as test objects, with the fuel loadings and their spatial distribution characteristics at different vertical layers compared and the fire behaviors in different stands analyzed. The relationships between the fuel loadings and the environmental factors were also analyzed by canonical correspondence analysis (CCA). In different stands, there existed significant differences in the vertical distribution of fuels. Pinus yunnanensisoakSyzygium aromaticum, Pinus yunnanensisoak, and Pinus yunnanensis forests were likely to occur floor fire but not crown fire, while Pinus yunnanensisPlatycladus orientalis, Pinus yunnanensisKeteleeria fortune, and Keteleeria fortunePinus yunnanensis were not only inclined to occur floor fire, but also, the floor fire could be easily transformed into crown fire. The crown fuels were mainly affected by the stand age, altitude, DBH, and tree height, while the floor fuels were mainly by the canopy density, slope grade, altitude, and stand age.

Effects of Phyllostachys edulis expansion on soil nitrogen mineralization and its availability in evergreen broadleaf forest.

SONG Qing-ni, YANG Qing-pei, LIU Jun, YU Ding-kun, FANG Kai, XU Pei, HE Yu-juan

2013, 24(2):  338-344. 

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By the methods of spacetime substitution and PVC tube closedtop in situ incubation, this paper studied the soil mineralizedN content, N mineralization rate, and N uptake rate in Phyllostachys edulisbroadleaf mixed forest (PBMF) formed by P. edulis expansion and its adjacent evergreen broadleaf forest (EBF) in Dagangshan Mountain of Jiangxi Province, China. There existed the same spatiotemporal variation trend of soil total mineralizedN (TMN) content between the two forests. The annual average N mineralization rate was slightly lower in PBMF than in EBF. In PBMF, soil N mineralization was dominated by ammonification; while in EBF, soil ammonification and nitrification were wellmatched in rate, and soil nitrification was dominated in growth season (from April to October). The N uptake by the plants in PBMF and EBF in a year was mainly in the form of NH₄⁺-N, but that in EBF in growth season was mainly in the form of NO₃^--N. These findings indicated that the expansion of P. edulis into EBF could promote the ammonification of soil N, weakened soil nitrification and total N mineralization, and also, increased the NH₄⁺-N uptake but decreased the NO₃^--N and TMN uptake by the plants.

Effects of broadleaf plantation and Chinese fir (Cunninghamia lanceolata) plantation on soil carbon and nitrogen pools.

WAN Xiao-hua1,2, HUANG Zhi-qun1,2, HE Zong-ming3, HU Zhen-hong1,2, YANG Jing-yu3, YU Zai-peng1,2, WANG Min-huang1,2

2013, 24(2):  345-350. 

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A comparative study was conducted on the soil C and N pools in a 19year-old broadleaf plantation and a Chinese fir (Cunninghamia lanceolata) plantation in subtropical China, aimed to understand the effects of tree species on the soil C and N pools. In the broadleaf plantation, the C and N stocks in 0-40 cm soil layer were 99.41 Mg·hm^-2 and 6.18 Mg·hm^-2, being 33.1 % and 22.6 % larger than those in Chinese fir plantation, respectively. The standing biomass and the C and N stocks of forest floor in the broadleaf plantation were 1.60, 1.49, and 1.52 times of those in Chinese fir plantation, respectively, and the differences were statistically significant. There was a significant negative relationship between the forest floor C/N ratio and the soil C and N stocks. In the broadleaf plantation, the fine root biomass in 0-80 cm soil layer was 1.28 times of that in the Chinese fir plantation, and the fine root biomass in 0-10 cm soil layer accounted for 48.2 % of the total fine root biomass. The C and N stocks in the fine roots in the broadleaf plantation were also higher than those in the Chinese fir plantation. In 0-10 cm soil layer, its C stock had a significant positive relationship with the fine root C stock. It was suggested that as compared with  Chinese fir plantation, the soil in broadleaf plantation had a greater potential to accumulate organiccarbon.

Effects of light regime on the growth and photosynthetic characteristics of Alnus formosana and A. cremastogyne seedlings.

LIU Shi-liang1， MA Ming-dong1,2， PAN Yuan-zhi1， WEI Liu-li1,3， HE Cheng-xiang1， YANG Kai-mao1

2013, 24(2):  351-358. 

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Three light intensities (100%, 56.2%, and 12.5%) were installed to simulate the light regimes of opening field (cutting blank), forest gap, and understory, respectively, aimed to understand the effects of different light regimes on the seedling growth, photosynthetic characteristics, and biomass accumulation and allocation of alien species Alnus formosana and native species A. cremastogyne. Low light regime limited the seedling growth of the two alder species, while the light regime of forest gap was more favorable for the growth, in comparison with that of the opening field. Regardless of the light regimes, A. formosana seedlings had higher specific leaf area (SLA), relative growth rate (RGR), leaf area, leaf length, leaf width, plant height, and basal diameter, but smaller leaf number, leaf area ratio (LAR), and petiole length. Under low light regime, A. formosana seedlings had higher maximum net photosynthetic rate (P_{n max}), light saturation point (LSP), and apparent quantum yield (AQY), but smaller light compensation point (LCP) and dark respiration rate (R_day). With the decrease of light intensity, A. formosana seedlings had much higher root mass ratio (RMR) and much lower leaf mass ratio (LMR), implying that more carbon was allocated and stored to the roots rather than new leaves, whereas the A. cremastogyne seedlings were in adverse, i.e., more carbon was allocated to the above-ground parts, which might increase the risk of animal feeding and mechanical damage.

Physiological characteristics of Pinus densiflora var. zhangwuensis and Pinus sylvestris var. mongolica seedlings on sandy lands under salt-alkali stresses.

MENG Peng1,2, LI Yu-ling1, ZHANG Bai-xi2

2013, 24(2):  359-365. 

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For the popularization of Pinus densiflora var. zhangwuensis, a new afforestation tree species on the desertified and salinized-alkalized lands in Northern China, and to  evaluate the salinityalkalinity tolerance of the tree species and to better understand the tolerance mechanisms, a pot experiment with 4year old P. densiflora var. zhangwuensis and P. sylvestris var. mongolica was conducted to study their seedlings growth and physiological and biochemical indices under the effects of three types salt (NaCl, Na₂CO₃, and NaHCO₃) stresses and of alkali (NaOH) stress. Under the saltalkali stresses, the injury level of P. densiflora var. zhangwuensis was lower, and the root tolerance index was higher. The leaf catalase (CAT) activity increased significantly by 22.6 times at the most, as compared with the control; the leaf malondialdehyde (MDA) content had no significant increase; the leaf chlorophyll (Chl) content had a smaller decrement; and the leaf water content (LWC) increased slightly. P. sylvestris var. mongolica responded differently to the salt-alkali stresses. Its leaf CAT activity had less change, MDA content increased significantly, Chl content had significant decrease, and LWC decreased slightly. It was suggested that P. densiflora var. zhangwuensis had a greater salinity-alkalinity tolerance than P. sylvestris var. mongolica. The higher iron concentration in P. densiflora var. zhangwuensis needles enhanced the CAT activity and Chl content, whereas the higher concentrations of zinc and copper were associated with the stronger salinity-alkalinity tolerance.

Temporal variations of soil microbial biomass and enzyme activities during the secondary succession of primary broadleavedPinuskoraiensis forests in Changbai Mountains of Northeast China.

HU Song1,2, ZHANG Ying1, SHI Rong-jiu1， HAN Si-qin1, LI Hui1， XU Hui1

2013, 24(2):  366-372. 

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By the method of spacefortime substitution, and taking the matured (200 years old) and overmatured (>200 years old) primary broadleavedPinus koraiensis forests and their secondary forests at different succession stages (20-, 30-, 50-, 80-, and 100 years old Betula platphylla forests) in Changbai Mountains of Northeast China as test objects, this paper studied the temporal variations of soil or ganic carbon, soil microbial biomass, and soil enzyme activities during the secondary succession of primary broadleavedPinus koraiensis forests in the Mountains. Under the 20- and 80 years old B. platphylla forests, the soil organic carbon content in humus layer was the highest (154.8 and 154.3 g·kg^-1, respectively); while under the matured and overmatured primary broadleavedPinus koraiensis forests, this organic carbon content was relatively low, being 141.8 and 133.4 g·kg^-1, respectively. The soil microbial biomass carbon and microbial quotient and the activities of soil cellulase, peroxidase, acid phosphatase, and cellobiase under the 50 and  80 years old B. platphylla forests were the highest, but the activity of soil polyphenol oxidase was the lowest, which revealed that under middleaged and matured B. platphylla forests, soil organic carbon had a faster turnover rate, and was probably in a stronger accumulation phase. Statistical analysis showed that the soil microbial biomass carbon had significant positive correlations with the soil organic carbon, total nitrogen, and available phosphorus (r=0.943, 0.963, and 0.953, respectively; P<0.01).

Air negative ion concentration in different modes of courtyard forests in southern mountainous areas of Jinan, Shandong Province of East China.

WANG Xiao-lei1, LI Chuan-rong2, XU Jing-wei3, HU Ding-meng3, ZHAO Zhen-lei2, ZHANG Liu-dong2

2013, 24(2):  373-378. 

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Taking five typical courtyard forests and a nonforest courtyard in southern mountains areas of Jinan as test objects, a synchronous observation was conducted on the air negative ion concentration and related meteorological factors in March-December, 2010. The air negative ion concentration in the test courtyards showed an obvious seasonal variation, being in the order of summer > autumn > spring > winter. The diurnal variation of the air negative ion concentration presented a double peak curve, with the maximum in 10:00-11:00 and 16:00-17:00 and the minimum around 12:00. The daily air quality was the best at 10:00 and 16:00, and better in afternoon than in the morning. Summer time and garden sketch mode had the best air quality in a year. The mean annual air negative ion and the coefficient of air ion (CI) of the test courtyards were in the order of garden sketch > economic fruit forest > natural afforested forest > flowers and bonsai > farm tourist > non-forest, with the air negative ion concentration being 813, 745, 695, 688, 649, and 570 ions·cm^-3, and the CI being 1.22, 1.11, 0.85, 0.84, 0.83, and 0.69, respectively. It could be concluded that garden sketch was the ideal courtyard forest mode. The air negative ion concentration was significantly positively correlated with air temperature and relative humidity, but irrelevant to light intensity.

Crown interception of apple trees in loess hilly and gully region, Northwest China.

LI Jing-jing1, BAI Gang-shuan1,2

2013, 24(2):  379-387. 

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Taking the apple trees at their full-fruit stage in the loess hilly and gully region of Shaanxi as test objects, a three-year consecutive monitoring was conducted on the precipitation outside the tree crown, the through fall of the crown, and the stem flow from 2008 to 2010, with the effects of different precipitation factors on the crown interception analyzed. In the study region, the stem flow rate and crown interception rate of the trees accounted for 0.8% and 8.9% of the precipitation, respectively, the inter-plant interception was higher than the inter-row interception, and the interception increased with the decreasing distance to the stem. In rainy season, the crown interception was greater while the interception rate was smaller; in drought season, it was in adverse. The crown interception increased with increasing precipitation amount, precipitation intensity, precipitation duration, and precipitation interval, and the relationships followed power function or logarithmic function. The interception rate was negatively correlated with precipitation amount, precipitation intensity, and precipitation duration, but positively correlated with precipitation interval, and the relationships were in power function. Among the precipitation factors, precipitation amount had the greatest effects on the crown interception capability of the apple trees.

Moisture and nutrient characteristics of deep layer soil in apple orchards on the Luochuan highland of Shaanxi, Northwest China.

CAO Yu1, JUMAHAN·Kasimu2, FAN Peng2, ZHANG Li-na2, LI Jun1

2013, 24(2):  388-396. 

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Taking the 11-, 15-, 20-, and 43 years old apple orchards on the Luochuan highland of Shaanxi, Northwest China as test objects, this paper measured the moisture content in 0-1500 cm soil layer and the organic matter and total and available nitrogen, phosphorous, and potassium contents in 0-300 cm soil layer, with the soil moisture and nutrient regimes as well as their variation characteristics with apple tree age and soil depth analyzed. The moisture content in 0-1500 cm soil layer in 11-, 15-, 20-, and 43 years old apple orchards was averagely 18.6%, 13.7%, 17.0%, 11.5%, and 13.1%, respectively, and decreased with apple tree age. Soil desiccation did not occurr in the orchards with supplementary irrigation, but a slight or medium soil desiccation  occurred in the rainfed orchards. Nevertheless, the moisture content in 0-300 cm soil layer in the rainfed orchards was still higher than that in wheat field. The contents of organic matter and total and available nitrogen in 0-300 cm soil layer in the five apple orchards were less than 10 g·kg^-1, 0.75 g·kg^-1, and 50 mg·kg^-1, respectively, all at shortage level, whilst the content of available phosphorous in 0-300 cm soil layer was 3.30-6.42 mg·kg^-1, being moderate in upper soil layer and scarce in deep soil layer. The content of available potassium in 0-300 cm soil layer was 78.09-98.31 mg·kg^-1, presenting abundant. The contents of  nutrients were all higher in 0-100 cm soil layer than in 100-300 cm soil layer. The soil organic matter and total and available nitrogen contents and the soil nutrient index (SNI) all presented a trend of decrease after an initial increase with the increasing apple tree age. The contents of the test nutrients except total potassium in 0-100 cm soil layer all decreased rapidly with soil depth, while those in deeper soil layers kept relatively stable. There existed significant correlations between the contents of soil organic matter, total nitrogen, available nitrogen, total phosphorous, available phosphorous, and available potassium, but no significant correlations between the contents of soil total potassium and other nutrient factors.

Characteristics and adaptation of seasonal drought in southern China under the background of climate change. Ⅲ. Spatiotemporal characteristics of seasonal drought in southern China based on the percentage of precipitation anomalies.

HUANG Wan-hua1,2, SUI Yue2,3, YANG Xiao-guang2, DAI Shu-wei2,4, LI Mao-song5

2013, 24(2):  397-406. 

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To analyze the spatiotemporal characteristics and occurrence regularity of seasonal drought can provide theoretical basis for constituting the countermeasures of drought resistance and drought mitigation under the background of global climate change. Based on the 1959-2008 daily precipitation and atmospheric temperature data collected from the meteorological stations in 15 provinces (municipalities, and autonomous regions) of southern China, and using the percentages of precipitation anomalies (Pa) in the national standard “Meteorological Drought Classification”, which were locally modified, the drought indices in southern China in 1959-2008 were calculated, and the spatial distribution characteristics of drought frequency in southern China in each year, each season, and each month, as well as the interannual changes of the drought intensity and the proportions of the stations with seasonal drought were analyzed. In the study period, the annual drought risk in southern China was generally low. There existed obvious seasonal differences in the spatial distribution characteristics of the drought. Autumn drought was most frequent and most intensive, mainly occurred in the middle and lower reaches of Yangtze River, South China and in the other major agricultural areas, winter drought was also frequent and intensive, mainly occurred in the west of Southwest China and the South China and other winter crop planting areas, while spring drought and summer drought were relatively less frequent or intensive. Spring drought mostly occurred in the southwest of Southwest China, the south of South China, and Huaibei area etc., and summer drought mostly occurred in the middle and lower reaches of Yangtze River, southeastern coastal area of Fujian, and northeast of Southwest China. The area with drought frequently occurred showed an obvious monthly fluctuation and space transformation, which was decreased with time from November to next May, increased with time from May to November, in the smallest range from April to June, and in the widest range from November to December. The annual drought area showed a slight decrease while the drought intensity should a slight increase, but the situation differed with season, i.e., spring drought area slightly decreased and the drought intensity weakened, summer drought area had an obvious decrease and the drought intensity weakened, autumn drought area increased obviously and the drought intensity increased, while winter drought area decreased and the drought intensity weakened.

Effects of water and nitrogen management modes on the leaf photosynthetic characters and yield formation of cotton with under-mulch drip irrigation. 

LUO Hong-hai1, ZHANG Hong-zhi1,2, TAO Xian-ping1, ZHANG Ya-li1, ZHANG Wang-feng1

2013, 24(2):  407-415. 

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Taking different genotype cotton varieties as test materials, a soil column culture experiment was conducted to study the effects of water and nitrogen management modes on the photosynthetic characters and yield formation of cotton with undermulch drip irrigation in Xinjiang, Northwest China. Under the management mode W₄N₂, i.e., pre-sowing irrigation + limited drip irrigation before full-flowering + abundant drip irrigation after fullflowering in combining with basal 20% N + topdressing 80% N, the chlorophyll content, net photosynthetic rate (P_n), stomatal conductance (g_s), actual photochemical efficiency of photosystemⅡ (Φ_PSⅡ), and photochemical quenching coefficient (q_P) at full-flowering stage all decreased significantly, the non-photochemical quenching (NPQ) increased, and the aboveground dry matter accumulation was inhibited, as compared with those under common drip irrigation. From fullflowering stage to bollopening stage, the chlorophyll content, g_s, P_n, Φ_PSⅡ, and q_P increased with increasing water and nitrogen supply, and the aboveground dry matter accumulation was enhanced by compensation, which benefited the translocation and distribution of photosynthates to seed cotton. Under the fertilization mode of basal 20% N + topdressing 80% N, the seed cotton yield of Xinluzao13 was the highest in treatment pre-sowing irrigation + common drip irrigation (W₃), but that of Xinluzao43 was the highest in treatment pre-sowing irrigation + limited drip irrigation before full-flowering + abundant drip irrigation after full-flowering (W₄). It was concluded that under the condition of pre-sowing irrigation, to appropriately decrease the water and nitrogen supply before full-flowering stage and increase the water and nitrogen supply at middle and late growth stages could extend the active photosynthesis duration and promote the photosynthates allocation to reproductive organ, which would fully exploit the yield-increasing potential of cotton with under-mulch drip irrigation.

Coupling effects of  partitioning alternative drip irrigation with plastic mulch and nitrogen fertilization on cotton dry matter accumulation and nitrogen use.

LI Pei-ling1, ZHANG Fu-cang2

2013, 24(2):  416-422. 

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A field experiment with complete combination design was conducted to study the effects of  partitioning alternative drip irrigation with plastic mulch and nitrogen fertilization on the dry matter accumulation and nitrogen use efficiency of cotton plant. Three levels of irrigation (260, 200, and 140 mm) and of nitrogen fertilizer (270, 180, and 90 kg·hm^-2) were installed. The cotton dry mass was the highest in treatments medium nitrogen/high water and high nitrogen/high water. As compared with that in high nitrogen/high water treatment, the nitrogen use efficiency for dry matter accumulation in medium nitrogen/high water treatment was increased by 34.0%-44.6%, with an average of 34.7%, while the water use efficiency was decreased by 6.4%-10.7%, averagely 10.2%. As for the nitrogen accumulation in cotton plant, the nitrogen use efficiency was the highest in medium nitrogen/high water treatment, and the water use efficiency was the highest in high nitrogen/medium water treatment. Compared with high nitrogen/high water treatment, medium nitrogen/high water treatment increased the nitrogen use efficiency for cotton nitrogen accumulation by 29.0%-41.7%, but decreased the water use efficiency for cotton nitrogen accumulation by 5.5%-14.0%. Among the treatments of coupling water and nitrogen of higher cotton yield, treatment medium nitrogen/high water had the higher cotton nitrogen recovery rate, nitrogen agronomic efficiency, and apparent use efficiency than the treatments high nitrogen/medium water and high nitrogen/high water, but no significant differences were observed in the nitrogen absorption ratio and nitrogen physiological efficiency. Treatment medium nitrogen/high water was most beneficial to the coupling effects of water and nitrogen under  partitioning alternate drip irrigation with plastic mulch and nitrogen fertilization.

Characteristics of dry matter and potassium accumulation and distribution in potato plant in semi-arid rainfed areas.

LU Jian-wu1,2, QIU Hui-zhen1,2,3, ZHANG Wen-ming1,2,3, WANG Di1,3,4, ZHANG Jun-lian1,3,4, ZHANG Chun-hong1,2,3, HOU Shu-yin1,2

2013, 24(2):  423-430. 

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In 2010, a field experiment with potato (Solanum tuberosum) cultivar ‘Xindaping’ was conducted at the Dingxi Extension Center of Gansu Province, Northwest China, aimed to understand the accumulation and distribution patterns of dry matter (DM) and potassium (K) in the organs of potato plant in semiarid rainfed areas. During the whole growth period of the cultivar, the DM accumulation in root, stem, and leaf all showed a unimodal curve, with the DM accumulation rate being leaf > stem > root, whereas the DM accumulation in whole plant and tuber was an S-curve. The maximum DM accumulation rate of the whole plant was higher than that of the tuber, and appeared 17 days earlier. The distribution of DM in different organs showed two turning points, i.e., during the tuber formation (TF) period and the tuber growth (TG) period. During TF period, the DM accumulation was the greatest in leaf, followed by in tuber. The TF period was also the DM balance period, which occurred 90 days after emergence. Before the DM balance period, the DM accumulation in tuber was lesser than that in root, stem, and leaf, and there was a positive correlation between the DM accumulation in tuber and in root, stem, and leaf. However, after the DM balance period, the DM accumulation in tuber was greater than that in root, stem, and leaf, and the correlation was negative. At seedling stage and in TF period, TG period, starch accumulation period, and maturity period, the DM accumulation in whole plant was 5%, 30%, 60%, 4%, and 1%, while that in tuber was 0, 18%, 62%, 18%, and 2%, respectively. In the whole growth period, more than 50% of the DM was formed in TG period. The K concentration was the highest in stem and the lowest in tuber, though the K was mostly concentrated in root before the DM balance period. The K accumulation before the DM balance period was mostly in root, stem, and leaf, with the sequence of stem > leaf > root, but after the DM balance period, the K was mainly allocated in tuber, with >60% of the K accumulated in tuber in maturity period.

Quantitative relationships between satellite channels-based spectral parameters and wheat canopy leaf nitrogen status.

YAO Xia, LIU Xiao-jun, TIAN Yong-chao, CAO Wei-xing, ZHU Yan, ZHANG Yu

2013, 24(2):  431-437. 

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Using spaceborne remote sensing information to monitor the crop canopy nitrogen status and crop productivity in a largescale is of great significance and application prospect in modern agriculture. With the hyperspectral reflectance data from the wheat canopy under different nitrogen fertilization levels, this paper constructed the spectral indices (including the single wavelength, ratio spectral index, and normalized difference spectral index) simulated by satellite channels, and established the nitrogen estimation equations by quantifying the relationships between the simulated channels spectral indices and the leaf nitrogen index. The results indicated that the spectral indices based on NDVI (MSS₇, MSS₅), NDVI (RBV₃, RBV₂), TM₄, CH₂, MODIS₁,and MODIS₂  could be reliably used for estimating the leaf nitrogen content (LNC), with R₂ over 0.60, and the spectral indices based on NDVI (PB₄, PB₂, NDVI (CH₂, CH₁), NDVI (MSS₇, MSS₅), RVI (MSS₇, MSS₅), MODIS₁, and MODIS2 could be accurately used for predicting the leaf nitrogen accumulation (LNA), with R₂ greater than 0.86. Comparatively, NDVI (MSS₇, MSS₅) and NDVI (PB₄, PB₂) could be the more suitable spectral indices for predicting the wheat canopy LNC and LNA, respectively.

Effects of stubble-standing mode on the grain yield and water use efficiency of wheat and maize in wheat/maize intercropping system.

LIU Chao-wei1,2, WANG Qi3, LIU Qing-lin1, GUAN Xiao-kang4, YANG Yong5, ZHANG En-he1

2013, 24(2):  438-444. 

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Wheat/maize intercropping is the main intercropping pattern in the irrigation region of Hexi Oasis, Northwest China, but the traditional intercropping needs much water, making the regional water resource lacked increasingly. In 2010, a field experiment was conducted in the irrigation region of Shiyang River basin oasis, Gansu Province of Northwest China, aimed to study the effects of traditional stubbleburning, stubblereturning, and stubblestanding on the grain yield, water use efficiency (WUE), and economical benefits of wheat and maize in wheat/maize intercropping system. Compared with stubbleburning and stubblereturning, stubblestanding increased the grain yield of mono and intercropped wheat by 7.2% and 5.1%, and 6.2 %, 5.1 %, and that of mono and intercropped maize by 4.7% and 2.5%, and 7.2% and 3.3%, and increased the WUE of mono and intercropped wheat by 20.4% and 16.2%, and 17.9% and 14.6%, and that of mono and intercropping maize by 16.7% and 10.9%, and 11.8% and 17.0%, respectively. As for the mono and intercropped wheat and maize, their average net economical benefits under stubbleburning, stubble returning, and stubblestanding were 10946, 11471, and 13454 RMB·hm^-2, respectively. In considering the grain yield, WUE, and economic benefits, stubble-standing would be the optimal mode of wheat/maize intercropping in the oasis of Hexi irrigation region, Northwest China.

 

Effects of nighttime warming on winter wheat root growth and soil nutrient availability.

ZHANG Ming-qian1, CHEN Jin1, GUO Jia1, TIAN Yun-lu1, YANG Shi-jia1, ZHANG Li1, YANG Bing1, ZHANG Wei-jian1,2

2013, 24(2):  445-450. 

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Climate warming has an obvious asymmetry between day and night, with a greater increment of air temperature at nighttime than at daytime. By adopting passive nighttime warming (PNW) system, a two-year field experiment of nighttime warming was conducted in the main production areas of winter wheat in China (Shijiazhuang of Hebei Province, Xuzhou of Jiangsu Province, Xuchang of Henan Province, and Zhenjiang of Jiangsu Province) in 2009 and 2010, with the responses of soil pH and available nutrient contents during the whole growth periods and of wheat root characteristics at heading stage determined. As compared with the control (no nighttime warming), nighttime warming decreased the soil pH and available nutrient contents significantly, and increased the root dry mass and root/shoot ratio to a certain extent. During the whole growth period of winter wheat, nighttime warming decreased the soil pH in Shijiazhuang, Xuzhou, Xuchang, and Zhenjiang averagely by 0.4%, 0.4%, 0.7%, and 0.9%, the soil alkaline nitrogen content averagely by 8.1%, 8.1%, 7.1%, and 6.0%, the soil available phosphorus content averagely by 15.7%, 12.1%, 19.6%, and 25.8%, and the soil available potassium content averagely by 11.5%, 7.6%, 7.6%, and 10.1%, respectively. However, nighttime warming increased the wheat root dry mass at heading stage in Shijiazhuang, Xuzhou, and Zhenjiang averagely by 31.5%, 27.0%, and 14.5%, and the root/shoot ratio at heading stage in Shijiazhuang, Xuchang, and Zhenjiang averagely by 23.8%, 13.7% and 9.7%, respectively. Our results indicated that nighttime warming could affect the soil nutrient supply and winter wheat growth via affecting the soil chemical properties.

Effects of PASP-KTNAA on the grain-filling of maize in different accumulated temperature zones of Heilongjiang Province, Northeast China.

XU Tian-jun, DONG Zhi-qiang, GAO Jiao, CHEN Chuan-xiao, JIAO Liu,XIE Zhen-xing

2013, 24(2):  451-458. 

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Taking the two maize varieties Zhengdan 958 and Fengdan 3 grown on the three accumulated temperature zones (Ⅰ，Ⅱ and Ⅲ) in Heilongjiang Province as test materials, a field investigation was made in 2010 and 2011 to study the effects of PASPKTNAA (PKN), a compound of exogenous plant growth regulators, on the grain filling and yield of the varieties under different environmental temperatures. From  zone Ⅰ to  Ⅲ, the air temperature at the grain filling stage had a decreasing trend, with the average minimum temperature being 12.16, 11.40, and 9.56 ℃, respectively. The effective accumulated temperature at the midlate stage of grain filling was too low to be sufficient for grain filling, which severely affected the grain filling process. Applying N, P and K promoted the dry matter accumulation of maize grain and the grain filling rate in the  three zones, delayed the peak time (T_max) of the grain filling rate of Fengdan 3 but advanced that of Zhengdan 958， promoted the growth capacity at peak time of grain filling rate and the maximum grain filling rate of the two varieties, and shortened their active grain filling period. Applying N, P, and K increased the grain yield of the two varieties in the three zones obviously, and, as compared with those in zones Ⅰ and Ⅱ, the grain yields of Zhengdan 958 and Fengdan 3 in zone Ⅲ were increased by 8.2% and 5.1%, and 3.4% and 0.8%, respectively. Therefore, applying N, P and K could help maize utilizing the limited accumulation temperature, improve the grain filling rate, decrease the grain water content, and ultimately, increase the maize yield.

Prediction of soil nutrients spatial distribution based on neural network model combined with goestatistics.

LI Qi-quan1, WANG Chang-quan1, ZHANG Wen-jiang2, YU Yong3, LI Bing1, YANG Juan1, BAI Gen-chuan1, CAI Yan1

2013, 24(2):  459-466. 

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In this study, a radial basis function neural network model combined with ordinary kriging (RBFNN_OK) was adopted to predict the spatial distribution of soil nutrients (organic matter and total N) in a typical hilly region of Sichuan Basin, Southwest China, and the performance of this method was compared with that of ordinary kriging (OK) and regression kriging (RK). All the three methods produced the similar soil nutrient maps. However, as compared with those obtained by multiple linear regression model, the correlation coefficients between the measured values and the predicted values of soil organic matter and total N obtained by neural network model increased by 12.3% and 16.5%, respectively, suggesting that neural network model could more accurately capture the complicated relationships between soil nutrients and quantitative environmental factors. The error analyses of the prediction values of 469 validation points indicated that the mean absolute error (MAE), mean relative error (MRE), and root mean squared error (RMSE) of RBFNN_OK were 6.9%, 7.4%, and 5.1% (for soil organic matter), and 4.9%, 6.1%, and 4.6% (for soil total N) smaller than those of OK (P<0.01), and 2.4%, 2.6%, and 1.8% (for soil organic matter), and 2.1%, 2.8%, and 2.2% (for soil total N) smaller than those of RK, respectively (P<0.05).

 

Effects of nitrogen fertilization and straw amendment on  soil microbial biomass and soil functions after heat stress. 

CHEN Xiao-yun, CHEN Shi, LIU Man-qiang, JIAO Jia-guo, LI Hui-xin, HU Feng

2013, 24(2):  467-472. 

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A 60-day incubation experiment was conducted to study the effects of nitrogen fertilization (N), rice straw amendment (R), and their combination (RN) on the changes of soil microbial biomass and soil functions (basal respiration, substrateinduced respiration, and straw decomposition) after heat stress (40 ℃ for 18 h). Heat stress tended to promote the soil microbial biomass and soil functions, but the effects were weak and transient. Either with or without heating, treatment R and especially RN could greatly stimulate soil microbial biomass, basal respiration, substrate-induced respiration and straw decomposition, as compared to no straw amendment and with nitrogen fertilization alone, but the parameters in treatment N  had less change, and even, presented a decreasing trend. It was suggested that straw amendment and its combination with nitrogen fertilization could improve soil functions in natural conditions or after environmental stress.

Diversity of carbon source metabolism of microbial community in farmland soils in an arsenic mining area.

HUA Jian-feng1, LIN Xian-gui2, JIANG Qian2, ZHANG Hua-yong2, CHEN Qian3, YIN Yun-long1

2013, 24(2):  473-480. 

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By using Biolog technique, this paper studied the diversity of carbon source metabolism of microbial community in three farmland soils with different levels of arsenic (As) in an As mining area, and the relationships between the diversity of the carbon source metabolism and the main soil chemical properties. The total N (TN), total P (TP), total K (TK), organic matter (OM), total Cu, and total Zn contents in the three soils were in the order of medium level As > high level As > low level As. The average well color development (AWCD), Shannon index (H′), Simpson index (D), and McIntosh index (U) of soil microbes were significantly higher in the soils with medium and high levels As than in the soil with low level As. The principal component analysis  and the fingerprints of the physiological carbon metabolism of the microbial community in the three soils demonstrated that the microbes in the soils with medium and high levels As had a significantly higher (P<0.05) utilization rate in carbohydrates and amino acids than the microbes in the soil with low level As. The correlation analysis showed that the AWCD, H′, D, and U were significantly positively correlated with the contents of soil TN, TP, OM, total As, total Cu, total Pb, and total Zn (P<0.05), and the canonical correspondence analysis revealed that soil TP, OM, total Pb, total Zn, TN, and pH rather than soil total As were the main soil chemical properties affecting the carbon source metabolism of soil microbial community. It was considered that soil nutrients could be the main factors affecting the community structure and functions of soil microbes in long-term contaminated soils.

Differences in  seed kernel quality and related enzyme activities of different quality type peanut cultivars.

ZHANG Jia-lei1, GAO Fang2, LIN Ying-jie3, WANG Yuan-yuan1, YANG Chuan-ting1, ZHANG Feng1, LI Yan-hong1, LI Xiang-dong1

2013, 24(2):  481-487. 

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Taking high-protein peanut cultivar KB008, high-fat peanut cultivar Hua17 (H17), and higholeic acid/linoleic acid (O/L) peanut cultivar Nongda818 as test materials, a field experiment was conducted in 2010 and 2011 to study the differences in the contents of protein, fat, and their components of the seed kernels, and the differences in the activities of the carbon and nitrogen metabolism enzymes related to the quality synthesis in the blades. As compared with that of H17 and Nongda818, the seed kernel of KB008 had significantly higher protein content but significantly lower soluble sugar content and O/L ratio, and the contents of the amino acid components, especially glutamic acid and lysine, in the seed kernel of KB008 were significantly higher. During the whole growth period, the activities of nitrate reductase (NR), glutamine synthetase (GS), glutamate dehydrogenase (GDH), glutamate synthase (GOGAT), and glutamate pyruvate transaminase (GPT) in the blades of the three cultivars were in the order of KB008>H17> Nongda818. At pod setting stage, the activities of PEPCase and RuBPCase in the blades of the three cultivars were ranked as KB008>H17> Nongda818. The higher PEPCase and RuBPCase activities of KB008 facilitated the protein synthesis and accumulation. The sucrose synthase (SS) activity in the blades was in the order of H17> Nongda818>KB008. The sucrose phosphate synthase (SPS) activity of KB008’s blades was significantly lower than that of the other two cultivars, while the SPS activity of H17’s blades was still higher even in the 60 days after anthesis, suggesting that the higher activities of SS and SPS in the blades were in favor of the fat formation in peanut seed kernel.

Environmental impacts of sewage treatment system based on emergy analysis.

LI Min, ZHANG Xiao-hong, LI Yuan-wei, ZHANG Hong, ZHAO Min, DENG Shi-huai

2013, 24(2):  488-496. 

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“Integrated sewage treatment system” (ISTS) consists of sewage treatment plant system and their products (treated water and dewatered sludge) disposal facilities, which gives a holistic view of the whole sewage treatment process. During its construction and operation, ISTS has two main impacts on the environment, i.e. the consumption of resources and the damage of discharged pollutants on the environment, while the latter was usually ignored by the previous researchers when they assessed the impacts of wastewater treatment system. In order to more comprehensively understanding the impacts of sewage treatment on the environment, an analysis was made on the ISTS based on the theories of emergy analysis, and, in combining with ecological footprint theory, the sustainability of the ISTS was also analyzed. The results showed that the emergy of the impacts of water pollutants on the environment was far larger than that of the impacts of air pollutants, and NH₃ ^-_-N was the main responsible cause. The emergy consumption of ISTS mainly came from the emergy of wastewater and of local renewable resources. The “sewage treatment plant system + landfill system” had the highest emergy utilization efficiency, while the “sewage treatment plant system + reclaimed water reuse system + incineration system” had the lowest one. From the aspect of environmental sustainability, the “sewage treatment plant system + reclaimed water reuse system + landfill system” was the best ISTS, while the “sewage treatment plant system + incineration system” was the worst one.

Analysis of hydrodynamics parameters of runoff erosion and sediment-yielding on unpaved road.

HUANG Peng-fei1, WANG Wen-long1,2, LUO Ting3, WANG Zhen4, WANG Zheng-li5, LI Ren6

2013, 24(2):  497-502. 

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By the method of field runoff washout experiment, a simulation study was conducted on the relationships between the soil detachment rate and the hydrodynamic parameters on unpaved road, and the related quantitative formulas were established. Under the conditions of different flow discharges and road gradients, the averaged soil detachment rate increased with increasing flow discharge and road gradient, and the relationships between them could be described by a power function. As compared with road gradient, flow discharge had greater effects on the soil detachment rate. The soil detachment rate had a power relation with water flow velocity and runoff kinetic energy, and the runoff kinetic energy was of importance to the soil detachment rate. The soil detachment rate was linearly correlated with the unit runoff kinetic energy. The averaged soil erodibility was 0.120 g·m^-1·J^-1, and the averaged critical unit runoff kinetic energy was 2.875 g·m^-1·J^-1. Flow discharge, road gradient, and unit runoff kinetic energy could be used to accurately describe the soil erosion process and calculate the soil erosion rate on unpaved road.

Dynamic coupling and spatial disparity of economic development and water environmental quality in Songhua River Basin of Jilin Province, Northeast China. 

YANG Li-hua1,2, TONG Lian-jun1

2013, 24(2):  503-510. 

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By using coupling model, this paper analyzed the relationships between the economic development and water environment quality in Songhua River Basin of Jilin Province from 1991 to 2010. During the study period, both the economic development index and the water environment index in the Basin showed an uptrend, basically in a coordination state. From the perspective of coupling coordination degree, the economic development and the water environment system were in interactive coupling, with the features of complexity, nonlinearity, and timevariation. As a whole, the coupling experienced three stages, i.e., low level stage, antagonistic stage, and breakingin stage. As for the coupling degree, the coupling of the economic development and the water environment system was in the first quadrant, i.e., at a development stage of basic coordination. From the perspective of spatial disparity, the coupling degree of the economic development and the water environment system was higher in the upper reaches of the Songhua River Basin, including Changchun and Jilin, than in the lower reaches, including Songyuan and Baicheng. The coupling degree was not only significantly positively correlated with regional economic development, but also affected by the links between the regions as well as the industrial structure within the regions. The economic development of the cities in the upper reaches of the Songhua River Basin was obviously higher than that in the lower reaches, and, due to the adopting of more strict and effective measures for environmental protection and pollution emissions reduction, the water environment quality in the upper reaches of the Songhua River Basin was better.

Species-area and species-abundance relationships of arthropod community in various vegetation restoration areas in Zhifanggou watershed, Shaanxi Province of Northwest China.

ZHANG Feng1,2, HONG Bo1, LI Ying-mei1, CHEN Zhi-jie1, ZHANG Shu-lian1, ZHAO Hui-yan2

2013, 24(2):  511-516. 

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Taking the Zhifanggou watershed in Ansai, Shaanxi Province of Northwest China as a study unit, an investigation on the arthropods in 8 forest stands was conducted from 2006 to 2008, with the speciesarea and speciesabundance relationships of the arthropods in these stands analyzed by various mathematical models. In these forest stands, the species-area relationship of the arthropods accorded with the formula S=CA_m. With the increase of investigation area, the species number approached to a constant, and the corresponding smallest investigation area was in the order of natural bush > natural forest > Populus davidiana＋Robinia pseudoacacia forest > Hippaphae rhamnoides+Caragana mocrophylla forest> Periploca sepium forest >Hippaphae rhamnoides forest > Robinia pseudoacacia forest > Caragana mocrophylla forest, indicating that the more complex the stands, the larger the minimum area needed to be investigated. Based on sampling investigation, the species-abundance models of the arthropods in various stands were established. Lognormal distribution model (LN) was most suitable to fit the arthropod community in natural recovery stands, suggesting that in the arthropod community, there were more species with medial individual amount and fewer abundant species and rare species, and no obvious dominant species. LogCauchy distribution model (LC) was most suitable to fit the arthropod community in mixed and pure stands. As compared with natural recovery stand, mixed and pure stands had more abundant and rare species, and more dominant species.

Ecological risk assessment of hydropower dam construction on aquatic species in middle reaches of Lancang River, Southwest China based on ESHIPPO model.

LI Xiao-yan1, PENG Ming-chun2, DONG Shi-kui1, LIU Shi-liang1, LI Jin-peng, YANG Zhi-feng1

2013, 24(2):  517-526. 

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An investigation was conducted on the phytoplankton, zooplankton, and fish at 8 sampling sections in the Manwan Reservoir before and after the construction of Xiaowan Hydropower Dam. The modified ESHIPPO model was applied to study the changes of the featured aquatic species, including endangered species, endemic species, resource species, and native fish, aimed to make an ecological risk assessment of the dam construction on the aquatic species. The dam construction had definite ecological risk on the aquatic species, especially the endemic fish, in Langcang River, due to the changes of hydrological conditions. The endemic species including Bangia atropurpurea, Lemanea sinica, Prasiola sp., Attheyella yunnanensis, and Neutrodiaptomus mariadvigae were at high ecological risk, and thus, besides monitoring, protection measures were needed to be taken to lower the possibility of the species extinction. The widely distributed species of phytoplankton and zooplankton were at medium ecological risk, and protection measures besides monitoring should be prepared. Twelve kinds of native fish, including Barbodes huangchuchieni, Sinilabeo laticeps, Racoma lantsangensis, Racoma lissolabiatus, Paracobitis anguillioides, Schistura latifasciata, Botia nigrolineata, Vanmanenia striata, Homaloptera yunnanensis, Platytropius longianlis, Glyptothorax zanaensis, and Pseudecheneis immaculate, were at high ecological risk, and protection measures needed to be developed to prevent the possibility of the species loss and extinction.

Effects of environmental factors on the distribution of dominant wintering waterfowl species in East Dongting Lake wetland, Southcentral China.

YUAN Yu-jie1,2, LIANG Jie1,2, HUANG Lu1,2, LONG Yong1,2, SHEN Sheng1,2, PENG Ye-ru1,2, WU Hai-peng1,2, ZENG Guang-ming1,2

2013, 24(2):  527-534. 

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East Dongting Lake is one of the national nature reserves in China, and an important habitat for the wintering of waterfowls in China, and even, global wetlands. To study the relationships between waterfowl community and environmental factors is of vital significance in providing useful data and necessary information for the restoration of bird habitat. In the winters of 2010 and 2011, a survey was conducted on the wintering waterfowls in East Dongting Lake wetland, and canonical correspondence analysis (CCA) was adopted to reveal the relationships between the distribution of dominant wintering waterfowl species and environmental factors. The partial CCA was also employed to assess the respective importance of environmental factors on the waterfowl species distribution and diversity. The factors including the distance to roads, distance to residents, patch density, number of vegetation types, water area, and sedge area had significant effects on the waterfowl distribution (P<0.05), with the affecting intensity in the order of sedge area > patch density > distance to residents > number of vegetation types > water area > distance to road. Sedge area and patch density had highly significant effects (P<0.01) on the distribution of the waterfowls, being the two major factors affecting the wintering waterfowls in the wetland, while landscape diversity index and reed area had no significant effects (P>0.05). The regression analysis showed that environmental factors had different effects on the species richness. The richness of Platalea leucorodia, Anas falcata, and Calidris alpina decreased with the increase of sedge area, while increased with the increase of patch density. However, the richness of Anser fabalis, Anser albifrons, Anser erythropus, and Anas crecca increased with increase of sedge area while decreased with the increase of patch density. It was suggested that the distribution of wintering waterfowls in East Dongting Lake wetland was affected by a variety of environmental factors, among which, sedge area and patch density played the most important roles.

Roles of moisture in constructing man-made algal crust with Micocoleus vaginatus.

ZHANG Bing-chang, WANG Jing-zhu, ZHANG Yuan-ming, SHAO Hua

2013, 24(2):  535-540. 

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To explore the roles of moisture in the construction of man-made algal crust with inoculated Micocoleus vaginatus, a laboratory experiment was conducted to study the variations of the microalgal biomass, algal crust thickness, crust compressive strength, and crust microstructure under six moisture doses and four moisture treatment intervals. When M. vaginatus was inoculated to the naked sands without moisture addition, the microalgal biomass was very low, and no algal crust was formed. With increasing dose of moisture, the microalgal biomass, algal crust thickness, and crust compressive strength increased significantly, and the algal filaments and extracellular polysaccharides (EPS) had a gradual increase, wrapped around the sands and formed a complex network. After 15 days moisture treatment, stable algal crust was formed, which had the highest microalgal biomass, crust thickness, and crust compressive strength. The optimal moisture dose for  M. vaginatus to form manmade algal crust was 3-4 L·m^-2·d^-1, and the addition of moisture should be continued for 15 d. The availability of the moisture promoted the metabolic processes of M. vaginatus and the synthesis of the algal EPS, which increased the microalgal biomass and its ability to resist desiccation. The moisture availability at early stage was the key factor for M. vaginatus to successfully form algal crust. This study could offer some guidance for the recovery of biological soil crusts in the field.

 

Optimization of real-time quantitative fluorescence PCR system in detecting cytochrome b gene of Prorocentrum donghaiense Lu.

WANG Qu-yuan1, ZHEN Yu2, YUAN Jian1, MI Tie-zhu2, YU Zhi-gang3

2013, 24(2):  541-548. 

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To quantitatively detect the cytochrome b (Cyt b) gene of Prorocentrum donghaiense Lu in the filed samples, a specific primer was designed, and the quantities of the RNA templates added into the reaction system for reverse transcription as well as the reaction conditions of realtime fluorescent quantitative PCR (RFQ-PCR) were optimized. The results illustrated that the designed primer had good specificity, being able to be used to differentiate different algal species effectively. In detecting the filed samples, the suitable qualities of the templates for the 20 μL reverse transcription system were 50-200 ng. 10fold diluting the templates or adding the bovine serum albumin (BSA) with a final concentration 0.2 μg·μL^-1 into the RFQ-PCR system could effectively decrease the inhibitory effect of the inhibitors in the filed samples, and thus, decrease the interferences. The established realtime fluorescent quantitative PCR (RFQ-PCR) assay would facilitate us to study the intrinsic mechanisms of P. donghaiense outbreak and extinction at molecular level.

Sublethal effect of chlorantraniliprole on the experimental population of nontarget insect Nilaparvata lugens (Stl).

YANG Hong, WANG Zhao, JIN Dao-chao

2013, 24(2):  549-555. 

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Chlorantraniliprole is a newly developed insecticide targeting at lepidopteron pests in rice fields, whereas Nilaparvata lugens (St-l) is one of the important nontarget pests of the insecticide. In this paper, the rice stem dipping method was adopted to test the toxicity of chlorantraniliprole to the 3rd instar nymphs and adults of N. lugens. The LC_50 of chlorantraniliprole to the 3rd instar nymphs and adults was 26.85 and 35.53 mg·L^-1, respectively. When the 3rd instar nymph was exposed to the LC₁₀ and LC₂₅ of chlorantraniliprole, the life span of the survived female adults was not significantly affected. However, when treated with LC_25 dosage, the fecundity of the survived female adults was significantly reduced by 45.6 eggs. After the 3rd instar nymph was treated with the sublethal doses LC₁₀ and LC₂₅ of chlorantraniliprole, the fecundity of the F₁ females were decreased significantly by 43.5  and 72.9 eggs, and the life span of the F₁ females was shortened by 1.35 and 2.87 d, respectively. The developmental periods of all the instars of F₁ generation were delayed after treated with the sublethal doses LC₁₀ and LC₂₅ of chlorantraniliprole. The intrinsic rate of increase (r_m) was decreased by 12.8% and 23.5%, and the net reproductive rate (R₀) was decreased by 37.4% and 68.7%, respectively. Meanwhile, the mean generation time (T) and population doubling time (t) were delayed. Overall, the sublethal doses of chlorantraniliprole could suppress the population growth of N. lugens.


Application of ecosystem service value in land use change research: Bottlenecks and prospects.

ZHANG Zhou, WU Ci-fang, TAN Rong

2013, 24(2):  556-562. 

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In recent years, the application of ecosystem service value in land use change research is a hot topic in many famous international journals. However, policy makers are seldom taking into account the achievements of the related studies in practice. This paper summarized the three main bottlenecks in applying ecosystem service value in land management practices, i.e., the difficulty in measuring the service values, the complexity of driving factors, and the bias of evaluation criteria. Some solutions on the bottlenecks were provided, and the future research directions in China were prospected. It was suggested that in the studies of land use change based on ecosystem service value, it would be more appropriate to adopt comparative analysis method in small scale case studies, especially focusing on the natural ecological resources and the excessive loss of theirvalues.

Carbonyl compounds emission and uptake by plant: Research progress.

LI Jian, CAI Jing, YAN Liu-shui, LI Ling-na, TAO Min

2013, 24(2):  563-570. 

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This paper reviewed the researches on the carbonyl compounds emission and uptake by plants, and discussed the compensation point of the bidirectional exchange of carbonyl compounds between plants and atmosphere. The uptake by leaf stomata and stratum corneum is the principal way for the purification of air aldehydes by plants. After entering into plant leaves, most parts of carbonyl compounds can be metabolized into organic acid, glucide, amino acid, and carbon dioxide, etc., by the endoenzymes in leaves. The exchange direction of the carbonyl compounds between plants and atmosphere can be preliminarily predicted by the compensation point and the concentrations of ambient carbonyl compounds. This paper summarized the analytical methods such as DNPH/HPLC/UV and PFPH/GC/MS used for the determination of carbonyl compounds emitted from plants or in plant leaves. The main research interests in the future were pointed out, e.g., to improve and optimize the analytical methods for the determination of carbonyl compounds emitted from plants and the researches on systems (e.g., plantsoil system), to enlarge the detection species of carbonyl compounds emitted from plants, to screen the plant species which can effectively metabolize the pollutants, and to popularize the phytoremediation techniques for atmospheric pollution.

DNDC model, a model of biogeochemical processes: Research progress and applications.

GUO Jia-wei1,2, ZOU Yuan-chun1, HUO Li-li1,2, LU Xian-guo1

2013, 24(2):  571-580. 

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Denitrificationdecomposition (DNDC) model can estimate the emission fluxes of soil trace gases such as carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O) via the coupling of the denitrification and decomposition processes driven by soil environmental factors. At present, DNDC model is one of the most successful models in the world in simulating the terrestrial biogeochemical cycles. This paper mainly reviewed the development process of the DNDC model, its structure, model validation, and sensitive factor analysis, and summarized the hot fields in the applications of the model.

Effects of global change on soil fauna diversity: A review.

WU Ting-juan

2013, 24(2):  581-588. 

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Terrestrial ecosystem consists of aboveground and belowground components, whose interaction affects the ecosystem processes and functions. Soil fauna plays an important role in biogeochemical cycles. With the recognizing of the significance of soil fauna in ecosystem processes, increasing evidences demonstrated that global change has profound effects on soil fauna diversity. The alternation of land use type, the increasing temperature, and the changes in precipitation pattern can directly affect soil fauna diversity, while the increase of atmospheric CO₂ concentration and nitrogen deposition can indirectly affect the soil fauna diversity by altering plant community composition, diversity, and nutrient contents. The interactions of different environmental factors can coaffect the soil fauna diversity. To understand the effects of different driving factors on soil fauna diversity under the background of climate change would facilitate us better predicting how the soil fauna diversity and related ecological processes changed in the future.

Degradation and transformation of engineering carbon nanomaterials in the environment: A review.

YUE Fang-ning1,2,3, LUO Shui-ming1,2,3, ZHANG Cheng-dong1,2,3

2013, 24(2):  589-596. 

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With the large amount production and application of engineering carbon nanomaterials, their potential ecological risk has attracted extensive attention. The degradation and transformation of the carbon nanomaterials in the environment directly affect the fates and ecotoxicity of the nanomaterials in the environment, and the research of the degradation and transformation processes of the nanomaterials in the environment is the key link for the determination of the environmental capacity of the nanomaterials and for the evaluation of the nanomaterials life cycle in the environment. This paper briefly introduced the chemical transformation, microbial degradation, and photodegradation of the major engineering carbon nanomaterials (carbon nanotubes and fullerene) in the environment, and summarized the environmental and structural factors affecting the degradation of the nanomaterials and the related intrinsic mechanisms. The shortcomings of the related researches and the directions of the future research were also put forward.

Methods for the assessment of organic compounds biodegradability: A review.

LU Kang, YANG Shang-yuan, LIANG Zhi-wei, WANG Yun-long, LI Xin, YU Hua-dong, WU Wei-xiang

2013, 24(2):  597-606. 

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There are plenty of methods used for the assessment of organic compounds biodegradability, but lack of comprehensive literatures in systematically introducing the assessment methods and guiding the choice of the methods. This paper briefly introduced the indicative parameters in assessing organic compounds biodegradability and the assessment methods of aerobic and anaerobic biodegradation, with the focus on the principles and criteria in the choice of the assessment methods, and analyzed in detail the reasons for the differences in the biodegradation rates of organic compounds when different test methods were adopted. Taking the standards established by the Organization for Economic Co-operation and Development (OECD) as an example, the process of choosing and applying the assessment methods was introduced, the systematic method-choosing route was integrated, and the advantages of the OECD standard methods were pointed out.