Table of Content

18 December 2015, Volume 26 Issue 12

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Dynamic changes in vegetation NDVI from 1982 to 2012 and its responses to climate change and human activities in Xinjiang, China.

DU Jia-qiang1,2, JIAERHENG Ahati3, ZHAO Chen-xi3, FANG Guang-ling1,2, YIN Jun-qi3, XIANG Bao1,2, YUAN Xin-jie3, FANG Shi-feng4

2015, 26(12):  3567-3578. 

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Vegetation plays an important role in regulating the terrestrial carbon balance and the climate system, and also overwhelmingly dominates the provisioning of ecosystem services. Therefore, it has significance to monitor the growth of vegetation. Based on AVHRR GIMMS NDVI and MODIS NDVI datasets, we analyzed the spatiotemporal patterns of change in NDVI and their linkage with climate change and human activity from 1982 to 2012 in the typical arid region, Xinjiang of northwestern China, at pixel and regional scales. At regional scale, although a statistically significant positive trend of growing season NDVI with a rate of 4.09×10^-4·a^-1 was found during 1982-2012, there were two distinct periods with opposite trends in growing season NDVI before and after 1998, respectively. NDVI in growing season first significantly increased with a rate of 10×10^-4·a^-1 from 1982 to 1998, and then decreased with a rate of -3×10^-4·a^-1 from 1998 to 2012. The change in trend of NDVI from increase to decrease mainly occurred in summer, followed by autumn, and the reversal wasn’t observed in spring. At pixel scale, the NDVI in farmland significantly increased; the NDVI changes in the growing season and all seasons showed polarization: Areas with significant change mostly increased in size as the NDVI record grown in length. The rate of increase in size of areas with significantly decreasing NDVI was larger than that with significantly increasing NDVI, which led to the NDVI increase obviously slowing down or stopping at regional scale. The vegetation growth in the study area was regulated by both climate change and human activity. Temperature was the most important driving factor in spring and autumn, whereas precipitation in summer. Extensive use of fertilizers and increased farmland irrigated area promoted the vegetation growth. However, the rapid increase in the proportion of cotton cultivation and use of drip irrigation might reduce spring NDVI in the part of farmlands, and the increase in stocking levels of livestock might lead to a decrease in NDVI in some grasslands.

Seasonal characteristics of δ_D and δ¹⁸O in precipitation and its water vapor sources in the Xiaolangdi Reservoir area of Yellow River, China.

TIAN Chao1,2, MENG Ping1,2, ZHANG Jin-song1,2, SUN Shou-jia1,2, HE Chun-xia1,2, JIA Chang-rong3, LI Jian-zhong3

2015, 26(12):  3579-3587. 

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The seasonal characteristics of δ_D and δ¹⁸O in precipitation and the influence factors were studied in the Xiaolangdi Reservoir area at the eastern monsoon region of China. The precipitation samples and the corresponding meteorological data were collected between April and October from the year 2011 to 2014. The local meteoric water lines (LMWL) of different seasons were established, and the water vapor sources in different seasons were investigated. The results showed that the δ_D and δ¹⁸O in precipitation exhibited an extremely wide range and a distinct seasonal variation, and they were enriched in the spring, and depleted in the fall. The δ_D and δ¹⁸O values showed negative correlations with the amount of precipitation from April to October and the fall, respectively. The δ_D values and the mean air temperature showed a negative correlation from April to October, but showed no correlation in seasonal precipitation. Both the slopes of LMWL and excess deuterium (d values) of precipitation were the smallest in the summer, and the largest in the fall. The results of air mass back trajectories of seasonal precipitation using the HYSPLIT model indicated a dominant effect of southeast and southwest maritime monsoon air masses in the summer and the coinfluence of continental and oceanic monsoons air masses in the spring and fall in the study area．

Spatial variability of surface soil nutrients in the landslide area of Beichuan County, Southwest China, after 5·12 Wenchuan Earthquake.

MAI Ji-shan1, ZHAO Ting-ning2, ZHENG Jiang-kun1, SHI Chang-qing2

2015, 26(12):  3588-3594. 

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Based on grid sampling and laboratory analysis, spatial variability of surface soil nutrients was analyzed with GS⁺ and other statistics methods on the landslide area of Fenghuang Mountain, Leigu Town, Beichuan County. The results showed that except for high variability of available phosphorus, other soil nutrients exhibited moderate variability. The ratios of nugget to sill of the soil available phosphorus and soil organic carbon were 27.9% and 28.8%, respectively, showing moderate spatial correlation, while the ratios of nugget to sill of the total nitrogen (20.0%), total phosphorus (24.3%), total potassium (11.1%), available nitrogen (11.2%), and available potassium (22.7%) suggested strong spatial correlation. The total phosphorus had the maximum range (1232.7 m), followed by available nitrogen (541.27 m), total nitrogen (468.35 m), total potassium (136.0 m), available potassium (128.7 m), available phosphorus (116.6 m), and soil orga-nic  carbon (93.5 m). Soil nutrients had no significant variation with the increase of altitude, but gradually increased from the landslide area, the transition area, to the littleimpacted area. The total and available phosphorus contents of the landslide area decreased by 10.3% and 79.7% compared to that of the littleimpacted area, respectively. The soil nutrient contents in the transition area accounted for 31.1%-87.2% of that of the little-impacted area, with the least and largest reductions in total and available phosphorus contents, respectively. The disturbance by earthquake landslide was the dominant reason for the spatial variability of surface soil nutrients.

Species-abundance distribution patterns along succession series of Phyllostachys glauca forest in a limestone mountain.

SHI Jian-min1,2, FAN Cheng-fang3, LIU Yang4, YANG Qing-pei1,2, FANG Kai1,2, FAN Fang-li3, YANG Guang-yao1,2

2015, 26(12):  3595-3601. 

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To detect the ecological process of the succession series of Phyllostachys glauca forest in a limestone mountain, five niche models, i.e., broken stick model (BSM), niche preemption model (NPM), dominance preemption model (DPM), random assortment model (RAM) and overlapping niche model (ONM) were employed to describe the speciesabundance distribution patterns (SDPs) of 15 samples. x² test and Akaike information criterion (AIC) were used to test the fitting effects of the five models. The results showed that the optimal SDP models for P. glauca forest, bamboobroadleaved mixed forest and broadleaved forest were DPM (x²=35.86, AIC=-69.77), NPM (x²=1.60, AIC=-94.68) and NPM (x²=0.35, AIC=-364.61), respectively. BSM also well fitted the SDP of bamboo-broadleaved mixed forest and broad-leaved forest, while it was unsuitable to describe the SDP of P. glauca forest. The fittings of RAM and ONM in the three forest types were all rejected by the x² test and AIC. With the development of community succession from P. glauca forest to broadleaved forest, the species richness and evenness increased, and the optimal SDP model changed from DPM to NPM. It was inferred that the change of ecological process from habitat filtration to interspecific competition was the main driving force of the forest succession. The results also indicated that the application of multiple SDP models and test methods would be beneficial to select the best model and deeply understand the ecological process of community succession.

Relationships between decomposition rate of leaf litter and initial quality across the alpine timberline ecotone in Western Sichuan, China.

YANG Lin, DENG Chang-chun, CHEN Ya-mei, HE Run-lian, ZHANG Jian, LIU Yang

2015, 26(12):  3602-3610. 

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The relationships between litter decomposition rate and their initial quality of 14 representative plants in the alpine forest ecotone of western Sichuan were investigated in this paper. The decomposition rate k of the  litter ranged from 0.16 to 1.70. Woody leaf litter and moss litter decomposed much slower, and shrubby litter decomposed a little faster. Then, herbaceous litters decomposed fastest among all plant forms. There were significant linear regression relationships between the litter decomposition rate and the N content, lignin content, phenolics content, C/N, C/P and lignin/N. Lignin/N and hemicellulose content could explain 78.4% variation of the litter decomposition rate (k) by path analysis. The lignin/N could explain 69.5% variation of k alone, and the direct path coefficient of lignin/N on k was -0.913. Principal component analysis (PCA) showed that the contribution rate of the first sort axis to k  and the decomposition time (t) reached 99.2%. Significant positive correlations existed between lignin/N, lignin content, C/N, C/P and the first sort axis, and the closest relationship existed between lignin/N and the first sort axis (r=0.923). Lignin/N was the key quality factor affecting plant litter decomposition rate across the alpine timberline ecotone, with the higher the initial lignin/N, the lower the decomposition rate of leaf litter.

Characterization of mid-subtropical evergreen broad-leaved forest gap based on light detection and ranging (LiDAR).

LIU Feng1, TAN Chang1,WANG Hong1, ZHANG Jiang1, WAN Ying2, LONG Jiang-ping1, LIU Rui-xi1

2015, 26(12):  3611-3618. 

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Light Detection and Ranging (LiDAR) is an active remote sensing technology for acquiring three-dimensional structure parameters of vegetation canopy with high accuracy over multiple spatial scales, which is greatly important to the promotion of forest disturbance ecology and the application on gaps. This paper focused on mid-subtropical evergreen broad-leaved forest in Hunan Province, and small footprint LiDAR point data were adopted to identify canopy gaps and measure geomagnetic characteristics of gaps. The optimal grid model resolution and interpolation methods were chosen to generate canopy height model, and the computer graphics processing was adopted to estimate characteristics of gaps which involved gap size, canopy height and gap shape index, then field investigation was utilized to validate the estimation results. The results showed that the gap recognition rate was 94.8%, and the major influencing factors were gap size and gap maker type. Linear correlation was observed between LiDAR estimation and field investigation, and the R² values of gap size and canopy height case were 0.962 and 0.878, respectively. Compared with field investigation, the size of mean estimated gap was 19.9% larger and the mean estimated canopy height was 9.9% less. Gap density was 12.8 gaps·hm^-2 and the area of gaps occupied 13.3% of the forest area. The average gap size, canopy height and gap shape index were 85.06 m², 15.33 m and 1.71, respectively. The study site usually contained small gaps in which the edge effect was not obvious.

Response of leaf anatomical characteristics of Cyclobalanopsis gilva seedlings to drought stress.

WU Li-jun, LI Zhi-hui, YANG Mo-hua, WANG Pei-lan

2015, 26(12):  3619-3626. 

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In this study, the leaf anatomical characteristics and transpiration rate of one-year-old seedlings from three study areas including Qingyuan of Zhejiang Province, Dongkou and Jingzhou of Hunan Province were investigated using a pot planting experiment in which relative soil water content was kept as 75%-80% (control), 55%-60% (mild drought stress), 45%-50% (moderate drought stress), 30%-35% (severe drought stress), respectively. The results showed that drought stress significantly reduced the total thickness of the seedling leaves, the thickness of their upper and lower epidermis and the thickness of palisade tissue. The ratio of  the palisade tissue to spongy tissue, stomatal length and width also decreased significantly, while the stomatal density increased significantly as the drought stress became more intense. The treatments of drought stress had no significant effect on the thickness of the main veins of the leaves although their xylem thickness varied depending on the seedlings from the different study sites. The change of leaf structure caused the change of  physiological function. As drought stress was intensified, the transpiration rate of C. gilva seedlings decreased significantly. The ratio of the palisade tissue to spongy tissue, the thickness of the lower epidermis and stomatal density of the seedlings from Dongkou of Hunan Province were significantly greater, while the transpiration rate was significantly lower than those from other two study sites for all the drought stress treatments, implying that the C. gilva seedlings from Dongkou of Hunan Province had a stronger drought-resistance ability.

Relationships among leaf traits and their expression in different vegetation zones in Yanhe River basin, Northwest China.

GUO Ru1,2, WEN Zhong-ming1,3, WANG Hong-xia3, QI De-hui4

2015, 26(12):  3627-3633. 

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This article selected zonal plant communities as the research objects in different vegetation zones in Yanhe River basin. We measured six leaf traits of the dominant species and main accompanying species in each community, and then analyzed the relationships and their changes along with environmental gradients between these traits in order to understand the plant adaptation strategies to the environment changes. The results showed that the specific leaf area was significantly nega-tively correlated to leaf tissue density, area-based leaf nitrogen and phosphorus concentrations, and significantly positively correlated to massbased leaf phosphorus concentration. Both the scaling relationships among these traits and plant life strategies were different among the three vegetation zones, the scaling-dependent relationship between leaf tissue density and specific leaf area was stronger in steppe and forest-steppe zones than in forest zone, but the correlations among areabased leaf nitrogen/phosphorus concentrations and specific leaf area and leaf tissue density were more significant in forest zone than in steppe zone. In the arid grassland and forest-steppe zone, plants give priority to defensive and stress resistance strategies, and in relatively moist nutrient-rich forest zone, plants give priority to fast growth and resource optimization allocation strategies.

Effect of afforestation modes on soil microbial community and nitrogen functional genes in Hippophae rhamnoides plantation.

YANG Dan1,2, YU Xuan1,2, LIU Xu3, LIU Jin-liang1,2, ZHANG Shun-xiang1,2, YU Ze-qun1,2

2015, 26(12):  3634-3640. 

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The study aimed to assess the effect of different afforestation modes on microbial composition and nitrogen functional genes in soil. Soil samples from a pure Hippophae rhamnoides stand (SS) and three mixed stands, namely, H. rhamnoides and Pinus tabuliformis (SY), H. rhamnoides and Platycladus orientalis (SB), H. rhamnoides and Robinia pseucdoacacia (SC) were selected. The results showed that the total PLFA (TPLFA), bacterial PLFA, gram positive bacterial PLFA (G⁺PLFA) were significantly higher in soil samples from other three stands than those of the pure one. However, no significant difference was found for fungal PLFA among them. The abundance of nifH, amoA, nirK and narG genes were higher in SY and SC than in SS. The TPLFA, G⁺PLFA, gram negative bacterial PLFA (G^-PLFA), and all of the detected gene abundance were significantly and positively correlated with soil pH, total organic carbon, total nitrogen, ammonium nitrogen and available potassium. Afforestation modes affected indirectly soil microbial composition and functional genes through soil properties. Mixing P. tabuliformis or P. orientalis with H. rhamnoides might be suitable afforestation modes, which might improve soil quality.

 

Adaptive adjustment of rhizome and root system on morphology, biomass and nutrient in Phyllostachys rivalis under long-term waterlogged condition.

LIU Yu-fang, CHEN Shuang-lin, LI Ying-chun, GUO Zi-wu, YANG Qing-ping

2015, 26(12):  3641-3648. 

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The research was to approach the growth strategy of rhizome and roots based on the morphology, biomass and nutrient in Phyllostachys rivalis under long-term waterlogged conditions, and provided a theoretical basis for its application for vegetation restoration in wetland and water-level fluctuation belts. The morphological characteristics, physiological and biochemical indexes of annual bamboo rhizome and roots were investigated with an experiment using individually potted P. rivalis which was treated by artificial waterlogging for 3, 6, and 12 months. Accordingly the morphological characteristics, biomass allocation, nutrient absorption and balance in rhizome and roots of P. rivalis were analyzed. The results showed that there was no obvious impact of long-term water-logging on the length and diameter of rhizomes, diameter of roots in P. rivalis. The morphological characteristics of rhizome had been less affected generally under water-logging for 3 months. And less rhizomes were submerged, while the growth of roots was inhibited to some extent. Furthermore, with water-logging time extended, submerged roots and rhizomes grew abundantly, and the roots and rhizomes in soil were promoted. Moreover for ratios of rhizome biomass in soil and water, there were no obvious

variations, the same for the root biomass in soil to total biomass. The ratio of root biomass in water to total biomass and the ratio of root biomass in water to root biomass in soil both increased  significantly. The results indicated that P. rivalis could adapt to waterlogged conditions gradually through growth regulation and reasonable biomass distribution. However, the activity of rhizome roots in soil decreased and the nutrient absorption was inhibited by long-term water-logging, although it had no effect on stoichiometric ratios of root nutrient in soil. The activity of rhizome root in water increased and the stoichiometric ratios adjusted adaptively to waterlogged conditions, the ratio of N/P increased, while N/K and P/K decreased, which implied that roots in water absorbed oxygen and nutrients could help P. rivalis adapt to long-term waterlogged environment effectively.

Soil microbial functional diversity of different altitude Pinus koraiensis forests.

HAN Dong-xue, WANG Ning, WANG Nan-nan, SUN Xue, FENG Fu-juan

2015, 26(12):  3649-3656. 

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In order to comprehensively understand the soil microbial carbon utilization characteristics of Pinus koraiensis forests, we took the topsoil ( 0-5 cm and 5-10 cm ) along the 700-1100 m altitude in Changbai Mountains and analyzed the vertical distributed characteristics and variation of microbial functional diversity along the elevation gradient by Biolog microplate method. The results showed that there were significant differences in functional diversity of microbial communities at different elevations. AWCD increased with the extension of incubation time and AWCD at the same soil depth gradually decreased along with increasing altitude; Shannon, Simpson and McIntosh diversity index also showed the same trend with AWCD and three different diversity indices were significantly different along the elevation gradient; Species diversity and functional diversity showed the same variation. The utilization intensities of six categories carbon sources had differences while amino acids were constantly the most dominant carbon source. Principal component analysis (PCA) identified that soil microbial carbon utilization at different altitudes had obvious spatial differentiation, as reflected in the use of carbohydrates, amino acids and carboxylic acids. In addition, the cluster of the microbial diversity indexes and AWCD values of different altitudes showed that the composition of vegetation had a significant impact on soil microbial composition and functional activity.

Evaluation of three-dimensional flammability of eight forest fuels based on thermogravime-tric analysis in Nanchang region, China.

JIN Sen, WANG Shun-rao

2015, 26(12):  3657-3662. 

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Pyrolysis characteristics of litter of eight tree species in Nanchang were studied based on thermogarvimetric analysis results. Three components of flammability of the eight species, i.e. ignitibility, combustibility and sustainability, were evaluated by pyrolysis parameters obtained from the analysis. Results showed that the eight species could be grouped into two categories: the first one included Camellia oleifera and Cinnamomum camphora, which were highly ignitable but low combustible and sustainable, the other included Cedrus deodara, Liriodendron chinensis, Phyllostachys heterocycla, Cinnamomum burmanni, Osmanthus fragrans and Ginkgo biloba, which were low igni-table but highly combustible and sustainable. This further indicated that rankings by each flammability component were usually not identical, showing the complexity of flammability and necessity of multi-dimensional flammability evaluation. Three-dimensional flammability evaluation could reflect different profiles of the feature and aid better understanding and explanation of fire behavior.

Genetic diversity of rhizobia isolated from common legumes in the Karst area, Northwest Guangxi.

LIU Lu1,2,3, HE Xun-yang1,2, XIE Qiang4, WANG Ke-lin1,2

2015, 26(12):  3663-3669. 

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Legumes, with a strong resistance to the adverse environmental conditions, are pioneer plants in degraded habitats, and play an important role in ecosystem restoration. In this study, the nodulation characteristics of 24 legumes were surveyed in the Karst area of Northwest Guangxi. A total of 39 nodule samples were collected from 15 legumes, the DNA was extracted and the 16S rDNA and nifH gene were amplified. A phylogenetic tree was then constructed to analyze the genetic diversity of rhizobia. The results showed that 15 legumes were nodulated, of which 14 belonged to the Papilionoideae, one to the Mimosaceae, and none to the Caesalpinoideae. No nodules were found on some legumes that were reported as nodulated, which might result from soil water stress in Karst. BLAST result and phylogenetic analyse indicated that most of the legumes were associated with rhizobia that belonged to the genus Bradyrhizobium, with the exception of two samples from Callerya nitida that were associated with the genus Mesorhizobium. In the phylogenetic tree, the sequences obtained from the same plot or the sequences from the same host species clustered together in most cases. This finding suggested that host selection and the ecological environment are the major factors that influence the genotype of rhizobia.

Temporal and spatial variation of the optimal sowing dates of summer maize based on both statistical and processes models in Henan Province, China.

TAN Mei-xiu1, WANG Jing1, YU Wei-dong2, HE Di1, WANG Na1, DAI Tong1, SUN Yan3, TANG Jian-zhao1, CHANG Qing1

2015, 26(12):  3670-3678. 

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Sowing date is one of the vital factors for determining crop yield. In this study, temporal and spatial variation of optimal sowing date of summer maize was analyzed by statistical model and the APSIM-Maize model in Henan Province, China. The results showed that average summer maize optimal sowing dates ranged from May 30 to June 13 across Henan Province with earlier sowing before June 8 in the southern part and later sowing from June 4 to June 13 in the northern part. The optimal sowing date in mountain area of western Henan Province should be around May 30. Latematuring variety Nongda 108 should be planted at least two days earlier than middle-maturing variety Danyu 13. Under climate warming background, maize sowing should be postponed for at least 3 days if maize harvesting date could be delayed for a week. It was proposed that sowing should be delayed for about a week for a yearly less precipitation pattern while advanced for about a week for a yearly more precipitation pattern compared to the normal one. Across Henan Province, the optimal sowing dates of summer maize showed no significant change trend in 1971-2010, while the potential sowing period had been extended for some regions, such as south from Zhumadian, Yichuan, Neixiang and Nanyang in the middle part of Henan, Linzhou in the northern Henan and Sanmenxia in the western Henan, as a result from advanced maturity of winter wheat due to increasing temperature and winter wheat cultivar change. Optimal sowing dates at 76.7% of the study stations showed no significant difference between the two methods. It was recommended that the northern Henan should sow maize immediately after any rainfall and replant afterward, while the southern Henan should not sow maize until that there were valid precipitation (3.9 mm and 8.3 mm for upper south and south parts, respectively) during sowing period, both required enough precipitation during key water requirement period and optimal temperature during grain-filling period.

Response of water coupling with N supply on maize nitrogen uptake, water and N use efficiency, and yield in drip irrigation condition.

GUO Bing-yu, GAO Hui, TANG Cheng, LIU Tao, CHU Gui-xin

2015, 26(12):  3679-3686. 

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Water and nitrogen are two major limiting factors for upland crop growth and development in arid region. Optimizing regulation irrigation schedule, rates and coupling with N fertigation is an effective way for realizing crop production improvement as well as water and nutrient use efficiency enhancement. In the present study, a field trial was carried out to study the influence of water (4500, 6750, 9000 m³·hm^-2) coupling with N (0, 225, 330, 435, 540 kg·hm^-2) supply on maize dry matter accumulation, N uptake, yield and nitrogen fertilizer use efficiency in drip irrigated high cultivated density (≥105000 plant·hm^-2) condition. There was an obvious tendency that the amounts of corn dry matter accumulated and plant N absorbed increased with levels of water and N supply, however, those decreased gradually when the N applied rate beyond 435 kg·hm^-2 and irrigation level above 9000 m³·hm^-2. For instance, the effect of irrigation level on corn dry matter accumulation order exhibited W₆₇₅₀ (36359 kg·hm^-2)>W₉₀₀₀(35077 kg·hm^-2)> W₄₅₀₀ (33451 kg·hm^-2), the sequence of amount of N absorbed showed N₄₃₅(462.0 kg·hm^-2) > N₅₄₀ (459.4 kg·hm^-2)> N₃₃₀ (423.4 kg·hm^-2)> N₂₂₅(348.1 kg·hm^-2), the amount of N absorbed in N₄₃₅ treatment increased by 9.1% and 32.7%, respectively, in contrast with treatments of N₃₃₀ and N₂₂₀, whereas, the amount of N absorbed in N₅₄₀ decreased by 0.6% than that in N₄₃₅ treatment. The highest N absorption rate increased with N application rate increasing within N supply range of 0-435 kg·hm^-2, it reached peak value of 6.57 kg·hm^-2·d^-1 at N application rate of 435 kg·hm^-2, then had decline trend with increasing N rate. Both irrigation and N supply exerted a significant role on maize yield as well as yield component of kernel number per spike and kernel mass per spike. An obvious positive interaction was obtained between water and nitrogen; moreover, the effect of N on yield was substantially higher than that of irrigation. N fertilizer use efficiency increased with  increasing N level within N supply range of 0-435 kg·hm^-2, and then dropped markedly when N rate above 435 kg·hm-2. It was found that the water productivity of irrigation (WP_#em/em#) increased with  increasing N level, while, that decreased with  increasing irrigation rate. At the suitable irrigation range of 4500-6750 m³·hm^-2, the WP_i of 2.57-3.80 kg·m^-3 could be achieved. The maximum corn yield of 18072 kg·hm^-2 was reached at N rate of 567.0 kg·hm^-2. The best N rate of 427.9-467.7 kg N·hm^-2 obtained the optimum yield of 17109-17138 kg·hm^-2, with the nitrogen partial factor productivity of 122 kg N·hm^-2 and nitrogen use efficiency of 45.0% reached. In sum, optimizing water coupling with N supply was the effective strategy for realizing corn yield improvement as well as resources of water and N use efficiency in drip irrigation condition in arid region.

Response of photosynthesis and growth to weak light regime in different Adzuki bean (Vigna angularis) varieties.

ZOU Chang-ming1, WANG Yun-qing2, CAO Wei-dong3, LIU Ying2, ZHANG Xiao-hong1, TANG Shan2

2015, 26(12):  3687-3692. 

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In order to determine the adaptability of Adzuki beans as the interplanting crops in fruit yards, field and pot experimental treatments with full natural light and weak light (48% of full natural light) regimes were conducted to test the shade tolerance and physiological responses of three Adzuki bean varieties including Funan green Vigna angularis (FGVA), earlymature black V. angularis (EBVA) and latemature black V. angularis (LBVA). The leaf photosynthetic characteristic parameters, photosynthetic pigment contents and the activity of RuBPCase  were measured during the first bloom stage. The response of growth to weak light was likewise studied. The results showed that the photosynthetic characteristic parameters, i.e., the maximum net photosynthetic rate, light saturation point and light compensation point of the three Adzuki bean varieties under the weak light stress changed differently. The weak light stress induced the reduction of net photosynthetic rate, water use efficiency and RuBPCase activity of the three Adzuki bean varieties significantly. The contents of chlorophyll a and chlorophyll b in leaves of FGVA increased significantly, while Chl a/b and carotenoid content in the leaves decreased significantly after shading. But the other two varieties did not change obviously in photosynthetic pigments content after shading. The weak light changed the growth of the three Adzuki bean varieties, such as decreasing dry matter yield and dry matter accumulation efficiency, reducing root nodule and root-shoot ratio, debasing leaves quantity and leaf area index. The first bloom stage and maturing stage of FGVA advanced, while that of EBVA delayed under weak light. However, flowers were not strong enough to seed for LBVA under the weak light. In conclusion, according to the photosynthetic characteristics changes after shading, as well as the growth status, we concluded that the shade tolerance of the three Adzuki beans was ranked as FGVA>EBVA>LBVA.

Effects of supplemental irrigation based on soil moisture on photosynthetic characteristics and enzyme activity of flag leaf in wheat.

HE Jian-ning1, SHI Yu1, ZHAO Jun-ye2, ZHANG Yong-li1， YU Zhen-wen1

2015, 26(12):  3693-3699. 

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A field experiment was conducted to study the effects of supplemental irrigation based on soil moisture on the photosynthesis characteristics and enzyme activity of flag leaf using the wheat cultivar Jimai 20. Three irrigation treatments were designed with target soil moisture of 65% (W₆₅), 70% (W₇₀) and 75% (W₇₅) both at jointing and anthesis stages. Zeroirrigation (CK) was used as the control. The results showed that the net photosynthetic rate (P_n) of flag leaf in treatment W₇₀ was dramatically higher than in other treatments from 14 to 21 days after anthesis, as well as sucrose content and sucrose phosphate synthase (SPS) activity. The dry matter mass per area of W₇₀ was higher than that of W₆₅ and CK, and was not significantly different from that of W₇₅. The single stem mass of W₇₀ was higher than that of the other treatments. The activities of superoxide dismutase (SOD) and catalase (CAT) and the soluble protein concentration in flag leaf of W₇₀ were significantly higher than in other treatments from 14 to 28 days after anthesis. The malondialdehyde (MDA) content of W₇₀ was lower than that of W₆₅ and CK, and was not significantly different from that of W₇₅ from 14 to 21 days after anthesis. Grain yields of W₇₀ were 8941.4 and 9125.4 kg·hm^-2 in the 2012-2013 and 2013-2014 wheat growing seasons, showing no significant difference with those of W₇₅, but obviously higher than those of W₆₅ and CK. And the water use efficiency (WUE) of W₇₀ was the highest. Considering grain yield and WUE, maintaining the relative soil water content at 70% by supplemental irrigation both at jointing and anthesis stages was the best treatment.

Effects of single-seed sowing on canopy microenvironment, photosynthetic characteristics and pod yield of peanut (Arachis hypogaca).

LIANG Xiao-yan1,2,3, GUO Feng2,3, ZHANG Jia-lei2,3, MENG Jing-jing2,3, LI Lin1, WAN Shu-bo3,4, LI Xin-guo2,3

2015, 26(12):  3700-3706. 

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The largeseed peanut cultivar of Huayu 22 was used to study the differences of canopy microenvironment, photosynthetic characteristics, and pod yield at three singleseed sowing densities, i.e., 225000 (S₁), 195000 (S₂) and 165000 (S₃) holes per hectare, in field experiments. The results showed that the canopy light transmittance, canopy air temperature and canopy CO₂ concentration all increased at these three single-seed sowing densities compared with those of double-seed sowing pattern (150000 holes per hectare), while the canopy humidity decreased. It seemed that singleseed sowing was helpful to improve microenvironment and the growth of peanut, especially at late growth stage. Meanwhile, the photosynthetic pigment contents and the net photosynthetic rate of peanut under singleseed sowing, especially in S₂ and S₃, were remarkably higher than those under traditional doubleseed sowing. S₂ had the optimum population size with an equal distribution of individuals, which reduced the contradiction between individuals and population, optimized the canopy microenvironment, enhanced the photosynthetic characteristics, and increased the synthesis and accumulation of photosynthetic products to maximize the yield production of peanut.

Natural inducing factors of grape bud dormancy and their regulation on respiratory metabolism during dormancy induction.

WANG Hai-bo1,2, WANG Xiao-di1,2, SHI Xiang-bin1,2, WANG Bao-liang1,2, ZHENG Xiao-cui1,2, LIU Feng-zhi1,2

2015, 26(12):  3707-3714. 

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High chilling requirement grape (Vitis vinifera-V. labrusca cv. Summer Black) was used to evaluate its dormancy under short sunlight day (SD), long sunlight day (LD) and natural condition (CK). The results indicated that grape bud dormancy could be induced by natural low temperature and short sunlight alone or together. Short sunlight was the main contributor to the dormancy of grape bud, followed by natural low temperature. SD had more effect on dormancy induction under the same temperature when compared with LD. The grape dormancy induction stopped when the total respiratory rate reached the highest level. During the dormancy induction period, the proportion of pentose phosphate pathway (PPP) operation activity or capacity to total respiratory rate increased from 16.0% to 20.1% or 22.3% to 26.0%, respectively; similarly, the proportion of operation activity or capacity of alternate pathway to total respiratory rate rapidly increased, i.e., from 19.4% to 27.3% or 38.2% to 46.8%. Both low temperature and short sunlight could induce change of respiratory pathway on electron transport chain level.

Interactive impact of water and nitrogen on yield, quality of watermelon and use of water and nitrogen in gravel-mulched field.

DU Shao-ping1, MA Zhong-ming2, XUE Liang3

2015, 26(12):  3715-3722. 

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In order to develop the optimal coupling model of water and nitrogen of watermelon under limited irrigation in gravel-mulched field, a field experiment with split-plot design was conducted to study the effects of supplementary irrigation volume, nitrogen fertilization, and their interactions on the growth, yield, quality and water and nitrogen use efficiency of watermelon with 4 supplementary irrigation levels (W: 0, 35, 70, and 105 m³·hm^-2 ) in main plots and 3 nitrogen fertilization levels (N: 0, 120, and 200 kg N·hm^-2) in subplots. The results showed that the photosynthetic rate, yield, and water and nitrogen use efficiency of watermelon increased with the increasing supplementary irrigation, but the nitrogen partial productivity and nitrogen use efficiency decreased with increasing nitrogen fertilization level. The photosynthetic rate and quality indicators increased with increasing nitrogen fertilization level as the nitrogen rate changed from 0 to 120 kg N·hm^-2, but no further significant increase as the nitrogen rate exceeded 120 kg·hm^-2. The interactive effects between water and nitrogen was significant for yield and water and nitrogen use efficiency of watermelon, supplementary irrigation volume was a key factor for the increase yield compared with the nitrogen fertilizer, and the yield reached the highest for the W₇₀N₂₀₀ and W₁₀₅ N₁₂₀ treatments, for which the yield increased by 42.4% and 40.4% compared to CK. Water use efficiency (WUE) was improved by supplementary irrigation and nitrogen rate, the WUE of all nitrogen fertilizer treatments were more than 26 kg·m^-3 under supplemental irrigation levels 70 m³·hm^-2 and 105 m³·hm^-2. The nitrogen partial productivity and nitrogen use efficiency reached the highest in the treatment of W₁₀₅N₁₂₀. It was considered that under the experimental condition, 105 m³·hm^-2 of supplementary irrigation plus 120 kg·hm^-2 of nitrogen fertilization was the optimal combination of obtaining the high yield and high efficiency.

Effects of different tillage methods on tea garden soil physical characteristics and tea yield.

SU You-jian1,2, WANG Ye-jun1, ZHANG Yong-li1, DING Yong1, LUO Yi1, SONG Li1, LIAO Wan-you1

2015, 26(12):  3723-3729. 

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The effects of three tillage methods, i.e., no tillage, rotary tillage, deep tillage, on tea garden soil compaction, soil moisture, soil bulk density, yield component factors and tea yield were studied through field experiments in Langxi Country of Anhui Province. The results indicated that the effects of three tillage methods on soil bulk density and soil compaction were in order of deep tillage>rotary tillage>no tillage. Deep tillage and rotary tillage could effectively break the argillic horizon layer and decrease the soil compaction. Compared with no tillage, soil compaction and soil bulk density (0-30 cm) under deep tillage decreased 16.4% and 13.4%-27.5%, respectively. Deep tillage could significantly increase soil water storage space and enhance the water holding capacity of the soil. Compared with no tillage, the soil moisture of 15-30 cm soil layer was increased by 7.7% under deep tillage. The different tillage methods had little effect on soil porosity. Rotary tillage and deep tillage could increase soil specific surface area and the ratios of soil gas and soil liquid. The diurnal changes of photosynthetic rate and transpiration rate of tea both exhibited doublepeak pattern. There was a significant midday depression caused principally by stomatal factors. Under deep tillage, the tea leaf transpiration rate decreased, shoot density increased, 100bud dry mass and water use efficiency increased significantly, and the tea yield increased by 17.6% and 6.8% compared with no tillage and rotary tillage, respectively. Deep tillage was the most appropriate tillage practice in tea garden of east Anhui Province.

Effects of canopy shapes of grape on canopy microenvironment, leaf and fruit quality in greenhouse.

SHI Xiang-bin1,2, LIU Feng-zhi1,2, CHENG Cun-gang1,2, WANG Xiao-di1,2, WANG Bao-liang1,2, ZHENG Xiao-cui1,2, WANG Hai-bo1,2

2015, 26(12):  3730-3736. 

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The effects of three canopy shapes, i.e., vertical canopy, V shaped canopy and horizontal canopy, on canopy microenvironment, quality of leaves and fruits were studied in the 3-year-old grape ‘Jingmi’ grafted on ‘Beta’ in greenhouse. The results showed that gap fraction and openness of vertical canopy were significantly higher than that of Vshaped canopy and horizontal canopy, and leaf area index, light interception rate and canopy temperature difference between day and night were significantly lower than those of V shaped canopy and horizontal canopy. There was no significant difference between the latter two treatments. The palisade thickness of V-shaped canopy was significantly greater than that of vertical canopy, and horizontal canopy was in the middle. The chlorophyll and carotenoid contents of V shaped canopy were significantly higher than those of vertical canopy and horizontal canopy, and those in the latter two treatments had no significant difference. The fruit quality of V shaped canopy was the best, and that of horizontal canopy was the worst. The results of GC-MS analysis showed that 29 types of volatile aroma compounds were detected in V-shaped canopy, but just 17 and 16 in vertical canopy and horizontal canopy, respectively. In V shaped canopy, the characteristic aroma in grape ‘Jingmi’ was higher, except ethanol, trans-2-hexene-1-alcohol, 2-octyl ketone and formic acid ester. The linalool content in vertical canopy and V shaped canopy was higher than that in horizontal canopy. The nerol content in Vshaped canopy was higher than that in vertical canopy and horizontal canopy, and the leaf alcohol content in Vshaped canopy and horizontal canopy was higher than that in vertical canopy. The citronellol was detected only in Vshaped canopy. In greenhouse, the fruit aroma of Vshaped canopy grape was stronger, and well reflected the variety characteristics.

Isolation and identification of root endophytic and rhizosphere bacteria of rice landraces in Yuanyang Terrace, China.

ZHAO Juan, LIU Tao, PAN Lei, JIN Bai-hui, ZHAO Dan, CHEN Chen, ZHU You-yong, HE Xia-hong

2015, 26(12):  3737-3745. 

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To reveal root endophytic and rhizosphere bacteria constitution of rice landraces in Yuanyang Terrace,  isolation was carried out by tissue isolation method and soil dilution plate method for two landraces of Yuelianggu and Hongjiaolaojing. A total of 399 bacterial strains isolated were identified by morphological characteristics, physiological and biochemical identification. The results showed that there were 8 genera isolated from the root of Yuelianggu and 5 genera from its rhizosphere soil, and 5 genera were same. For Hongjiaolaojing, there were 10 genera isolated from its root and 7 genera from its rhizosphere soil, and 6 genera were same. By molecular biology identification, a total of 11 species and 5 genera were isolated from the root of Yuelianggu, 8 species and 4 genera from its rhizosphere soil, and 5 species and 4 genera were same. As for Hongjiaolaojing, there were 9 species and 5 genera isolated from its root, and 10 species and 3 genera from its rhizosphere soil, and 4 species and 2 genera were same. The results of physiological and biochemical characteristics identification method and molecular identification method were basically same at the genus level, while most of the strains could be identified to species by molecular identification. There were certain species homology and specificity in the root endophytic and rhizosphere bacteria of Yuanyang rice landraces.

Response of reactive oxygen metabolism in melon chloroplasts to shortterm salinityalkalinity stress regulated by exogenous γ-aminobutyric acid.

XIANG Li-xia1,2,3， HU Li-pan1,2,3, HU Xiao-hui1,2,3, PAN Xiong-bo1,2,3, REN Wen-qi1,2,3

2015, 26(12):  3746-3752. 

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The regulatory effect of exogenous γaminobutyric acid (GABA) on metabolism of reactive oxygen species (ROS) in melon chloroplasts under shortterm salinityalkalinity stress were investigated in melon variety ‘Jinhui No.1’, which was cultured with deep flow hydroponics. The result showed that under salinityalkalinity stress, the photosynthetic pigment content, MDA content, superoxide anion (O^-_·2) production rate and hydrogen peroxide (H₂O₂) content in chloroplast increased significantly, the contents of antioxidants ascorbic acid (AsA) and glutathione (GSH) increased, and the activities of H⁺-ATPase and H⁺-PPiase were inhibited obviously. With exogenous GABA application, the accumulations of O^-_·2, MDA and H₂O₂ induced by salinityalkalinity stress were inhibited. Exogenous GABA alleviated the increase of photosynthetic pigment content, improved the activity of SOD, enzymes of AsAGSH cycle, total AsA and total GSH while decreased the AsA/DHA ratio and GSH/GSSH ratio. Foliar GABA could enhance the H⁺-ATPase and H⁺-PPiase activities. Our results suggested that the exogenous GABA could accelerate the ROS metabolism in chloroplast, promote the recycle of AsA-GSH, and maintain the permeability of cell membrane to improve the ability of melon chloroplast against salinityalkalinity stress.

Influences of different kinds of water retentive agents on water use efficiency and root morphology of winter wheat.

LI Zhong-yang1,2,3, LYU Mou-chao1, FAN Xiang-yang1,2,3, DU Zhen-jie1,2,3, HU Chao1,2,3

2015, 26(12):  3753-3758. 

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The effects of 5 different kinds of water retentive agents at 2 application levels on yield, water use efficiency and root morphology of winter wheat were studied through field experiments. The results showed that there were significant differences in tiller number, flag leaf area, yield and water use efficiency (WUE) among the water retentive agent treatments of different varieties and application levels. Compared with the control, the yield increased by 1.3%-7.9%, and the WUE increased from 17.1 kg·hm^-2·mm^-1 to 18.0-20.7 kg·hm^-2·mm^-1 under these 5 different kinds of water retentive agent treatments. The influences of water retentive agents on average root diameter, total root length and total root surface of winter wheat all reached a significant level. The total root length increased by 3.7%-19.1% and 6.3%-27.3%, and the total root surface area increased by 6.5%-21.7% and 2.9%-18.5% in the 0-20 and 20-40 cm soil layers, respectively. The root morphology characteristics were significantly positively correlated with both yield and WUE of winter wheat. The compound water retentive agent of acrylamide/inorganic mineral had the most significant influence on the increase of WUE and the promotion of root growth of winter wheat.

 

Suppression of three soil-borne diseases of cucumber by a rhizosphere fungal strain.

LYU Heng1,2, NIU Yong-chun2, DENG Hui2, LIN Xiao-min1, JIN Chun-li2

2015, 26(12):  3759-3765. 

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To understand the effect of rhizosphere fungi on soilborne diseases of cucumber, 16 fungal strains from rhizosphere soil were investigated for the antagonistic activity to three soilborne pathogenic fungi with dual culture method and for suppression of cucumber diseases caused by the pathogens in pot experiments. Four strains showed antagonism to one or more pathogenic fungi tested. The strain JCL143, identified as Aspergillus terreus, showed strong antagonistic activity to the three pathogenic fungi Fusarium oxysporum f. sp. cucumerinum, Rhizoctonia solani and Sclerotinia sclerotiorum. In greenhouse pot experiments, inoculation with strain JCL143 provided 74% or more of relative control effect to all the three diseases of cucumber seedling caused by the above three pathogenic fungi, and provided 85% or more of relative control effect to Rhizoctonia root rot and Sclerotinia root and stem rot in pot experiment with nonsterilized substrate. In pot experiment with natural soil as substrate, inoculation with strain JCL143 provided average 84.1% of relative control effect to Fusarium wilt of cucumber at vine elongation stage. The fermentation broth of strain JCL143 showed inhibitory effect in different degrees on the colonial growth of the three pathogenic fungi tested, and reached 63.3% of inhibitory rate of colonial growth to S. sclerotiorum. The inhibitory activity of the fermentation broth decreased with increasing treatment temperature, was liable to decrease to alkaline pH than acid pH, and stable to protease treatment. The results indicated that A. terreus is an important factor in suppression of plant soil-borne diseases, and strain JCL143 with stable disease suppression is potential in biocontrol application.

Difference of rhizosphere microbe quantity and functional diversity among three flue-cured tobacco cultivars with different resistance.

CAI Qiuhua1, ZUO Jinxiang1, LI Zhonghuan2, ZHANG Yaping3, ZHAO Yonggang1, DENG Qiao2, OUYANG Jin2, HUANG Junjie1, YU Lu1, ZOU Jian1, ZHAO Zhengxiong1

2015, 26(12):  3766-3772. 

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Field experiments were conducted in Shilin and Xundian respectively to study the difference of rhizosphere microbe quantity and functional diversity with plate culture method and Biolog technique among Hongda (high susceptibility, S), Yun87 (middle resistance, MR) and K326 (high resistance, R), three flue-cured tobacco cultivars with different resistance to bacterial wilt and black shank. The results indicated that the amounts of bacteria, actinomycetes and the total number of microbes in tobacco plants’ rhizosphere were positively correlated with the cultivar’s resistance, while it was opposite for the fungi. The consistent tendency was obtained not only at 35 d, 55 d and 75 d after transplanting, but also at two experimental sites. Cultivar and experimental conditions  greatly affected the utilization of six types of carbon source by rhizospheric microbes, as well as the AWCD value. In Xundian site, rhizospheric microbes’ utilization of carbohydrates, amino acids, carboxylic acids, polymers, amines and the AWCD value were all higher at 55 d and 75 d after transplanting for the resistant cultivar than the susceptible one, but it was opposite at 75 d after transplanting for the phenolic acids. In Shilin, significant differences existed among the three cultivars at 35 d, 55 d and 75 d after transplanting for the indices mentioned above, although they were not consistent with cultivars’ resistance. Principal component (PC) analysis even showed that utilization of carbon sources by rhizosphere microorganisms differed significantly among the three cultivars at the two sites, and it was better reflected by PC1 and PC2 at 55 d and 75 d after transplanting, respectively. In conclusion, rhizosphere microbial community structure and functional diversity were greatly affected not only by the cultivars’ difference in resistance, but also by experimental conditions.

Metabolic profiling of the shortterm responses of Nicotiana tabacum leaves cultivated under different LED lights.

MENG Lin, LIANG Meng, WANG Cheng-dong, LIU Xiao-bing, SONG Wen-jing, SHI Jiao, XU Yi-min

2015, 26(12):  3773-3780. 

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The physiologically mature tobacco (Nicotiana tabacum) leaves was exposed to different light-emitting diode (LED) lights, i.e.  ultraviolet A (UV-A), blue, green, yellow, red, white, to investigate their short-term response. Results showed that: 1) 68 GC/MSstable metabolites were detected by non-targeted method. In the PLS-DA score plot, tobacco leaf samples showed clear grouping in each light cultivating condition. 61 metabolites were identified in mass spectra library. Besides, 45 metabolites, mainly including organic acids, carbohydrates, TCA cycle intermediate metabolites and amino acids, showed significant differences among the six light treatments. Hierarchical cluster analysis (HCA) and heat map showed that differential metabolites could be divided into five groups, and there were significant differences among the six treatments, especially under red and blue lights. Except for the metabolites of group B, almost all other metabolites contents in tobacco leaves treated with red light were higher than those under blue light. 2) Contents of solanesol, 3 alkaloids and 5 polyphenols were measured with targeted method. 4 alkaloids, including nicotine detected by nontargeted method, showed similar variation among all treatments, of which red and yellow light increased alkaloid accumulation significantly. The kaempferol 3-O-rutinoside and rutin showed similar variation among the six treatments, with the lowest content under blue light and the highest content under yellow light, nevertheless, 3 other polyphenols were differently affected by light qualities. The aolanesol accumulation was significantly repressed by yellow light, but showed highest content under blue light. In conclusion, light quality affected many metabolic pathways significantly in tobacco, such as fatty acid metabolism, glycometabolism, alkaloid metabolism, amino acid metabolism, tricarboxylic acid cycle and shikimate pathway.

Effects of biochar on the micro-ecology of tobacco-planting soil and physiology of flue-cured tobacco.

CHEN Yi1, CHEN Wei1, LIN Ye-chun1, CHENG Jian-zhong2, PAN Wen-jie1

2015, 26(12):  3781-3787. 

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Biochar is one of the research hotspots in the field of the agroforestry waste utilization. A field experiment was carried out to investigate the effects of different amounts of tobacco stem biochar (0, 1, 10, 50 t·hm^-2) on soil micro-ecology and physiological properties of flue-cured tobacco. The results showed that soil water content (SWC) increased at all tobacco growth stages as the amounts of biochar applications increased. There were significant differences of SWC between the treatment of 50 t·hm^-2 and other treatments at the period of tobacco vigorous growth. As the application of biochar increased, the total soil porosity and capillary porosity increased, while soil bacteria, actinomyces, fungi amount increased firstly and then decreased. The amount of soil bacteria, actinomyces, fungi reached the maximum at the treatment of 10 t·hm^-2. Soil respiration rate (SRR) at earlier stage increased with the increase of biochar application. Compared with the control, SSR under biochar treatments increased by 7.9%-36.9%, and there were significant differences of SRR between high biochar application treatments (50 t·hm^-2 and 10 t·hm^-2) and the control.  Biochar improved leaf water potential, carotenoid and chlorophyll contents. Meanwhile, the dry mass of root, shoot and total dry mass under biochar application were higher than that of the control. These results indicated that the biochar played active roles in improving tobacco-planting soil micro-ecology and regulating physiological properties of flue-cured tobacco.

Influence of land use change on dissolved organic carbon export in Naoli River watershed, Northeast China.

YIN Xiao-min, LYU Xian-guo, LIU Xing-tu, XUE Zhen-shan

2015, 26(12):  3788-3794. 

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The present study was conducted to evaluate the influence of land use change on dissolved organic carbon (DOC) export in Naoli River watershed, Northeast China. Seasonal variation of DOC concentrations of the river water and its relationship with land use in the whole watershed and 100 m riparian zone at the annual average scale were analyzed using the method of field sampling, laboratory analysis, GIS and statistics analysis. The results showed that the concentrations of DOC under base flow conditions in spring and summer were significantly higher than that in fall in the study watershed. The seasonal trend of DOC concentrations in wetlandwatersheds was similar to that in all the subwatersheds, while significantly different from that in non-wetland watersheds. On the annual average scale, percentage of wetland in the whole watershed and paddy field in the 100 m riparian zone had positive relationship with the DOC concentration in the river water, while percentage of forest in the whole watershed had negative relationship with it (P<0.05). It indicated that wetland in the subwatershed played a significant role in the seasonal variation of DOC in river water of Naoli River watershed. Wetland in the watershed and paddy field in the 100 m riparian zone significantly promoted DOC export, while forest alleviated it. Land use change in the watershed in the past few decades dramatically changed the DOC balance of river water.

Spatial variation in riparian soil properties and its response to environmental factors in typical reach of the middle and lower reaches of the Yellow River.

ZHAO Qing-he1,2, LIU Qian1,2, MA Li-jiao1,2, DING Sheng-yan1,2, LU Xun-ling1,2, TANG Qian1,2, XU Shan-shan1,2

2015, 26(12):  3795-3802. 

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Soil and vegetation are the foundation of maintaining riparian ecosystem services, and their spatial distribution and variations can determine the effects of ecological functions. In the present study, selecting the typical reach of the middle and lower reaches of the Yellow River as the study area, the spatial distributions of riparian soil physicochemical properties and their response to environmental factors were analyzed by employing methods of field investigation, experimental analysis, and redundancy analysis (RDA). The results showed that soil particle was composed significantly of silt in the study area, with the increase of riparian buffer distance, soil bulk density increased initially and then decreased, whereas soil moisture showed the opposite pattern. Changes in total soil phosphorus (TP), available phosphorus (AP), total carbon (TC), total organic carbon (TOC), total nitrogen (TN), ammonium nitrogen (NH₄⁺-N) and nitrate nitrogen (NO₃^--N) contents under different riparian buffer distance showed  no statistically significant differences.  The spatial distribution of soil chemical properties was generally insignificantly different through changes between two vegetation types. Pearson correlation analysis showed that there was close relationship between soil physical and chemical properties, therein, TOC content in the study area was positively and significantly related to TN (P<0.01), NO₃^--N (P<0.01), and NH₄⁺-N (P<0.05) contents, respectively. Both the TN and TOC contents were significantly negatively related to sand content (P<0.01), while was significantly positively related to clay content (P<0.01), indicating that high sand content could promote porosity and permeability of soil and then accelerate the degradation rate of organic matters in soils. In addition, the results of RDA indicated that TOC and NH₄⁺-N contents increased with increasing the height and coverage of the tree layer. Soil TP and NO₃^--N contents increased with increasing the plant diameter at breast height (DBH) of the tree layer and coverage of the herb layer. Meanwhile, with the increase of elevation gradient, the content of soil NH₄⁺-N presented an increasing trend, indicating that soil properties were significantly influenced by the effects of community structure and elevation gradient in the study area.

Landscape pattern changes at village scale using high resolution satellite images: A case study in lowslope hilly area of Dali City, Northwestern Yunnan Province.

ZHAO Ming-yue, PENG Jian, LIU Yan-xu, ZHANG Tian

2015, 26(12):  3803-3810. 

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Human activity is the main driving force of the change of land cover and landscape patterns. However, there are few studies focusing on the mechanism of humaninduced change of land cover and landscape patterns at village scale. In this study, taking lowslope hilly area of Dali City, Northwestern Yunnan Province as a case study area, high resolution satellite images were introduced to find out the rules of land cover and landscape pattern changes, i.e. GeoEye-1 of 2009 and WorldView-3 of 2014. The objectoriented and humancomputerinteraction approaches were applied to interpret the images using ArcGIS 10.2 and ENVI 5.2. The results showed that, the main land cover types in the study area were forest land, paddy field and dry land in 2009, with forest, bulldozed unbuilt ground and paddy field in 2014, accounting for 82.8% and 70.9% of the total area, respectively. The land cover transition showed that, during 2009-2014, the main land cover change flows were from forest land, paddy field and dry land, to bulldozed unbuilt ground and construction land. Furthermore, the area of bulldozed but unbuilt land had increased to be 531.57 hm² in 2014, which mainly came from forest land (42.8%), dry land (21.7%), and paddy field (14.2%). Landscape pattern change was characterized as the increase of patch quantity and density, the decrease of mean patch size, the complication of patch shape, the fragmentation of landscape patches, and the diversification of landscape patterns.

 

Dynamic monitoring of ecological environment in loess hilly and gully region of Loess Plateau based on remote sensing: A case study on Fuxian County in Shaanxi Province, Northwest China.

LI Fen-ling1,2, CHANG Qin-rui1,2, SHEN Jian1, LIU Jing1,2

2015, 26(12):  3811-3817. 

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Based on the principal component analysis (PCA), four ecological evaluation indicators including vegetation index, wet index, land surface temperature and soil index were combined to evaluate the ecological environment quality of Fuxian County in hilly and gully area of Loess Plateau from year 1995 to 2014. The results showed that the RSEI integrated RS and PCA method could reveal regional ecological changes objectively and quantitatively. The level of overall regional ecological status in Fuxian County was good with a high vegetation fraction and rich biodiversity. The synthetical ecological environment quality index increased from 3.17 to 3.53 indicating the ecological environment had been improved greatly in recent 20 years. The area with best ecological environment quality was located in Niuwu town. The magnitude of change increased progressively from northwest to southeast, and the biggest change occurred in Jiaodao and Nandaode towns. From 1995 to 2014, the areas with decreased and increased ecological environment quality were 16.7% and 42.7% of the study area, respectively, and the improved regions were mainly distributed in plateau and hilly area in the center, rocky low mountainous area in northeast and the Ziwuling Nature Reserve area in southwest of the county.

Change of resource environmental bearing capacity of BeijingTianjinHebei region and its driving factors.

GUO Ke, WANG Li-qun

2015, 26(12):  3818-3826. 

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Based on the evaluation index system established for measuring the resource environmental bearing capacity (REBC), this paper measured the REBC of BeijingTianjinHebei region by applying the state space model and analyzed their driving factors by using the Tobit model. The results showed that the REBC of BeijingTianjinHebei region was in the available state and at the rising stage as well during 2000-2012. The social economic growth had great pressure on the resources and environment. The bearing ratios of the REBCs of Beijing, Tianjin and Hebei all presented a U curve and located at low levels, which meant that there was high REBC potential in these regions. Both of the permanent population and the urban residents ‘Engel’s coefficient were the influence factors of the REBC of BeijingTianjinHebei region. The population problem was likely to become the bottleneck to restrict the regional social and economic development, and also threaten the resources and environment. The specific driving factors of the REBC were different in Beijing, Tianjin and Hebei. For example, energy consumption per unit of GDP only had significant impact on Tianjin. At last, the paper proposed that the three regions should complement each other in resources and environment, social development, and economic structure, also the REBC should be taken a reference in decision and policy making.

 

Spatial-temporal evolution characteristic of coordination between urbanization and eco-environment in Jilin Province, Northeast China.

TAN Jun-tao1,2, ZHANG Ping-yu1, LI Jing1, LIU Shi-wei1

2015, 26(12):  3827-3834. 

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By building urbanization and eco-environment evaluation index systems, the levels of urbanization and eco-environment, and the degree of their coupling coordination of Jilin Province from 2000 to 2012 were evaluated. The level of comprehensive urbanization showed a continued growth trend, and the economic urbanization contributed the largest share. The eco-environment comprehensive level fluctuated upward. The eco-environment state, response and pressure increased faster since the implementation of the strategy of revitalizing Northeast China and other old industrial regions. Coupling coordination degree between urbanization and eco-environment increased continuously, from uncoordinated status to advanced coordinated status, changing from eco-environment lagged to urbanization lagged. The level of urbanization in central region was higher than east and west regions in Jilin Province, but its ecoenvironment level was low. Coupling coordination degree in Changchun was the highest, and that of Baishan was the lowest. Coupling coordination degree of ChangJi integrated region was always at the leading level, but the level of eco-environment lagged behind was growing since 2000. Coupling coordination degree of Siping, Liaoyuan, Songyuan and Yanbian increased, but that of Baicheng decreased.

Cointegration test and variance decomposition for the relationship between economy and environment based on material flow analysis in Tangshan City, Hebei, China.

HAN Rui-ling, ZHU Shao-hua, LI Zhi-yong

2015, 26(12):  3835-3842. 

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The material flow account of Tangshan City was established by material flow analysis (MFA) method to analyze the periodical characteristics of material input and output in the operation of economyenvironment system, and the impact of material input and output intensities on economic development. Using econometric model, the longterm interaction mechanism and relationship among the indexes of gross domestic product (GDP), direct material input (DMI), domestic processed output (DPO) were investigated after unit root hypothesis test, Johansen cointegration test, vector error correction model, impulse response function and variance decomposition. The results showed that during 1992-2011, DMI and DPO both increased, and the growth rate of DMI was higher than that of DPO. The input intensity of DMI increased, while the intensity of DPO fell in volatility. Longterm stable cointegration relationship existed between GDP, DMI and DPO. Their interaction relationship showed a trend from fluctuation to gradual ste adiness. DMI and DPO had strong, positive impacts on economic development in shortterm, but the economyenvironment system gradually weakened these effects by shortterm dynamically adjusting indicators inside and outside of the system. Ultimately, the system showed a longterm equilibrium relationship. The effect of economic scale on economy was gradually increasing. After decomposing the contribution of each index to GDP, it was found that DMI’s contribution grew, GDP’s contribution declined, DPO’s contribution changed little. On the whole, the economic development of Tangshan City has followed the traditional production path of resourcebased city, mostly depending on the material input which caused high energy consumption and serous environmental pollution.

Cooperative relations between non-cropped habitats and soil animals in suburban farmland Landscape: A case in Shenbei New District in Shenyang, China.

BIAN Zhen-xing1, YU Zhen-rong2, WANG Qiu-bing1, LI Jin-hong1

2015, 26(12):  3843-3848. 

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Non-cropped habitat in farm landscape plays a significant role in biodiversity, the functions of arable land and crop yields.  This study focused on Shenbei New District in Shenyang City of Liaoning Province in Northeast China, which was a typical area with contradiction between biodiversity conservation and the high demand of agricultural production in the process of urbanization. Information entropy model, handpicking and Baermann method were used for survey and identification of arthropods and nematodes in soils in urban suburban (US), urban fringe area (UFA) and rural area (RA). The cooperative relations between the number of soil animals and types, structure as well as the total amount of noncropped habitat were investigated in these three types of areas using linear regression. Our results showed that the area of single patch in noncropped habitat was smaller than one hectare in Shenbei New District, and the types and the proportion of noncropped habitat patches were increasing along with the increase of their distance to the urban center. But the proportion of non-cropped habitats areas appeared under an inverted U type change. The proportion of noncropped habitat patches was from 8.6% to 27.8%. The individual number of soil animals showed the Utype trend, while their species number changed irregularly. The individual number of soil animals increased with the increase of the proportion of non-cropped habitat patches in RA and US. There was no obvious correlation between the individual number of soil animal and the proportion of non-cropped habitat patches in UFA. The individual number of soil animals decreased with the increase of the proportion of non-cropped habitats areas. There was no cooperative relation in the proportion of non-cropped habitats and the number of soil animal species.

Application of land economic ecological niche in landscape pattern analysis at county level: A case study of Jinghe County in Xinjiang, China.

YU Hai-yang1,2, ZHANG Fei1,2,3, WANG Juan1,2, ZHOU Mei1,2

2015, 26(12):  3849-3857. 

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The theory of land economic ecological niche was used to analyze the regional landscape pattern in this article, with an aim to provide a new method for the characterization and representation of landscape pattern. The Jinghe County region, which is ecologically fragile, was selected as an example for the study, and the Landsat images of 1990, 1998, 2011 and 2013 were selected as remote sensing data. The land economic ecological niche of land use types calculated by ecostateecorole theory, combined with landscape ecology theory, was discussed in application of land economic ecological niche in county landscape pattern analysis. The results showed that, during the study period, the correlations between land economic ecological niche of farmland, construction land, and grassland with the parameters, including landscape patch number (NP), aggregated index (AI), fragmented index (FN) and fractal dimension (FD), were significant. Regional landscape was driven by the changes of land economic ecological niche, and the trend of economic development could be represented by land economic ecological niche change in Jinghe County. Land economic ecological niche was closely related with the land use types which could yield direct economic benefits, which could well explain the landscape pattern characteristics in Jinghe County when combined with the landscape indices.

Effects of mercury concentration on life table demography of Moina macrocopa under different Scenedesmus obliquus densities.

HUANG Ya, WANG Ling, MU Wei-ping, REN Tong-tong, PAN Ling, XI Yi-long

2015, 26(12):  3858-3864. 

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In order to compare the chronic toxicity of pollutants to organisms in an aquatic environment under different food densities, the cladoceran Moina macrocopa was used as test animal to investigate the effects of Hg²⁺ concentrations (0, 0.4, 1.1, 1.8, 2.5, 3.2 and 3.9 μg·L^-1) on its life table demography under low (0.5×10⁶ cells·mL^-1), medium (1.0×10⁶ cells·mL^-1) and high (2.0×10⁶ cells·mL^-1) densities of Scenedesmus obliquus. The results showed that at low and high food levels, certain concentrations of Hg²⁺ had inhibitory effects on survival, reproduction and population growth of M. macrocopa. However, at the medium food level, the inhibitory effects disappeared. Compared with the control, at the low food level, Hg²⁺ at 0.4-2.5 and 3.9 μg·L^-1 significantly decreased the life expectancy at hatching, Hg²⁺ at 0.4, 1.1, 2.5 and 3.9 μg·L^-1 decreased the generation time, Hg²⁺ at 1.1, 2.5 and 3.9 μg·L^-1 decreased the net reproduction rate, and Hg²⁺ at 3.9 μg·L^-1 decreased the gross reproduction rate of M. macrocopa. At the high food level, Hg²⁺ at 1.1 μg·L^-1 decreased the intrinsic rate of population increase, and Hg²⁺ at 3.9 μg·L^-1 decreased the life expectancy at hatching and the net reproduction rate of M. macrocopa. However, at the medium food level, Hg²⁺ at 3.2 μg·L^-1 increased the life expectancy at hatching of M. macrocopa. When S. obliquus density was 0.5×10⁶ cells·mL^-1, there were significant doseeffect relationships between Hg^2+ concentration and the life expectancy at hatching, the generation time as well as the cross reproduction rate of M. macrocopa. However, when S. obliquus density was 1.0×10⁶ or 2.0×10⁶ cells·mL^-1, there were no any significant doseeffect relationships between Hg²⁺ concentration and each of the life table demographic parameters of M. macrocopa.

Factors affecting the estimation of pollen limitation in Sagittaria trifolia.

QIN Dao-feng1, LI Ting1, DAI Can1,2,3

2015, 26(12):  3865-3870. 

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This study explored whether the degree of pollen limitation was affected by the experimental level (a single flower or inflorescence) and pollen quality (selfpollen or outcrosspollen) of supplemental pollination in Sagittaria trifolia. The results showed that the experimental level caused varying degree of pollen limitation. Compared with the inflorescence level, pollination at the single flower level led to a redistribution of resources among flowers, therefore affecting seed numbers. Pollen quality also played a vital role in the estimation of pollen limitation. Compared with selfpollen, supplemental pollination with outcrosspollen resulted in significantly more seeds and a higher germination rate. This proved that in the research system the reproduction was limited by pollen quality rather than quantity. Our study revealed that both experimental level and pollen quality had effects on the estimation of pollen limitation. It was suggested that in future studies we should evaluate pollen limitation at the inflorescence or whole plant level, and also consider comparing self and outcrosspollen when applicable.