Northeast Institute of Geography and Agroecology, Chinese Academy Of Sciences
Not a member yet
4476 research outputs found
Sort by
Comparative Analysis of Mechanisms of Cd2+ and Ni2+ Biosorption by Living and Nonliving Mucoromycote sp XLC
No full textThe biosorption of cadmium (Cd2+) and nickel (Ni2+) using living and nonliving biomass of Mucoromycote sp. XLC as a biosorbent was investigated in this study. The optimum conditions were established with batch biosorption experiments. The data from equilibrium experiments showed that all kinds of biosorbents fitted the Langmuir model. For the living and nonliving biosorbent, the predicted maximum Cd2+ uptake capacity was 79.65 mg g(-1) and 56.51 mg g(-1), while the maximum Ni2+ uptake capacity was 51.26 mg g(-1) and 44.32 mg g(-1), respectively. Acid digestion results indicated that intracellular metal ions might be the main reason for the metal uptake capacity difference between living and nonliving biosorbents. FTIR analysis and potentiometric titration indicated freeze dehydration-autoclaving treatment of nonliving biomass slightly changed the surface structure of the cell wall and the functional groups involved in biosorption were carboxylic, phosphoryl, amine and hydroxyl groups. Our results suggest the living biosorbent had a second biosorption process by intracellularly accumulating metal ions, hence possessing a higher Cd(2+)or Ni2+ uptake capacity than nonliving biosorbent
Decomposition and heavy metal variations of the typical halophyte litters in coastal marshes of the Yellow River estuary, China
No full textThe concentrations of C, Pb, Cr, Cu, Zn, Ni and Mn were determined in decomposing litters of Phragmites australis, Suaeda salsa and Suaeda glauca in three plots of the Yellow River estuary to investigate the variations of metal stocks. Results showed that the decomposition rates significantly differed among species (p S. salsa (0.000814 d(-1)) > P. australis (0.000766 d(-1)). The concentrations of Cu and Zn in the three litters (particularly S. glauca) generally showed increasing tendency, while those of Pb, Cr, Ni and Mn exhibited different temporal variations. Compared to P. australis and S. salsa, the key mechanisms affecting the variation of metals in S. glauca might be more complex. In most periods, Pb stocks in P. australis, S. salsa and S. glauca, Zn stocks in S. salsa and S. glauca, and Cr, Ni and Mn stocks in P. australis and S. glauca were lower than the initial ones, implying that release exceeded incorporation. Comparatively, Zn stocks in P. australis, Cr, Ni and Mn stocks in S. salsa and in particular Cu stocks in the three litters were generally positive, evidencing incorporation of these metals in most sampling times. The three halophytes were particular efficient in binding Cu and releasing Pb, indicating that the potential eco-toxic risk of Pb exposure might be serious. This study emphasized the strong influences of key biotic (litter types, carbon/metal ratios and activities of microbial organisms) and abiotic variables (salinity, sediment resuspension induced by tidal inundation and passive sorption onto recalcitrant organic fractions) on metal cycling in coastal marshes of the Yellow River estuary. (C) 2015 Elsevier Ltd. All rights reserved
Rice yield corresponding to the seedling growth under supplemental green light in mixed light-emitting diodes
No full textThe objective of this study was to investigate the effect of different supplemental intensity of green light in mixed light-emitting diodes (LEDs) on rice (Oryza sativa L.) seedling growth, and their after-effect on grain yield. The rice seedlings were nursed in greenhouse with 30-days continuous supplemental lighting (6 h/day) from three light sources: 75% red + 25% blue (photon flux density) LED (RB), 62.5% red + 25% blue + 12.5% green LED (RBG(12.5)) and 50% red + 25% blue + 25% green LED (RBG(25)), and then transplanted into paddy field in two consecutive years (2014 and 2015). The results showed that both shoot and root growth of rice seedlings were enhanced by the addition of green light into red and blue LEDs, but the response of different organ systems depended on the intensity of green light. The low percentage of green light in the light source (RBG(12.5)) could not only promote the stem elongation, the shoot dry weight accumulation and the root respiration activity but also could change the root morphology (indicated by the total surface area and the average diameter of root), while the high percentage of green light (RBG(25)) only changed the root morphology and increased the root respiration activity. The influence of light on rice during the seedling stage extends to the end of the maturity stage, with the highest rice grain yield, spikelets per panicle and the grain filling percentage in RBG(25)
The spatiotemporal distribution of dissolved carbon in the main stems and their tributaries along the lower reaches of Heilongjiang River Basin, Northeast China
No full textThe Heilongjiang River Basin in the eastern Siberia, one of the largest river basins draining to the North Pacific Ocean, is a border river between China, Mongolia, and Russia. In this study, we examined the spatial and seasonal variability in dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), and dissolved total carbon (DTC) concentrations along lower reaches of Heilongjiang River Basin, China. Water samples were collected monthly along the mouths of main rivers (Heilongjiang River, Wusuli River, and Songhua River) and their ten tributary waters for 2 years. The DOC concentrations of waters ranged from 1.74 to 16.64 mg/L, with a mean value of 8.90 +/- 0.27 mg/L (n = 165). Notably, mean DIC concentrations were 9.08 +/- 0.31 mg/L, accounting for 13.26 similar to 83.27 % of DTC. DIC concentrations increased significantly after the Heilongjiang River passed through Northeast China, while DOC concentrations decreased. Over 50 % of DIC concentrations were decreased during exports from groundwater to rice fields and from rice fields to ditches. Water dissolved carbon showed large spatial and temporal variations during the 2-year measurement, suggesting that more frequently samplings were required. Carbon (DIC + DOC) loads from the Heilongjiang River to the Sea of Okhotsk were estimated to be 3.26 Tg C/year in this study, accounting for 0.64 % of the global water dissolved carbon flux. DIC export contributed an average of 51.84 % of the estimated carbon load in the Heilongjiang River, acting as an important carbon component during riverine transport. Our study could provide some guides on agricultural water management and contribute to more accurately estimate global carbon budgets
Tillage, seasonal and depths effects on soil microbial properties in black soil of Northeast China
No full textTillage practice can alter the content and distribution of soil organic matter by burying crop residue and soil disturbance, which would impact soil microbial properties. The objective of the present study was to evaluate the effects of tillage practices (no tillage, NT; ridge tillage, RT; mouldboard plow, MP) and sampling date (April, June, September) on soil microbial properties at different soil depths. Soil core samples were taken at 0-5,5-10 and 10-20 cm depths from a long-term tillage experiment site (initiated in 2001) in black soils in northeast China. Microbial biomass and extractable organic C were determined using by chloroform-fumigation-extraction method. Microbial abundance and community structure were determined using the phospholipid fatty acid (PLFA) method. Principal response curve (PRC) analysis revealed the magnitude of the effect of sampling date on the PLFA relative abundance decreased with depth within the tilled layer, whereas increased with depth for tillage practice. Microbial biomass carbon, abundance and the F/B ratio varied with the variation in available substrates at the 0-5 cm depths. NT and RT improved microbial abundance (total, fungal and bacterial abundance) in the 0-5 cm depth soil, but they did not contribute to a higher F/B ratio in the 0-5 cm depth soil, and had a lower F/B ratio than MP in the deeper soils below 5 cm depth. These results demonstrated that long-term conservation tillage practice has potential for improving microbial properties in surface soil, but may not cause a shift of microbial community structure in Northeast China. (C) 2015 Elsevier B.V. All rights reserved
