Chen Q.,University of Jinan |
Yang B.,University of Jinan |
Wang H.,University of Jinan |
Wang H.,State Key Laboratory of Forest and Soil Ecology |
And 3 more authors.
Environmental Science and Pollution Research | Year: 2014
Intensive use of atrazine and extensive dispersal of lead (Pb) have occurred in farmland with chemical agriculture development. However, the toxicological effect of their presence on soil microorganism remains unknown. The objective of this study was to investigate the impacts of atrazine or Pb on the soil microbiota, soil net nitrogen mineralization, and atrazine residues over a 28-day microcosm incubation. The Shannon-Wiener diversity index, typical microbe species, and a Neighbor-joining tree of typical species from sequencing denaturing gradient gel electrophoresis (DGGE) bands were determined across periodical sampling times. The results showed that the existence of atrazine or Pb (especially high concentration) in soils reduced microbial diversity (the lowest H value is 2.23) compared to the control (H = 2.59) after a 28-day incubation. The species richness reduced little (from 17~19 species to 16~17 species) over the research time. But soil microbial community was significantly affected by the incubation time after the exposure to atrazine or Pb. The combination of atrazine and Pb had a significant inhibition effect on soil net nitrogen nitrification. Atrazine and Pb significantly stimulated soil cumulative net nitrogen mineralization and nitrification. Pb (300 and 600 mg kg−1) accelerated the level of atrazine dissipation. The exposure might stimulate the significant growth of the autochthonous soil degraders which may use atrazine as C source and accelerate the dissipation of atrazine in soils. © 2014, Springer-Verlag Berlin Heidelberg.
Shi S.-N.,State Key Laboratory of Forest and Soil Ecology |
Yu Z.-Y.,State Key Laboratory of Forest and Soil Ecology |
Zhao Q.,State Key Laboratory of Forest and Soil Ecology
Journal of Forestry Research | Year: 2014
Nitrogen was the main limiting nutrient of net primary production in the southeastern Keerqin Sandy Lands, Northeast China. Species richness declined and biomass increased after five consecutive years of nitrogen fertilization of these sandy grasslands (2004-2008). After fertilization had been stopped for three years (2009-2011), we surveyed vegetation on previously fertilized plots to quantify changes in community composition. Respect species richness showed an increasing trend over time since the cessation of fertilization. Respect vegetation height and coverage showed decreasing trends over time since the cessation of fertilization. Species composition changed after fertilization ceased, the dominant species shifting from Cannabis sativa, Phragmites communis and Chenopodium acuminatum in 2008 to Cannabis sativa, Phragmites communis and Artemisia scoparia in 2011. Dominance of dominant species declined from 66.2% in 2008 to 57.5% in 2011. The importance value of annual plants in the earlier nitrogen addition plots was higher than in control plots, but the differences were not significant in 2011. The importance value of perennial plants differed significantly between treatments from 2009 to 2011. The reversion rate not only differed between community characteristics, but also between functional groups in the same community characteristic. Although the residual effect of nitrogen addition on vegetation was still observed three years after fertilization ceased, the vegetation showed signs of recovery. © 2014 Northeast Forestry University and Springer-Verlag Berlin Heidelberg.
Liu Z.,CAS Shenyang Institute of Applied Ecology |
Liu Z.,University of Chinese Academy of Sciences |
Liu Z.,State Key Laboratory of Forest and Soil Ecology |
Xie J.,CAS Shenyang Institute of Applied Ecology |
And 5 more authors.
Journal of Pure and Applied Microbiology | Year: 2014
Organophosphorus compounds (OP compounds) are toxic, because they can inhibit the acetylcholine esterase in central nervous system of human and animals. OP compounds are extensively used for insecticides control. Water, soil and agricultural products have been contaminated seriously by OP compounds in some regions. It is urgent to find effective methods to remove OP compounds contamination. In this study, an organophosphorus-degrading bacterium (strain YF-5) was isolated from sludge. Based on the results of phenotypic features and phylogenetic similarity of 16S rRNA gene sequences, strain YF-5 was identified as Pseudomonas sp. In liquid culture, 100 mg l-1 methyl parathion and chlorpyrifos were decomposed completely by strain YF-5 (105 cells mL-1) within 8 h and 20 h, respectively. The methyl parathion degrading (mpd) gene was cloned from strain YF-5. Result of sequence BLAST indicated that this gene has 99% similarity to mpd of Plesiomonas sp. M6.
Musa A.,CAS Shenyang Institute of Applied Ecology |
Ya L.,CAS Shenyang Institute of Applied Ecology |
Ya L.,University of Chinese Academy of Sciences |
Anzhi W.,CAS Shenyang Institute of Applied Ecology |
And 3 more authors.
Geoderma | Year: 2016
The freeze-thaw process can lead to water enrichment in freezing layers of soil, and may have beneficial effects on vegetation restoration efforts in sandy land habitats. This study determined the characteristics of soil water migration in dunes and interdune areas during freeze-thaw process, and discussed its potential application to the restoration and recovery of sandy land plant communities. In this research, the mobile sand dunes and interdune lowlands were chosen as the study objects in Horqin Sandy Land, north China. We investigated the soil temperature and moisture content on depths of 20 cm, 50 cm, 100 cm and 150 cm during soil freeze-thaw period (from September 20, 2010 to April 9, 2011), and determined the migrated water during freezing-thawing processes on soil of sand dunes and interdune lowlands, and discussed its potential application on plant recovery processes. Results showed that the soil freeze-thaw process occurred mostly at a depth of 0-100. cm, and the longest period of soil that remained frozen is 104 days at a depth of 20 cm and the shortest period is 39 days at a depth of 100 cm in sand dunes. The number of freeze-thaw cycles was not different between sand dune and interdune area over winter. Most freeze-thaw cycles occurred in the thawing process, and mostly at a depth of 0-50. cm. The freeze-thaw cycles of interdune areas only occurred in the thawing process, but the freeze-thaw cycles of sand dunes occurred both in the process of freezing and thawing. More water of the interdune areas apparently migrated than did in the sand dunes. The range of soil water storage content at depths of 0 to 100 cm increased to 92.4. mm on interdune, and 10.8. mm on sand dunes during the freeze-thaw process. A negative correlation was found between soil temperature and moisture at depths of 100 cm and 150 cm, and while a positive correlation existed at depths of 20 cm and 50 cm. The freeze-thaw process can lead to water enrichment in freezing layer of soil on sand dunes and interdune. Soil texture affected the quantity of soil water migrating during the freeze/thaw process, and more water migrated in interdune areas than in sand dune habitat. © 2015 Published by Elsevier B.V.