Dynamics models of soil organic carbon

As the largest pool of terrestrial organic carbon, soils interact strongly with atmosphere composition, climate, and land change. Soil organic carbon dynamics in ecosystem plays a great role in global carbon cycle and global change. With development of mathematical models that simulate changes in soil organic carbon, there have been considerable advances in understanding soil organic carbon dynamics. This paper mainly reviewed the composition of soil organic matter and its influenced factors, and recommended some soil organic matter models worldwide. Based on the analyses of the developed results at home and abroad, it is suggested that future soil organic matter models should be developed toward based-process models, and not always empirical ones. The models are able to reveal their interaction between soil carbon systems, climate and land cover by technique and methods of GIS (Geographical Information System) and RS (Remote Sensing). These models should be developed at a global scale, in dynamically describing the spatial and temporal changes of soil organic matter cycle. Meanwhile, the further researches on models should be strengthen for providing theory basis and foundation in making policy of green house gas emission in China.

小开河引黄泥沙堆积区综合修复措施的改土效应评价

黄河是高含沙河流,引黄必然引沙,小开河引黄灌区沉沙池的清淤弃土区多年累计了大量泥沙,又称泥沙堆积区,因缺乏植被保护,土地沙化和水土流失现象特别严重。2011年采取工程技术及配套生物修复措施进行了综合治理并跟踪监测,探讨了泥沙堆积区不同植被类型对土壤有机质含量的影响和对土壤速效N、P、K含量的影响,对引黄泥沙的综合治理具有指导意义。

Labile Organic Matter Content and Distribution as Affected by Six-year Soil Amendments to Eroded Chinese Mollisols

Labile organic carbon （LOC） is a fraction of soil organic carbon （SOC） with rapid turnover time and is affected by soil fertilization. This investigation characterized the SOC content, LOC content and LOC distribution in the treatment plots of surface soil erosion at five levels （0-, 5-, 10-, 20- and 30-cm erosion）. The soil had received contrasting fertilizer treatments （i.e., chemical fertilizer or chemical fertilizer ＋ manure） for 6 years. This study demonstrated that both SOC and various LOC fractions contents were higher in the plots with fertilizer ＋ manure than in those with fertilizer alone under the same erosion conditions. The SOC and LOC contents de- creased as the erosion depth increased. Light fraction organic carbon, particulate organic carbon, easily oxidizable organic carbon （KMnO4-oxydizable organic carbon）, and microbial biomass carbon were 27% 57%, 37%-7%, 20%-25%, and 29%-33% higher respectively in the fertilizer ＋ manure plots, than in the fertilizer alone plots. Positive correlations （p 〈 0.05） between SOC content and different fractions contents were observed in all plots except the correlation between total SOC content and water-soluble organic carbon content in the different fertilization treatments. Obviously, fertilizer ＋ manure treatments would be conducive to the accumulation of LOC and SOC in the Black soil of Northeast China.

Spatial impact of organic matters from point sources on stream water quality

To get a better understanding of the spatial impact of organic discharges on stream water quality,a "scenario-testing" approach was proposed to examine how a change in plant treatment efficiency would affect dissolved oxygen(DO) concentration along a stream.An "upper-lower" boundary technique was applied to conduct sensitivity analysis to observe the responses of DO concentration to different DO-related parameters.The results show a non-linear discrepancy of biochemical oxygen demand(BOD) and DO concentration among different treatment scenarios,which indicates the higher the efficiency of the plant treatment,the shorter the time the stream needs to recover.The sensitivity analysis reveals that the larger the amount of the waste discharge,the more sensitive the BOD to the biological removal parameter.In addition,the DO is more sensitive to the biological removal parameter than to the reaeration parameter.

Pollution Monitoring Methods and Results of Primorsky Kray Shoreline

The amount of human-caused environmental impact can be evaluated by the degree of pollution. Active coastal marine environmental exploitation has given rise to another problem： marine litter. The period of time allowing to evaluate the change in the degree of the shore pollution with litter is that from 1999 till 2014. Litter can be classified both by qualitative and quantitative character. Regarding qualitative character litter is divided into organic substance （garbage, wood） and non-organic substance （glass, plastics, rubber, metal）. As to the size there are three categories： small, middle, large. As to small litter it is still predominating in the litter structure of the shoreline pollution but its average amount has been decreased significantly. As to the litter distribution, it is mostly concentrated within the beach zone. It is thus natural to assume the land-based origin of the litter, such as litter brought by holiday-makers or introduced by nearby enterprises.