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This study aimed to: (i) investigate the agronomic properties of biochars derived from selected invasive wetland weeds and (ii) examine the effect of biochar on soil organic carbon (SOC) dynamics and stability of tropical Ultisol soil. The biochars were analyzed for proximate properties, surface characteristics, elemental composition, functional groups, and thermal and carbon stability. Plant growth studies supplemented with biochar under greenhouse conditions for 1 year were conducted. The SOC, its fractions, and its dynamics were studied. The biochar incorporation significantly increased the SOC and its stable fractions like mineral Organic Carbon (MOC), fine-particulate organic carbon (fPOC), and Non-labile Carbon (NLC) by 24.54–7.82, 5.79–2.0, and 9.50–2.16 g kg−1 than control. The labile carbon fractions like Dissolved Organic Carbon (DOC), and coarse-Particulate Organic Carbon (cPOC) showed a substantial reduction by 0.72–0.26 and 2.92–1.29 g kg−1 respectively. However, the easily oxidizable carbon (EOC) and microbial biomass carbon (MBC) content increased by 2.10–4.87 g kg−1 and 28.33–158.55 mg kg−1 respectively. The addition of biochars resulted in the stabilization of soil aggregates. Likewise, substantial CO2 emission reduction (75.24–46.60%) has been achieved during the trials. The carbon pool management index (CPMI) values recorded a substantial increase of 40–7.2% between the trials. The findings imply that the inherent nature of weed biomasses determines the characteristics of the resulting biochar, and their application significantly influenced the carbon dynamics of the tropical Ultisol soil. [ABSTRACT FROM AUTHOR]

In this work we characterize the public perception of one kind of ecological risk—blue-algae bloom in Hongze Lake, China, based on the psychometric paradigm method. In the first survey of May 2008, 300 respondents of Sihong County adjacent to Hongze Lake were investigated, with a total of 156 questionnaires returned. Then in a second survey of July 2008, 500 respondents from the same research area were investigated, with 318 questionnaires collected. This research firstly attempted to explore the local respondents’ degree of concern regarding ecological changes to Hongze Lake in the last ten years. Secondly, to explore the public perception of blue-algae bloom compared to three typical kinds of hazards including earthquake, nuclear power and public traffic. T-test was used to examine the difference of risk perception in these four hazards over time. The third part of this research, with demographic analysis and nonparametric statistical test, predicted the different groups of respondents’ willingness to accept (WTA) risk of blue-algae bloom in two surveys. Using multiple linear regression analysis, the risk perception model explained 28.3% of variance in the WTA blue-algae bloom risk. The variables of Knowledge, Social effect, Benefit, Controllability and Trust in government were significantly correlated with WTA, which implied that these variables were the main influencing factors explaining the respondents’ willingness to accept risk. The results would help the Chinese government to comprehend the public’s risk perception of the lake ecosystem, inducing well designed communication of risks with public and making effective mitigation policies to improve people’s rational risk judgment. [ABSTRACT FROM AUTHOR]