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Context The effect of glyphosate–copper complex on copper mobility had been studied in aqueous conditions. The effect on copper distribution through the soil profile is little understood and controversial. Aims This study aims to investigate the effect of glyphosate on copper mobility and distribution through the soil profile and to identify the specific copper binding change at the molecular level. Methods The experiments were performed in microcosm soil spiked with copper and glyphosate. Sequential extraction and X-ray absorption spectroscopy techniques were applied for copper speciation. Key results The organic bound fraction was the highest fraction (50%) in the top soil layer, while Cu(CH3COO)2 (43%) and Cu(NO3)2 (49%) were the highest fraction in linear combination fit (LCF) analysis. In the presence of glyphosate, the readily mobile fraction of copper (water soluble and exchangeable fractions) increased, while the mobilised fractions decreased within 1 day of glyphosate application. The LCF analysis revealed that CuSO4 and Cu3(PO4)2 increased in the presence of glyphosate. The effects of glyphosate were no longer detected by 14 days after application. During the 40 days of the experiment, the released copper did not leach beyond 4 cm deep in soil. Conclusions The existence of glyphosate in soil induced the release of copper into the readily mobilised fraction within 1 day of glyphosate contamination. The effect was found within 4 cm depth and declined in correspondence with the degradation half-life of glyphosate. Implications The finding is important in evaluating the risk of metal diffusion and nutrient leaching from co-contaminated soil through the soil profile over time and at a molecular scale.

This study evaluated the relationship of biodiversity with the patch size of village common forests (VCF) by analyzing floral biodiversity based on data from 25 selected VCFs in the Chittagong Hill Tracts (CHT), Bangladesh. The study took 225 quadratic plots by taking nine 10 m × 10 m plots from each VCF—three from each of base, mid, and top hill slopes. The coefficient of similarity (CS) among VCFs and forest community features including species richness, basal area, and popular diversity indices were calculated. Generalized linear model (GLM) assessed the bearings of patch size, slope, and elevation on stand parameters. In all, the study recorded the occurrence of 165 plant species from 52 families. Euphorbiaceae was the dominant family with 18 species. Seven least concerned and four threatened species as per the IUCN red data list of Bangladesh were found in VCFs. Vitex peduncularis had the highest importance value index (IVI) score followed by Lannea coromandelica and Ficus hispida. The mean CS of the VCFs was 0.54. The VCFs were rich in biodiversity, as indicated by observed species richness (644 species/ha), stem density (7111 plants/ha), basal area (65.56 m2/ha). Scores in biodiversity indices, viz. Shannon–Wiener diversity index (2.59), Simpson index (0.90), and evenness index (0.61), also concluded rich but heterogeneous biodiversity among VCFs comparable to other natural forests in the country. The GLM revealed the absence of significant (p ≤ 0.05) bearings of patch size, elevation, or slope on community parameters. The insensitivity of forest community parameters to patch size and elevation indicated the value of conserving VCFs irrespective of sizes and locations.

Village Common Forests (VCFs) are patches of tropical evergreen and semi-evergreen hill forests in Chittagong Hill Tracts (CHTs), Bangladesh that are conserved through voluntary community participation for community perceived sustenance of ecosystem services. VCFs are currently under informal management without any optimal model of Community-Based Management (CBM). By using strength, weakness, opportunity, threat (SWOT) technique combined with the Analytical Hierarchy Process (AHP), this paper assessed the perceptions of four major stakeholder groups. Their perceptions were analyzed to ascertain the priority factors related to CBM adoption in VCFs of CHT. The four stakeholder groups were – researchers from academia, government officials, NGO staffers and local indigenous community leaders. Results indicated an overall negative perception among all the stakeholders regarding the adoption of CBM in VCFs. “No land tenure security” was the most serious weakness factor for the implementation of CBM in VCFs among all stakeholder groups except government officials. “Unity and easy decision process”, “Positive community attitude” and “Low management cost” were the most important strength factors respectively from academia, government, NGOs and community leaders. All the stakeholder groups identified “Relationship development between government and community” as the most important opportunity factor for CBM of VCFs. “Uncertainty of peace accord 1997 and 1900 CHT regulation implementation” was treated as the most damaging threat factor against the adoption of CBM in VCFs. Therefore, rebuilding indigenous peoples' confidence in government initiatives by counting them in the high-level decision-making process, ensuring land tenure security have been identified as the key initial interventions.

Journal of Metals Materials and Minerals, 30, 2, 110-116

This research investigated the effects of elevated ozone and carbon dioxide on photosynthesis of rice ('Oryza sativa' L.) cultivar Khao Dawk Mali 105. Seedlings were kept in indoor climate control chambers which were set to typically background level of ozone (