RESUMEN
The soil pollution caused by diesel oil and heavy metals has become an increasingly serious environmental issue, with negative global-scale impacts. The remediation of contaminated soil requires special attention, in which phytoremediation has emerged as an ecofriendly solution. However, the response of plants to the combined stress of diesel oil and heavy metals remains largely unknown. In this study, the aim was to investigate the potential of Populus alba and P. russkii for phytoremediation by examining their response to combined diesel oil and heavy metal stress. In a greenhouse experiment using soil contaminated with 15 mg kg-1 of diesel oil and varying concentrations of Sr (0, 10, or 100 mg kg-1), we studied the physiological and biochemical changes, as well as the Sr absorption, of P. alba and P. russkii. The results showed that at high concentrations of Sr and diesel oil, the growth of both species was substantially inhibited, but P. alba exhibited higher resistance due to its higher antioxidant enzyme activities and increased accumulation of soluble sugar and proline. Additionally, P. alba concentrated Sr in the stem, whereas P. russkii accumulated Sr in the leaf, exacerbating its negative effects. Diesel oil treatments were beneficial for Sr extraction due to cross-tolerance. Our findings indicate that P. alba is more suitable for the phytoremediation of Sr contamination due to its superior tolerance to combined stress, and we identified potential biomarkers for monitoring pollution. Therefore, this study provides a theoretical basis and implementation strategy for the remediation of soil contaminated by both heavy metals and diesel oil.
RESUMEN
BACKGROUND: The local Dong people in Qiandongnan Prefecture, Guizhou Province, China, with rich biocultural diversity, have developed the traditional rice-duckweed-fish-duck agroecosystem (RDFDA) to support biodiversity conservation and to meet food and cultural needs. However, there is still not much research on traditional ecological knowledge (TEK) in this area. In particular, there is a lack of traditional knowledge of edible plants used by the Dong people as flavoring to grill fish (Cyprinus carpio) collected from RDFDA, which is extremely valuable in their traditional culture. The study focused on documenting plant species used in grilling fish and analyzing the status of its TEK. METHODS: Twenty-one sampling points of three Dong minority villages in Qiandongnan were selected for the research. The local TEK associated with plant resources for fish-grilling was recorded through free listing and semi-structured interviews. Fidelity level (FL) and ethnoecological importance value (EIV) indicators were designed to determine the socioeconomic influence of TEK. The non-metric multidimensional scaling (NMDS) method was used to evaluate the differentiation of edible plant species distribution in dissimilar accessibility types. RESULTS: A total of 430 people were interviewed about grilled fish, of whom 75% were men and 85% were farmers. Thirty-four edible plants were documented for fish-grilling in three Dong villages. They belong to 16 plant families, such as Apiaceae, and Asteraceae. The life forms included herbaceous (76%), shrubs (18%) and trees (6%). Leaves are the most commonly used part of for grilling fish, followed by aerial parts, and whole plants. Among these edible plants, Allium hookeri, A. macrostemon and Houttuynia cordata with the highest fidelity level (100%) were cited as edible plants for grilling fish by all informants. The NMDS showed different accessibility types of collection sites, with different importance values. Paddy rice field edge (2.03) has the highest value, followed by forest-farming ecotone (1.74), streamsides (1.71) and woodland (0.48). CONCLUSION: The purpose of this study was to investigate the traditional knowledge of edible plant materials used by the Dong people for grilling fish. The results demonstrate the strong connection between local people, the bio-environment and agroecosystem services. The survey and comparative analysis revealed that plant species with high FL values may be potential sources of natural flavors.
