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Pagli C, Chamizo S, Migliore G, Rugnini L, De Giudici G, Braglia R, Canini A, Cantón Y. Isolation of biocrust cyanobacteria and evaluation of Cu, Pb, and Zn immobilisation potential for soil restoration and sustainable agriculture. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 946:174020. [PMID: 38897475 DOI: 10.1016/j.scitotenv.2024.174020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2024] [Revised: 04/30/2024] [Accepted: 06/13/2024] [Indexed: 06/21/2024]
Abstract
Soil contamination by heavy metals represents an important environmental and public health problem of global concern. Biocrust-forming cyanobacteria offer promise for heavy metal immobilisation in contaminated soils due to their unique characteristics, including their ability to grow in contaminated soils and produce exopolysaccharides (EPS). However, limited research has analysed the representativeness of cyanobacteria in metal-contaminated soils. Additionally, there is a lack of studies examining how cyanobacteria adaptation to specific environments can impact their metal-binding capacity. To address this research gap, we conducted a study analysing the bacterial communities of cyanobacteria-dominated biocrusts in a contaminated area from South Sardinia (Italy). Additionally, by using two distinct approaches, we isolated three Nostoc commune strains from cyanobacteria-dominated biocrust and we also evaluated their potential to immobilise heavy metals. The first isolation method involved acclimatizing biocrust samples in liquid medium while, in the second method, biocrust samples were directly seeded onto agar plates. The microbial community analysis revealed Cyanobacteria, Bacteroidota, Proteobacteria, and Actinobacteria as the predominant groups, with cyanobacteria representing between 13.3 % and 26.0 % of the total community. Despite belonging to the same species, these strains exhibited different growth rates (1.1-2.2 g L-1 of biomass) and capacities for EPS production (400-1786 mg L-1). The three strains demonstrated a notable ability for metal immobilisation, removing up to 88.9 % of Cu, 86.2 % of Pb, and 45.3 % of Zn from liquid medium. Cyanobacteria EPS production showed a strong correlation with the removal of Cu, indicating its role in facilitating metal immobilisation. Furthermore, differences in Pb immobilisation (40-86.2 %) suggest possible environmental adaptation mechanisms of the strains. This study highlights the promising application of N. commune strains for metal immobilisation in soils, offering a potential bioremediation tool to combat the adverse effects of soil contamination and promote environmental sustainability.
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Affiliation(s)
- Carlotta Pagli
- Department of Biology, University of Rome Tor Vergata, Italy; Department of Agronomy, University of Almería, Spain; PhD Program in Evolutionary Biology and Ecology, University of Rome Tor Vergata, Italy.
| | - Sonia Chamizo
- Department of Agronomy, University of Almería, Spain; Department of Desertification and Geo-Ecology, Experimental Station of Arid Zones (EEZA-CSIC), Almería, Spain
| | - Giada Migliore
- ENEA, Territorial and Production Systems Sustainability Department, Italy
| | - Lorenza Rugnini
- Department of Biology, University of Rome Tor Vergata, Italy
| | - Giovanni De Giudici
- Department of Chemical and Geological Sciences, University of Cagliari, Italy
| | - Roberto Braglia
- Department of Biology, University of Rome Tor Vergata, Italy
| | | | - Yolanda Cantón
- Department of Agronomy, University of Almería, Spain; Center for Research on Scientific Collections of the University of Almeria (CECOUAL), Spain
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Zheng J, Arif M, He X, Liu X, Li C. Distinguishing the mechanisms driving multifaceted plant diversity in subtropical reservoir riparian zones. FRONTIERS IN PLANT SCIENCE 2023; 14:1138368. [PMID: 36909398 PMCID: PMC9998900 DOI: 10.3389/fpls.2023.1138368] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 02/13/2023] [Indexed: 06/18/2023]
Abstract
Understanding the multifaceted plant diversity and its maintenance mechanisms is crucial for biodiversity conservation. Dam-induced water level fluctuations dramatically alter various aspects of riparian diversity, such as taxonomic (TD), phylogenetic (PD), or functional (FD) diversity. However, few studies simultaneously evaluated plant TD, FD, and PD, especially in the subtropical reservoir riparian zone. Here we sampled plant diversity and environmental drivers along inundation gradients of the Three Gorges Reservoir Region in China. We integrated multifaceted plant diversity to assess how distinct ecological processes affect the plant community assembly and how they respond to inundation gradients, spatial variability, climate, and soils in dam-regulated riparian zones. We found that alpha TD, PD, and FD diversity exhibited decreasing trends with increasing inundation gradients and significant positive correlations with soil organic matter. The number of clustering plant communities increases along the inundation gradients. Beta TD and PD diversity were mainly dominated by species turnover with fewer contributions from nestedness, while beta FD diversity was mainly dominated by nestedness with fewer contributions from species turnover. The explainable rates of different dimensions of beta diversity, turnover, and nestedness ranged from 11% to 61%, with spatial factors explaining the highest beta diversity in different dimensions, followed by inundation gradients, soil properties, and climate variables. Our results suggest dispersal limitations are more important for species turnover in dam-regulated riparian zones at regional scales, while inundation gradients and soil fertility are more critical in shaping plant community assemblages at the local scale. This study emphasizes that environmental and spatial gradients are critical for understanding the assembly mechanisms driving multifaceted plant communities at local and regional scales and reinforces the importance of protecting seed sources and dispersal pathways and maintaining river connectivity when implementing restoration projects.
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Affiliation(s)
- Jie Zheng
- Key Laboratory of Eco-environments in the Three Gorges Reservoir Region, Ministry of Education, Chongqing, China
- Chongqing Key Laboratory of Plant Ecology and Resources Research in the Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing, China
| | - Muhammad Arif
- Key Laboratory of Eco-environments in the Three Gorges Reservoir Region, Ministry of Education, Chongqing, China
- Chongqing Key Laboratory of Plant Ecology and Resources Research in the Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing, China
- Biological Science Research Center, Academy for Advanced Interdisciplinary Studies, Southwest University, Chongqing, China
| | - Xinrui He
- Key Laboratory of Eco-environments in the Three Gorges Reservoir Region, Ministry of Education, Chongqing, China
- Chongqing Key Laboratory of Plant Ecology and Resources Research in the Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing, China
| | - Xiaolin Liu
- Key Laboratory of Eco-environments in the Three Gorges Reservoir Region, Ministry of Education, Chongqing, China
- Chongqing Key Laboratory of Plant Ecology and Resources Research in the Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing, China
| | - Changxiao Li
- Key Laboratory of Eco-environments in the Three Gorges Reservoir Region, Ministry of Education, Chongqing, China
- Chongqing Key Laboratory of Plant Ecology and Resources Research in the Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing, China
- Biological Science Research Center, Academy for Advanced Interdisciplinary Studies, Southwest University, Chongqing, China
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Madrigal-González J, Luzuriaga AL, Escudero A, Ferrandis P, Calatayud J. Warming reverses directionality in the richness-abundance relationship in ephemeral Mediterranean plant communities. Ecology 2023; 104:e3870. [PMID: 36116044 DOI: 10.1002/ecy.3870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 07/22/2022] [Accepted: 08/02/2022] [Indexed: 02/01/2023]
Abstract
Recent findings in forests worldwide have demonstrated how directionality in the richness-abundance causality shifts along global climate gradients: The so-called more-species hypothesis (richness determines abundance) prevails in Earth's most productive climates, whereas the opposite, the so-called more-individuals hypothesis (abundance determines richness), is more likely to prevail in climatically harsh conditions. Since temporal variability is the norm, a critical question is whether this directionality shift is also a function of temporal climatic fluctuations locally. Here, we analyze whether directionality in the richness-abundance relationship is contingent on temporal variability over 10 annual consecutive realizations in ephemeral plant assemblages. Our results support the idea that the more-species hypothesis prevailed in the most benign years, whereas the more-individuals hypothesis did so during less productive years, which were significantly linked to the warmest years. These results support the idea that rising temperatures can reverse directionality in the richness-abundance relationship in these annual plant communities, and therefore, climate warming can have a significant effect on the relationship between diversity and ecosystem functions, such as productivity, by altering the prevalence of primary mechanisms involved in species assembly.
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Affiliation(s)
- Jaime Madrigal-González
- Área de Ecología, Departamento de Biología Animal, Ecología, Parasitología, Edafología y Química agrícola, Universidad de Salamanca, Salamanca, Spain.,Departamento de Ciencias Agroforestales, EiFAB, University of Valladolid, Soria, Spain
| | - Arantzazu L Luzuriaga
- Área Biodiversidad y Conservación, Departamento de Biología, Geología, Física Aplicada y Química Inorgánica, ESCET, Universidad Rey Juan Carlos, Madrid, Spain
| | - Adrián Escudero
- Área Biodiversidad y Conservación, Departamento de Biología, Geología, Física Aplicada y Química Inorgánica, ESCET, Universidad Rey Juan Carlos, Madrid, Spain
| | - Pablo Ferrandis
- Instituto Botánico de la Universidad de Castilla-La Mancha, Albacete, Spain
| | - Joaquín Calatayud
- Área Biodiversidad y Conservación, Departamento de Biología, Geología, Física Aplicada y Química Inorgánica, ESCET, Universidad Rey Juan Carlos, Madrid, Spain
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