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He Y, Bond-Lamberty B, Myers-Pigg AN, Newcomer ME, Ladau J, Holmquist JR, Brown JB, Falco N. Effects of spatial variability in vegetation phenology, climate, landcover, biodiversity, topography, and soil property on soil respiration across a coastal ecosystem. Heliyon 2024; 10:e30470. [PMID: 38726202 PMCID: PMC11079102 DOI: 10.1016/j.heliyon.2024.e30470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 03/21/2024] [Accepted: 04/26/2024] [Indexed: 05/12/2024] Open
Abstract
Coastal terrestrial-aquatic interfaces (TAIs) are crucial contributors to global biogeochemical cycles and carbon exchange. The soil carbon dioxide (CO2) efflux in these transition zones is however poorly understood due to the high spatiotemporal dynamics of TAIs, as various sub-ecosystems in this region are compressed and expanded by complex influences of tides, changes in river levels, climate, and land use. We focus on the Chesapeake Bay region to (i) investigate the spatial heterogeneity of the coastal ecosystem and identify spatial zones with similar environmental characteristics based on the spatial data layers, including vegetation phenology, climate, landcover, diversity, topography, soil property, and relative tidal elevation; (ii) understand the primary driving factors affecting soil respiration within sub-ecosystems of the coastal ecosystem. Specifically, we employed hierarchical clustering analysis to identify spatial regions with distinct environmental characteristics, followed by the determination of main driving factors using Random Forest regression and SHapley Additive exPlanations. Maximum and minimum temperature are the main drivers common to all sub-ecosystems, while each region also has additional unique major drivers that differentiate them from one another. Precipitation exerts an influence on vegetated lands, while soil pH value holds importance specifically in forested lands. In croplands characterized by high clay content and low sand content, the significant role is attributed to bulk density. Wetlands demonstrate the importance of both elevation and sand content, with clay content being more relevant in non-inundated wetlands than in inundated wetlands. The topographic wetness index significantly contributes to the mixed vegetation areas, including shrub, grass, pasture, and forest. Additionally, our research reveals that dense vegetation land covers and urban/developed areas exhibit distinct soil property drivers. Overall, our research demonstrates an efficient method of employing various open-source remote sensing and GIS datasets to comprehend the spatial variability and soil respiration mechanisms in coastal TAI. There is no one-size-fits-all approach to modeling carbon fluxes released by soil respiration in coastal TAIs, and our study highlights the importance of further research and monitoring practices to improve our understanding of carbon dynamics and promote the sustainable management of coastal TAIs.
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Affiliation(s)
- Yinan He
- Earth and Environmental Sciences Area, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA, 94720-8126, USA
| | - Ben Bond-Lamberty
- Joint Global Change Research Institute, Pacific Northwest National Laboratory, College Park, MD, 20740, USA
| | - Allison N. Myers-Pigg
- Marine and Coastal Research Laboratory, Pacific Northwest National Laboratory, Sequim, WA, 98382, USA
- Department of Environmental Sciences, University of Toledo, Toledo, OH, 43606, USA
| | - Michelle E. Newcomer
- Earth and Environmental Sciences Area, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA, 94720-8126, USA
| | - Joshua Ladau
- Computational Biosciences Group, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA, 94720, USA
| | - James R. Holmquist
- Smithsonian Environmental Research Center, 647 Contees Wharf Road, Edgewater, MD, 21037, USA
| | - James B. Brown
- Computational Biosciences Group, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA, 94720, USA
| | - Nicola Falco
- Earth and Environmental Sciences Area, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA, 94720-8126, USA
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Xiao X, Peng Y, Zhang W, Yang X, Zhang Z, Ren B, Zhu G, Zhou S. Current status and prospects of algal bloom early warning technologies: A Review. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 349:119510. [PMID: 37951110 DOI: 10.1016/j.jenvman.2023.119510] [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: 07/26/2023] [Revised: 10/21/2023] [Accepted: 10/31/2023] [Indexed: 11/13/2023]
Abstract
In recent years, frequent occurrences of algal blooms due to environmental changes have posed significant threats to the environment and human health. This paper analyzes the reasons of algal bloom from the perspective of environmental factors such as nutrients, temperature, light, hydrodynamics factors and others. Various commonly used algal bloom monitoring methods are discussed, including traditional field monitoring methods, remote sensing techniques, molecular biology-based monitoring techniques, and sensor-based real-time monitoring techniques. The advantages and limitations of each method are summarized. Existing algal bloom prediction models, including traditional models and machine learning (ML) models, are introduced. Support Vector Machine (SVM), deep learning (DL), and other ML models are discussed in detail, along with their strengths and weaknesses. Finally, this paper provides an outlook on the future development of algal bloom warning techniques, proposing to combine various monitoring methods and prediction models to establish a multi-level and multi-perspective algal bloom monitoring system, further improving the accuracy and timeliness of early warning, and providing more effective safeguards for environmental protection and human health.
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Affiliation(s)
- Xiang Xiao
- College of Civil Engineering, Hunan University of Science and Technology, Xiangtan, 411201, China
| | - Yazhou Peng
- College of Civil Engineering, Hunan University of Science and Technology, Xiangtan, 411201, China.
| | - Wei Zhang
- School of Hydraulic and Environmental Engineering, Changsha University of Science & Technology, Changsha, 410114, China.
| | - Xiuzhen Yang
- College of Civil Engineering, Hunan University of Science and Technology, Xiangtan, 411201, China
| | - Zhi Zhang
- Laboratory of Three Gorges Reservoir Region, Chongqing University, Chongqing, 400045, China
| | - Bozhi Ren
- School of Earth Sciences and Spatial Information Engineering, Hunan University of Science and Technology, Xiangtan, 411201, Hunan, China
| | - Guocheng Zhu
- College of Civil Engineering, Hunan University of Science and Technology, Xiangtan, 411201, China
| | - Saijun Zhou
- College of Civil Engineering, Hunan University of Science and Technology, Xiangtan, 411201, China
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Gao Y, Tian Y, Zhan W, Li L, Sun H, Zhao T, Zhang H, Meng Y, Li Y, Liu T, Ding J. Characterizing legacy nitrogen-induced time lags in riverine nitrogen reduction for the Songhuajiang River Basin: Source analysis, spatio-seasonal patterns, and impacts on future water quality improvement. WATER RESEARCH 2023; 242:120292. [PMID: 37413751 DOI: 10.1016/j.watres.2023.120292] [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: 02/06/2023] [Revised: 06/18/2023] [Accepted: 06/28/2023] [Indexed: 07/08/2023]
Abstract
Legacy nitrogen (N) originating from net N inputs (NNI) may pose ongoing threats to riverine water quality worldwide and even cause serious time-lags between water quality restoration and NNI declines. A better understanding of legacy N effects on riverine N pollutions in different seasons is essential to improve riverine water quality. Here, we investigated contributions of legacy N on riverine dissolved inorganic N (DIN) changes in different seasons and quantified spatio-seasonal time-lags in the Songhuajiang River basin (SRB), a hotspot of NNI with four distinct seasons, by exploring long-term (1978-2020) NNI-DIN relationships. Results firstly showed a significant seasonal difference in NNI, with the highest value observed in spring (average, 2184.1 kg/km2), 1.2, 5.0, and 4.6 times higher than that in summer, autumn, and winter, respectively. Cumulative legacy N had dominated riverine DIN changes, with a relative contribution of approximately 64% in 2011-2020, causing time-lags of 11-29 years across the SRB. The longest seasonal lags existed in spring (average, 23 years) owing to greater impacts of legacy N to riverine DIN changes in this season. Mulch film application, soil organic matter accumulation, N inputs, and snow cover were identified as the key factors that strengthened seasonal time-lags by collaboratively enhancing legacy N retentions in soils. Furthermore, a machine learning-based model system suggested that timescales for water quality improvement (DIN, ≤1.5 mg/L) varied considerably (from 0 to >29 years, Improved N Management-Combined scenario) across the SRB, with greater lag effects contributing to slower recovery. These findings can provide a more comprehensive insight into sustainable basin N management in the future.
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Affiliation(s)
- Yedong Gao
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Yu Tian
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin 150090, China.
| | - Wei Zhan
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Lipin Li
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Huihang Sun
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Tianrui Zhao
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Haoran Zhang
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Yiming Meng
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Yanliang Li
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Tao Liu
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Jie Ding
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin 150090, China
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Specific bacterial microbiome enhances the sexual reproduction and auxospore production of the marine diatom, Odontella. PLoS One 2022; 17:e0276305. [PMID: 36260629 PMCID: PMC9581435 DOI: 10.1371/journal.pone.0276305] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 10/04/2022] [Indexed: 11/19/2022] Open
Abstract
Auxospore production is a sexual reproductive strategy by diatoms to re-attain normal size after the size-reducing effect of clonal reproduction. Aside from the minimum size threshold used as a sex clock by diatoms, the environmental or chemical triggers that can induce sex in diatoms are still not well understood. Here we investigated the influence of six marine bacteria from five families on the production of sexual cells and auxospores of the ubiquitous marine polar centric diatom, Odontella sp. Microbiome association and co-occurrence with the diatom in culture and in nature were investigated using 16S rRNA amplicon sequencing. Indole acetic acid (IAA) secretion, a phytohormone that regulates plants' growth and sexual development, was explored as a potential inducer of sexual reproduction in Odontella and compared between bacterial associates. We found that Odontella co-cultured with Flavobacteriaceae (Polaribacter and Cellulophaga) have significantly more sexual cells and auxospores than bacteria-free Odontella and Odontella co-cultured with other bacteria from Vibrionaceae (Vibrio), Pseudoalteromonadaceae (Pseudoalteromonas), Rhodobacteraceae (Sulfitobacter), or Planococcaceae (Planococcus) family. Differences in IAA secretion were observed between bacterial isolates, but this did not correspond consistently with the diatom's clonal growth or production of sexual cells and auxospores. Microbiome composition survey of Odontella cultures showed that the diatom harbors homologous sequences of the four bacterial isolates at varying proportions, with Sulfitobacter and Polaribacter at high abundances. Microbiome surveys at Santa Cruz Wharf, Monterey Bay, from 2014-2015 showed that Odontella abundance is positively correlated with Flavobacteriaceae and Rhodobacteraceae abundances. Our study demonstrates that specific members of the diatom microbiome can enhance the host's sexual reproduction, with the interkingdom interaction driven by partner compatibility and long-term association. Sex-enhancing bacteria may even be needed by the diatom host to carry out the optimal inducement of sex under normal conditions, allowing for size restitution and maintaining genetic diversity in culture and in nature.
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