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Lochin P, Malherbe P, Marteau B, Godfroy J, Gerle F, Marshall J, Puijalon S, Singer MB, Stella JC, Piégay H, Vernay A. The ant and the grasshopper: Contrasting responses and behaviors to water stress of riparian trees along a hydroclimatic gradient. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 952:175916. [PMID: 39226962 DOI: 10.1016/j.scitotenv.2024.175916] [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: 03/29/2024] [Revised: 08/27/2024] [Accepted: 08/29/2024] [Indexed: 09/05/2024]
Abstract
Riparian trees are particularly vulnerable to drought because they are highly dependent on water availability for their survival. However, the response of riparian tree species to water stress varies depending on regional hydroclimatic conditions, making them unevenly vulnerable to changing drought patterns. Understanding this spatial variability in stress responses requires a comprehensive assessment of water stress across broader spatial and temporal scales. Yet, the precise ecophysiological mechanisms underlying these responses remain poorly linked to remotely sensed indices. To address this gap, the implementation of remote sensing methods coupled with in situ validation is essential to obtain consistent results across diverse spatial and temporal contexts. We conducted a multi-tool analysis combining multispectral and thermal remote sensing indices with in situ ecophysiological measurements at different temporal scales to analyze the responses of white poplar (Populus alba) to seasonal changes in drought along a hydroclimatic gradient. Using this approach, we demonstrate that white poplars along the Rhône River (France) exhibit contrasting responses and behaviors during drought depending on the latitudinal context. White poplars in a Mediterranean climate show rapid stomatal closure to reduce water loss and maintain high minimum water potential levels, although this results in a decrease in remotely sensed greenness. Conversely, white poplars located upstream in a temperate climate show high transpiration and stable greenness but lower minimum water potential and water content. A site in the middle of the gradient has intermediate responses. These results demonstrate that white poplars along a climate gradient can have a range of responses to drought along the iso/anisohydricity continuum. These results are important for future climatic conditions because they show that the same species can have different mechanisms of drought resilience, even in the same river valley. This raises questions regarding how these riparian tree populations will respond to future climatic and hydrological conditions.
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Affiliation(s)
- Pierre Lochin
- ENS de Lyon, UMR 5600 Environnement Ville société, CNRS, Lyon, France.
| | - Pauline Malherbe
- ENS de Lyon, UMR 5600 Environnement Ville société, CNRS, Lyon, France
| | - Baptiste Marteau
- ENS de Lyon, UMR 5600 Environnement Ville société, CNRS, Lyon, France; LETG UMR 6554, Université Rennes 2, Rennes, France
| | - Julien Godfroy
- ENS de Lyon, UMR 5600 Environnement Ville société, CNRS, Lyon, France; Univ. Grenoble Alpes, INRAE, LESSEM, F-38402 St-Martin d'Hères, France
| | - Flavie Gerle
- Université Claude Bernard Lyon 1, LEHNA UMR 5023, CNRS, ENTPE, F-69622, Villeurbanne, France
| | - John Marshall
- Global Change Research Institute, Czech Academy of Sciences, Bělidla 4a, 603 00 Brno, Czech Republic; Leibniz-Zentrum für Agrarlandschaftsforschung, 15374 Müncheberg, Germany; Department of Geological Sciences, Gothenburg University, Gothenburg, Sweden
| | - Sara Puijalon
- Université Claude Bernard Lyon 1, LEHNA UMR 5023, CNRS, ENTPE, F-69622, Villeurbanne, France
| | - Michael Bliss Singer
- Earth Research Institute, University of California, Santa Barbara, CA 93106, USA; Water Research Institute, Cardiff University, Cardiff CF10 3AX, UK; School of Earth and Environmental Sciences, Cardiff University, Cardiff CF10 3AT, UK
| | - John C Stella
- Department of Sustainable Resources Management, State University of New York College of Environmental Science and Forestry, Syracuse, NY 13210, USA
| | - Hervé Piégay
- ENS de Lyon, UMR 5600 Environnement Ville société, CNRS, Lyon, France
| | - Antoine Vernay
- Université Claude Bernard Lyon 1, LEHNA UMR 5023, CNRS, ENTPE, F-69622, Villeurbanne, France
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Hajdukiewicz H, Hajdukiewicz M, Ruiz-Villanueva V, Radecki-Pawlik A, Zawiejska J. Exploring historical changes in mountain river hydrodynamics induced by human impact. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 948:174742. [PMID: 39004370 DOI: 10.1016/j.scitotenv.2024.174742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 07/08/2024] [Accepted: 07/11/2024] [Indexed: 07/16/2024]
Abstract
During the 20th-century many mountain rivers in Europe were subjected to intensive human impacts which substantially modified their channel morphology. How these changes affected river hydrodynamics and response to floods remains uncertain. In this work, we perform hydraulic modelling using data from archival aerial photos to explore relations between hydraulic parameters of floods and human-induced channel incision occurring on the Czarny Dunajec River (Polish Carpathians) between 1964 and 2012. Data on vertical position of the channel used for two-dimensional modelling of flood flows were extracted (as Digital Elevation Models DEMs) from archival aerial photos from 1964 and 1983 and ALS (Airborne Laser Skanning)-derived DEM from 2012. Water depth, flow velocity, bed shear stress, and sediment critical diameter were modelled for four flood scenarios (2-year, 5-year, 20-year, and 50-year floods) as well as the extent of flooded area and additionally the grain size of channel sediment was calculated. The values of water depth, flow velocity, bed shear stress and sediment critical diameter increased significantly between 1964 and 1983, especially for 20-year and 50-year floods. Only the flow velocity within the floodplain zone did not increase for the two largest flood scenarios due to the expansion of riparian forest in the second half of the twentieth century. The increase in flow rate was accompanied by a progressive reduction of the extent of flooded area, especially between 1964 and 1983, as well as by increase in mean grain size of channel sediment. Between 1983 and 2012 changes in hydraulic parameters were less pronounced, and coarser and well packed channel sediment dominated on the river bed. Our work demonstrates that reconstruction of past river hydrodynamics, rather than river state at time horizons, can give essential insights into functioning of the river channel and floodplain during the intensification of human impacts after 1950s.
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Affiliation(s)
- Hanna Hajdukiewicz
- Institute of Nature Conservation, Polish Academy of Sciences, al. Mickiewicza 33, 31-120 Kraków, Poland.
| | - Maciej Hajdukiewicz
- Department of Environmental Engineering, Geomatics and Energetics, Kielce University of Technology, al.Tysiąclecia Państwa Polskiego 7, 25-314 Kielce, Poland
| | - Virginia Ruiz-Villanueva
- Geomorphology, Natural Hazards and Risks Research Unit, Institute of Geography, University of Bern, Hallerstrasse 12, 3012 Bern, Switzerland; Faculty of Geoscience and Environment, Institute of Earth Surface Dynamics, University of Lausanne Geopolis, 1015 Lausanne, Switzerland
| | - Artur Radecki-Pawlik
- Kraków University of Technology, Faculty of Civil Engineering, Warszawska 24, 31155 Kraków, Poland
| | - Joanna Zawiejska
- Institute of Biology and Earth Sciences, University of National Education Commission, Krakow, ul. Podchorążych 2, 30-084 Kraków, Poland
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Camarero JJ, Colangelo M, Rodríguez-Gonzalez PM. Historical disconnection from floodplain alters riparian forest composition, tree growth and deadwood amount. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 896:165266. [PMID: 37406690 DOI: 10.1016/j.scitotenv.2023.165266] [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: 05/05/2023] [Revised: 06/30/2023] [Accepted: 06/30/2023] [Indexed: 07/07/2023]
Abstract
Riparian forests are among the most dynamic but threatened terrestrial ecosystems. Their dynamism and conservation depend on historical changes in river geomorphology, which can be evaluated through changes in channel sinuosity. However, we lack long-term assessments on sinuosity and how they impact riparian forest composition, tree growth and deadwood amount. To fill this research gap, we reconstructed river sinuosity in 14 sites across the middle Ebro basin, north-eastern Spain, using historical aerial photographs taken in 1927, 1956, 1998-2003 and 2014-2015. Relationships between sinuosity, stand composition and deadwood amount and decay degree were calculated. We also reconstructed radial growth of the major tree species (Populus alba, Populus nigra, Fraxinus angustifolia, Salix alba and Ulmus minor) in two sites to evaluate how coupled it was with changes in river flow after dam building. From 1927 to 2015, sinuosity decreased passing from 1.39 to 1.20. The river dynamics were altered in the 1950s and 1960s after dam and dyke building. Sites with high sinuosity values in 1956 corresponded to mature stands with large P. nigra individuals. Sinuosity was negatively related to F. angustifolia (rs = -0.83, p < 0.001) and P. alba (rs = -0.64, p = 0.02) abundance, whereas sites dominated by P. alba and U. minor presented abundant decayed deadwood. A loss of sinuosity and a contraction of the riverbank gradient increased disconnection of active channel from floodplain, with a mixing of more (e.g., P. nigra) and less phreatophytic species (e.g., U. minor). River flow diversion reduced growth and increased the tree-to-tree P. alba growth coherence. Hydrological droughts contributed to growth decline and dieback of U. minor, which is sensitive to spring river flow. Conservation and restoration of riparian forests must consider historical changes in river geomorphology related to human activities.
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Affiliation(s)
- J Julio Camarero
- Pyrenean Institute of Ecology (IPE-CSIC), Avda. Montañana 1005, 50192 Zaragoza, Spain.
| | - Michele Colangelo
- Pyrenean Institute of Ecology (IPE-CSIC), Avda. Montañana 1005, 50192 Zaragoza, Spain; School of Agricultural, Forestry, Food and Environmental Sciences, University of Basilicata, Viale dell'Ateneo Lucano 10, 85100 Potenza, Italy.
| | - Patricia M Rodríguez-Gonzalez
- Forest Research Centre and Associate Laboratory TERRA, School of Agriculture, University of Lisbon, Lisbon 1349-017, Portugal.
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Fanton H, Affre L, Franquet E, Bertrand C, Cavalli L, Dumas E, Guiller C, Kaldonski N, Meineri E, Mutillod C, Oursel B, Pavon D, Thorel M, Tatoni T, Fayolle S. Heavy ionic pollution disrupts assemblages of algae, macroinvertebrates and riparian vegetation. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 331:121791. [PMID: 37201567 DOI: 10.1016/j.envpol.2023.121791] [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: 01/09/2023] [Revised: 05/04/2023] [Accepted: 05/07/2023] [Indexed: 05/20/2023]
Abstract
Urban streams display consistent ecological symptoms that commonly express degraded biological, physical, and chemical conditions: the urban stream syndrome (USS). Changes linked to the USS result in consistent declines in the abundance and richness of algae, invertebrates, and riparian vegetation. In this paper, we assessed the impacts of extreme ionic pollution from an industrial effluent in an urban stream. We studied the community composition of benthic algae and benthic invertebrates and the indicator traits of riparian vegetation. The dominant pool of benthic algae, benthic invertebrates and riparian species were considered as euryece. However, ionic pollution impacted these three biotic compartments' communities, disrupting these tolerant species assemblages. Indeed, after the effluent, we observed the higher occurrence of conductivity-tolerant benthic taxa, like Nitzschia palea or Potamopyrgus antipodarum and plant species reflecting nitrogen and salt contents in soils. Providing insights into organisms' responses and resistance to heavy ionic pollution, this study sheds light on how industrial environmental perturbations could alter the ecology of freshwater aquatic biodiversity and riparian vegetation.
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Affiliation(s)
- Hadrien Fanton
- IMBE, Aix Marseille Univ, Avignon Université, CNRS, IRD, Marseille, France.
| | - Laurence Affre
- IMBE, Aix Marseille Univ, Avignon Université, CNRS, IRD, Marseille, France
| | - Evelyne Franquet
- IMBE, Aix Marseille Univ, Avignon Université, CNRS, IRD, Marseille, France
| | - Céline Bertrand
- IMBE, Aix Marseille Univ, Avignon Université, CNRS, IRD, Marseille, France
| | - Laurent Cavalli
- IMBE, Aix Marseille Univ, Avignon Université, CNRS, IRD, Marseille, France
| | - Estelle Dumas
- IMBE, Aix Marseille Univ, Avignon Université, CNRS, IRD, Marseille, France
| | - Clémence Guiller
- IMBE, Aix Marseille Univ, Avignon Université, CNRS, IRD, Marseille, France
| | - Nicolas Kaldonski
- IMBE, Aix Marseille Univ, Avignon Université, CNRS, IRD, Marseille, France
| | - Eric Meineri
- IMBE, Aix Marseille Univ, Avignon Université, CNRS, IRD, Marseille, France
| | | | - Benjamin Oursel
- IMBE, Aix Marseille Univ, Avignon Université, CNRS, IRD, Marseille, France
| | - Daniel Pavon
- IMBE, Aix Marseille Univ, Avignon Université, CNRS, IRD, Marseille, France
| | - Maxine Thorel
- IMBE, Aix Marseille Univ, Avignon Université, CNRS, IRD, Marseille, France
| | - Thierry Tatoni
- IMBE, Aix Marseille Univ, Avignon Université, CNRS, IRD, Marseille, France
| | - Stéphanie Fayolle
- IMBE, Aix Marseille Univ, Avignon Université, CNRS, IRD, Marseille, France
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5
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Functional stability of vegetation following biocontrol of an invasive riparian shrub. Biol Invasions 2023. [DOI: 10.1007/s10530-022-02967-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
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Havrdová A, Douda J, Doudová J. Threats, biodiversity drivers and restoration in temperate floodplain forests related to spatial scales. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 854:158743. [PMID: 36108840 DOI: 10.1016/j.scitotenv.2022.158743] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 08/19/2022] [Accepted: 09/09/2022] [Indexed: 06/15/2023]
Abstract
Floodplain forests offer a diversity of habitats and resources for a very wide range of plant and animal species. They also offer many benefits to humankind and are considered essential to the mitigation of the effects of climate change. Nevertheless, throughout the world they are suffering the most intense of anthropogenic pressures so are, of all ecosystems, among the most endangered. Here, we bring together and synthesise existing ecological understanding of the mechanisms underlying the high heterogeneity and diversity of temperate floodplain forests and of the pressures threatening their high biological value due to habitat homogenisation. Floodplain forests depend on the periodic disturbances under which they evolved, including fluvial dynamics, traditional management practices and the activities of herbivores. However, they have been heavily degraded by climate change, invasion of exotic species, river-flow regulation, landscape fragmentation, eutrophication and the cessation of traditional management. We can now observe two general trends in temperate floodplain forests: (1) Due to intensive landscape exploitation, they are now more open and thus prone to the spread of competitive species, including of invasive exotics and (2) Due to the cessation of traditional management, along with modified hydrological conditions, they are composed of species in the later successional stages (i.e., more shade-tolerant and mesic) while light-demanding species are quickly vanishing. Restoration practices have brought about contrasting results when restoration of floodplains to their natural states has been problematic. This is likely because of interplay between various natural and artificial processes not previously taken into proper consideration. We would like to draw attention to the fact that restoration projects or the preservation of existing floodplain forest ecosystems should combine the restoration of watercourses with the mitigation of other important threats acting at different scales of the landscape (spread of invasive species, eutrophication of watersheds and inappropriate forest management).
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Affiliation(s)
- Alena Havrdová
- Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, Praha-Suchdol 165 00, Czech Republic.
| | - Jan Douda
- Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, Praha-Suchdol 165 00, Czech Republic
| | - Jana Doudová
- Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, Praha-Suchdol 165 00, Czech Republic
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7
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Shu Y, Jiang L, Liu F, Lv G. Effects of plant diversity and abiotic factors on the multifunctionality of an arid desert ecosystem. PLoS One 2022; 17:e0266320. [PMID: 35687606 PMCID: PMC9187101 DOI: 10.1371/journal.pone.0266320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 03/18/2022] [Indexed: 11/30/2022] Open
Abstract
Many studies suggest that species diversity and abiotic factors promote ecosystem multifunctionality. However, whether ecosystem multifunctionality is impacted by phylogenetic diversity remains controversial. The present study tested this in an arid desert ecosystem in Ebinur Lake Basin using soil C:N ratio, soil pH, and soil salinity as abiotic factors, and species diversity and phylogenetic diversity as indicators of plant diversity. The effects of plant diversity and abiotic factors on single ecosystem functions (nutrient cycling, carbon stocks, water regulation, and wood production) and ecosystem multifunctionality were studied. We used structural equation modeling to assess the relationships among different functional groups and factors. The results showed that: (1) abiotic factors, particularly pH and C:N ratio in soil, had the strongest positive impact on multifunctionality (P < 0.001). The phylogenetic diversity and species diversity showed inconsistent changes, and their contribution to multifunctionality were not outstanding. (2) Abiotic factors were closely related to different ecosystem functions. Soil C:N had a significant positive effect on carbon stocks (P < 0.001), with an effect index of 0.89. Soil pH significantly enhanced nutrient cycling and water regulation. The role of plant diversity varied with the combination of different ecosystem functions. Phylogenetic diversity and species diversity influenced wood production, but showed opposite functions. (3) The importance of four single-ecosystem functions in an arid region was ranked as follows: carbon stocks > water regulation > nutrient cycling > wood production, emphasizing the importance of carbon elements in these ecosystems. These results improve our understanding of the drivers of multifunctionality in arid ecosystems, facilitating the elucidation of the influence of abiotic factors and phylogenetic diversity.
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Affiliation(s)
- Yulin Shu
- College of Ecology and Environment, Xinjiang University, Urumqi, Xinjiang, China
- Key Laboratory of Oasis Ecology of Education Ministry, Xinjiang University, Urumqi, PR China
| | - Lamei Jiang
- College of Ecology and Environment, Xinjiang University, Urumqi, Xinjiang, China
- Key Laboratory of Oasis Ecology of Education Ministry, Xinjiang University, Urumqi, PR China
| | - Feiyi Liu
- College of Ecology and Environment, Xinjiang University, Urumqi, Xinjiang, China
- Key Laboratory of Oasis Ecology of Education Ministry, Xinjiang University, Urumqi, PR China
| | - Guanghui Lv
- College of Ecology and Environment, Xinjiang University, Urumqi, Xinjiang, China
- Key Laboratory of Oasis Ecology of Education Ministry, Xinjiang University, Urumqi, PR China
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Janssen P, Chevalier R, Chantereau M, Dupré R, Evette A, Hémeray D, Mårell A, Martin H, Rodrigues S, Villar M, Greulich S. Can vegetation clearing operations and reprofiling of bars be considered as an ecological restoration measure? Lessons from a 10‐year vegetation monitoring program (Loire River, France). Restor Ecol 2022. [DOI: 10.1111/rec.13704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Philippe Janssen
- Univ. Grenoble Alpes, INRAE, LESSEM, F‐38402 St‐Martin‐d'Hères France
| | | | | | - Rémi Dupré
- Conservatoire Botanique National du Bassin Parisien, F‐45064 Orléans France
| | - André Evette
- Univ. Grenoble Alpes, INRAE, LESSEM, F‐38402 St‐Martin‐d'Hères France
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Hoppenreijs JHT, Eckstein RL, Lind L. Pressures on Boreal Riparian Vegetation: A Literature Review. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2021.806130] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Riparian zones are species-rich and functionally important ecotones that sustain physical, chemical and ecological balance of ecosystems. While scientific, governmental and public attention for riparian zones has increased over the past decades, knowledge on the effects of the majority of anthropogenic disturbances is still lacking. Given the increasing expansion and intensity of these disturbances, the need to understand simultaneously occurring pressures grows. We have conducted a literature review on the potential effects of anthropogenic pressures on boreal riparian zones and the main processes that shape their vegetation composition. We visualised the observed and potential consequences of flow regulation for hydropower generation, flow regulation through channelisation, the climate crisis, forestry, land use change and non-native species in a conceptual model. The model shows how these pressures change different aspects of the flow regime and plant habitats, and we describe how these changes affect the extent of the riparian zone and dispersal, germination, growth and competition of plants. Main consequences of the pressures we studied are the decrease of the extent of the riparian zone and a poorer state of the area that remains. This already results in a loss of riparian plant species and riparian functionality, and thus also threatens aquatic systems and the organisms that depend on them. We also found that the impact of a pressure does not linearly reflect its degree of ubiquity and the scale on which it operates. Hydropower and the climate crisis stand out as major threats to boreal riparian zones and will continue to be so if no appropriate measures are taken. Other pressures, such as forestry and different types of land uses, can have severe effects but have more local and regional consequences. Many pressures, such as non-native species and the climate crisis, interact with each other and can limit or, more often, amplify each other’s effects. However, we found that there are very few studies that describe the effects of simultaneously occurring and, thus, potentially interacting pressures. While our model shows where they may interact, the extent of the interactions thus remains largely unknown.
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Arif M, Jie Z, Wokadala C, Songlin Z, Zhongxun Y, Zhangting C, Zhi D, Xinrui H, Changxiao L. Assessing riparian zone changes under the influence of stress factors in higher-order streams and tributaries: Implications for the management of massive dams and reservoirs. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 776:146011. [PMID: 33647660 DOI: 10.1016/j.scitotenv.2021.146011] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 02/17/2021] [Accepted: 02/17/2021] [Indexed: 06/12/2023]
Abstract
Riparian ecosystem services along higher-order streams and connected tributaries may change over time as disturbances continuously increase, resulting in diverse deterioration of buffer zones. How habitat, plant cover, regeneration, erosion, and exotic parameters (riparian health conditions) change within huge dams and reservoirs worldwide is an unanswered question. We used multivariate statistical techniques to assess changes in riparian health parameters affected by disturbances identified in 304 transects within the Three Gorges Dam Reservoir, China, and associated tributaries. Kruskal-Wallis tests (p < 0.01) revealed high diversity in habitat, plant cover, regeneration, erosion, and overall stream condition. There was also notable variance relating to exotic and pressure parameters. The critical variables of riparian health indicators and stress factors identified by principal component analysis explained 58.40% and 74.6% (in the main waterway) and 53.23% and 71.0% (in the tributaries) of the total variance. Among riparian health indicators, one habitat parameter (riparian vegetation width) in the main waterway and one regeneration parameter (tree size classes) in tributaries contributed greatly, along with other specified parameters. Furthermore, stress factors such as farming systems, land-use types, and pollutant activity variables had the highest impact on these water bodies. In comparison, counting stress factors alone showed more deterioration in the main waterway with a range of (r = -0.527- 0.493), as determined using Pearson correlation (p < 0.05). Furthermore, after indexing, the parameters exhibited weaker coefficient values in tributaries, where exotic correlated negatively with other indexed values. These findings are relevant for managers of massive dam and reservoir ecosystems seeking to mitigate environmental and socioeconomic losses.
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Affiliation(s)
- Muhammad Arif
- Key Laboratory of Eco-Environments in the Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources Research in the Three Gorges Reservoir Region, College of Life Sciences, Southwest University, Chongqing 400715, China; Punjab Forest Department, Government of Punjab, Lahore 54000, Pakistan.
| | - Zheng Jie
- Key Laboratory of Eco-Environments in the Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources Research in the Three Gorges Reservoir Region, College of Life Sciences, Southwest University, Chongqing 400715, China.
| | - Charles Wokadala
- Key Laboratory of Eco-Environments in the Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources Research in the Three Gorges Reservoir Region, College of Life Sciences, Southwest University, Chongqing 400715, China
| | - Zhang Songlin
- Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China.
| | - Yuan Zhongxun
- Key Laboratory of Eco-Environments in the Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources Research in the Three Gorges Reservoir Region, College of Life Sciences, Southwest University, Chongqing 400715, China.
| | - Chen Zhangting
- Key Laboratory of Eco-Environments in the Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources Research in the Three Gorges Reservoir Region, College of Life Sciences, Southwest University, Chongqing 400715, China.
| | - Dong Zhi
- Key Laboratory of Eco-Environments in the Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources Research in the Three Gorges Reservoir Region, College of Life Sciences, Southwest University, Chongqing 400715, China.
| | - He Xinrui
- Key Laboratory of Eco-Environments in the Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources Research in the Three Gorges Reservoir Region, College of Life Sciences, Southwest University, Chongqing 400715, China.
| | - Li Changxiao
- Key Laboratory of Eco-Environments in the Three Gorges Reservoir Region (Ministry of Education), Chongqing Key Laboratory of Plant Ecology and Resources Research in the Three Gorges Reservoir Region, College of Life Sciences, Southwest University, Chongqing 400715, China.
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11
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Rohde MM, Stella JC, Roberts DA, Singer MB. Groundwater dependence of riparian woodlands and the disrupting effect of anthropogenically altered streamflow. Proc Natl Acad Sci U S A 2021; 118:e2026453118. [PMID: 34161277 PMCID: PMC8237578 DOI: 10.1073/pnas.2026453118] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Riparian ecosystems fundamentally depend on groundwater, especially in dryland regions, yet their water requirements and sources are rarely considered in water resource management decisions. Until recently, technological limitations and data gaps have hindered assessment of groundwater influences on riparian ecosystem health at the spatial and temporal scales relevant to policy and management. Here, we analyze Sentinel-2-derived normalized difference vegetation index (NDVI; n = 5,335,472 observations), field-based groundwater elevation (n = 32,051 observations), and streamflow alteration data for riparian woodland communities (n = 22,153 polygons) over a 5-y period (2015 to 2020) across California. We find that riparian woodlands exhibit a stress response to deeper groundwater, as evidenced by concurrent declines in greenness represented by NDVI. Furthermore, we find greater seasonal coupling of canopy greenness to groundwater for vegetation along streams with natural flow regimes in comparison with anthropogenically altered streams, particularly in the most water-limited regions. These patterns suggest that many riparian woodlands in California are subsidized by water management practices. Riparian woodland communities rely on naturally variable groundwater and streamflow components to sustain key ecological processes, such as recruitment and succession. Altered flow regimes, which stabilize streamflow throughout the year and artificially enhance water supplies to riparian vegetation in the dry season, disrupt the seasonal cycles of abiotic drivers to which these Mediterranean forests are adapted. Consequently, our analysis suggests that many riparian ecosystems have become reliant on anthropogenically altered flow regimes, making them more vulnerable and less resilient to rapid hydrologic change, potentially leading to future riparian forest loss across increasingly stressed dryland regions.
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Affiliation(s)
- Melissa M Rohde
- Graduate Program in Environmental Science, State University of New York College of Environmental Science and Forestry, Syracuse, NY 13210;
- California Water Program, The Nature Conservancy, Sacramento, CA 95811
| | - John C Stella
- Department of Sustainable Resources Management, State University of New York College of Environmental Science and Forestry, Syracuse, NY 13210
| | - Dar A Roberts
- Department of Geography, University of California, Santa Barbara, CA 93106
| | - Michael Bliss Singer
- School of Earth and Environmental Sciences, Cardiff University, CF10 3AT Cardiff, United Kingdom
- Water Research Institute, Cardiff University, CF10 3AX Cardiff, United Kingdom
- Earth Research Institute, University of California, Santa Barbara, CA 93106
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12
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Zhao J, Peng W, Ding M, Nie M, Huang G. Effect of Water Chemistry, Land Use Patterns, and Geographic Distances on the Spatial Distribution of Bacterioplankton Communities in an Anthropogenically Disturbed Riverine Ecosystem. Front Microbiol 2021; 12:633993. [PMID: 34025599 PMCID: PMC8138559 DOI: 10.3389/fmicb.2021.633993] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 04/13/2021] [Indexed: 11/13/2022] Open
Abstract
The spatial distribution of bacterioplankton communities in rivers is driven by multiple environmental factors, including local and regional factors. Local environmental condition is associated with effect of river water chemistry (through species sorting); ecological process in region is associated with effects of land use and geography. Here, we investigated variation in bacterioplankton communities (free-living, between 0.22 and 5 μm) in an anthropogenically disturbed river using high-throughput DNA sequencing of community 16S rRNA genes in order to investigate the importance of water chemistry, land use patterns, and geographic distance. Among environmental factors, sulfate (SO4 2-), manganese (Mn), and iron (Fe) concentrations were the water chemistry parameters that best explained bacterioplankton community variation. In addition, forest and freshwater areas were the land use patterns that best explained bacterioplankton community variation. Furthermore, cumulative dendritic distance was the geographic distance parameter that best explained bacterial community variation. Variation partitioning analysis revealed that water chemistry, land use patterns, and geographic distances strongly shaped bacterioplankton communities. In particular, the direct influence of land use was prominent, which alone contributed to the highest proportion of variation (26.2% in wet season communities and 36.5% in dry season communities). These results suggest that the mechanisms of species sorting and mass effects together control bacterioplankton communities, although mass effects exhibited higher contributions to community variation than species sorting. Given the importance of allochthonous bacteria input from various land use activities (i.e., mass effects), these results provide new insights into the environmental factors and determinant mechanisms that shape riverine ecosystem communities.
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Affiliation(s)
- Jun Zhao
- School of Geography and Environment, Jiangxi Normal University, Nanchang, China.,Key Laboratory of Poyang Lake Wetland and Watershed Research, Ministry of Education, Jiangxi Normal University, Nanchang, China
| | - Wang Peng
- School of Geography and Environment, Jiangxi Normal University, Nanchang, China.,Key Laboratory of Poyang Lake Wetland and Watershed Research, Ministry of Education, Jiangxi Normal University, Nanchang, China
| | - Mingjun Ding
- School of Geography and Environment, Jiangxi Normal University, Nanchang, China.,Key Laboratory of Poyang Lake Wetland and Watershed Research, Ministry of Education, Jiangxi Normal University, Nanchang, China
| | - Minghua Nie
- School of Geography and Environment, Jiangxi Normal University, Nanchang, China.,Key Laboratory of Poyang Lake Wetland and Watershed Research, Ministry of Education, Jiangxi Normal University, Nanchang, China
| | - Gaoxiang Huang
- School of Geography and Environment, Jiangxi Normal University, Nanchang, China.,Key Laboratory of Poyang Lake Wetland and Watershed Research, Ministry of Education, Jiangxi Normal University, Nanchang, China
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13
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Janssen P, Stella JC, Räpple B, Gruel CR, Seignemartin G, Pont B, Dufour S, Piégay H. Long-term river management legacies strongly alter riparian forest attributes and constrain restoration strategies along a large, multi-use river. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 279:111630. [PMID: 33213995 DOI: 10.1016/j.jenvman.2020.111630] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 09/17/2020] [Accepted: 10/20/2020] [Indexed: 06/11/2023]
Abstract
Many terrestrial ecosystems have undergone profound transformation under the pressure of multiple human stressors. This may have oriented altered ecosystems toward transient or new states. Understanding how these cumulative impacts influence ecosystem functions, services and ecological trajectories is therefore essential to defining effective restoration strategies. This is particularly the case in riverine ecosystems, where the profound alteration of natural disturbance regimes can make the effectiveness of restoration operations questionable. Using the case study of legacy dike fields, i.e., area delimited by longitudinal and lateral dikes, along the regulated Rhône River, we studied the impacts of long-term channelization and flow regulation on environmental conditions and riparian forests attributes along a 200 km climatic gradient. We characterized the imprint of human stressors on these forests by comparing the dike field stands to more natural stands in both young and mature vegetation stages. Across four reaches of the river between Lyon and the Mediterranean Sea, we found that channelization consistently promoted high rate of overbank sedimentation and rapid disconnection of dike field surfaces from the channel. The rapid terrestrialisation of dike field surfaces, i.e., the process by which former aquatic areas transition to a terrestrial ecosystem as a result of dewatering or sedimentation, fostered a pulse of riparian forest regeneration in these resource-rich environments that differs from more natural sites in structure and composition. Within the dike fields, older pre-dam stands are dominated by post-pioneer and exotic species, and post-dam stands support large, aging pioneer trees with a largely exotic understory regeneration layer. These patterns were associated with differences in the relative surface elevation among dike fields, whereas species shifts generally followed the river's longitudinal climate gradient. To enhance the functionality of these human-made ecosystems, restoration strategies should target the reconnection of dike fields to the river by dismantling part of the dikes to promote lateral erosion, forest initiation and community succession, as well as increasing minimum flows in channels to improve connection with groundwater. However, since a river-wide return to a pre-disturbance state is very unlikely, a pragmatic approach should be favoured, focusing on local actions that can improve abiotic and biotic function, and ultimately enhancing ecosystem services such biodiversity, habitat, and recreation opportunities.
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Affiliation(s)
- Philippe Janssen
- Univ. Lyon, UMR 5600 Environnement Ville Société, CNRS, Site of ENS Lyon, Lyon, France; Univ. Grenoble Alpes, INRAE, LESSEM, St-Martin-d'Hères, France.
| | - John C Stella
- Department of Sustainable Resources Management, State University of New York College of Environmental Science and Forestry, Syracuse, NY, USA.
| | - Bianca Räpple
- Univ. Lyon, UMR 5600 Environnement Ville Société, CNRS, Site of ENS Lyon, Lyon, France.
| | - Charles-Robin Gruel
- Univ. Lyon, UMR 5600 Environnement Ville Société, CNRS, Site of ENS Lyon, Lyon, France; Asian School of the Environment, Nanyang Technological University, Singapore.
| | | | - Bernard Pont
- Réserves Naturelles de France, Quétigny, France.
| | | | - Hervé Piégay
- Univ. Lyon, UMR 5600 Environnement Ville Société, CNRS, Site of ENS Lyon, Lyon, France.
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14
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Lozanovska I, Rivaes R, Vieira C, Ferreira MT, Aguiar FC. Streamflow regulation effects in the Mediterranean rivers: How far and to what extent are aquatic and riparian communities affected? THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 749:141616. [PMID: 32827828 DOI: 10.1016/j.scitotenv.2020.141616] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 08/08/2020] [Accepted: 08/08/2020] [Indexed: 06/11/2023]
Abstract
Dam-induced disruption of the natural continuum of rivers has manifold consequences on fluvial ecosystems, but how distinct plant groups and plant adaptive strategies can mediate the regulation effects is largely unexplored. In this work, we focused on how different plant groups (macrophytes, bryophytes, and riparian woody vegetation) respond to hydrological alterations along the river and across the riparian zone downstream of dams. We specifically aimed to determine the degree of regulation [DOR] and distance from dam [DFD], where river regulation no longer significantly affects plant communities in two case studies - a run-of-river dam and a reservoir in Portugal. We collected data on plant species cover in 7 unregulated and 24 regulated sites in June-July 2019. We performed a cluster and ordination analysis to derive guilds using flow-responsive traits and applied linear models to predict guild alterations along the gradient of DOR and DFD. We established three macrophytes, six bryophytes, and five riparian guilds. Our results showed that the vegetation response to regulation was plant group-reliant and guild-specific. Overall, plant responses were expressed by changes in plant cover, and not by guilds' loss. We observed (1) an increase of the guild cover of macrophytes and a decrease in bryophytes cover with increasing regulation gradient and diverse responses for riparian guilds; (2) an encroachment of riparian vegetation guilds into the channel downstream of the storage reservoir and expansion outwards downstream of the run-of-river dam; (3) a higher number of significant alterations for reservoir sites compared with run-of-river sites. Finally, for particular guilds, we determined specific DOR and DFD from which guild covers became significantly indistinct from respective guild cover in unregulated circumstances. Understanding the communities' responses to diverse regulation types and the extent that different plant adaptations may counter regulation effects can be vital for optimizing river restoration projects.
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Affiliation(s)
- Ivana Lozanovska
- Centro de Estudos Florestais, Instituto Superior de Agronomia, Universidade de Lisboa, Tapada da Ajuda, 1349-017 Lisboa, Portugal.
| | - Rui Rivaes
- Centro de Estudos Florestais, Instituto Superior de Agronomia, Universidade de Lisboa, Tapada da Ajuda, 1349-017 Lisboa, Portugal
| | - Cristiana Vieira
- Museu de História Natural e da Ciência da Universidade do Porto (MHNC-UP; UPorto/PRISC), Praça Gomes Teixeira, 4099-002 Porto, Portugal
| | - Maria Teresa Ferreira
- Centro de Estudos Florestais, Instituto Superior de Agronomia, Universidade de Lisboa, Tapada da Ajuda, 1349-017 Lisboa, Portugal
| | - Francisca C Aguiar
- Centro de Estudos Florestais, Instituto Superior de Agronomia, Universidade de Lisboa, Tapada da Ajuda, 1349-017 Lisboa, Portugal
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