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Rindi L, Mintrone C, Ravaglioli C, Benedetti-Cecchi L. Spatial signatures of an approaching regime shift in Posidonia oceanica meadows. MARINE ENVIRONMENTAL RESEARCH 2024; 198:106499. [PMID: 38640690 DOI: 10.1016/j.marenvres.2024.106499] [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: 02/05/2024] [Revised: 04/04/2024] [Accepted: 04/08/2024] [Indexed: 04/21/2024]
Abstract
Determining the proximity of ecosystems to tipping points is a critical yet complex task, heightened by the growing severity of climate change and local anthropogenic stressors on ecosystem integrity. Spatial Early Warning Signals (EWS) have been recognized for their potential in preemptively signaling regime shifts to degraded states, but their performance in natural systems remains uncertain. In this study, we investigated the performance of 'recovery length' - the spatial extent of recovery from a perturbation - and spatial EWS as early warnings of regime shifts in Posidonia oceanica meadows. Our experimental approach involved progressively thinning the P. oceanica canopy, from 0 to 100%, at the edge of a dead-matte area - a structure formed by dead P. oceanica rhizomes and colonized by algal turfs - to promote the propagation of algal turfs. We calculated recovery length as the distance from the dead-matte edge to the point where algal turfs colonized the canopy-thinned region. Our results showed a linear increase in recovery length with canopy thinning, successfully anticipated the degradation of P. oceanica. While spatial skewness decline with increased canopy degradation, other spatial EWS, such as Moran correlation at lag-1, low-frequency spatial spectra, and spatial variance, were ineffective in signaling this degradation. These findings underscore the potential of recovery length as a reliable early warning indicator of regime shifts in marine coastal ecosystems.
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Affiliation(s)
- Luca Rindi
- Department of Biology, University of Pisa, Via Derna 1, Pisa, Italy; CoNISMa, Piazzale Flaminio 9, 00196, Rome, Italy.
| | - Caterina Mintrone
- Department of Biology, University of Pisa, Via Derna 1, Pisa, Italy; CoNISMa, Piazzale Flaminio 9, 00196, Rome, Italy
| | - Chiara Ravaglioli
- Department of Biology, University of Pisa, Via Derna 1, Pisa, Italy; CoNISMa, Piazzale Flaminio 9, 00196, Rome, Italy
| | - Lisandro Benedetti-Cecchi
- Department of Biology, University of Pisa, Via Derna 1, Pisa, Italy; CoNISMa, Piazzale Flaminio 9, 00196, Rome, Italy
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Johnson CR, Dudgeon S. Understanding change in benthic marine systems. ANNALS OF BOTANY 2024; 133:131-144. [PMID: 38079203 PMCID: PMC10921837 DOI: 10.1093/aob/mcad187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 12/10/2023] [Indexed: 03/09/2024]
Abstract
BACKGROUND The unprecedented influence of human activities on natural ecosystems in the 21st century has resulted in increasingly frequent large-scale changes in ecological communities. This has heightened interest in understanding such changes and effective means to manage them. Accurate interpretation of state changes is challenging because of difficulties translating theory to empirical study, and most theory emphasizes systems near equilibrium, which may not be relevant in rapidly changing environments. SCOPE We review concepts of long-transient stages and phase shifts between stable community states, both smooth, continuous and discontinuous shifts, and the relationships among them. Three principal challenges emerge when applying these concepts. The first is how to interpret observed change in communities - distinguishing multiple stable states from long transients, or reversible shifts in the phase portrait of single attractor systems. The second is how to quantify the magnitudes of three sources of variability that cause switches between community states: (1) 'noise' in species' abundances, (2) 'wiggle' in system parameters and (3) trends in parameters that affect the topography of the basin of attraction. The third challenge is how variability of the system shapes evidence used to interpret community changes. We outline a novel approach using critical length scales to potentially address these challenges. These concepts are highlighted by a review of recent examples involving macroalgae as key players in marine benthic ecosystems. CONCLUSIONS Real-world examples show three or more stable configurations of ecological communities may exist for a given set of parameters, and transient stages may persist for long periods necessitating their respective consideration. The characteristic length scale (CLS) is a useful metric that uniquely identifies a community 'basin of attraction', enabling phase shifts to be distinguished from long transients. Variabilities of CLSs and time series data may likewise provide proactive management measures to mitigate phase shifts and loss of ecosystem services. Continued challenges remain in distinguishing continuous from discontinuous phase shifts because their respective dynamics lack unique signatures.
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Affiliation(s)
- Craig R Johnson
- Institute for Marine & Antarctic Studies, University of Tasmania, Private Bag 129, Hobart, Tasmania, Australia 7001, and
| | - Steve Dudgeon
- Department of Biology, California State University, Northridge, CA 91330-8303, USA
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Kéfi S, Génin A, Garcia-Mayor A, Guirado E, Cabral JS, Berdugo M, Guerber J, Solé R, Maestre FT. Self-organization as a mechanism of resilience in dryland ecosystems. Proc Natl Acad Sci U S A 2024; 121:e2305153121. [PMID: 38300860 PMCID: PMC10861902 DOI: 10.1073/pnas.2305153121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 12/11/2023] [Indexed: 02/03/2024] Open
Abstract
Self-organized spatial patterns are a common feature of complex systems, ranging from microbial communities to mussel beds and drylands. While the theoretical implications of these patterns for ecosystem-level processes, such as functioning and resilience, have been extensively studied, empirical evidence remains scarce. To address this gap, we analyzed global drylands along an aridity gradient using remote sensing, field data, and modeling. We found that the spatial structure of the vegetation strengthens as aridity increases, which is associated with the maintenance of a high level of soil multifunctionality, even as aridity levels rise up to a certain threshold. The combination of these results with those of two individual-based models indicate that self-organized vegetation patterns not only form in response to stressful environmental conditions but also provide drylands with the ability to adapt to changing conditions while maintaining their functioning, an adaptive capacity which is lost in degraded ecosystems. Self-organization thereby plays a vital role in enhancing the resilience of drylands. Overall, our findings contribute to a deeper understanding of the relationship between spatial vegetation patterns and dryland resilience. They also represent a significant step forward in the development of indicators for ecosystem resilience, which are critical tools for managing and preserving these valuable ecosystems in a warmer and more arid world.
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Affiliation(s)
- Sonia Kéfi
- Institut des Sciences de l’Evolution de Montpellier (ISEM), CNRS, Univ. de Montpellier, Institut de recherche pour le développement (IRD), Montpellier34095, France
- Santa Fe Institute, Santa Fe, NM87501
- Ecosystem Modeling Group, Center for Computational and Theoretical Biology, University of Würzburg, Würzburg, Germany
| | - Alexandre Génin
- Institut des Sciences de l’Evolution de Montpellier (ISEM), CNRS, Univ. de Montpellier, Institut de recherche pour le développement (IRD), Montpellier34095, France
- Environmental Sciences, Copernicus Institute of Sustainable Development, Utrecht University, Utrecht3508TC, The Netherlands
- Estación Costera de Investigaciones Marinas, Pontificia Universidad Católica de Chile, Las Cruces2690000, Chile
| | - Angeles Garcia-Mayor
- Environmental Sciences, Copernicus Institute of Sustainable Development, Utrecht University, Utrecht3508TC, The Netherlands
- Department of Biodiversity, Ecology and Evolution, Faculty of Biology, Complutense University of Madrid, Madrid28040, Spain
| | - Emilio Guirado
- Instituto Multidisciplinar para el Estudio del Medio “Ramón Margalef,” Universidad de Alicante, Alicante03690, Spain
| | - Juliano S. Cabral
- Ecosystem Modeling Group, Center for Computational and Theoretical Biology, University of Würzburg, Würzburg, Germany
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, BirminghamB15 2TT, United Kingdom
| | - Miguel Berdugo
- Department of Biodiversity, Ecology and Evolution, Faculty of Biology, Complutense University of Madrid, Madrid28040, Spain
| | - Josquin Guerber
- Institut des Sciences de l’Evolution de Montpellier (ISEM), CNRS, Univ. de Montpellier, Institut de recherche pour le développement (IRD), Montpellier34095, France
- Centre d’Ecologie et des Sciences de la Conservation (CESCO), MNHN, CNRS, Sorbonne Univ., 75005 Paris, France
| | - Ricard Solé
- Santa Fe Institute, Santa Fe, NM87501
- Catalan Institution for Research and Advanced Studies-Complex Systems Lab, Universitat Pompeu Fabra, Barcelona08003, Spain
- Institute of Evolutionary Biology, Spanish National Research Council (CSIC)-Universitat Pompeu Fabra, Barcelona08003, Spain
| | - Fernando T. Maestre
- Instituto Multidisciplinar para el Estudio del Medio “Ramón Margalef,” Universidad de Alicante, Alicante03690, Spain
- Departamento de Ecología, Universidad de Alicante, Alicante03690, Spain
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Orlando-Bonaca M, Trkov D, Klun K, Pitacco V. Diversity of Molluscan Assemblage in Relation to Biotic and Abiotic Variables in Brown Algal Forests. PLANTS 2022; 11:plants11162131. [PMID: 36015433 PMCID: PMC9415959 DOI: 10.3390/plants11162131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 08/03/2022] [Accepted: 08/11/2022] [Indexed: 11/16/2022]
Abstract
Canopy-forming macroalgae, mainly those belonging to the order Fucales, form the so-called brown algal forests, which are among the most productive assemblages in shallow coastal zones. Their vertical, branching canopies increase nearshore primary production, provide nursery areas for juvenile fish, and sustain understory assemblages of smaller algae and both sessile and vagile fauna. The majority of benthic invertebrates inhabiting these forests have larval stages that spend some time floating freely or swimming in the plankton. Therefore, canopy-forming macroalgae play an important role as species collectors related to larval supply and hydrodynamic processes. During the past several decades, brown algal forests have significantly reduced their extension and coverage in the Mediterranean basin, due to multiple interacting natural and anthropogenic pressures, with negative consequences also for the related fauna. The aim of this research was to examine how differences in macrophyte abundance and structure, as well as environmental variables, affect the associated molluscan communities in the shallow northern Adriatic Sea. Sampling sites with well-developed vegetation cover dominated by different canopy-forming species were selected in the shallow infralittoral belt of the northern Adriatic Sea in the spring–summer period of the years 2019 and 2020. Our results confirm the importance of algal forests for molluscan assemblage, with a total of 68 taxa of molluscs found associated with macrophytes. Gastropods showed the highest richness and abundance, followed by bivalves. Mollusc richness and diversity (in terms of biotic indices) were not related with the degree of development of canopy-forming species (in terms of total cover and total volume), nor with the ecological status of benthic macroalgae at different depths. On the contrary, the variability in molluscan taxa abundances was explained by some environmental variables, such as temperature, pH, light, and nitrates concentration.
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Stelzer JAA, Mesman JP, Adrian R, Ibelings BW. Early warning signals of regime shifts for aquatic systems: Can experiments help to bridge the gap between theory and real-world application? ECOLOGICAL COMPLEXITY 2021. [DOI: 10.1016/j.ecocom.2021.100944] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Orlando-Bonaca M, Pitacco V, Slavinec P, Šiško M, Makovec T, Falace A. First Restoration Experiment for Gongolaria barbata in Slovenian Coastal Waters. What Can Go Wrong? PLANTS (BASEL, SWITZERLAND) 2021; 10:239. [PMID: 33530631 PMCID: PMC7911296 DOI: 10.3390/plants10020239] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/22/2021] [Accepted: 01/22/2021] [Indexed: 11/16/2022]
Abstract
The global decline of brown algal forests along rocky coasts is causing an exceptional biodiversity loss. Regardless of conservation efforts, different techniques have been developed for large-scale restoration strategies in the Mediterranean Sea. In this study we tested ex situ pilot restoration of Gongolaria barbata (=Treptacantha barbata) for the first time in Slovenian coastal waters. Healthy apical fronds of the species were collected and the development of recruits on clay tiles was followed under laboratory conditions for 20 days. Despite the experimental difficulties experienced, especially due to the lack of antibiotics to prevent the growth of the biofilm, G. barbata recruits were outplanted in the sea on two concrete plates with 48 tiles each, protected by purpose-built cages to avoid grazing by herbivorous fish. The high survival rate of juveniles after four months in the field (89% of the tiles on the plate that was constantly protected) suggests that outplanting G. barbata is an operable approach for restoration efforts in the northern Adriatic Sea. Our first experiment in Slovenian coastal waters provides new information for the optimization of the best practices during the laboratory cultivation and addresses the early steps of restoration and introduction of young thalli in the natural environment.
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Affiliation(s)
- Martina Orlando-Bonaca
- Marine Biology Station Piran, National Institute of Biology, Fornače 41, SI-6330 Piran, Slovenia; (V.P.); (P.S.); (M.Š.); (T.M.)
| | - Valentina Pitacco
- Marine Biology Station Piran, National Institute of Biology, Fornače 41, SI-6330 Piran, Slovenia; (V.P.); (P.S.); (M.Š.); (T.M.)
| | - Petra Slavinec
- Marine Biology Station Piran, National Institute of Biology, Fornače 41, SI-6330 Piran, Slovenia; (V.P.); (P.S.); (M.Š.); (T.M.)
| | - Milijan Šiško
- Marine Biology Station Piran, National Institute of Biology, Fornače 41, SI-6330 Piran, Slovenia; (V.P.); (P.S.); (M.Š.); (T.M.)
| | - Tihomir Makovec
- Marine Biology Station Piran, National Institute of Biology, Fornače 41, SI-6330 Piran, Slovenia; (V.P.); (P.S.); (M.Š.); (T.M.)
| | - Annalisa Falace
- Department of Life Sciences, University of Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy;
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Tamburello L, Papa L, Guarnieri G, Basconi L, Zampardi S, Scipione MB, Terlizzi A, Zupo V, Fraschetti S. Are we ready for scaling up restoration actions? An insight from Mediterranean macroalgal canopies. PLoS One 2019; 14:e0224477. [PMID: 31652294 PMCID: PMC6814225 DOI: 10.1371/journal.pone.0224477] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 10/15/2019] [Indexed: 11/23/2022] Open
Abstract
Extensive loss of macroalgal forests advocates for large-scale restoration interventions, to compensate habitat degradation and recover the associated ecological functions and services. Yet, restoration attempts have generally been limited to small spatial extensions, with the principal aim of developing efficient restoration techniques. Here, the success of outplanting Cystoseira amentacea v. stricta germlings cultured in aquaria was experimentally explored at a scale of tens of kms, by means of a multifactorial experimental design. In the intertidal rocky shores of SE Italy, locations with a continuous distribution for hundreds of meters or with few thalli forming patches of few centimeters of C. amentacea canopy were selected. In each location, the effects of adult conspecifics and the exclusion of macrograzers (salema fish and sea urchins) on the survival of germlings were tested. We evaluated the most critical determinants of mortality for germlings, including the overlooked pressure of mesograzers (e.g. amphipods, small mollusks, polychaetes). Despite the high mortality observed during outplanting and early settlement stages, survival of C. amentacea germlings was consistently favored by the exclusion of macrograzers, while the presence of adult conspecifics had no effects. In addition, the cost analysis of the interventions showed the feasibility of the ex-situ method, representing an essential tool for preserving Cystoseira forests. Large scale restoration is possible but requires baseline information with an in-depth knowledge of the species ecology and of the areas to be restored, together with the development of specific cultivation protocols to make consistently efficient restoration interventions.
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Affiliation(s)
- Laura Tamburello
- CoNISMa, Roma, Italy
- Stazione Zoologica Anton Dohrn, Napoli, Italy
| | - Loredana Papa
- Department of Biology, and Environmental Sciences and Technologies, University of Salento, Lecce, Italy
| | - Giuseppe Guarnieri
- CoNISMa, Roma, Italy
- Department of Biology, and Environmental Sciences and Technologies, University of Salento, Lecce, Italy
| | - Laura Basconi
- Department of Environmental Sciences, Informatics and Statistics, Ca’ Foscari University, Venice, Italy
| | | | | | - Antonio Terlizzi
- CoNISMa, Roma, Italy
- Stazione Zoologica Anton Dohrn, Napoli, Italy
- Department of Life Sciences, University of Trieste, Trieste, Italy
| | | | - Simonetta Fraschetti
- CoNISMa, Roma, Italy
- Stazione Zoologica Anton Dohrn, Napoli, Italy
- Department of Biology, University of Naples Federico II, Napoli, Italy
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Tamburello L, Ravaglioli C, Mori G, Nuccio C, Bulleri F. Enhanced nutrient loading and herbivory do not depress the resilience of subtidal canopy forests in Mediterranean oligotrophic waters. MARINE ENVIRONMENTAL RESEARCH 2019; 149:7-17. [PMID: 31136874 DOI: 10.1016/j.marenvres.2019.05.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 05/17/2019] [Accepted: 05/20/2019] [Indexed: 06/09/2023]
Abstract
The interaction between top-down and bottom-up forces determines the recovery trajectory of macroalgal forests exposed to multiple stressors. In an oligotrophic system, we experimentally investigated how nutrient inputs affected the recovery of Cystoseira brachycarpa following physical disturbance of varying intensities, both inside forested areas and at the boundary with sea urchin barrens. Unexpectedly, Cystoseira forests were highly resilient to disturbance, as they were able to recover from any partial damage. In general, the addition of nutrients sped up the recovery of Cystoseira. Thus, only the total canopy removal, in combination with either low nutrient availability or intense grazing pressure, promoted the expansion of mat-forming algae or urchin barrens, respectively. Our study suggests that the effects of enhanced nutrient levels may vary according to the trophic characteristics of the waterbody, and hence, are likely to vary among regions of the Mediterranean basin.
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Affiliation(s)
| | - Chiara Ravaglioli
- Dipartimento di Biologia, Università di Pisa, CoNISMa, Via Derna 1, Pisa, 56126, Italy
| | - Giovanna Mori
- Dipartimento di Biologia, Università di Firenze, Via Micheli 1, Firenze, 50121, Italy
| | - Caterina Nuccio
- Dipartimento di Biologia, Università di Firenze, Via Micheli 1, Firenze, 50121, Italy
| | - Fabio Bulleri
- Dipartimento di Biologia, Università di Pisa, CoNISMa, Via Derna 1, Pisa, 56126, Italy
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