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Yarnall AH, Fodrie FJ. Predation patterns across states of landscape fragmentation can shift with seasonal transitions. Oecologia 2020; 193:403-413. [PMID: 32556593 DOI: 10.1007/s00442-020-04675-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Accepted: 05/28/2020] [Indexed: 11/26/2022]
Abstract
Nested scales of habitat heterogeneity may independently or synergistically influence faunal interactions. Fragmentation effects (i.e., the breaking apart of landscapes) and edge effects (i.e., ecological differences between edges and interiors of patches, nested within landscapes) are distinct yet related ecological concepts, linked mathematically by the habitat edge-to-area ratio. Our study quantified the separate and interactive effects of fragmentation and edge on predation using temperate seagrass. To assess how predation and generalized consumption were influenced by fragmentation state (i.e., continuous, fragmented), and proximity to edge (i.e., edges, interiors), we used tethering assays with two prey-items: juvenile crabs, Callinectes sapidus, and "squidpops" (dried squid mantle). We also investigated whether faunal densities (a proxy for consumption potential) and temperature (a proxy for a broad suite of seasonal changes) correlated with predation across landscapes. Results showed fragmentation state affected predation (i.e., crab) mortality, yet edge effects did not. Moreover, the directionality of fragmentation effects shifted across a temperature/seasonal gradient. Predation mortality more than doubled in continuous landscapes amidst temperature increases, surpassing initially higher mortality in fragmented landscapes, which did not systematically vary with temperature. This mortality magnitude "flip" matched spatiotemporal trends in faunal densities between continuous and fragmented meadows. Consumption rates of both prey-items increased alongside temperature and neither demonstrated edge effects. However, crabs showed fragmentation effects not seen with squidpops, suggesting differing foraging strategies used by consumers of these prey-items. We conclude that fragmentation and edge effects have dynamic influences on temperate predator-prey interactions, as faunal favorability of habitat heterogeneity can "flip" temporally.
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Affiliation(s)
- Amy H Yarnall
- Institute of Marine Sciences, University of North Carolina at Chapel Hill, 3431 Arendell Street, Morehead City, NC, 28557, USA.
| | - F Joel Fodrie
- Institute of Marine Sciences, University of North Carolina at Chapel Hill, 3431 Arendell Street, Morehead City, NC, 28557, USA
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Jahnke M, Casagrandi R, Melià P, Schiavina M, Schultz ST, Zane L, Procaccini G. Potential and realized connectivity of the seagrassPosidonia oceanicaand their implication for conservation. DIVERS DISTRIB 2017. [DOI: 10.1111/ddi.12633] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Affiliation(s)
| | - Renato Casagrandi
- Dipartimento di Elettronica, Informazione e Bioingegneria; Politecnico di Milano; Milano Italy
- Consorzio Nazionale Interuniversitario per le Scienze del Mare; Roma Italy
| | - Paco Melià
- Dipartimento di Elettronica, Informazione e Bioingegneria; Politecnico di Milano; Milano Italy
- Consorzio Nazionale Interuniversitario per le Scienze del Mare; Roma Italy
| | - Marcello Schiavina
- Dipartimento di Elettronica, Informazione e Bioingegneria; Politecnico di Milano; Milano Italy
- Consorzio Nazionale Interuniversitario per le Scienze del Mare; Roma Italy
| | | | - Lorenzo Zane
- Consorzio Nazionale Interuniversitario per le Scienze del Mare; Roma Italy
- Dipartimento di Biologia; Università di Padova; Padova Italy
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Lefcheck JS, Marion SR, Lombana AV, Orth RJ. Faunal Communities Are Invariant to Fragmentation in Experimental Seagrass Landscapes. PLoS One 2016; 11:e0156550. [PMID: 27244652 PMCID: PMC4887026 DOI: 10.1371/journal.pone.0156550] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 05/16/2016] [Indexed: 11/28/2022] Open
Abstract
Human-driven habitat fragmentation is cited as one of the most pressing threats facing many coastal ecosystems today. Many experiments have explored the consequences of fragmentation on fauna in one foundational habitat, seagrass beds, but have either surveyed along a gradient of existing patchiness, used artificial materials to mimic a natural bed, or sampled over short timescales. Here, we describe faunal responses to constructed fragmented landscapes varying from 4–400 m2 in two transplant garden experiments incorporating live eelgrass (Zostera marina L.). In experiments replicated within two subestuaries of the Chesapeake Bay, USA across multiple seasons and non-consecutive years, we comprehensively censused mesopredators and epifaunal communities using complementary quantitative methods. We found that community properties, including abundance, species richness, Simpson and functional diversity, and composition were generally unaffected by the number of patches and the size of the landscape, or the intensity of sampling. Additionally, an index of competition based on species co-occurrences revealed no trends with increasing patch size, contrary to theoretical predictions. We extend conclusions concerning the invariance of animal communities to habitat fragmentation from small-scale observational surveys and artificial experiments to experiments conducted with actual living plants and at more realistic scales. Our findings are likely a consequence of the rapid life histories and high mobility of the organisms common to eelgrass beds, and have implications for both conservation and restoration, suggesting that even small patches can rapidly promote abundant and diverse faunal communities.
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Affiliation(s)
- Jonathan S Lefcheck
- Virginia Institute of Marine Science, The College of William & Mary, Gloucester Point, Virginia, 23062, United States of America
| | - Scott R Marion
- Oregon Department of Fish & Wildlife, Marine Resources Program, Newport, Oregon, 97365, United States of America
| | - Alfonso V Lombana
- Virginia Institute of Marine Science, The College of William & Mary, Gloucester Point, Virginia, 23062, United States of America
| | - Robert J Orth
- Virginia Institute of Marine Science, The College of William & Mary, Gloucester Point, Virginia, 23062, United States of America
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Macroalgal Composition Determines the Structure of Benthic Assemblages Colonizing Fragmented Habitats. PLoS One 2015; 10:e0142289. [PMID: 26554924 PMCID: PMC4640819 DOI: 10.1371/journal.pone.0142289] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 10/20/2015] [Indexed: 11/19/2022] Open
Abstract
Understanding the consequences of fragmentation of coastal habitats is an important topic of discussion in marine ecology. Research on the effects of fragmentation has revealed complex and context-dependent biotic responses, which prevent generalizations across different habitats or study organisms. The effects of fragmentation in marine environments have been rarely investigated across heterogeneous habitats, since most studies have focused on a single type of habitat or patch. In this study, we assessed the effects of different levels of fragmentation (i.e. decreasing size of patches without overall habitat loss). We measured these effects using assemblages of macro-invertebrates colonizing representative morphological groups of intertidal macroalgae (e.g. encrusting, turf and canopy-forming algae). For this purpose, we constructed artificial assemblages with different combinations of morphological groups and increasing levels of fragmentation by manipulating the amount of bare rock or the spatial arrangement of different species in mixed assemblages. In general, our results showed that 1) fragmentation did not significantly affect the assemblages of macroinvertebrates; 2) at greater levels of fragmentation, there were greater numbers of species in mixed algal assemblages, suggesting that higher habitat complexity promotes species colonization. Our results suggest that predicting the consequences of fragmentation in heterogeneous habitats is dependent on the type and diversity of morphological groups making up those habitats.
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Lanham BS, Gribben PE, Poore AGB. Beyond the border: effects of an expanding algal habitat on the fauna of neighbouring habitats. MARINE ENVIRONMENTAL RESEARCH 2015; 106:10-8. [PMID: 25749309 DOI: 10.1016/j.marenvres.2015.02.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 02/12/2015] [Accepted: 02/23/2015] [Indexed: 06/04/2023]
Abstract
The impacts of novel habitat-forming organisms on associated fauna have been difficult to predict, and may affect the fauna of neighbouring habitats due to changes in the spatial configuration of habitat patches of differing quality. Here, we test whether the localised expansion of a native habitat-forming macroalga, Caulerpa filiformis, on subtidal reefs can affect the abundance of fauna associated with a neighbouring macroalgal habitat. C. filiformis was a functionally distinct habitat for fauna, and the total abundance of epifauna associated with the resident alga, Sargassum linearifolium, was reduced at some sites when in close proximity to or surrounded by C. filiformis. Experimental manipulation of habitat configuration demonstrated that the low abundance of gastropods on S. linearifolium when surrounded by C. filiformis was likely explained by C. filiformis acting as a physical dispersal barrier for mobile fauna. Changes to the spatial configuration of novel and resident habitats can thus affect the abundance of fauna in addition to the direct replacement of habitats by species undergoing range expansions or increasing in abundance.
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Affiliation(s)
- Brendan S Lanham
- Evolution & Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia.
| | - Paul E Gribben
- Plant Functional Biology and Climate Change Cluster, School of the Environment, University of Technology Sydney, Sydney, NSW 2007, Australia
| | - Alistair G B Poore
- Evolution & Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia
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Ollivier QR, Bramwell NA, Hammill E, Foster-Thorpe C, Booth DJ. Are the effects of adjacent habitat type on seagrass gastropod communities being masked by previous focus on habitat dyads? AUST J ZOOL 2015. [DOI: 10.1071/zo15057] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Variation in abundance and diversity of organisms along habitat edges has long been a key research focus in both terrestrial and marine ecosystems. Previous investigations into edge effects in seagrass ecosystems have predominantly focussed on the seagrass–sandy substrate boundary. However, little is known about what role other habitats (e.g. rocky algal reefs) may play in faunal assemblage patterns. This study investigated the strength to which habitat type influenced gastropod assemblages within seagrass (Posidonia australis) beds, bordered by both sandy substrate and rocky algal reef. We found that benthic invertebrate community composition significantly changed with distance from rocky algal reef, but not with distance from sandy substrate. Proximity to rocky reef had a stronger effect on community composition than other local drivers examined (seagrass biomass and sand particle size). We hypothesise that gastropod affinity for rocky algal reef may be a result of both species-specific habitat preference, and lower predation pressure along adjacent rocky algal reef habitats. This study provides evidence that heterogeneous habitats within close proximity to seagrass beds may exert previously overlooked effects on the distribution of gastropod assemblages, highlighting the need for the inclusion of adjacent habitat type in experimental design for gastropod assemblage distribution studies.
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Smith TM, Hindell JS, Jenkins GP, Connolly RM, Keough MJ. Fine-scale spatial and temporal variations in diets of the pipefish Stigmatopora nigra within seagrass patches. JOURNAL OF FISH BIOLOGY 2011; 78:1824-1832. [PMID: 21651530 DOI: 10.1111/j.1095-8649.2011.02977.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Diets of the pipefish Stigmatopora nigra were analysed to determine if food availability was causing S. nigra to distribute according to habitat edge effects. Gut analysis found little difference in the diets of S. nigra at the edge and interior of seagrass patches, regardless of time of day or season. Fish diets did, however, vary with seagrass density: S. nigra in denser seagrass consumed more harpacticoid copepods and fewer planktonic copepods. The lack of difference in prey eaten by S. nigra at the edge and interior of patches suggests either that food was not determining S. nigra distribution patterns within patches or that differences in fish densities across patches meant that relative fish-prey densities were similar at edge and interior positions. Alternatively, any edge effects in diet might be masked by gradients in seagrass structure.
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Affiliation(s)
- T M Smith
- Victorian Marine Science Consortium, P. O. Box 114, Queenscliff, Vic 3225 Australia.
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Macreadie PI, Hindell JS, Keough MJ, Jenkins GP, Connolly RM. Resource distribution influences positive edge effects in a seagrass fish. Ecology 2010; 91:2013-21. [PMID: 20715624 DOI: 10.1890/08-1890.1] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Peter I Macreadie
- Department of Zoology, University of Melbourne, Parkville 3010, Australia.
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Affiliation(s)
- Timothy M Smith
- Department of Zoology, University of Melbourne, Parkville, Vic. 3010, Australia.
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10
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MURPHY HANNAHM, JENKINS GREGORYP, HINDELL JEREMYS, CONNOLLY RODM. Response of fauna in seagrass to habitat edges, patch attributes and hydrodynamics. AUSTRAL ECOL 2009. [DOI: 10.1111/j.1442-9993.2009.02062.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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MACREADIE PETERI, CONNOLLY RODM, KEOUGH MICHAELJ, JENKINS GREGORYP, HINDELL JEREMYS. Short-term differences in animal assemblages in patches formed by loss and growth of habitat. AUSTRAL ECOL 2009. [DOI: 10.1111/j.1442-9993.2009.02060.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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