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PLoS One
2009 Oct 14;410:e7423. doi: 10.1371/journal.pone.0007423.
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Species-specific traits rather than resource partitioning mediate diversity effects on resource use.
Godbold JA
,
Rosenberg R
,
Solan M
.
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BACKGROUND: The link between biodiversity and ecosystem processes has firmly been established, but the mechanisms underpinning this relationship are poorly documented. Most studies have focused on terrestrial plant systems where resource use can be difficult to quantify as species rely on a limited number of common resources. Investigating resource use at the bulk level may not always be of sufficient resolution to detect subtle differences in resource use, as species-specific nutritional niches at the biochemical level may also moderate diversity effects on resource use.
METHODOLOGY/PRINCIPAL FINDINGS: Here we use three co-occurring marine benthic echinoderms (Brissopsis lyrifera, Mesothuria intestinalis, Parastichopus tremulus) that feed on the same phytodetrital food source, to determine whether resource partitioning is the principal mechanism underpinning diversity effects on resource use. Specifically we investigate the use of phytodetrital pigments (chlorophylls and carotenoids) because many of these are essential for biological functions, including reproduction. Pigments were identified and quantified using reverse-phase high performance liquid Chromatography (HPLC) and data were analysed using a combination of extended linear regression with generalised least squares (GLS) estimation and standard multivariate techniques. Our analyses reveal no species-specific selectivity for particular algal pigments, confirming that these three species do not partition food resources at the biochemical level. Nevertheless, we demonstrate increased total resource use in diverse treatments as a result of selection effects and the dominance of one species (B. lyrifera).
CONCLUSION: Overall, we found no evidence for resource partitioning at the biochemical level, as pigment composition was similar between individuals, which is likely due to plentiful food availability. Reduced intra-specific competition in the species mixture combined with greater adsorption efficiency and differences in feeding behaviour likely explain the dominant use of resources by B. lyrifera.
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19829703
???displayArticle.pmcLink???PMC2759289 ???displayArticle.link???PLoS One
Figure 1. Mean change in total phytopigment concentration (µg gDW−1 ± SD) for echinoderm species in (a) monoculture and (b) mixture.Change is determined as differences in total pigment concentration between the initial background sediment and the faecal casts of B. lyrifera (black), M. intestinalis (dark grey) and P. tremulus (light grey) in monoculture and mixture. Abbreviations of the pigment types are: 19-But, 19 – Butanoyloxyfucoxanthin; Fucox, Fucoxanthin; 19-Hex, 19 – Hexanoyloxyfucoxanthin; Pras, Prasinoxanthin; Viol, Violaxanthin; Diadin, Diadinoxanthin; Allox, Alloxanthin; Diatox, Diatoxanthin; Zeax, Zeaxanthin; Lutein, Lutein; Chlb, Chlorophyll b; Chla, Chlorophyll a; b-Carot, β - Carotene; Phorb, Phaeophorbide a; Phytin, Phaeophytin a.
Figure 2. The effects of echinoderm species identity on the change in total phytopigment concentration (ΔTPC, µg gDW−1).Change is determined as differences in total pigment concentration between the faecal casts and the background sediment of B. lyrifera (BL), M. intestinalis (MI), P. tremulus (PT) and aquaria containing no macrofauna (CNTRL). Horizontal bars represent predicted values for each species identity. Individual data points are removed because the GLS analysis allows for differences in spread for species identity.
Figure 3. Hierarchical cluster analysis of change in phytopigment composition of species in (a) monoculture and (b) mixture.In (a) and (b) abbreviations are changes in pigment composition between the initial background sediment and the faecal casts of 1, B. lyrifera; 2, M. intestinalis; 3, P. tremulus in monoculture and in (b) 4, of the three species in mixture. Distance = dissimilarity in pigment composition between observations.
Figure 4. Summary of indices to identify the mechanisms through which echinoderm richness modifies phytopigment concentration.See Figure 1 for abbreviations of pigment type. Total represents the ΔTPC.
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Cardinale,
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Finke,
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Griffin,
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Hiratsuka,
Feeding rates and absorption efficiencies of four species of sea urchins (genus Echinometra) fed a prepared diet.
2007,
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,
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Huston,
Hidden treatments in ecological experiments: re-evaluating the ecosystem function of biodiversity.
1997,
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Loreau,
Partitioning selection and complementarity in biodiversity experiments.
2001,
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McKie,
Ecosystem functioning in stream assemblages from different regions: contrasting responses to variation in detritivore richness, evenness and density.
2008,
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Norberg,
Resource-niche complementarity and autotrophic compensation determines ecosystem-level responses to increased cladoceran species richness.
2000,
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Tilman,
Plant diversity and ecosystem productivity: theoretical considerations.
1997,
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Wojdak,
Consequences of niche overlap for ecosystem functioning: an experimental test with pond grazers.
2007,
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