INTERACTIVE EFFECTS OF SPATIAL VARIANCE AND MEAN INTENSITY OF GRAZING ON ALGAL COVER IN ROCK POOLS
2005; Wiley; Volume: 86; Issue: 8 Linguagem: Inglês
10.1890/04-1223
ISSN1939-9170
AutoresLisandro Benedetti‐Cecchi, Stefano Vaselli, Elena Maggi, Iacopo Bertocci,
Tópico(s)Soil and Water Nutrient Dynamics
ResumoEcologyVolume 86, Issue 8 p. 2212-2222 Article INTERACTIVE EFFECTS OF SPATIAL VARIANCE AND MEAN INTENSITY OF GRAZING ON ALGAL COVER IN ROCK POOLS Lisandro Benedetti-Cecchi, Lisandro Benedetti-Cecchi Dipartimento di Scienze dell'Uomo e dell'Ambiente, Via A. Volta 6, I-56126 Pisa, Italy E-mail: [email protected]Search for more papers by this authorStefano Vaselli, Stefano Vaselli Dipartimento di Scienze dell'Uomo e dell'Ambiente, Via A. Volta 6, I-56126 Pisa, ItalySearch for more papers by this authorElena Maggi, Elena Maggi Dipartimento di Scienze dell'Uomo e dell'Ambiente, Via A. Volta 6, I-56126 Pisa, ItalySearch for more papers by this authorIacopo Bertocci, Iacopo Bertocci Dipartimento di Scienze dell'Uomo e dell'Ambiente, Via A. Volta 6, I-56126 Pisa, ItalySearch for more papers by this author Lisandro Benedetti-Cecchi, Lisandro Benedetti-Cecchi Dipartimento di Scienze dell'Uomo e dell'Ambiente, Via A. Volta 6, I-56126 Pisa, Italy E-mail: [email protected]Search for more papers by this authorStefano Vaselli, Stefano Vaselli Dipartimento di Scienze dell'Uomo e dell'Ambiente, Via A. Volta 6, I-56126 Pisa, ItalySearch for more papers by this authorElena Maggi, Elena Maggi Dipartimento di Scienze dell'Uomo e dell'Ambiente, Via A. Volta 6, I-56126 Pisa, ItalySearch for more papers by this authorIacopo Bertocci, Iacopo Bertocci Dipartimento di Scienze dell'Uomo e dell'Ambiente, Via A. Volta 6, I-56126 Pisa, ItalySearch for more papers by this author First published: 01 August 2005 https://doi.org/10.1890/04-1223Citations: 20 Corresponding Editor (ad hoc): M. N. Dethier Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat Abstract An increasing number of studies suggest that the variance around the mean of predictor variables is an important determinant of the structure of assemblages, but few have separated effects of mean from those of variance of predictor variables experimentally. We addressed these issues by examining the effects of limpets on algal recovery in littoral rock pools. An initial experiment indicated that algal cover was a negative accelerating function of density of limpets, although this effect was weak. Superimposed to this effect there was a clear trend of variability in algal cover among pools that decreased with increasing density of limpets. These results suggested that mean intensity and spatial variance of grazing could affect algal colonization both within and among pools. This proposition was tested with a novel experimental design in which the mean intensity and the spatial variance of grazing were manipulated in factorial combinations. The experiment was repeated twice to examine possible generalities of outcomes. In both runs spatial variance of grazing enhanced spatial variance in algal cover, although this effect occurred under weak intensity of grazing in the first run and in combination with strong intensity of grazing in the second run. In contrast, intensity and variability in grazing operated independently on mean algal cover, with strong intensity depressing colonization of algae and large variance increasing colonization consistently in time. By manipulating the mean intensity and the spatial variance of grazing simultaneously, we were able to explain spatial patterns in algal cover that would have been classified as unexplained variation otherwise. We suggest that this novel experimental design may be fruitful to understand spatially variable processes in a wide range of ecological systems. Literature Cited Adler, P. B., D. A. Raff, and W. K. Lauenroth . 2001. Effects of grazing on the spatial heterogeneity of vegetation. Oecologia 128: 465–479. Benedetti-Cecchi, L. . 2000a. Variance in ecological consumer–resource interactions. Nature 407: 370–374. Benedetti-Cecchi, L. . 2000b. Predicting direct and indirect interactions during succession in a midlittoral rocky shore assemblage. Ecological Monographs 70: 45–72. Benedetti-Cecchi, L. . 2003. The importance of the variance around the mean effect size of ecological processes. Ecology 84: 2335–2346. Benedetti-Cecchi, L. . 2005. The importance of the variance around the mean effect size of ecological processes: reply. Ecology 86, in press.. Berlow, E. L. . 1999. Strong effects of weak interactions in ecological communities. Nature 398: 330–334. Branch, G. M. . 1981. The biology of limpets: physical factors, energy flow, and ecological interactions. Oceanography and Marine Biology: An Annual Review 19: 235–380. Butler IV., M. J. 1989. Community responses to variable predation: field studies with sunfish and freshwater macroinvertebrates. Ecological Monographs 59: 311–328. Cardinale, B. J., M. A. Palmer, C. M. Swan, S. Brooks, and N. L. Poff . 2002. The influence of substrate heterogeneity on biofilm metabolism in a stream ecosystem. Ecology 83: 412–422. Chase, J. M. . 1999. Food web effects of prey size refugia: variable interactions and alternative stable equilibria. American Naturalist 156: 559–570. Danielson, B. J. . 1991. Communities in a landscape: the influence of habitat heterogeneity on the interactions between species. American Naturalist 138: 1105–1120. Day, K. J., M. J. Hutchings, and E. A. John . 2003. The effects of spatial pattern of nutrient supply on yield, structure and mortality in plant populations. Journal of Ecology 91: 541–553. Della Santina, P. . 1990. Eco-etologia dei Patellidae (Mollusca: Gastropoda) sul litorale tirrenico. Dissertation. University of Florence, Florence, Italy. Dethier, M. N., E. S. Graham, S. Cohen, and L. M. Tear . 1993. Visual versus random-point percent cover estimation: 'objective' is not always better. Marine Ecology Progress Series 96: 93–100. Fairweather, P. G. . 1988. Predation creates haloes of bare space among prey on rocky seashores in New South Wales. Australian Journal of Ecology 13: 401–409. Gaines, S. D. and J. Roughgarden . 1985. Larval settlement rate: a leading determinant of structure in an ecological community of the marine intertidal zone. Proceedings of the National Academy of Sciences (USA) 82: 3707–3711. Gould, S. J. . 1988. Trends as changes in variance: a new slant on progress and directionality in evolution. Journal of Paleontology 62: 319–329. Hawkins, S. J. and R. G. Hartnoll . 1983. Grazing of intertidal algae by marine invertebrates. Oceanography and Marine Biology: an Annual Review 21: 195–282. Holling, C. S. . 1992. Cross-scale morphology, geometry, and dynamics of ecosystems. Ecological Monographs 62: 447–502. Hutchings, M. J., E. A. John, and D. Wijesinghe . 2003. Toward understanding the consequences of soil heterogeneity for plant populations and communities. Ecology 84: 2322–2334. Inouye, B. D. . 2005. The importance of the variance around the mean effect size of ecological processes: comment. Ecology 86, in press.. Jensen, J. L. . 1906. Sur les fonctions convexes et les iné gualités entre les valeurs moyennes. Acta Mathematica 30: 175–193. Johnson, M. P., M. T. Burrows, R. G. Hartnoll, and S. J. Hawkins . 1997. Spatial structure on moderately exposed rocky shores: patch scales and the interactions between limpets and algae. Marine Ecology Progress Series 160: 209–215. Levin, S. A. . 1992. The problem of pattern and scale in ecology. Ecology 73: 1943–1967. Lively, C. M., P. T. Raimondi, and L. F. Delph . 1993. Intertidal community structure: space–time interactions in the Northern Gulf of California. Ecology 74: 162–173. Lubchenco, J. and S. D. Gaines . 1981. A unified approach to marine plant–herbivore interactions. I. Populations and communities. Annual Review of Ecology and Systematics 12: 405–437. McCabe, D. J. and N. J. Gotelli . 2000. Effects of disturbance frequency, intensity, and area on assemblages of stream invertebrates. Oecologia 124: 270–279. McCann, K., A. Hastings, and G. R. Huxel . 1998. Weak trophic interactions and the balance of nature. Nature 395: 794–798. McCullagh, P. and J. A. Nelder . 1989. Generalized linear models. Chapman and Hall, New York, New York, USA. Menge, B. A., E. L. Berlow, C. A. Blanchette, S. A. Navarrete, and S. B. Yamada . 1994. The keystone species concept: variation in interaction strength in a rocky intertidal habitat. Ecological Monographs 64: 249–286. Navarrete, S. A. . 1996. Variable predation: effects of whelks on a mid-intertidal successional community. Ecological Monographs 66: 301–321. Osenberg, C. W., O. Sarnelle, and S. D. Cooper . 1997. Effect size in ecological experiments: the application of biological models in meta-analysis. American Naturalist 150: 709–812. Paine, R. T. . 1992. Food-web analysis through field measurement of per capita interaction strength. Nature 355: 73–75. Perrson, L., J. Andersson, E. Wahlström, and P. Eklöv . 1996. Size-specific interactions in lake systems: predator gape limitation and prey growth rate and mortality. Ecology 77: 900–911. Roughgarden, J., S. D. Gaines, and H. Possingham . 1988. Recruitment dynamics in complex life cycles. Science 241: 1460–1466. Ruel, J. J. and M. P. Ayres . 1999. Jensen's inequality predicts effects of environmental variation. Trends in Ecology and Evolution 14: 361–366. Sih, A., P. Crowley, M. McPeek, J. Petranka, and K. Strohmeier . 1985. Predation, competition, and prey communities: a review of field experiments. Annual Review in Ecology and Systematics 16: 269–311. Strauss, S. Y. . 1991. Indirect effects in community ecology: their definition, study and importance. Trends in Ecology and Evolution 6: 206–210. Taylor, L. R. . 1961. Aggregation, variance and the mean. Nature 189: 732–735. Tonn, W. M., J. J. Magnuson, M. Rask, and J. Toivonen . 1990. Intercontinental comparison of small-lake fish assemblages: the balance between local and regional processes. American Naturalist 136: 345–375. Turner, M. G. . 1989. Landscape ecology: the effect of pattern on process. Annual Review in Ecology and Systematics 20: 171–197. Underwood, A. J. . 1985. Physical factors and biological interactions: the necessity and nature of ecological experiments. Pages 372–390 in P. G. Moore and R. Seed, editors. The ecology of rocky coasts. Hodder and Stoughton, London, U.K. Underwood, A. J. and E. J. Denley . 1984. Paradigms, explanations, and generalizations in models for the structure of intertidal communities on rocky shores. Pages 151–180 in D. R. Strong, D. Simberloff, L. G. Abele, and A. B. Thistle, editors. Ecological communities: conceptual issues and the evidence. Princeton University Press, Princeton, New Jersey, USA. Underwood, N. . 2004. Variance and skew of the distribution of plant quality influence herbivore population dynamics. Ecology 85: 686–693. Weiner, J., H-W. Griepentrog, and L. Kristensen . 2001. Suppression of weeds by spring wheat Triticum aestivum increases with crop density and spatial uniformity. Journal of Applied Ecology 38: 784–790. Wiens, J. A., N. C. Stenseth, B. Van Horne, and R. A. Ims . 1993. Ecological mechanisms and landscape ecology. Oikos 66: 369–380. Winer, B. J., D. R. Brown, and K. M. Michelis . 1991. Statistical principles in experimental design. Third edition. McGraw-Hill, New York, New York, USA. Wootton, J. T. . 1994. The nature and consequences of indirect effects in ecological communities. Annual Review in Ecology and Systematics 25: 443–466. Wu, J. and O. L. Loucks . 1995. From balance of nature to hierarchical patch dynamics: a paradigm shift in ecology. Quarterly Review of Biology 70: 439–466. Citing Literature Volume86, Issue8August 2005Pages 2212-2222 ReferencesRelatedInformation
Referência(s)