Scale‐dependence in Ecological Systems

Judi E Hewitt, National Institute of Water and Atmospheric Research, Hamilton, New Zealand
Simon F Thrush, National Institute of Water and Atmospheric Research, Hamilton, New Zealand
Carolyn Lundquist, National Institute of Water and Atmospheric Research, Hamilton, New Zealand

Published online: January 2010

DOI: 10.1002/9780470015902.a0021903

Scale has a profound influence on how we conduct ecological studies, interpret results and understand the links between processes operating at different rates. All of these factors profoundly influence our ability to predict responses to change. The ecological patterns and variability we observe range from millimetres to across ocean basins and from seconds to the expanse of evolutionary history. Patterns apparent at one scale can collapse to noise when viewed from other scales, indicating that perceptions of the importance of different processes vary in a scale-dependent manner. Moreover, rather than the environment simply providing an arena within which organisms are born grow and die, many organisms interact with the environment, altering it for both for themselves and for other species. Because of these factors, studying ecological systems is far from simple and scale needs to be considered in study design and analysis.

Key concepts:

  • The pattern you see depends on the scale at which you study it.
  • Threats from human activities occur at varying scales, from small point sources to large diffuse threats and changes in disturbance regimes across landscapes.
  • How organisms interact with the environment depends on how they perceive it and how patchy it is.
  • How an organism moves and how far it can move is crucial to how an organism perceives and responds to their environment.
  • Many organisms can alter their environment, both for themselves and for other species.
  • Because most processes are scale-dependent, studies must explicitly consider scale in their design.
  • Understanding both the scale of threats and the scale over which species live are essential for successful management and conservation.

Keywords: scale; mobility; metapopulations; study design; conservation; protected area networks

Figure 1. Three categories of species mobility and their implications for integrations of spatial variability over time. Species that migrate seasonally will exhibit home ranges (initial flat section of curve) much smaller than their migration distance and most of the increase in spatial scale will be incorporated within a year. Species that widely disperse within one generation as larvae, juveniles or adults (e.g. some marine invertebrates and terrestrial insects), will still exhibit home ranges on short temporal scales and dispersal over multiple generations is still likely to change geographical distributions. Species with limited dispersal at all life stages will have defined home ranges and their spatial distributions will change only slowly over multiple generations. NB Actual intercepts, slopes and inflexion points will depend on individual species characteristics and the media through which they move (air, land and water).
Figure 2. In hierarchy theory, environmental processes set the background for small-scale biotic processes. In multiscale theory both environmental and biotic processes operate across the potential range of scales with interactions occurring between them.
close
 References
    book Allen TFH and Starr TB (1982) Hierarchy Perspectives for Ecological Complexity. Chicago: University of Chicago Press.
    Arrhenius O (1921) Species and area. Journal of Ecology 9: 95–99.
    book Barry JP and Dayton PK (1991) "Physical heterogeneity and the organisation of marine communities". In: Kolasa K and Pickett STA (eds) Ecological Heterogeneity, pp. 270–320. New York: Springer.
    Botsford LW, Hastings A and Gaines SD (2001) Dependence of sustainability on the configuration of marine reserves and larval dispersal distance. Ecology Letters 4: 144–150.
    Bruno JF, Stachowicz JJ and Bertness MD (2003) Inclusion of facilitation into ecological theory. Trends in Ecology and Evolution 18: 119–125.
    Coco G, Thrush SF, Green MO and Hewitt JE (2006) The role of feedbacks between bivalve (Atrina zelandica) density, flow and suspended sediment concentration on patch stable states. Ecology 87: 2862–2870.
    Connell JH (1961) The influence of interspecific competition and other factors on the distribution of the barnacle. Chthamalus stellatus Ecology 42: 710–723.
    Diamond JM (1975) The island dilemma: lessons of modern biogeographic studies for the design of nature reserves. Biological Conservation 7: 129–146.
    Englund G and Cooper SD (2003) Scale effects and extrapolation in ecological experiments. Advances in Ecological Research 33: 161–213.
    Finlay BJ (2002) Global dispersal of free-living microbial eukaryote species. Science 296: 1061–1163.
    Fluharty D (2000) Habitat protection, ecological issues, and implementation of the Sustainable Fisheries Act. Ecological Applications 10: 325–337.
    book Gilpin ME and Hanski IA (1991) Metapopulation Dynamics – Empirical and Theoretical Investigations. London: Academic Press.
    Goss-Custard JD (1980) Competition for food and interference among waders. Ardea 68: 31–52.
    Grant J (1983) The relative magnitude of biological and physical sediment reworking in an intertidal community. Journal of Marine Research 41: 673–689.
    Halpern BS, Gaines SD and Warner RR (2004) Confounding effects of the export of production and the displacement of fishing effort from marine reserves. Ecological Applications 14: 1248–1256.
    book Hanski I and Simberloff D (1997) "The metapopulation approach; its history, conceptual domian and application to conservation". In: Hanski I and Gilpin ME (eds) Metapopulation Biology: Ecology, Genetics, and Evolution, pp. 5–26. San Deigo: Academic Press.
    Hanski IA (1994) Patch occupancy dynamics in fragmented landscapes. Trends in Ecology and Evolution 9: 131–134.
    book Hassell MP (1978) Arthropod Predator–Prey Systems. Princeton: Princeton University Press.
    book Haury LR (1978) "Patterns and processes in the time-scales of plankton distributions". In: Steele J (ed.) Spatial Pattern in Plankton Communities, pp. 277–327. New York: Plenum Press.
    Hewitt JE, Thrush SF, Dayton PK and Bonsdorf E (2007) The effect of spatial and temporal heterogeneity on the design and analysis of empirical studies of scale-dependent systems. American Naturalist 169: 398–408.
    Hines AH, Whitlatch RB, Thrush SF et al. (1997) Nonlinear foraging response of a large marine predator to benthic prey: eagle ray pits and bivalves in a New Zealand sandflat. Journal of Experimental Marine Biology and Ecology 216: 211–228.
    Kaplan DM (2006) Alongshore advection and marine reserves: consequences for modeling and management. Marine Ecology Progress Series 309: 11–24.
    Kotliar NB and Weins JA (1990) Multiple scales of patchiness and patch structure: a hierarchical framework for the study of heterogeneity. Oikos 59: 253–260.
    book Levin SA (1988) "Pattern, scale and variability: an ecological perspective". In: Hastings A (ed.) Community Eecology, pp. 1–12. Berlin: Springer.
    Levins R (1969) Some demographic and genetic consequences of environmental heterogeneity for biological control. Bulletin of the Entomological Society of America 15: 237–240.
    book MacArthur RH and Wilson EO (1967) The Theory of Island Biogeography. Princeton: Princeton University Press.
    book Milne BR (1991) "Heterogeneity as a multiscale characteristic of landscapes". In: Kolasa J and Pickett STA (eds) Ecological Heterogeneity, pp. 69–84. New York: Springer.
    Moilanen A (2005) Reserve selection using non-linear species distribution models. American Naturalist 165: 695–706.
    Murphy DD, Freas KE and Weiss SB (1990) An environment-metapopulation approach to population viability analysis for a threatened invertebrate. Conservation Biology 4: 41–51.
    Nachman G (2006) The effects of prey patchiness, predator aggregation, and mutual interference on the functional response of Phytoseiulus persimilis feeding on Tetranychus urticae (Acari: Phytoseiidae, Tetranychidae). Experimental Applied Acarology 38: 87–111.
    book Noss RE (1993) "Wildlife corridors". In: Smith DS and Hellmud PC (eds) Ecology of Greenways, pp. 43–68. Minneapolis: University of Minesota Press.
    book O'Neill RV, DeAngelis DL, Waide JB and Allen TFH (1986) A Hierarchical Concept of Ecosystems. Princeton, NJ: Princeton University Press.
    Pikitch EK, Santora C, Babcock EA et al. (2004) Ecosystem-based fishery management. Science 305: 346–347.
    book Polis GA, Power ME and Huxel GR (2004) Food Webs at the Landscape Level. Chicago: University of Chicago Press.
    Rabalais NN, Turner RE and Wiseman WJJ (2002) Gulf of Mexico hypoxia, a.k.a. “the dead zone.” Annual Review of Ecology and Systematics 33: 235–260.
    Rietkerk M and Van de Koppel J (2008) Regular pattern formation in real ecosystems. Trends in Ecology and Evolution 23: 169–175 (doi:10.1016/j.tree.2007.10.013).
    Roughgarden J and Iwasa Y (1986) Dynamics of a metapopulation with space-limited sub-populations. Theoretical Population Biology 29: 235–261.
    book Sale PF, Hanski I and Kritzer JP (2006) "The merging of metapopulation theory and marine ecology: establishing the historical context". In: Kritzer JP and Sale PF (eds) Marine Metapopulations, pp. 3–28. Amsterdam: Elsevier Academic Press.
    Schneider DC (1991) Role of fluid dynamics in the ecology of marine birds. Oceanography Marine Biology Review 29: 487–521.
    Schneider DC, Gagnon J-M and Gilkinson KD (1987) Patchiness of epibenthic megafauna on the outer Grand Banks of Newfoundland. Marine Ecology Progress Series 39: 1–13.
    Smallegange IM, van der Meer J and Kurvers RHJM (2006) Disentangling interference competition from exploitative competition in a crab-bivalve system using a novel experimental approach. Oikos 113: 157–167.
    Thomas CD and Kunin WE (1999) The spatial structure of populations. Journal of Animal Ecology 68: 647–657.
    Thrush SF and Dayton PK (2002) Disturbance to marine benthic habitats by trawling and dredging – implications for marine biodiversity. Annual Review of Ecology and Systematics 33: 449–473.
    Thrush SF, Hewitt JE, Cummings VJ et al. (2000) The generality of field experiments: interactions between local and broad-scale processes. Ecology 81: 399–415.
    Thrush SF, Hewitt JE, Hickey CW and Kelly S (2008) Multiple stressor effects identified from species abundance distributions: interactions between urban contaminants and species habitat relationships. Journal of Experimental Marine Biology and Ecology 366: 160–168.
    Thrush SF, Pridmore RD, Hewitt JE and Cummings VJ (1994) The importance of predators on a sandflat: interplay between seasonal changes in prey densities and predator effects. Marine Ecology Progress Series 107: 211–222.
    Wu JC, Jelinski DE, Luck M and Tueller PT (2000) Multiscale analysis of landscape heterogeneity: scale variance and pattern metrics. Geographic Information Science 6: 6–19.
 Further Reading
    Belovsky GE, Botkin DB, Crowl TA et al. (2004) Ten suggestions to strengthen the science of ecology. Bioscience 54: 345–348.
    book Dayton PK and Tegner MJ (1984) "The importance of scale in community ecology: a kelp forest example with terrestrial analogs". In: Price PW, Slobodchikoff CN and Gaud WS (eds) A New Ecology: Novel Approaches to Interactive Systems, pp. 457–483. New York: Wiley.
    book Hildrew AG, Giller PS and Raffaelli D (1994) Aquatic Ecology: Scale, Pattern and Processes. Oxford: Blackwell Scientific.
    Levin SA (1992) The problem of pattern and scale in ecology. Ecology 73: 1943–1967.

Related Sub-Topics:

Biomes and Ecosystems | Organisms and the Physical Environment | Population Ecology
Contact Editor close
Submit a note to the editor about this article by filling in the form below.

* Required Field

Article Title: Scale‐dependence in Ecological Systems
 
How to Cite close
Hewitt, Judi E, Thrush, Simon F, and Lundquist, Carolyn(Jan 2010) Scale‐dependence in Ecological Systems. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1002/9780470015902.a0021903]