Article Contentsp. 177p. 178p. 179p. 180p. 181p. 182p. 183p. 184p. 185p. 186p. 187p. 188p. 189p. 190p. 191p. 192Issue Table of ContentsOikos, Vol. 84, No. 2 (Feb., 1999), pp. 177-352Front MatterAnniversary Mini-ReviewAre There General Laws in Ecology? [pp. 177-192]Bat Predation and Flight Timing of Winter Moths, Epirrita and Operophtera Species (Lepidoptera, Geometridae) [pp. 193-198]Adaptation of Coyote Brush to the Abiotic Environment and Its Effects on Susceptibility to a Gall-Making Midge [pp. 199-208]Vertebrate Predation Does Not Limit Density of a Common Forest-Floor Wolf Spider: Evidence from a Field Experiment [pp. 209-214]Moose, Trees, and Ground-Living Invertebrates: Indirect Interactions in Swedish Pine Forests [pp. 215-226]Environmental Heterogeneity in Space and Time: Patch Use, Recruitment and Dynamics of a Rock Pool Population of a Gyrinid Beetle [pp. 227-238]Experimental Evidence for the Origin of Alternative Communities on Rocky Intertidal Shores [pp. 239-245]Functional Redundancy among Tidal Marsh Halophytes: A Test [pp. 246-260]Application and Evaluation of Dale's Non-Parametric Method for Detecting Community Structure through Zonation [pp. 261-265]Flooding Reverted Grazing Effects on Plant Community Structure in Mesocosms of Lowland Grassland [pp. 266-276]Effects of Atmospheric CO, Light Availability and Tree Species on the Quality of Leaf Detritus as a Resource for Treehole Mosquitoes [pp. 277-283]Patterns of Variation in Meristem Allocation across Genotypes and Species in Monocarpic Brassicaceae [pp. 284-292]Complex Life Cycles in Andricus kollari (Hymenoptera, Cynipidae) and Their Impact on Associated Parasitoid and Inquiline Species [pp. 293-301]OpinionsOn Critical Thresholds in Landscape Connectivity: A Management Perspective [pp. 302-305]Habitat Fragmentation, the Random Sample Hypothesis and Critical Thresholds [pp. 306-308]Why Rapoport's Rule Does Not Generalise [pp. 309-312]ForumPlant Adaptations to Herbivory: Mutualistic versus Antagonistic Coevolution [pp. 313-320]The Fallacy of Ratios and the Testability of Models in Biology [pp. 321-326]Investigating the Disparity in Host Specificity between AM and EM Fungi: Lessons from Theory and Better-Studied Systems [pp. 327-332]Are Gall Insects Large Rhizobia? [pp. 333-342]Notes on Asymmetrical Similarity Indices [pp. 343-345]Expert Estimates about Effects of Biodiversity on Ecosystem Processes and Services [pp. 346-352]Back MatterNordic Society OikosAre There General Laws in Ecology?Author(s): John H. LawtonSource: Oikos, Vol. 84, No. 2 (Feb., 1999), pp. 177-192Published by: Blackwell Publishing on behalf of Nordic Society OikosStable URL: http://www.jstor.org/stable/3546712Accessed: 29/10/2008 14:10Your use of the JSTOR archive indicates your acceptance of JSTOR's Terms and Conditions of Use, available athttp://www.jstor.org/page/info/about/policies/terms.jsp. JSTOR's Terms and Conditions of Use provides, in part, that unlessyou have obtained prior permission, you may not download an entire issue of a journal or multiple copies of articles, and youmay use content in the JSTOR archive only for your personal, non-commercial use.Please contact the publisher regarding any further use of this work. Publisher contact information may be obtained athttp://www.jstor.org/action/showPublisher?publisherCode=black.Each copy of any part of a JSTOR transmission must contain the same copyright notice that appears on the screen or printedpage of such transmission.JSTOR is a not-for-profit organization founded in 1995 to build trusted digital archives for scholarship. We work with thescholarly community to preserve their work and the materials they rely upon, and to build a common research platform thatpromotes the discovery and use of these resources. For more information about JSTOR, please contact [email protected] Publishing and Nordic Society Oikos are collaborating with JSTOR to digitize, preserve and extendaccess to Oikos.http://www.jstor.orgLawton, J. H. 1999. Are there general laws in ecology? - Oikos 84: 177-192. The dictionary definition of a law is: "Generalized formulation based on a series of events or processes observed to recur regularly under certain conditions; a widely observable tendency". I argue that ecology has numerous laws in this sense of the word, in the form of widespread, repeatable patterns in nature, but hardly any laws that are universally true. Typically, in other words, ecological patterns and the laws, rules and mechanisms that underpin them are contingent on the organisms involved, and their environment. This contingency is manageable at a relatively simple level of ecological organisation (for example the population dynamics of single and small numbers of species), and re-emerges also in a manageable form in large sets of species, over large spatial scales, or over long time periods, in the form of detail-free statistical patterns - recently called 'macroecology'. The contingency becomes over- whelmingly complicated at intermediate scales, characteristic of community ecology, where there are a large number of case histories, and very little other than weak, fuzzy generalisations. These arguments are illustrated by focusing on examples of typical studies in community ecology, and by way of contrast, on the macroecological relationship that emerges between local species richness and the size of the regional pool of species. The emergent pattern illustrated by local vs regional richness plots is extremely simple, despite the vast number of contingent processes and interactions involved in its generation. To discover general patterns, laws and rules in nature, ecology may need to pay less attention to the 'middle ground' of community ecology, relying less on reductionism and experimental manipulation, but increasing research efforts into macroecology. John H. Law1ton, NERC Centre for Population Biology, Imperial College at Silwood Park, Ascot, Berkshire, UK SL5 7PY (O.lawton@,ic.ac.uk). Introduction and definitions Of course there are general laws in ecology. However, our science has rather few universal laws. My dictionary gives several different definitions of the word law. The most appropriate is: "Generalized formulation based on a series of events or processes observed to recur regularly under certain conditions; a widely observable tendency". Notice that there is nothing in this definition to say that a law has to be universally true; only that laws are usually true.