DOCSLIB.ORG

Energy Flow and Ecosystems

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Energy Flow and Ecosystems ENERGY FLOW AND ECOSYSTEMS Alan P. Covich Colorado State University I. Ecosystem Boundaries: Inputs, Outputs, and photoautotrophs These, such as green plants and some Transformations of Energy bacteria, use solar energy and inorganic compounds II. Multiple Energy Pathways to synthesize organic matter as primary producers. III. Internal and External Nutrient Cycling primary productivity The rate of synthesis of organic IV. Biodiversity Effects on Energy Flow matter by plants (biomass per unit area of habitat V. Why Species Matter per unit time or, in some cases, biomass per unit VI. Future Studies volume per unit time). secondary productivity The rate of assimilation and growth by animals (biomass per unit area of habitat per unit time or, in some cases, biomass per unit GLOSSARY volume per unit time). trophic cascades These occur when changes in the chemoautotrophs Microbes that use inorganic com- presence or absence (or shifts in abundance) of a pounds as a source of carbon and energy and func- top predator alter the production at several lower tion as primary producers. trophic levels; primary and secondary production at decomposition The biotic breakdown of dead organic lower levels are alternately constrained or uncon- matter (detritus) by bacteria and fungi that releases strained by the feeding activities of consumers at carbon dioxide and nutrients for recycling. upper levels. ecosystems Composed of species assemblages (pro- trophic levels Groups of individuals classified as pri- ducers and consumers) that interact with each other mary producers or primary or secondary consumers and their associated abiotic environment within within food webs; individuals feeding both as pri- well-defined natural or conceptual boundaries. mary and secondary consumers are omnivores. A food chains Composed of species that are connected single species may be represented on more than one by the flow of energy and material from producers trophic level. to consumers. food webs ‘‘Flow maps’’ that depict connections among multiple food chains. functional groups Aggregations of species that perform similar ecosystem processes, such as grazers, suspen- ECOSYSTEMS ARE THERMODYNAMICALLY OPEN, sion or filter feeders, leaf shredders, predators, and hierarchically organized communities of producers, decomposers. consumers, and decomposers together with the abiotic Encyclopedia of Biodiversity, Volume 2 Copyright 2001 by Academic Press. All rights of reproduction in any form reserved. 509 510 ENERGY FLOW AND ECOSYSTEMS factors that influence species growth, reproduction, and functions. Field testing of many concepts related to dispersal. These abiotic factors include the flow of en- understanding the importance of key species in ecosys- ergy and the circulation of materials together with the tem functioning is just beginning. Results of these long- geological, hydrological, and atmospheric forces that term ecosystem studies can provide guidelines for the influence habitat quality, species distributions, and spe- stewardship of biodiversity. cies abundances. Energy flows through many species, and the way in which this flow affects the persistence of ecosystems is influenced by land-use changes, precip- itation, soil erosion, and other physical constraints such I. ECOSYSTEM BOUNDARIES: INPUTS, as geomorphology. Energy flow through ecosystems is essential for OUTPUTS, AND TRANSFORMATIONS nutrients to cycle through food webs. These food OF ENERGY webs are often subwebs of more complex species assemblages and may be only partial descriptions of An ecosystem approach can be used to address many more complex hierarchies of energy flows. The hierar- different questions spanning scales from the global bio- chy of species’ interactions in natural food webs sphere to small ponds or patches of habitat. As the typically results in some important feedback loops questions change, so do the boundaries and the com- and recycling of nutrients and materials within the plexities of species interactions within and among dif- conceptually defined boundaries of an ecosystem. ferent compartments or across trophic levels. Ecosys- Many species of producers and consumers are usually tem boundaries are often defined to include natural interconnected and some may be interdependent. Food species assemblages and to analyze inputs and outputs webs are diagrams that can function as ‘‘flow maps’’ of energy and materials for cross-site comparisons of to document which species interact with other species, efficiencies in energy transfers and studies of changing either directly or indirectly, as energy flows through conditions. These analyses often take the form of mathe- the community and determines the movement of matical models such as computer simulations or indi- nutrients and other materials. vidual-based models of species and their specific func- Different species have important functional values, tions within the biotic assemblage and environmental such as for organic matter production (plant and animal conditions under study. growth) or organic matter breakdown (decomposition), One ecosystem may export nutrients and organic oxygen production, nitrogen fixation, and nutrient cy- matter (stored energy) to other ecosystems so that cling. These species have intrinsic values as the unique cross-site linkages often become important. For exam- end products of evolution, and native species are likely ple, in studies of nutrient cycling in terrestrial ecosys- to have adapted specific ways to respond to local or tems, the definition of boundaries would likely have regional environmental disturbances. Conceptually, the some compartments of organic matter production by loss of even a single native species, or the introduction living plants and their relationships with herbivores of a nonnative species, could alter how the other re- and carnivores. Macro- and micronutrient inputs would maining native species continue to perform different likely be derived from the atmosphere through dry de- ecosystem functions. Disruptions of ecosystem pro- position of particulates—nitrogen gas being taken up cesses are known to have occurred after certain well- by some nitrogen-fixing species of microbes. Other adapted, native species were lost through local extinc- sources of nutrients, especially phosphorus, would tion following intense (pulse) or prolonged (press) dis- come from weathering and erosion of soil and bedrock turbances. However, predicting which species are essen- deposits, with movement among other compartments tial to ecosystem functions has generally remained derived from actions of wind and water. This combina- difficult because information is lacking on many species tion of interactions illustrates the importance of defin- interactions as well as on life history, adaptations to ing clear boundaries for subsystems within the complete different disturbances, and dispersal abilities among key ecosystem so that measurements of movements (fluxes) species. Ecosystem studies can provide a broad perspec- among compartments can be measured accurately. Gen- tive regarding species relationships and recycling of erally, ecosystems and their boundaries are abstractions essential nutrients. Species’ shifts in patterns of abun- that can only be useful and insightful when combined dance (or local extinctions) following natural and an- with sufficient knowledge regarding the natural history thropogenic disturbances illustrate how some key spe- and general ecology of communities and their physical cies regulate nutrient cycling and other ecosystem environment. There is wide recognition that a combina- ENERGY FLOW AND ECOSYSTEMS 511 tion of direct field observation, experimentation, and ideas (Schulze and Mooney, 1994; Orians et al., 1996; modeling is essential when conducting ecosystem Lawton, 1997; Palmer et al., 1997; Naeem, 1998; studies. Wall, 1999). Currently, fundamental questions dealing with rela- tionships between energy flow and the species-specific A. A Historical Perspective: roles of organisms are attracting increased attention. For example, can results of controlled small-scaled The Ecosystem Concept (fine-grained) experimental studies of productivity be How energy moves from one group of species to another used to predict responses of other natural assemblages has been an active area of study at least since Charles at larger scales (coarse grained) of ecosystem dynamics? Darwin and Alfred Russel Wallace first wrote in the Does energy flow through an ecosystem increase, de- 1850s about the interconnections among species. They crease, or remain the same if one species goes locally were intrigued with the general proportions of popula- extinct but the abundances of other ‘‘similar species’’ tion abundances that were thought to exist among dif- change rapidly to compensate for the lost species? Un- ferent groups of large predators and their prey, and they der what environmental conditions do species substi- emphasized competition and predation as important tute for one another and compensate functionally for factors for regulating species interactions. These early the lost species? These and many other questions are observers lacked a conceptual approach to what was beginning to be answered, but studies related to biodi- later viewed as ecosystem-level dynamics. Darwin’s versity and the persistence of species assemblages re- studies of earthworms and their roles in soil develop- main incomplete. A series of symposia during the 1990s ment and his views on the roles of multiple species dealt with the relationships between
Load more

Recommended publications
  • Plant Species Richness and Species Area Relationships in a Florida Sandhill Monica Ruth Downer University of South Florida, [email protected]
    University of South Florida Scholar Commons Graduate Theses and Dissertations Graduate School January 2012 Plant Species Richness and Species Area Relationships in a Florida Sandhill Monica Ruth Downer University of South Florida, [email protected] Follow this and additional works at: http://scholarcommons.usf.edu/etd Part of the American Studies Commons, Biology Commons, and the Ecology and Evolutionary Biology Commons Scholar Commons Citation Downer, Monica Ruth, "Plant Species Richness and Species Area Relationships in a Florida Sandhill" (2012). Graduate Theses and Dissertations. http://scholarcommons.usf.edu/etd/4030 This Thesis is brought to you for free and open access by the Graduate School at Scholar Commons. It has been accepted for inclusion in Graduate Theses and Dissertations by an authorized administrator of Scholar Commons. For more information, please contact [email protected]. Plant Species Richness and Species Area Relationships in a Florida Sandhill Community by Monica Ruth Downer A thesis submitted in partial fulfillment Of the requirements for the degree of Master of Science Department of Biology College of Arts and Sciences University of South Florida Major Professor: Gordon A. Fox, Ph.D. Co-Major Professor: Earl D. McCoy, Ph.D. Co-Major Professor: Frederick B. Essig, Ph.D. Date of Approval: March 27, 2012 Keywords: Species area curve, burn regime, rank occurrence, heterogeneity, autocorrelation Copyright © 2012, Monica Ruth Downer ACKNOWLEDGEMENTS I would like to offer special thanks to my major professor, Dr. Gordon A. Fox, for his patience, guidance and many hours devoted to helping me in this endeavor. I would like to thank my committee, Dr.
    [Show full text]
  • Species Richness, Species–Area Curves and Simpson's Paradox
    Evolutionary Ecology Research, 2000, 2: 791–802 Species richness, species–area curves and Simpson’s paradox Samuel M. Scheiner,1* Stephen B. Cox,2 Michael Willig,2 Gary G. Mittelbach,3 Craig Osenberg4 and Michael Kaspari5 1Department of Life Sciences (2352), Arizona State University West, P.O. Box 37100, Phoenix, AZ 85069, 2Program in Ecology and Conservation Biology, Department of Biological Sciences and The Museum, Texas Tech University, Lubbock, TX 79409, 3W.K. Kellogg Biological Station, 3700 E. Gull Lake Drive, Michigan State University, Hickory Corners, MI 49060, 4Department of Zoology, University of Florida, Gainesville, FL 32611 and 5Department of Zoology, University of Oklahoma, Norman, OK 73019, USA ABSTRACT A key issue in ecology is how patterns of species diversity differ as a function of scale. The scaling function is the species–area curve. The form of the species–area curve results from patterns of environmental heterogeneity and species dispersal, and may be system-specific. A central concern is how, for a given set of species, the species–area curve varies with respect to a third variable, such as latitude or productivity. Critical is whether the relationship is scale-invariant (i.e. the species–area curves for different levels of the third variable are parallel), rank-invariant (i.e. the curves are non-parallel, but non-crossing within the scales of interest) or neither, in which case the qualitative relationship is scale-dependent. This recognition is critical for the development and testing of theories explaining patterns of species richness because different theories have mechanistic bases at different scales of action.
    [Show full text]
  • European Gradients of Resilience in the Face of Climate Extremes
    EUROPEAN GRADIENTS OF RESILIENCE IN THE FACE OF CLIMATE EXTREMES POLICY BRIEF Field site in Belgium with rainout shelters deployed in 2013 ©Sigi Berwaers This policy brief is based on the results Extreme weather events and the presence of invasive species can act as of the BiodivERsA-funded project pressures threatening biodiversity, resilience and ecosystem services of semi- ‘SIGNAL’ addressing the interaction of three major research areas, combined natural grasslands and drive them beyond thresholds of system integrity in ecology for the first time: biodiversity (tipping points and regime shifts). On the other hand, biodiversity itself may experiments, climate change research, and invasion research. The project made use buffer ecosystem functioning and services against change. Potential stabilising of coordinated experiments in different mechanisms include species richness, presence of key species such as legumes climates across Europe, thereby increasing and within-species diversity. These potential buffers can be promoted by the scope and relevance of the results. conservation management and policy adjustments. K EY POLICY RECOMMENDATIONS • Local biodiversity should be actively stimulated or preserved across European grasslands in order to increase the stability of ecosystem service provisioning, which is especially relevant as climate extremes are expected to become more frequent and intense. • Adjustment of mowing frequency and cutting height can help maintain or increase biodiversity. • More explicit consideration of within-species diversity is warranted, as this component of biodiversity can contribute to stabilising ecosystem functioning in the face of climate extremes. • Ecosystem responses to climate extremes of similar magnitude can vary significantly between climates and regions, suggesting that targeted policy requires tailor-made impact predictions.
    [Show full text]
  • "Species Richness: Small Scale". In: Encyclopedia of Life Sciences (ELS)
    Species Richness: Small Advanced article Scale Article Contents . Introduction Rebecca L Brown, Eastern Washington University, Cheney, Washington, USA . Factors that Affect Species Richness . Factors Affected by Species Richness Lee Anne Jacobs, University of North Carolina, Chapel Hill, North Carolina, USA . Conclusion Robert K Peet, University of North Carolina, Chapel Hill, North Carolina, USA doi: 10.1002/9780470015902.a0020488 Species richness, defined as the number of species per unit area, is perhaps the simplest measure of biodiversity. Understanding the factors that affect and are affected by small- scale species richness is fundamental to community ecology. Introduction diversity indices of Simpson and Shannon incorporate species abundances in addition to species richness and are The ability to measure biodiversity is critically important, intended to reflect the likelihood that two individuals taken given the soaring rates of species extinction and human at random are of the same species. However, they tend to alteration of natural habitats. Perhaps the simplest and de-emphasize uncommon species. most frequently used measure of biological diversity is Species richness measures are typically separated into species richness, the number of species per unit area. A vast measures of a, b and g diversity (Whittaker, 1972). a Di- amount of ecological research has been undertaken using versity (also referred to as local or site diversity) is nearly species richness as a measure to understand what affects, synonymous with small-scale species richness; it is meas- and what is affected by, biodiversity. At the small scale, ured at the local scale and consists of a count of species species richness is generally used as a measure of diversity within a relatively homogeneous area.
    [Show full text]
  • Species Richness and Evolutionary Niche Dynamics: a Spatial Pattern–Oriented Simulation Experiment
    vol. 170, no. 4 the american naturalist october 2007 ൴ Species Richness and Evolutionary Niche Dynamics: A Spatial Pattern–Oriented Simulation Experiment Thiago Fernando L. V. B. Rangel,1,* Jose´ Alexandre F. Diniz-Filho,2,† and Robert K. Colwell1,‡ 1. Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, Connecticut 06269; 2. Departamento de Biologia Geral, Instituto de Cieˆncias As early as the eighteenth and nineteenth centuries, nat- Biolo´gicas, Universidade Federal de Goia´s, CP 131, 74001-970 uralists described and documented what we today call geo- Goiaˆnia, Goiaˆnia, Brasil graphical gradients in taxon diversity (species richness), Submitted November 27, 2006; Accepted May 14, 2007; especially the general global pattern of increase in species Electronically published August 9, 2007 richness toward warm and wet tropical regions (Whittaker et al. 2001; Hawkins et al. 2003b; Willig et al. 2003; Hil- Online enhancements: appendixes. lebrand 2004). Initial hypotheses explaining this pattern were deduced solely by observing and describing nature and were based on nothing more rigorous than intuitive correspondence between climatic and biological patterns abstract: Evolutionary processes underlying spatial patterns in (Hawkins 2001). Surprisingly, even after 200 years of re- species richness remain largely unexplored, and correlative studies search in biogeography and ecology, the most common lack the theoretical basis to explain these patterns in evolutionary framework used in such investigations still relies on sta- terms. In this study, we develop a spatially explicit simulation tistical measurements of the concordance between the spa- model to evaluate, under a pattern-oriented modeling approach, whether evolutionary niche dynamics (the balance between niche tial patterns in species richness and multiple environmen- conservatism and niche evolution processes) can provide a parsi- tal factors.
    [Show full text]
  • Community Diversity
    Community Diversity Topics What is biodiversity and why is it important? What are the major drivers of species richness? Habitat heterogeneity Disturbance Species energy theory Metobolic energy theory Dynamic equilibrium hypothesis (interactions among disturbance and energy) Resource ratio theory How does biodiversity influence ecosystem function? Biodiversity and ecosystem function hypothesis Integration of biodiversity theory How might the drivers of species richness and hence levels of species richness differ among biomes? Community Diversity Defined Biodiversity Merriam-Webster - the existence of many different kinds of plants and animals in an environment. Wikipedia - the degree of variation of life forms within a given species, ecosystem, biome, or an entire planet. U.S. Congress Office of Technology Assessment - the variety and variability among living organisms and the ecological complexes in which they occur. Diversity can be defined as the number of different items and their relative frequency. For biological diversity, these items are organized at many levels, ranging from complete ecosystems to the chemical structures that are the molecular basis of heredity. Thus, the term encompasses different ecosystems, species, genes, and their relative abundance." Community Diversity Defined Species richness - Species evenness - Species diversity - Community Diversity Defined Species richness - number of species present in the community (without regard for their abundance). Species evenness - relative abundance of the species that are
    [Show full text]
  • Spatial and Temporal Trends in Species Richness and Abundance for The
    International Council for the ICES CM 2006/ D:02 Exploration of the Sea Census of Marine Life: Community and species biodiversity in marine benthic habitats from the coastal zone to the deep sea Spatial and temporal trends in species richness and abundance for the southerly and northerly components of the North Sea fish community separately, based on IBTS data 1977-2005 Niels Daan Abstract Based on the North Sea International Bottom Trawl Survey, the number of species recorded after 20 hauls is used as an index of biodiversity at a spatial scale of 10*10nm. The results show a clear pattern: species richness is lowest in the central North Sea and highest in Scottish waters, in the Kattegat and in the Channel area. When the community is split into its northerly and southerly components, the former reaches its highest diversity in waters typically deeper than 100m and the latter in waters less than 50m. The area of high richness of northerly species extends from Scottish waters along the Norwegian trench into the Kattegat. High richness of southerly species is not restricted to the southern North Sea but is observed also along the Scottish coast and in the Kattegat. These patterns are discussed in relation to hydrographical features that may control these differences. Temporal trends indicate that both components are characterized by a gradual increase in species richness over the past 25 years, a process that has affected the whole area while rates of change did hardly differ between the components or areas. A standardized index of abundance also indicates long-term gradual increases for both northerly and southerly species, although in this case the increase in southern species is larger.
    [Show full text]
  • Introduction to the Special Issue on Spatial Ecology
    International Journal of Geo-Information Editorial Space-Ruled Ecological Processes: Introduction to the Special Issue on Spatial Ecology Duccio Rocchini 1,2,3 1 University of Trento, Center Agriculture Food Environment, Via E. Mach 1, 38010 S. Michele all’Adige (TN), Italy; [email protected] 2 University of Trento, Centre for Integrative Biology, Via Sommarive, 14, 38123 Povo (TN), Italy 3 Fondazione Edmund Mach, Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Via E. Mach 1, 38010 S. Michele all’Adige (TN), Italy Received: 12 December 2017; Accepted: 23 December 2017; Published: 2 January 2018 This special issue explores most of the scientific issues related to spatial ecology and its integration with geographical information at different spatial and temporal scales. Papers are mainly related to challenging aspects of species variability over space and landscape dynamics, providing a benchmark for future exploration on this theme. The need for a spatial view in Ecology is a fact. Dealing with ecological changes over space and time represents a long-lasting theme, now faced by means of innovative techniques and modelling approaches (e.g., Chaudhary et al. [1], Palmer [2], Rocchini [3]). This special issue explores some of them, with challenging ideas facing different components of spatial patterns related to ecological processes, such as: (i) species variability over space [4–11]; and (ii) landscape dynamics [12,13]. Concerning biodiversity variability over space, key spatial datasets are needed to fully investigate biodiversity change in space and time, as shown by Geri et al. [7], who carried out innovative procedures to recover and properly map historical floristic and vegetation data for biodiversity monitoring.
    [Show full text]
  • Plant Species Richness and Composition of a Habitat Island
    Biodiversity Data Journal 8: e48704 doi: 10.3897/BDJ.8.e48704 Research Article Plant species richness and composition of a habitat island within Lake Kastoria and comparison with those of a true island within the protected Pamvotis lake (NW Greece) Alexandros Papanikolaou‡‡, Maria Panitsa ‡ Division of Plant Biology, Department of Biology, University of Patras, Patras, Greece Corresponding author: Maria Panitsa ([email protected]) Academic editor: Gianniantonio Domina Received: 22 Nov 2019 | Accepted: 07 Jan 2020 | Published: 15 Jan 2020 Citation: Papanikolaou A, Panitsa M (2020) Plant species richness and composition of a habitat island within Lake Kastoria and comparison with those of a true island within the protected Pamvotis lake (NW Greece). Biodiversity Data Journal 8: e48704. https://doi.org/10.3897/BDJ.8.e48704 Abstract Lake Kastoria is one of the potentially “ancient” Balkan lakes that has a great environmental importance and ecological value, attracts high touristic interest and is under various anthropogenic pressures. It belongs to a Natura 2000 Special Protection Area and a Site of Community Interest. The city of Kastoria is located at the western part of the lake and just next to it, towards the centre of the lake, is a peninsula, a habitat island. In the framework of research concerning the flora of lake islands of Greece, one of the main objectives of the present study is to fill a gap concerning plant species richness of the habitat island within the protected Lake Kastoria, which is surrounded by the lake except for its north-western part where the border of the city of Kastoria is located.
    [Show full text]
  • Extending Species-Area Relationships (SAR) to Diversity-Area Relationships (DAR)©
    Extending species-area relationships (SAR) to diversity-area relationships (DAR)© Zhanshan (Sam) Ma Computational Biology and Medical Ecology Lab State Key Lab of Genetic Resources and Evolution Kunming Institute of Zoology Chinese Academy of Sciences Kunming 650223, China [email protected] Abstract Aim: I extend the traditional SAR, which has achieved status of ecological law and plays a critical role in global biodiversity assessment, to the general (alpha- or beta-diversity in Hill numbers) diversity area relationship (DAR). The extension was motivated to remedy the limitation of traditional SAR that only address one aspect of biodiversity scaling—species richness scaling over space. Innovation: The extension was made possible by the fact that all Hill numbers are in units of species (referred to as the effective number of species or as species equivalents), and I postulated that Hill numbers should follow the same or similar pattern of SAR. I selected three DAR models, the traditional power law (PL), PLEC (PL with exponential cutoff) and PLIEC (PL with inverse exponential cutoff). I defined three new concepts and derived their quantifications: (i) DAR profile—z-q series where z is the PL scaling parameter at different diversity order (q); (ii) PDO (pair-wise diversity overlap) profile—g-q series where g is the PDO corresponding to q; (iii) MAD (maximal accrual diversity) profile—Dmax-q series where Dmax is the MAD corresponding to q. Furthermore, the PDO-g is quantified based on the self- similarity property of the PL model, and Dmax can be estimated from the PLEC parameters. The three profiles constitute a novel DAR approach to biodiversity scaling.
    [Show full text]
  • The Present Status of the Competitive Exclusion Principle
    TREE vol. 1, no. I, July 7986 could be expected to rise periodically some other nuclear power stations 6 Bumazyan, A./. f1975)At. Energi. 39, (particularly during the spring snow are beinq built much nearer to these 167-172 melting) for many years. cities than the Chernobyl station to 7 Mednik, LG., Tikhomirov, F.A., It is very likely that the Soviet Kiev. The Chernobvl disaster will Prokhorov, V.M. and Karaban, P.T. (1981) Ekologiya, no. 1,4C-45 Union, after some initial reluctance, affect future plans, and will certainly 8 Molchanova, I.V., and Karavaeva, E.N. will eventually adopt the same atti- make a serious impact on the nuclear (1981) Ekologiya, no. 5,86-88 tude towards nuclear power stations generating strategy in many other 9 Molchanova, I.V., Karavaeva, E.N., as was adopted by the United States countries as well. Chebotina. M.Ya., and Kulikov, N.V. after the long public enquiry into the (1982) Ekologiya, no. 2.4-g accident at Three Mile Island in 1979. 10 Buyanov, N.I. (1981) Ekologiya, no. 3, As well as ending the propaganda of Acknowledgements 66-70 the almost absolute safety of nuclear The author is grateful to Geoffrey R. 11 Nifontova, M.G., and Kulikov, N.V. Banks for reading the manuscript and for power plants and labelling them as (1981) Ekologiya, no. 6,94-96 comments and editorial assistance. 12 Kulikov, N.V. 11981) Ekologiya, no. 4, ‘potentially dangerous’, the US gov- 5-11 ernment also recommended that 13 Vennikov, V.A. (1975) In new nuclear power plants be located References Methodological Aspects of Study of in areas remote from concentrations 1 Medvedev, Z.A.
    [Show full text]
  • A Mechanistic Verification of the Competitive Exclusion Principle
    A mechanistic verification of the competitive exclusion principle Lev V. Kalmykov1,3 & Vyacheslav L. Kalmykov2,3* 1Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region, 142290 Russia; 2Institute of Cell Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region, 142290 Russia; 3Pushchino State Institute of Natural Sciences (the former Pushchino State University), Pushchino, Moscow Region, 142290 Russia. *e-mail: [email protected] Abstract Biodiversity conservation becoming increasingly urgent. It is important to find mechanisms of competitive coexistence of species with different fitness in especially difficult circumstances - on one limiting resource, in isolated stable uniform habitat, without any trade-offs and cooperative interactions. Here we show a mechanism of competitive coexistence based on a soliton-like behaviour of population waves. We have modelled it by the logical axiomatic deterministic individual-based cellular automata method. Our mechanistic models of population and ecosystem dynamics are of white-box type and so they provide direct insight into mechanisms under study. The mechanism provides indefinite coexistence of two, three and four competing species. This mechanism violates the known formulations of the competitive exclusion principle. As a consequence, we have proposed a fully mechanistic and most stringent formulation of the principle. Keywords: population dynamics; biodiversity paradox; cellular automata; interspecific competition; population waves. Introduction Background. Up to now, it is not clear why are there so many superficially similar species existing together1,2. The competitive exclusion principle (also known as Gause’s principle, Gause’s Rule, Gause’s Law, Gause’s Hypothesis, Volterra-Gause Principle, Grinnell’s Axiom, and Volterra-Lotka Law)3 postulates that species competing for the same limiting resource in one homogeneous habitat cannot coexist4,5.
    [Show full text]