Interspecific interaction strength influences population density more than carrying capacity in more complex ecological networks

Understanding the mechanisms determining population density of species in communities and ecological networks is an important task in ecological studies. Interactions and carrying capacity largely determine population density of species and then community structure. However, their impacts on population density have not been fully investigated in ecological networks. In this study, we examined the associations of interspecific interaction strength and carrying capacity with population density in three kinds of theoretical and empirical ecological networks with different complexity. We firstly demonstrated both the net direct and indirect interaction strength of a species received from the other species showed positive associations with population density of the species in all ecological networks (except for in predation networks), particularly in more complex ecological networks. Direct interaction was more important than indirect interaction in determining population density. Carrying capacity showed a positive association with population density, particularly in less complex ecological networks. Our results suggest that interspecific interaction strength is more important than carrying capacity in determining species dominance in more complex networks.

[1]  Joel E. Cohen,et al.  Temporal Variation in Food Web Structure: 16 Empirical Cases , 1991 .

[2]  J. Timothy Wootton,et al.  Indirect Effects, Prey Susceptibility, and Habitat Selection: Impacts of Birds on Limpets and Algae , 1992 .

[3]  Bernard C. Patten,et al.  Modified cycling index for ecological applications , 1984 .

[4]  Zhibin Zhang,et al.  Specific non-monotonous interactions increase persistence of ecological networks , 2014, Proceedings of the Royal Society B: Biological Sciences.

[5]  S. Carpenter,et al.  ESTIMATING COMMUNITY STABILITY AND ECOLOGICAL INTERACTIONS FROM TIME‐SERIES DATA , 2003 .

[6]  B. Menge,et al.  Indirect Effects in Marine Rocky Intertidal Interaction Webs: Patterns and Importance , 1995 .

[7]  Colin Fontaine,et al.  Stability of Ecological Communities and the Architecture of Mutualistic and Trophic Networks , 2010, Science.

[8]  Colin R. Townsend,et al.  IMPACTS ON STREAM FOOD WEBS OF NATIVE AND EXOTIC FOREST: AN INTERCONTINENTAL COMPARISON , 2003 .

[9]  Owen L. Petchey,et al.  Interaction strengths in food webs: issues and opportunities , 2004 .

[10]  D. Huggins,et al.  Ecosystem Modeling with Lisrel: A New Approach for Measuring Direct and Indirect Effects. , 1991, Ecological applications : a publication of the Ecological Society of America.

[11]  D. Simberloff,et al.  Ecological Specialization and Susceptibility to Disturbance: Conjectures and Refutations , 2002, The American Naturalist.

[12]  Jordi Bascompte,et al.  Structure and Dynamics of Ecological Networks , 2010, Science.

[13]  A. Hastings,et al.  Weak trophic interactions and the balance of nature , 1998, Nature.

[14]  R Core Team,et al.  R: A language and environment for statistical computing. , 2014 .

[15]  Pedro Jordano,et al.  Interaction frequency as a surrogate for the total effect of animal mutualists on plants , 2005 .

[16]  E. Rastetter,et al.  Resource-based niches provide a basis for plant species diversity and dominance in arctic tundra , 2002, Nature.

[17]  J. Wootton,et al.  ESTIMATES AND TESTS OF PER CAPITA INTERACTION STRENGTH: DIET, ABUNDANCE, AND IMPACT OF INTERTIDALLY FORAGING BIRDS , 1997 .

[18]  S. Pimm,et al.  Direct Estimation of Competition , 1979, The American Naturalist.

[19]  L. Oksanen,et al.  Exploitation Ecosystems in Gradients of Primary Productivity , 1981, The American Naturalist.

[20]  M. Power,et al.  TOP-DOWN AND BOTTOM-UP FORCES IN FOOD WEBS: DO PLANTS HAVE PRIMACY? , 1992 .

[21]  B. C. Patten,et al.  Review of the Foundations of Network Environ Analysis , 1999, Ecosystems.

[22]  O. Schmitz,et al.  Trait and density mediated indirect interactions in simple food webs , 2004 .

[23]  C. Krebs.  Ecology: The Experimental Analysis of Distribution and Abundance , 1973 .

[24]  Michael L. Dungan.  Three-Way Interactions: Barnacles, Limpets, and Algae in a Sonoran Desert Rocky Intertidal Zone , 1986, The American Naturalist.

[25]  J. Wootton,et al.  The Nature and Consequences of Indirect Effects in Ecological Communities , 1994 .

[26]  B. C. Patten,et al.  Rapid development of indirect effects in ecological networks , 2010 .

[27]  Neal M. Williams,et al.  Species abundance and asymmetric interaction strength in ecological networks , 2007 .

[28]  Stephen H. Levine,et al.  Competitive Interactions in Ecosystems , 1976, The American Naturalist.

[29]  Michael J. O. Pocock,et al.  The Robustness and Restoration of a Network of Ecological Networks , 2012, Science.

[30]  Q. Fang,et al.  Plant-pollinator interactions in a biodiverse meadow are rather stable and tight for 3 consecutive years. , 2016, Integrative zoology.

[31]  R. Solé,et al.  Ecological networks and their fragility , 2006, Nature.

[32]  Shinichi Nakagawa,et al.  A general and simple method for obtaining R2 from generalized linear mixed‐effects models , 2013 .

[33]  B. Menge,et al.  The Role of Indirect Effects in Food Webs , 1996 .

[34]  K. McCann.  The diversity–stability debate , 2000, Nature.

[35]  L. Lawlor.  Direct and indirect effects of n-species competition , 1979, Oecologia.

[36]  R. Paine.  Food webs : linkage, interaction strength and community infrastructure , 1980 .

[37]  Jordi Bascompte,et al.  Asymmetric Coevolutionary Networks Facilitate Biodiversity Maintenance , 2006, Science.

[38]  Jordi Bascompte,et al.  Interaction strength combinations and the overfishing of a marine food web. , 2005, Proceedings of the National Academy of Sciences of the United States of America.

[39]  Jordi Bascompte,et al.  Disentangling the Web of Life , 2009, Science.

[40]  Patrick C Phillips,et al.  Network thinking in ecology and evolution. , 2005, Trends in ecology & evolution.

[41]  Peter J. Wangersky,et al.  Lotka-Volterra Population Models , 1978 .

[42]  J. Timothy Wootton,et al.  PREDICTING DIRECT AND INDIRECT EFFECTS: AN INTEGRATED APPROACH USING EXPERIMENTS AND PATH ANALYSIS' , 1994 .

[43]  V. Volterra.  Fluctuations in the Abundance of a Species considered Mathematically , 1926 .

[44]  Si Tang,et al.  Stability criteria for complex ecosystems , 2011, Nature.

[45]  A. Hastings,et al.  Chaos in a Three-Species Food Chain , 1991 .

[46]  M. Emmerson,et al.  MEASUREMENT OF INTERACTION STRENGTH IN NATURE , 2005 .

[47]  S. Ernest,et al.  Relationships between body size and abundance in ecology. , 2007, Trends in ecology & evolution.

[48]  Bernard C. Patten,et al.  Systems Approach to the Concept of Environment , 1978 .

[49]  T. Miller,et al.  Direct and Indirect Species Interactions in an Early Old-Field Plant Community , 1994, The American Naturalist.

[50]  Benjamin Baiser,et al.  Geographic variation in network structure of a nearctic aquatic food web , 2012 .

[51]  A. Mougi,et al.  Diversity of Interaction Types and Ecological Community Stability , 2012, Science.

[52]  ROBERT M. MAY,et al.  Will a Large Complex System be Stable? , 1972, Nature.