title: Metacommunity patterns in larval odonates.
abstract: The growth of metacommunity ecology as a subdiscipline has increased interest in how processes at different spatial scales structure communities. However, there is still a significant knowledge gap with respect to relating the action of niche- and dispersal-assembly mechanisms to observed species distributions across gradients. Surveys of the larval dragonfly community (Odonata: Anisoptera) in 57 lakes and ponds in southeast Michigan were used to evaluate hypotheses about the processes regulating community structure in this system. We considered the roles of both niche- and dispersal-assembly processes in determining patterns of species richness and composition across a habitat gradient involving changes in the extent of habitat permanence, canopy cover, area, and top predator type. We compared observed richness patterns and species distributions in this system to patterns predicted by four general community models: species sorting related to adaptive trade-offs, a developmental constraints hypothesis, dispersal assembly, and a neutral community assemblage. Our results supported neither the developmental constraints nor the neutral-assemblage models. Observed patterns of richness and species distributions were consistent with patterns expected when adaptive tradeoffs and dispersal-assembly mechanisms affect community structure. Adaptive trade-offs appeared to be important in limiting the distributions of species which segregate across the habitat gradient. However, dispersal was important in shaping the distributions of species that utilize habitats with a broad range of hydroperiods and alternative top predator types. Our results also suggest that the relative importance of these mechanisms may change across this habitat gradient and that a metacommunity perspective which incorporates both niche- and dispersal-assembly processes is necessary to understand how communities are organized.
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109-1048, USA. mccaule@umich.edu
authors.forename: Shannon J
authors.initials: SJ
authors.lastname: McCauley
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Davis
authors.forename: Rick A
authors.initials: RA
authors.lastname: Relyea
authors.forename: Kerry L
authors.initials: KL
authors.lastname: Yurewicz
authors.forename: David K
authors.initials: DK
authors.lastname: Skelly
authors.forename: Earl E
authors.initials: EE
authors.lastname: Werner
mesh_terms: D000818:Animals; D044822:Biodiversity; D004463:Ecology; D017753:Ecosystem; D007313:Insecta / Q000502:physiology*; D007814:Larva / Q000502:physiology; D008824:Michigan; D008954:Models, Biological; D011157:Population Dynamics
references.citation: Oecologia. 2003 Aug;136(4):489-98
references.pmid: 12836009
references.citation: Ecology. 2006 Oct;87(10):2582-90
references.pmid: 17089666
references.citation: Am Nat. 1999 Oct;154(4):427-440
references.pmid: 10523489
references.citation: Proc Natl Acad Sci U S A. 2004 May 18;101(20):7651-6
references.pmid: 15128948
references.citation: Am Nat. 2000 Mar;155(3):311-325
references.pmid: 10718728
references.citation: Am Nat. 2003 Nov;162(5):586-96
references.pmid: 14618537
references.citation: Am Nat. 2006 Aug;168(2):157-67
references.pmid: 16874626
references.citation: Ecol Lett. 2005 Nov;8(11):1175-82
references.pmid: 21352441
references.citation: Philos Trans R Soc Lond B Biol Sci. 1994 Jul 29;345(1311):101-18
references.pmid: 7972351
references.citation: Am Nat. 2004 May;163(5):E88-111
references.pmid: 15122497
references.citation: Science. 2001 Sep 28;293(5539):2413-8
references.pmid: 11577228
references.citation: Am Nat. 2003 Aug;162(2):165-71
references.pmid: 12858261
references.citation: Science. 1978 Mar 24;199(4335):1302-10
references.pmid: 17840770
references.citation: Am Nat. 1993 Aug;142(2):242-72
references.pmid: 19425978