Download presentation
Presentation is loading. Please wait.
Published byDesmond Facey Modified over 9 years ago
1
Trait-based Analyses for Fishes and Invertebrates in Streams Mark Pyron Stoeckerecological.com
2
River Habitat Templet Ideas for species traits-environmental filters (from Southwood 1977; used by Poff 1997)
3
Why Traits? Compare evolutionarily distinct systems Species-habitat relationships Ecosystem processes
4
Major assumption! Present day habitat conditions match present day traits in organisms
5
Which traits? Which analyses? What are results? What are problems?
6
Which traits? Spatial and temporal heterogeneity of habitat define where and when the organisms use habitat
7
Traits: Should vary with ecological gradients
8
and... Organisms with same traits occur in multiple biogeographical regions – Different taxa
9
Traits of macroinvertebrates Trophic – Shredders, filterer-collector, grazer, predator Locomotion Body size Voltinism Respiration technique
10
Traits of macroinvertebrates Life history: reproductive strategies – Body size – Egg size, number, shape, attachment – Generations / year – Oviposition period -season – Incubation time – Clutch number
11
Traits of fishes Habitat preferences: – Stream size (small, medium, large) – Discharge – Temperature – Depth – Substrate size – Canopy
12
Traits of fishes Life history – Body size – Lifespan – Age at maturity – Egg size – Fecundity
13
Traits of fishes Dispersal ability Colonization ability
14
Traits of fishes Reproductive guilds IBI metrics Feeding and ecosystem interactions Morphology
15
Analyses – patterns Heino et al. 2013
16
Across catchment – RCC predictions – Do organisms respond same to environmental gradient?
17
Analyses – patterns Heino et al. 2013 Across catchment Among region differences or convergence – Same traits in different local communities? – Compare trait responses to same gradients in different geographical regions
18
Analyses – patterns Heino et al. 2013 Across catchment Among region differences or convergence Across community – large extent or w/in catchment – Trait variation across local communities in drainage basin at large geographical extent
19
Analyses – tests Heino et al. 2013 Indirect ordination: CA, PCA Direct ordination: CCA, RDA, RLQ Group test: MRPP Life history strategy: ANOVA Niche Model: Maximum Entropy Trait diversity: regression, ANOVA
20
Results: macroinvertebrate traits Human impacts – Traits discriminate river reaches – Taxonomy could not – Genus level or family level sufficient – Gayraud et al. 2003
21
Results: macroinvertebrate trait richness Increases along local, catchment, and geographical gradients Bêche & Statzner 2009
22
Results: macroinvertebrate traits studies Trait richness correlated with genus richness Beche & Statzner 2009
23
Results: fish traits Hydrologic variability: – Resource generalists vs. specialists – Poff & Allan 1995
24
Results: fish traits Hydrologic variability: – Life-history traits – Tedesco et al. 2008; Mims & Olden 2012
25
Results: fish traits studies Taxonomy explains regional / geographic distributions of fishes Traits better explain local habitat type and stability, and regional distribution Hoeinghaus et al. 2006
26
Results: fish traits studies Difference in fish traits across river basins – Result of glaciation: filter – Colonizers had opportunistic traits: small body size, brief lifespan, low age maturity, small eggs – Mims et al. 2010 – Jacquemin and Pyron 2011
27
Traits vs. taxa respond similarly to gradients? – Predicted by Heino et al. 2013: – Traits insensitive to geographical variation – Taxa more geographically structured Depends on spatial extent of study
28
Problems with traits Developmental trophic changes Poorly known taxa; broad family characterizations often incorrect Traits are intercorrelated: not independent
29
Problems with traits Data quality of traits varies – Fuzzy coding, continuous variables, categories
30
Summary Functional traits are useful Tend to respond more strongly to environmental gradients than taxonomy – Taxonomy is successful at distinguishing large- scale assemblage variation
31
Traits studies Gayraud et al. 2003 Goldstein & Meador 2005 Hoeinghaus et al. 2007 Frimpong & Angermeier 2010 Menezes et al. 2010 Pyron et al. 2011 Jacquemin & Pyron 2011 Pease et al. 2012 Heino et al. 2013
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.