Fine-scale species-area relationships of the vascular flora of the Southeast (USA) Jason Fridley, Robert Peet, Peter White, Joel Gramling, Todd Jobe, Jessica Kaplan, Meghan McKnight, Amanda Senft, and David Vandermast Plant Ecology Laboratory University of North Carolina at Chapel Hill

Species-area relationships (SPARs) Critically important for studying patterns and processes of biodiversityCritically important for studying patterns and processes of biodiversity –Conservation, reserve design, extinction rates –Spatial dependence of species richness –Relation of scale to process

Fine-scale SPARs 0.1 ha and below Typical form?Typical form? Variation?Variation? Representative of vegetation structure?Representative of vegetation structure? –Scale dependence of local species richness –Patterns indicate processes? Relationship to larger species-area curve?Relationship to larger species-area curve?

Carolina Vegetation Survey 0.1 ha vegetation plots across the Carolinas (+ GA, TN, FL)0.1 ha vegetation plots across the Carolinas (+ GA, TN, FL) Presence of rooted vascular plant species in nested subplots at equally spaced areas on a log 10 axis:Presence of rooted vascular plant species in nested subplots at equally spaced areas on a log 10 axis: 0.01, 0.1, 1.0, 10, 100, 1000 m 2

This study = 1454 plots

Methodology: functional form Gleason (exponential)

Methodology: functional form Arrhenius (power)

Methodology: functional form

Patterns: Vegetation Types Why important?Why important? –Show the signature of different processes at different scales small scales: plant size and density, competitionsmall scales: plant size and density, competition large scales: environment, species poolslarge scales: environment, species pools Scale dependence of species richnessScale dependence of species richness

Fine-scale SPAR functional types

Type A: “plots that keep on giving” Unusual: supply-side driven, influenced little by competition Unusual: supply-side driven, influenced little by competition Little spatial structure; disturbance important Little spatial structure; disturbance important

Type A: “plots that keep on giving” Unusual: supply-side driven, influenced little by competition Unusual: supply-side driven, influenced little by competition Little spatial structure; disturbance important Little spatial structure; disturbance important ( ↓ competitive exclusion) ( ↑ species pool)

Type B: high accumulation rate Fertile site means larger plants: low individual density Fertile site means larger plants: low individual density Large regional species pool: “sweet site” Large regional species pool: “sweet site”

(large plants: “megaforbs”) ( ↑ species pool) Type B: high accumulation rate Fertile site means larger plants: low individual density Fertile site means larger plants: low individual density Large regional species pool: “sweet site” Large regional species pool: “sweet site”

Type C: low accumulation rate High fine richness: small plants, high density High fine richness: small plants, high density Low regional species pool, stressful site Low regional species pool, stressful site

Type C: low accumulation rate High fine richness: small plants, high density High fine richness: small plants, high density Low regional species pool, stressful site Low regional species pool, stressful site (small plants) ( ↓ species pool)

Type D: poor sites Low individual density: stressful conditions or large plants Low individual density: stressful conditions or large plants Low regional species pool, stressful site Low regional species pool, stressful site

Type D: poor sites Low individual density: stressful conditions or large plants Low individual density: stressful conditions or large plants Low regional species pool, stressful site Low regional species pool, stressful site (very low individual density) ( ↓ species pool)

Rich vs. poor communities Pine woodlands and savannas

Fine scales to the globe Incorporate richness estimates of larger areasIncorporate richness estimates of larger areas “Full scale” SPARCs are rare; the few that exist are triphasic“Full scale” SPARCs are rare; the few that exist are triphasic Where is location of inflection point?Where is location of inflection point?

Fine scales to the globe

Acknowledgements 600+ participants in CVS600+ participants in CVS T. Wentworth, M. Schafale, A. Weakley, R. BrownT. Wentworth, M. Schafale, A. Weakley, R. Brown Financial support from USFS, NSFFinancial support from USFS, NSF National Parks Foundation for meeting supportNational Parks Foundation for meeting support