COS 33-2 - Continental-scale drivers of species-area relationships across the National Ecological Observatory Network (NEON)

Monday, August 7, 2023

3:45 PM – 4:00 PM PDT

Location: B119

Presenting Author(s)

BB

Benjamin Baiser

Associate Professor
Department of Wildlife Ecology and Conservation, University of Florida
Gainesville, FL, United States

Coauthor(s)

IF

Isadora Fluck-Essig

University of Florida, United States
SL

Shelby LeClare

Master's Student
University of Florida, Florida, United States
DL

Daijiang Li

Louisiana State University
Baton Rouge Baton Rouge, LA LA, United States
TM

Thomas J. Matthews

University of Brimingham, United Kingdom
SR

Sydne Record

Associate Professor
Department of Wildlife, Fisheries, and Conservation Biology, University of Maine, Maine, United States
AS

Angela Strecker

Associate Professor
Institute for Watershed Studies, Western Washington University
Bellingham, Washington, United States
PZ

Phoebe L. Zarnetske

Associate Professor
Department of Integrative Biology; Ecology, Evolution, and Behavior Program; Institute for Biodiversity, Ecology, Evolution, and Macrosystems, Michigan State University, United States

Abstract: The species–area relationship (SAR) is one of the most general patterns in ecology. SARs are most commonly modeled by a power law function S = cA^z that is log–log transformed for statistical utility. The exponent of the power-law SAR (z) has been studied to elucidate general rules for how species richness scales with area and to compare and contrast SARs across taxonomic groups, native and exotic species, and island and mainland systems. The intercept of the power-law SAR, c, interpreted as species richness per unit area, has received considerably less attention. However, dating back to pioneering studies on SARs, differences in sampling design and methodology have hampered comparisons of SARs. In this study, we used standardized data from the National Ecological Observatory Network (NEON) to assess relationships of SARs to biogeographical variables at the continental scale for ground beetles (Carabidae), birds, and small mammals. To relate SARs to biogeographic variables, we constructed species accumulation curves (SAC) for plots at each NEON site (n=47) for each taxa, fit power-law models to SACs, and extracted z and c from these models. We then used linear models to test the role of latitude, longitude, elevation, temperature, and precipitation on z and c. For beetles, z increased with mean temperature (p = 0.06) and values of c showed a positive relationship with longitude (p< 0.05). Values of z and c for bird SARs, were significantly influenced by longitude (p< 0.005) with c values increasing in more easterly NEON sites and z increasing in more westerly sites. SARs for small mammals had z values that decreased with temperature (p< 0.05). Variation in c for small mammals was not related to any of our predictor variables. Overall, we found that biogeographic relationships for power-law SARs at a continental scale differed among taxa.