The Maintenance of Species Diversity in Hyperdiverse Communities

What processes create, maintain, and modify biodiversity of species-rich communities?

Prescribed Fire in Longleaf Pine Savanna – Louisiana (top) & Species-Rich Groundcover Plant Community – Alabama (bottom)
(Photos: J. Myers)

Species-rich communities have inspired a rich body of theory to explain community assembly and the maintenance of biodiversity. In these communities, extreme numbers of species often occur together at small scales. Classic explanations for high local biodiversity emphasize the importance of deterministic abiotic and biotic processes that promote stable coexistence of species via niche selection. Yet species composition and diversity often varies substantially among communities with similar abiotic and biotic conditions, suggesting important roles for dispersal limitation, neutral species interactions, and other stochastic processes that cause ecological drift. Moreover, processes at larger spatiotemporal scales such as speciation and the dynamics of regional species pools may also determine how species-rich communities assemble. Species-rich communities therefore provide an ideal setting for exploring the ways in which processes at different scales interface to determine community assembly, diversity, and dynamics.

We are experimentally testing the relative importance of dispersal limitation, ecological drift, and niche selection (e.g., environmental filtering from drought and fire; competition within and among dominant bunchgrass species and rare species; species sorting across soil-resource gradients) as drivers of biodiversity and community assembly in the hyperdiverse longleaf pine (Pinus palustris) ecosystem. Historically, this ecosystem spanned the North American Coastal Plain, a global biodiversity hotspot that supports >1,600 endemic plant species (Noss et al. 2015). At local scales, the longleaf pine ecosystem supports the highest plant species richness in North America (40-50+ species/m²) and is among the world’s most threatened ecosystems (>98% habitat loss), providing abundant opportunities to contribute towards biodiversity conservation, ecological restoration, and land management.

Related Publications

Current and former members of our research group in bold.

Myers, Jonathan A. & Kyle E. Harms. 2011. Seed arrival and ecological filters interact to assemble high-diversity plant communities. Ecology 92: 676-686.     Abstract     PDF     Supporting Material

*Myers, Jonathan A. & Kyle E. Harms. 2009. Seed arrival, ecological filters, and plant species richness: A meta-analysis. Ecology Letters 12: 1250-1260.     Abstract     PDF     Supporting Material     *Review & Synthesis Paper

Myers, Jonathan A. & Kyle E. Harms. 2009. Local immigration, competition from dominant guilds, and the ecological assembly of high-diversity pine savannas. Ecology 90: 2745-2754.     Abstract     PDF     Supporting Material

Catano, Christopher P., Timothy L. Dickson & Jonathan A. Myers. 2017. Dispersal and neutral sampling mediate contingent effects of disturbance on plant beta-diversity: A meta-analysis. Ecology Letters 20: 347-356.     Abstract     PDF     Supporting Information     Cover Article

Kirkman, L. Katherine & Jonathan A. Myers. 2017. Mechanistic controls of community assembly and biodiversity. Chapter 5 In: Kirkman, L. Katherine & Steven B. Jack (editors) Ecological Restoration and Management of Longleaf Pine Forests. CRC Press, Boca Raton, FL.     PDF     View Book

Harms, Kyle E., Paul R. Gagnon, Heather A. Passmore, Jonathan A. Myers & William J. Platt. 2017. Groundcover community assembly in high-diversity pine savannas: Seed arrival and environmental filtering through fire-generated pores. Ecosphere 8: e01716.     Abstract     PDF     Supporting Information

Hovanes, Katherine, Kyle E. Harms, Paul R. Gagnon, Jonathan A. Myers & Bret D. Elderd. 2018. Overdispersed spatial patterning of dominant bunchgrasses in southeastern pine savannas.  The American Naturalist 191: 658-667.     Abstract     PDF

Gagnon, Paul R., Kyle E. Harms, William J. Platt, Heather A. Passmore & Jonathan A. Myers. 2012. Small-scale variation in fuel loads differentially affects two co-dominant bunchgrasses in a species-rich pine savanna. PLoS ONE 7: e29674.     Abstract     PDF

Gagnon, Paul R., Heather A. Passmore, Matthew Slocum, Jonathan A. Myers, Kyle E. Harms, William J. Platt & C.E. Timothy Paine. 2015. Fuels and fires influence vegetation via above- and below-ground pathways in a high-diversity plant community. Journal of Ecology 103: 1009-1019.     Abstract     PDF     Data

*Gagnon, Paul R., Heather A. Passmore, William J. Platt, Jonathan A. Myers, C.E. Timothy Paine & Kyle E. Harms. 2010. Does pyrogenicity protect burning plants? Ecology 91: 3481-3487.     Abstract     PDF     Cover Article     *Concepts & Synthesis Paper

Study Sites

Our study sites include wet (e.g., savanna), mesic (e.g., flatwood), and dry (e.g., sandhill) longleaf pine communities on private and public lands in Florida (e.g., Eglin Air Force Base) and Louisiana (e.g., Camp Whispering Pines Girl Scout Camp; Abita Creek Flatwoods & Lake Ramsay Natural Conservancy Preserves).

Quadrat (1 x 1 m) containing ~40 plant species in a longleaf pine savanna, Louisiana
(Photo: J. Myers)

Sundew (Drosera sp. [Droseraceae])
in a longleaf pine savanna, Florida
(Photo: J. Myers)

Longleaf “Diversity, Dominance & Disturbance (3D)” Team, Eglin Air Force Base, Florida – August 2013 (Photo: J. Myers)

Photo Gallery

 

A photo gallery including images from longleaf pine ecosystems in Florida (Apalachicola National Forest; Blackwater River State Park; Eglin Air Force Base; Ocala National Forest; Ordway-Swisher Biological Station; St. Joseph Bay State Buffer Preserve), Louisiana (Camp Whispering Pines; Abita Creek Flatwoods Nature Conservancy Preserve), Alabama (Splinter Hill Bog Nature Conservancy Preserve), and Mississippi (DeSoto National Forest).

Education & Outreach

In addition to our basic research in community assembly and fire ecology, abundant opportunities have emerged to also contribute towards conservation in longleaf ecosystems through educational and management-based outreach. Our outreach activities have included nature programs for Girl Scouts and the general public at Camp Whispering Pines (Louisiana) and a longleaf groundcover workshop at the Longleaf Alliance 10th Biennial Conference in Mobile, Alabama (e.g., our workshop report and recommendations we submitted to the 2014 Longleaf Partnership Council).

Acknowledgements

We thank the Eglin Air Force Base (especially Jackson Guard), the Girl Scouts of America and Camp Whispering Pines Girl Scout Camp, the Nature Conservancy and Abita Creek Flatwoods and Lake Ramsay Nature Conservancy Preserves, The Longleaf Alliance, and the National Science Foundation (DEB 1144084) for supporting our outreach activities and research.