Original Research ARTICLE
Simulating groundcover community assembly in a frequently burned ecosystem using a simple neutral model
- 1Center for Forest Disturbance Science, Southern Research Station, Forest Service (USDA), United States
- 2University of Nevada, Reno, United States
- 3Tall Timbers Research Station and Land Conservancy, United States
- 4Rocky Mountain Research Station, United States Forest Service, United States
Fire is a global keystone process that drives patterns of biodiversity globally. In frequently burned fire-dependent ecosystems, surface fire regimes allow for the coexistence of high plant diversity at fine-scales even where soils are uniform. The mechanisms on how fire impacts groundcover community dynamics are however, poorly understood. Because fire can act as a stochastic agent of mortality, we hypothesized that a neutral mechanism might be responsible for maintaining plant diversity. We used the demographic parameters of the Unified Neutral Theory of Biodiversity (UNTB) as a foundation to model groundcover species richness, using a southeastern U.S. pine woodland as an example. We followed the fate of over 7,000 individuals of 123 plant species for four years and two prescribed burns in frequently burned Pinus palustris sites in NW FL, USA. Using these empirical data and UNTB-based assumptions, we developed two parsimonious autonomous agent models, which were distinct by spatially explicit and implicit local recruitment processes. Using a parameter sensitivity test, we examined how empirical estimates, input species frequency distributions, and community size affected output species richness. We found that dispersal limitation was the most influential parameter, followed by mortality and birth, and that these parameters varied based on scale of the frequency distributions. Overall, these nominal parameters were useful for simulating fine-scale groundcover communities, although further empirical analysis of richness patterns, particularly related to fine-scale burn severity is needed. This modeling framework can be utilized to examine our premise that localized groundcover assemblages are neutral communities at high fire frequencies, as well as examine the extent to which niche-based dynamics determine community dynamics when fire frequency is altered.
Keywords: Neutral theory, Longleaf pine (Pinus palustris Mill.), cellular automata, groundcover communities, Frequent fire, scale, Spatial dispersal, Fourier amplitude sensitivity test (FAST)
Received: 18 Apr 2019;
Accepted: 13 Aug 2019.
Edited by:Brian N. Bailey, University of California, Davis, United States
Reviewed by:Dany P. Moualeu-Ngangue, Leibniz University Hannover, Germany
Leonor Calvo Galvan, Universidad de León, Spain
Copyright: © 2019 Loudermilk, Dyer, Pokswinski, Hudak, Hornsby, Richards, Dell, Goodrick, Hiers and O'Brien. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Dr. E. Louise Loudermilk, Center for Forest Disturbance Science, Southern Research Station, Forest Service (USDA), Athens, 30602, Georgia, United States, firstname.lastname@example.org