1
|
Zhang B, Kula A, Mack KML, Zhai L, Ryce AL, Ni WM, DeAngelis DL, Van Dyken JD. Carrying capacity in a heterogeneous environment with habitat connectivity. Ecol Lett 2017; 20:1118-1128. [PMID: 28712141 DOI: 10.1111/ele.12807] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 03/25/2017] [Accepted: 06/03/2017] [Indexed: 11/28/2022]
Abstract
A large body of theory predicts that populations diffusing in heterogeneous environments reach higher total size than if non-diffusing, and, paradoxically, higher size than in a corresponding homogeneous environment. However, this theory and its assumptions have not been rigorously tested. Here, we extended previous theory to include exploitable resources, proving qualitatively novel results, which we tested experimentally using spatially diffusing laboratory populations of yeast. Consistent with previous theory, we predicted and experimentally observed that spatial diffusion increased total equilibrium population abundance in heterogeneous environments, with the effect size depending on the relationship between r and K. Refuting previous theory, however, we discovered that homogeneously distributed resources support higher total carrying capacity than heterogeneously distributed resources, even with species diffusion. Our results provide rigorous experimental tests of new and old theory, demonstrating how the traditional notion of carrying capacity is ambiguous for populations diffusing in spatially heterogeneous environments.
Collapse
Affiliation(s)
- Bo Zhang
- Department of Biology, University of Miami, Coral Gables, FL, USA
| | - Alex Kula
- Department of Biology, University of Miami, Coral Gables, FL, USA
| | - Keenan M L Mack
- Department of Biology, Illinois College, Jacksonville, IL, USA
| | - Lu Zhai
- Department of Biology, University of Miami, Coral Gables, FL, USA.,Department of Mathematics, University of Miami, Coral Gables, FL, USA
| | - Arrix L Ryce
- Department of Biology, University of Miami, Coral Gables, FL, USA
| | - Wei-Ming Ni
- School of Mathematics, University of Minnesota, Minneapolis, MN, USA.,Center for Partial Differential Equations, East China Normal University, Putuo Qu, Shanghai Shi, China
| | - Donald L DeAngelis
- Wetland and Aquatic Research Center, U.S. Geological Survey, Gainesville, FL, USA
| | | |
Collapse
|