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Kimball S, Rath J, Coffey JE, Perea-Vega MR, Walsh M, Fiore NM, Ta PM, Schmidt KT, Goulden ML, Allison SD. Long-term drought promotes invasive species by reducing wildfire severity. Ecology 2024; 105:e4265. [PMID: 38380597 DOI: 10.1002/ecy.4265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 11/06/2023] [Accepted: 12/21/2023] [Indexed: 02/22/2024]
Abstract
Anthropogenic climate change has increased the frequency of drought, wildfire, and invasions of non-native species. Although high-severity fires linked to drought can inhibit recovery of native vegetation in forested ecosystems, it remains unclear how drought impacts the recovery of other plant communities following wildfire. We leveraged an existing rainfall manipulation experiment to test the hypothesis that reduced precipitation, fuel load, and fire severity convert plant community composition from native shrubs to invasive grasses in a Southern California coastal sage scrub system. We measured community composition before and after the 2020 Silverado wildfire in plots with three rainfall treatments. Drought reduced fuel load and vegetation cover, which reduced fire severity. Native shrubs had greater prefire cover in added water plots compared to reduced water plots. Native cover was lower and invasive cover was higher in postfire reduced water plots compared to postfire added and ambient water plots. Our results demonstrate the importance of fuel load on fire severity and plant community composition on an ecosystem scale. Management should focus on reducing fire frequency and removing invasive species to maintain the resilience of coastal sage scrub communities facing drought. In these communities, controlled burns are not recommended as they promote invasive plants.
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Affiliation(s)
- Sarah Kimball
- Center for Environmental Biology, University of California, Irvine, California, USA
- Department of Ecology and Evolutionary Biology, University of California, Irvine, California, USA
| | - Jessica Rath
- Department of Ecology and Evolutionary Biology, University of California, Irvine, California, USA
| | - Julie E Coffey
- UCI-Nature, University of California, Irvine, California, USA
| | - Moises R Perea-Vega
- Center for Environmental Biology, University of California, Irvine, California, USA
| | - Matthew Walsh
- Department of Ecology and Evolutionary Biology, University of California, Irvine, California, USA
| | - Nicole M Fiore
- Center for Environmental Biology, University of California, Irvine, California, USA
| | - Priscilla M Ta
- Center for Environmental Biology, University of California, Irvine, California, USA
| | - Katharina T Schmidt
- Center for Environmental Biology, University of California, Irvine, California, USA
| | - Michael L Goulden
- Department of Earth System Science, University of California, Irvine, California, USA
| | - Steven D Allison
- Department of Ecology and Evolutionary Biology, University of California, Irvine, California, USA
- Department of Earth System Science, University of California, Irvine, California, USA
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Barbour KM, Martiny JBH. Investigating eco-evolutionary processes of microbial community assembly in the wild using a model leaf litter system. THE ISME JOURNAL 2024; 18:wrae043. [PMID: 38506671 PMCID: PMC11008689 DOI: 10.1093/ismejo/wrae043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 02/13/2024] [Accepted: 03/19/2024] [Indexed: 03/21/2024]
Abstract
Microbial communities are not the easiest to manipulate experimentally in natural ecosystems. However, leaf litter-topmost layer of surface soil-is uniquely suitable to investigate the complexities of community assembly. Here, we reflect on over a decade of collaborative work to address this topic using leaf litter as a model system in Southern California ecosystems. By leveraging a number of methodological advantages of the system, we have worked to demonstrate how four processes-selection, dispersal, drift, and diversification-contribute to bacterial and fungal community assembly and ultimately impact community functioning. Although many dimensions remain to be investigated, our initial results demonstrate that both ecological and evolutionary processes occur simultaneously to influence microbial community assembly. We propose that the development of additional and experimentally tractable microbial systems will be enormously valuable to test the role of eco-evolutionary processes in natural settings and their implications in the face of rapid global change.
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Affiliation(s)
- Kristin M Barbour
- Department of Ecology and Evolutionary Biology, University of California, Irvine, Irvine, CA 92697, United States
| | - Jennifer B H Martiny
- Department of Ecology and Evolutionary Biology, University of California, Irvine, Irvine, CA 92697, United States
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