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Osburn ED, Badgley BD, Strahm BD, Aylward FO, Barrett JE. Emergent properties of microbial communities drive accelerated biogeochemical cycling in disturbed temperate forests. Ecology 2021; 102:e03553. [PMID: 34622940 DOI: 10.1002/ecy.3553] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 03/31/2021] [Accepted: 07/15/2021] [Indexed: 01/04/2023]
Abstract
Despite ever-increasing availability of detailed information about microbial community structure, relationships of microbial diversity with ecosystem functioning remain unclear. We investigated these relationships at the Coweeta Hydrologic Laboratory, where past forest disturbances (e.g., clear-cut) have altered both ecosystem processes (e.g., increased N export) and microbial communities (e.g., increased bacterial diversity). We sampled soils from disturbed and adjacent reference forests, characterized resident microbial communities, and measured several microbial C-cycle and N-cycle process rates. Microbial communities from historically disturbed soils exhibited altered ecosystem functioning, including generally higher rates of C- and N-cycle processes. Disturbed soil microbial communities also exhibited altered ecosystem multifunctionality, a composite variable consisting of all measured process rates as well as extracellular enzyme activities. Although we found few relationships between ecosystem functions and microbial alpha diversity, all functions were correlated with microbial community composition metrics, particularly r:K strategist ratios of bacterial phyla. Additionally, for both ecosystem multifunctionality and specific processes (i.e., C- and N-mineralization), microbial metrics significantly improved models seeking to explain variation in process rates. Our work sheds light on the links between microbial communities and ecosystem functioning and identifies specific microbial metrics important for modeling ecosystem responses to environmental change.
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Affiliation(s)
- Ernest D Osburn
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
| | - Brian D Badgley
- School of Plant and Environmental Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
| | - Brian D Strahm
- Department of Forest Resources and Environmental Conservation, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
| | - Frank O Aylward
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
| | - J E Barrett
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
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Jackson CR, Cecala KK, Wenger SJ, Kirsch JE, Webster JR, Leigh DS, Sanders JM, Love JP, Knoepp JD, Fraterrigo JM, Rosemond AD. Distinctive Connectivities of Near-Stream and Watershed-Wide Land Uses Differentially Degrade Rural Aquatic Ecosystems. Bioscience 2021. [DOI: 10.1093/biosci/biab098] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
The water-quality effects of low-density rural land-use activities are understudied but important because of large rural land coverage. We review and synthesize spatially extensive studies of oligotrophic mountain streams in the rural Southern Appalachian Mountains, concluding that rural land-use activities significantly degrade water quality through altered and mostly enhanced landscape–stream connections, despite high forest retention. Some connections (insolation, organic inputs, root–channel interactions, stream–field connectivity, individual landowner discharges) are controlled by near-stream land-use activities, whereas others (reduced nitrogen uptake and cycling, enhanced biological nitrogen fixation, nutrient subsidy, runoff from compacted soils, road runoff delivery) are controlled by basin-wide land use. These connections merge to alter basal resources and shift fish, salamander, and invertebrate assemblages toward species tolerant of higher turbidity and summer temperatures and those more competitive in mesotrophic systems. Rural water quality problems could be mitigated substantially with well-known best management practices, raising socioecological governance questions about best management practice adoption.
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Affiliation(s)
- C Rhett Jackson
- Warnell School, University of Georgia, Athens, Georgia, United States
| | - Kristen K Cecala
- Department of Biology, University of the South, Sewanee, Tennessee, United States
| | - Seth J Wenger
- Odum School of Ecology, University of Georgia, Athens, Georgia, United States
| | | | - Jackson R Webster
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, United States
| | - David S Leigh
- Department of Geography, University of Georgia, Athens, Georgia, United States
| | | | - Jason P Love
- Highlands Biological Station, Western Carolina University, Highlands, North Carolina, United States
| | - Jennifer D Knoepp
- US Forest Service Coweeta Hydrologic Laboratory, Otto, North Carolina, United States
| | - Jennifer M Fraterrigo
- Department of Natural Resources and Environmental Sciences at the University of Illinois, Urbana, Illinois, United States
| | - Amy D Rosemond
- Odum School of Ecology, University of Georgia, Athens, Georgia, United States
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Osburn ED, Simpson JS, Strahm BD, Barrett JE. Land Use History Mediates Soil Biogeochemical Responses to Drought in Temperate Forest Ecosystems. Ecosystems 2021. [DOI: 10.1007/s10021-021-00641-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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Osburn ED, McBride SG, Aylward FO, Badgley BD, Strahm BD, Knoepp JD, Barrett JE. Soil Bacterial and Fungal Communities Exhibit Distinct Long-Term Responses to Disturbance in Temperate Forests. Front Microbiol 2019; 10:2872. [PMID: 31921050 PMCID: PMC6917579 DOI: 10.3389/fmicb.2019.02872] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 11/28/2019] [Indexed: 11/24/2022] Open
Abstract
In Appalachian ecosystems, forest disturbance has long-term effects on microbially driven biogeochemical processes such as nitrogen (N) cycling. However, little is known regarding long-term responses of forest soil microbial communities to disturbance in the region. We used 16S and ITS sequencing to characterize soil bacterial (16S) and fungal (ITS) communities across forested watersheds with a range of past disturbance regimes and adjacent reference forests at the Coweeta Hydrologic Laboratory in the Appalachian mountains of North Carolina. Bacterial communities in previously disturbed forests exhibited consistent responses, including increased alpha diversity and increased abundance of copiotrophic (e.g., Proteobacteria) and N-cycling (e.g., Nitrospirae) bacterial phyla. Fungal community composition also showed disturbance effects, particularly in mycorrhizal taxa. However, disturbance did not affect fungal alpha diversity, and disturbance effects were not consistent at the fungal class level. Co-occurrence networks constructed for bacteria and fungi showed that disturbed communities were characterized by more connected and tightly clustered network topologies, indicating that disturbance alters not only community composition but also potential ecological interactions among taxa. Although bacteria and fungi displayed different long-term responses to forest disturbance, our results demonstrate clear responses of important bacterial and fungal functional groups (e.g., nitrifying bacteria and mycorrhizal fungi), and suggest that both microbial groups play key roles in the long-term alterations to biogeochemical processes observed following forest disturbance in the region.
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Affiliation(s)
- Ernest D. Osburn
- Department of Biological Sciences, College of Science, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Steven G. McBride
- Department of Biological Sciences, College of Science, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Frank O. Aylward
- Department of Biological Sciences, College of Science, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Brian D. Badgley
- School of Plant and Environmental Sciences, College of Agriculture and Life Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Brian D. Strahm
- Department of Forest Resources and Environmental Conservation, College of Natural Resources and Environment, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Jennifer D. Knoepp
- Coweeta Hydrologic Laboratory, USDA Forest Service Southern Research Station, Otto, NC, United States
| | - J. E. Barrett
- Department of Biological Sciences, College of Science, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
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Kominoski JS, Gaiser EE, Baer SG. Advancing Theories of Ecosystem Development through Long-Term Ecological Research. Bioscience 2018. [DOI: 10.1093/biosci/biy070] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- John S Kominoski
- Southeast Environmental Research Center and the Department of Biological Sciences at Florida International University, in Miami, and with the Florida Coastal Everglades Long Term Ecological Research Program
| | - Evelyn E Gaiser
- Southeast Environmental Research Center and the Department of Biological Sciences at Florida International University, in Miami, and with the Florida Coastal Everglades Long Term Ecological Research Program
| | - Sara G Baer
- Department of Plant Biology at Southern Illinois University, in Carbondale, and with the Konza Prairie Long Term Ecological Research Program
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Total C and N Pools and Fluxes Vary with Time, Soil Temperature, and Moisture Along an Elevation, Precipitation, and Vegetation Gradient in Southern Appalachian Forests. Ecosystems 2018. [DOI: 10.1007/s10021-018-0244-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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