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Hutchinson TF, Adams BT, Dickinson MB, Heckel M, Royo AA, Thomas-Van Gundy MA. Sustaining eastern oak forests: Synergistic effects of fire and topography on vegetation and fuels. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2024; 34:e2948. [PMID: 38351586 DOI: 10.1002/eap.2948] [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: 03/16/2023] [Revised: 08/25/2023] [Accepted: 10/03/2023] [Indexed: 04/04/2024]
Abstract
Across much of the eastern United States, oak forests are undergoing mesophication as shade-tolerant competitors become more abundant and suppress oak regeneration. Given the historical role of anthropogenic surface fires in promoting oak dominance, prescribed fire has become important in efforts to reverse mesophication and sustain oaks. In 2000 we established the Ohio Hills Fire and Fire Surrogate (FFS) study to examine whether repeated prescribed fire (Fire), mechanical partial harvest (Mech), and their combined application (Mech + Fire) reduced the dominance of subcanopy mesophytic competitors, increased the abundance of large oak-hickory advance regeneration, created a more diverse and productive ground-layer flora, and produced fuel beds more conducive to prescribed fire, reducing the risk of high-severity wildfire. Here we report on the ~20-year effects of treatments on vegetation and fuels and examine the support for interactive effects across a topographic-moisture and energy gradient. In general, we found that Fire and Mech + Fire treatments tended to reverse mesophication while the Mech-only treatment did not. The moderate and occasionally high-intensity fires resulted in effects that were ultimately very similar between the two fire treatments but were modulated by topography with increasing fire severity on drier sites. In particular, we found support for an interaction effect between treatment and topography on forest structure and tree regeneration responses. Fire generally reduced mesophytic tree density in the midstory and sapling strata across all site conditions, while leading to substantial gains in the abundance of large oak-hickory advance regeneration on dry and intermediate landscape positions. Fire also promoted ground-layer diversity and created compositionally distinct communities across all site conditions, primarily through the increased richness of native perennial herbs. However, the fire had limited effects on fine surface fuel loading and increased the loading of large woody fuels, potentially increasing the risk of high-severity wildfire during drought conditions. We conclude that two decades of repeated fires, with and without mechanical density reduction, significantly shifted the trajectory of mesophication across most of the landscape, particularly on dry and intermediate sites, highlighting the capacity of a periodic fire regime to sustain eastern oak forests and promote plant diversity but modulated by topography.
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Affiliation(s)
| | - Bryce T Adams
- Northern Research Station, US Forest Service, Delaware, Ohio, USA
| | | | - Maryjane Heckel
- Six Rivers National Forest US Forest Service, Eureka, California, USA
| | - Alejandro A Royo
- Northern Research Station, US Forest Service, Irvine, Pennsylvania, USA
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Middle Holocene Environment on the Ozark Margin in Southeast Missouri: Deciphering a Testudine Testament. QUATERNARY 2022. [DOI: 10.3390/quat5030029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Turtle taxa represented at Lepold site 23RI59 in southeastern Missouri, USA provide a record of environmental conditions spanning the Middle Holocene. Identified turtle taxa show that open water was present between 7500 and 4000 radiocarbon years ago. Aquatic resources seem to be more intensively exploited beginning about 6300 years ago, about 1200 years after intensive occupation of the site had begun. The observed turtle taxon composition is consistent with the presence of a floodplain with shallow, seasonal, overflow ponds, but with riverine and upland habitats also being represented.
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Jolly CJ, Dickman CR, Doherty TS, van Eeden LM, Geary WL, Legge SM, Woinarski JCZ, Nimmo DG. Animal mortality during fire. GLOBAL CHANGE BIOLOGY 2022; 28:2053-2065. [PMID: 34989061 DOI: 10.1111/gcb.16044] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 12/04/2021] [Indexed: 06/14/2023]
Abstract
Earth's rapidly warming climate is propelling us towards an increasingly fire-prone future. Currently, knowledge of the extent and characteristics of animal mortality rates during fire remains rudimentary, hindering our ability to predict how animal populations may be impacted in the future. To address this knowledge gap, we conducted a global systematic review of the direct effects of fire on animal mortality rates, based on studies that unequivocally determined the fate of animals during fire. From 31 studies spanning 1984-2020, we extracted data on the direct impacts of fire on the mortality of 31 species from 23 families. From these studies, there were 43 instances where direct effects were measured by reporting animal survival from pre- to post-fire. Most studies were conducted in North America (52%) and Oceania (42%), focused largely on mammals (53%) and reptiles (30%), and reported mostly on animal survival in planned (82%) and/or low severity (70%) fires. We found no studies from Asia, Europe or South America. Although there were insufficient data to conduct a formal meta-analysis, we tested the effect of fire type, fire severity, fire regime, animal body mass, ecological attributes and class on survival. Only fire severity affected animal mortality, with a higher proportion of animals being killed by high than low severity fires. Recent catastrophic fires across the globe have drawn attention to the plight of animals exposed to wildfire. Yet, our systematic review suggests that a relatively low proportion of animals (mean predicted mortality [95% CI] = 3% [1%-9%]) are killed during fire. However, our review also underscores how little we currently know about the direct effects of fire on animal mortality, and highlights the critical need to understand the effects of high severity fire on animal populations.
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Affiliation(s)
- Chris J Jolly
- Institute for Land, Water and Society, School of Environmental Science, Charles Sturt University, Albury, New South Wales, Australia
| | - Chris R Dickman
- National Environmental Science Program Threatened Species Recovery Hub, School of Life and Environmental Sciences, University of Sydney, Sydney, New South Wales, Australia
| | - Tim S Doherty
- School of Life and Environmental Sciences, University of Sydney, Sydney, New South Wales, Australia
| | - Lily M van Eeden
- Department of Environment Land, Water and Planning, Arthur Rylah Institute for Environmental Research, Heidelberg, Victoria, Australia
| | - William L Geary
- Department of Environment, Land, Water and Planning, Biodiversity Strategy and Knowledge Branch, Biodiversity Division, East Melbourne, Victoria, Australia
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Geelong, Victoria, Australia
| | - Sarah M Legge
- Research Institute for the Environment and Livelihoods, Charles Darwin University, Darwin, Northern Territory, Australia
- Centre for Biodiversity and Conservation Science, University of Queensland, St Lucia, Queensland, Australia
- Fenner School of Environment and Society, The Australian National University, Australian Capital Territory, Canberra, Australia
| | - John C Z Woinarski
- Research Institute for the Environment and Livelihoods, Charles Darwin University, Darwin, Northern Territory, Australia
- School of Ecosystem and Forest Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Dale G Nimmo
- Institute for Land, Water and Society, School of Environmental Science, Charles Sturt University, Albury, New South Wales, Australia
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Robertson EP, Tanner EP, Elmore RD, Fuhlendorf SD, Mays JD, Knutson J, Weir JR, Loss SR. Fire management alters the thermal landscape and provides multi-scale thermal options for a terrestrial turtle facing a changing climate. GLOBAL CHANGE BIOLOGY 2022; 28:782-796. [PMID: 34741780 DOI: 10.1111/gcb.15977] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 09/04/2021] [Accepted: 10/23/2021] [Indexed: 06/13/2023]
Abstract
As effects of climate change intensify, there is a growing need to understand the thermal properties of landscapes and their influence on wildlife. A key thermal property of landscapes is vegetation structure and composition. Management approaches can alter vegetation and consequently the thermal landscape, potentially resulting in underappreciated consequences for wildlife thermoregulation. Consideration of spatial scale can clarify how management overlaid onto existing vegetation patterns affects thermal properties of landscapes relevant to wildlife. We examined effects of temperature, fire management, and vegetation structure on multi-scale habitat selection of an ectothermic vertebrate (the turtle Terrapene carolina triunguis) in the Great Plains of the central United States by linking time-since-fire data from 18 experimental burn plots to turtle telemetry locations and thermal and vegetation height data. Within three 60-ha experimental landscapes, each containing six 10-ha sub-blocks that are periodically burned, we found that turtles select time-since-fire gradients differently depending on maximum daily ambient temperature. At moderate temperatures, turtles selected sub-blocks with recent (<1 year) time-since-fire, but during relatively hot and cool conditions, they selected sub-blocks with later (2-3 year) time-since-fire that provided thermal buffering compared with recently burned sub-blocks. Within 10-ha sub-blocks, turtles selected locations with taller vegetation during warmer conditions that provided thermal buffering. Thermal performance curves revealed that turtle activity declined as temperatures exceeded ~24-29°C, and on "heat days" (≥29°C) 73% of turtles were inactive compared with 37% on non-heat days, emphasizing that thermal extremes may lead to opportunity costs (i.e., foregone benefits turtles could otherwise accrue if active). Our results indicate that management approaches that promote a mosaic of vegetation heights, like spatiotemporally dynamic fire, can provide thermal refuges at multiple spatial scales and thus be an actionable way to provide wildlife with multiple thermal options in the context of ongoing and future climate change.
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Affiliation(s)
- Ellen P Robertson
- Department of Natural Resource Ecology and Management, Oklahoma State University, Stillwater, Oklahoma, USA
- South Central Climate Adaptation Science Center, Norman, Oklahoma, USA
| | - Evan P Tanner
- Department of Rangeland and Wildlife Science, Caesar Kleberg Wildlife Research Institute, Texas A&M University-Kingsville, Kingsville, Texas, USA
| | - R Dwayne Elmore
- Department of Natural Resource Ecology and Management, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Samuel D Fuhlendorf
- Department of Natural Resource Ecology and Management, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Jonathan D Mays
- Florida Fish and Wildlife Research Institute, Gainesville, Florida, USA
| | - Jennifer Knutson
- Department of Natural Resource Ecology and Management, Oklahoma State University, Stillwater, Oklahoma, USA
| | - John R Weir
- Department of Natural Resource Ecology and Management, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Scott R Loss
- Department of Natural Resource Ecology and Management, Oklahoma State University, Stillwater, Oklahoma, USA
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Jones MT, Willey LL, Mays JD, Dodd CK. Wildfire, Depredation, and Synergistic Management Challenges Contribute to the Decline of a Significant Population of Florida Box Turtles (Terrapene bauri). CHELONIAN CONSERVATION AND BIOLOGY 2021. [DOI: 10.2744/ccb-1480.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Michael T. Jones
- Department of Environmental Conservation, University of Massachusetts, Amherst, Massachusetts 01003 USA []
| | - Lisabeth L. Willey
- American Turtle Observatory, 90 Whitaker Road, New Salem, Massachusetts 01355 USA
| | - Jonathan D. Mays
- Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission, Gainesville, Florida 32601 USA []
| | - C. Kenneth Dodd
- Division of Herpetology, Florida Museum of Natural History, University of Florida, Gainesville, Florida 32611 USA []
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Harris KA, Clark JD, Elmore RD, Harper CA. Spatial Ecology and Resource Selection of Eastern Box Turtles. J Wildl Manage 2020. [DOI: 10.1002/jwmg.21945] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Katie A. Harris
- University of Tennessee, Forestry, Wildlife, and Fisheries 2431 Joe Johnson Drive Knoxville TN 37996 USA
| | - Joseph D. Clark
- U.S. Geological Survey, Northern Rocky Mountain Science Center, Southern Appalachian Research Branch, University of Tennessee Knoxville TN 37996 USA
| | - R. Dwayne Elmore
- Oklahoma State University, Natural Resource Ecology and Management 008 C Agricultural Hall Stillwater OK 74078 USA
| | - Craig A. Harper
- University of Tennessee, Forestry, Wildlife, and Fisheries 2431 Joe Johnson Drive Knoxville TN 37996 USA
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