Executive Summary: Paleoecology

Continental scientific drilling is essential for addressing the most pressing questions in understanding how the biosphere affects and is affected by other components of the earth system. The continental sedimentary record provides long, continuous, and unweathered samples, which enables detailed inventories of body, trace, and molecular fossils and chemical and physical signals that provide holistic insights on the dynamic evolution of ecosystems through time. The range of proxies that are available within drill cores is unmatched in comparison to other geological archives, and continental drilling reaches strata that are otherwise inaccessible, improving the spatiotemporal resolution of Earth’s history. These cores provide an archive of multiproxy legacy data that can be leveraged for decades (e.g., “big data” syntheses, modeling) via curation at the Continental Scientific Drilling Facility. Despite this, continental scientific drilling remains under-resourced, and new facilities and infrastructure are needed to push the boundaries of innovation. Advances in biomarkers, clumped isotopes, ancient DNA, UV-VIS/pigment analyses, geochronology, etc. are capable of transforming our understanding of biodiversity through time. Such datasets are vital cornerstones for community-curated open databases (e.g., Neotoma, PBDB, iDigBio) that enable new AI and machine learning techniques to unlock patterns and understand processes across all of Earth’s history and the entire Tree of Life.

1) What are the patterns and drivers of biological diversity through time? Our ability to address an ongoing extinction crisis is limited by our lack of understanding of the mechanisms that produced contemporary patterns of biodiversity. The number and distribution of species has varied throughout time as a result of speciation and extinction, but the various drivers and the patterns and rates of change in diversification (e.g. gradual vs. punctuated) remain unclear. This incomplete understanding prevents us from predicting future changes in biodiversity and understanding how changes in biodiversity affect critical ecosystem services that are vital for human survival. In the past two centuries, many species have been lost or become severely threatened, yet it is difficult to compare these extinctions with previous mass extinctions. Continental drilling records from periods of environmental and biodiversity change are essential for studying continuous and often abrupt changes in species assemblages, their diversification and extinction, the pace of these changes, and the associated external forcings.

2) How do tectonic processes and landscape evolution influence biodiversity and ecosystem dynamics? Tectonic processes influence evolutionary and ecological processes. Changes in continental configuration or topography alter population and genetic connectivity, create or destroy microhabitats, shape Earth’s climate system, and transform sedimentary processes and nutrient cycles linking organisms and ecosystems across upland and lowland basins. Continental drill cores enable the coupled analyses of physical, geochemical, and biological archives that can be used to holistically reconstruct landscape processes and their interactions with species and ecosystems. Deep drilling records can be connected to outcrops to understand the spatiotemporal patterns within evolving landscapes and climates. These stratigraphic data can be integrated with outputs from climate, landscape, and tectonic models to improve our understanding of ecosystem and biodiversity dynamics.

3) How are populations, species, and communities affected by climate change? The geological record shows that biodiversity can be highly sensitive to climate change, as species respond in distribution and abundance. And yet, life persists; ancestral lineages of extant species have experienced wildly different climate regimes over their evolutionary history, which has shaped the morphology and behavior of modern organisms. As we head towards a state of the climate system with no counterpart in human history, with atmospheric CO2 levels not seen on Earth since the Pliocene, continuous drill cores provide essential information about how species responded to warming events of varied rates, magnitudes, and durations, such as glacial terminations or hyperthermals (e.g., the PETM). We can also understand why some systems exhibited resilience or stasis despite climate change, or when biodiversity was influenced by a combination of climatic and non-climatic processes (e.g., biotic interactions).

4) How have fire and other disturbances affected and been affected by climate change, atmospheric chemistry, vegetation change, and humans? Devastating megafires are one of the pressing challenges of the 21st century; sedimentary records provide essential information about past disturbance regimes. To date, this work has largely focused on fire and its relationship to climate change and people across the late Quaternary. Longer records are critically needed to understand how aspects of the fire triangle (i.e., oxygen, fuel, ignition) influenced fire regimes during past warm periods in Earth’s history, enabled by new proxies (e.g., PAHs, levoglucosan) that allow the reconstruction of past fire regimes even without macroscopic charcoal. Further, disturbances such as pest/pathogen outbreaks or volcanic eruptions have received less attention but likely influence ecological and evolutionary processes. Pre-Industrial sediments provide records of natural disturbance regime variability, while past analogs for future climates enable us to assess potential future trajectories in disturbance regimes and their effects on ecosystems.

5) What is the relationship between Earth system change and human evolution and dispersal? Understanding the linkages between changes in the Earth system (cryosphere, hydrosphere, biosphere, geosphere, atmosphere) and the evolution and dispersal of hominins remains an enduring challenge of broad scientific and public interest. Continental drilling can target basins near human fossil localities, hypothesized migration routes, and human habitats to better understand 1) the availability, distribution, and seasonality of resources used by humans and 2) the effects of tectonics and climate on human evolution and dispersal. Recent drilling campaigns in Africa have yielded valuable paleoenvironmental data, but these records are few. New, strategically placed drill cores that overlap with key periods of human evolution and dispersal are necessary for high-resolution basin-to-basin comparisons and regional- to continental-wide syntheses within and outside of Africa.

6) How have biogeochemical cycles influenced climate and biodiversity? Weathering is intrinsically tied to biogeochemical cycles, which link terrestrial, aquatic, and marine ecosystems with the atmosphere and geosphere. In deep time, weathering and erosional processes are hypothesized to have influenced major climatic and biodiversity patterns, including extinctions (e.g., Snowball Earth, end-Devonian mass extinction). Importantly, biological processes may have influenced the physical Earth system via key feedbacks on carbon and other nutrient cycles. Photosynthesis is extremely sensitive to concentrations of oxygen and carbon dioxide, with both high and low CO2 levels influencing biodiversity and chemical weathering rates. Drill cores that access times of different atmospheric chemistry and weathering regimes are essential to test hypotheses about geobiological interactions due to global change.

What resources are required?

●      A modular, portable drilling platform with dynamic positioning, capable of supporting long-string drilling equipment, drillers, and scientific crew is needed, particularly for sampling remote, extant deepwater lakes with well-preserved pre-Quaternary strata. The absence of such a platform is a critical gap in the U.S. continental scientific drilling equipment pool.

●      Mobile laboratory facilities and onsite cold storage to allow for processing of genetic material from drill core sediments. These facilities would support cross disciplinary aims in the fields of both paleoecology (e.g., sedimentary ancient DNA) and geomicrobiology.

●      Increased support and infrastructure for project development and management, including legal contracts, budgeting, drilling design, and cross-disciplinary research efforts.

●      Coordinated and consistent collection of multi-proxy paleoecological measurements, both new and classic, so that many community/ecosystem/environment dimensions can be studied and integrated across broad spatiotemporal scales.

●      Support for continuous data systems that link the three major stages of post-coring workflow: 1) initial core description and logging at CSD, 2) proxy measurements made by individual labs, and 3) publication and sharing of data into community data resources, so that there is a low-friction data flow at all stages of paleoecological data generation, analysis, and broad-scale synthesis.

●      Workshops to train next-generation paleoecologists in field methods, core handling methods, scientific measurement systems, and macro-scale data handling and analysis.

●      Pilot and site-development resources

Suggested Citation:

Spanbauer, T., Gill, J., Beck, C., Currano, E., Fritz, S., Goring, S., Ivory, S., McGlue, M., Shuman, B., Williams, J., Yost, C., 2024. Paleoecology Science Planning for Continental Drilling and Coring 2024. https://sites.google.com/umn.edu/csdscienceplanning/home/paleoecology-executive-summary

Paleoecology Working Group

Catherine Beck , Hamilton College

Ellen Currano, University of Wyoming

Sherilyn Fritz, University of Nebraska Lincoln

Simon Goring, University of Wisconsin

Jacquelyn Gill, University of Maine

Sarah Ivory, Pennsylvania State University

Michael McGlue, University of Kentucky

Bryan Shuman, University of Wyoming

Trisha Spanbauer, University of Toledo

Jack Williams, University of Wisconsin Madison

Chad Yost, Indiana State University

Paleoecology Community Editors

Mark Abbott, University of Pittsburgh

Sajjad Abdullajintakam, Iowa State University

Kevin Anchukiatis, University of Arizona

Lesleigh Anderson, United States Geological Survey

Gail Ashley, Rutgers University

Eliot Atekwana, University of California Davis

Alexis Ault, Utah State University

Paul Baker, Duke University

Andrey Bekker, University of California Riverside

Kathleen Benison, West Virginia University

Asmeret Asefaw, Berhe University of California Merced

Melissa Berke, University of Notre Dame

Emily Beverly, University of Minnesota

Tripti Bhattacharya, Syracuse University

Broxton Bird, Indiana University

Jessica Blois, University of California Merced

Charles Mario Boateng, University of Ghana

Dave Boutt, University of Massachusetts

Janice Brahney, Utah State University

Latisha Brengman, University of Minnesota Duluth

Cedar Briem, Desert Research Institute

Julie Brigham-Grette, University of Massachusetts Amherst

Erik Brown, University of Minnesota Duluth

Andrea Brunelle , University of Utah

Chris Campisano, Arizona State University

Isla Castaneda, University of Massachusetts Amherst

Christine Chen, Lawrence Livermore National Laboratory

Victoria Chraibi, Tarleton State University

Douglas Clark, Western Washington University

Will Clyde, University of New Hampshire

Andy Cohen, University of Arizona

Marie-Helene Cormier, University of Rhode Island Graduate School of Oceanography

Brad Cramer, University of Iowa

Brandon Curry, Illinois State Geological Survey

Marieke Dechesne, United States Geological Survey

Al Deino, Berkeley Geochronology Center

Rene Dommain, Nanyang Technological University Singapore

Andrea Dutton, University of Wisconsin Madison

Julien Emile-Geay, University of Southern California Dornsife

Peter Fawcett, University of New Mexico

Brady Foreman, Western Washington University

Sarah Fowell, University of Alaska Fairbanks

Andrew Gillreath-Brown, Yale University

Steven Goldstein, Lamont-Doherty Earth Observatory Columbia University

David Greenwood, Brandon University

Dulcinea Groff, University of Maine

Robert Guralnick, University of Florida

Scott Harris, College of Charleston

Nicholas Heaven, Viridien

Clifford Heilm, University of Rhode Island Graduate School of Oceanography

Yongsong Huang, Brown University

Scott Hynek, United States Geological Survey

Virginia Iglesias, University of Colorado Boulder

Randall Irmis, University of Utah

Emi Ito, University of Minnesota

Britta Jensen, University of Alberta

Tom Johnson, University Minnesota Duluth

Kathleen Johnson, University of California Irvine

Darrell Kaufman, Northern Arizona University

Natalie Kehrwald, United States Geological Survey

Dennis Kent, Lamont-Doherty Earth Observatory Columbia

Sean Kinney, Rutgers University

Matt Kirby, California State University Fullerton

Bronwen Konecky, Washington University in St. Louis

Stephen Kuehn, Concord University

Chad Lane, University of North Carolina Wilmington

Jennifer Latimer, Indiana State University

Kerstin Lehnert, Lamont-Doherty Earth Observatory Columbia

Lonnie Leithold, North Carolina State University

Tim Lowenstein, Binghamton University

John Lukzaj, University of Wisconsin Green Bay

Steve Lund, University of Southern California Dornsife

Francis MacDonald, University of California Santa Barbara

David Marchetti, Western Colorado University

Shaun Marcott, University of Wisconsin Madison

Paul McCarthy, University of Alaska Fairbanks

David McGee, Massachusetts Institute of Technology

Jenny McGuire, Georgia Institute of Technology

Nicholas McKay, Northern Arizona University

Jason McLachlan, Notre Dame University

Kenneth Miller, Rutgers University

Joseph Mohan, University of Maine

Isabel Montañez, University of California Davis

Leah Morgan, United States Geological Survey

LeeAnn Munk, University of Alaska Anchorage

Franca Oboh Ikuenobe, Missouri University of Science and Technology

Johnathan Obrist Farner, Missouri University of Science and Technology

Paul Olsen, Lamont-Doherty Earth Observatory Columbia University

Kristian Olson, Binghamton University

Molly Patterson, Binghamton University

Lily Pfeifer, Rowan University

Jeff Pietras, Binghamton University

Noah Planavsky, Yale University

Mitchell Power, University of Utah

Sarah Ramdeen, Ronin Institute for Independent Scholarship

Brendan Reilly, Lamont-Doherty Earth Observatory Columbia

Alberto Reyes, University of Alberta

Kenneth Ridgway, Purdue University

Tammy Rittenour, Utah State University

Marci Robinson, United States Geological Survey

Donald Rodbell, Union College

Jess Rodysill, United States Geological Survey

Dana Royer, Wesleyan University

James Russell, Brown University

Jean Self-Trail, United States Geological Survey

Juan Carlos Silva-Tamayo, IE University Spain

Peter Siver, Connecticut College

Alison Smith, Kent State University

Emmy Smith, Johns Hopkins University

Gerilyn Soreghan, University of Oklahoma

Byron Steinman , University of Minnesota Duluth

Jeffery Stone, Indiana State University

Joseph Stoner, Oregon State University

Laura Streib, Syracuse University

Justin Stroup, State University of New York Oswego

Celina Suarez, University of Arkansas

Frederick Taylor, University of Texas Austin

Zachary Taylor, Berry College

Rebecca Teed, Wright State University

Dennis Terry, Temple University

Jessica Tierney, University of Arizona

Aradhna Tripati, University of California Los Angeles

Michael Tuite, NASA Jet Propulsion Laboratory

Josef Werne, University of Pittsburgh

Lisa White, University of California Berkeley

Debra Willard, United States Geological Survey

Alexander Wolfe, University of Winnipeg

Fasong Yuan, Cleveland State University

James Zachos, University of California Santa Cruz

Susan Zimmerman, Lawrence Livermore National Laboratory