Freshwater | Science | Publications & Reports

A decision‐support framework for dam removal planning and its application in northern California

Suman Jumani, Lucy Andrews, Theodore E. Grantham, S. Kyle McKay, Jeffrey Duda, Jeanette Howard

California has a dam problem. Since the start of the 20th century, the state has built thousands of dams on its rivers and streams. Now, more than 75% of the largest dams are greater than 50 years old. This means that a significant proportion of the state’s dams have or are reaching the end of their designed lifespan and are no longer performing their intended functions. What do we do about these "deadbeat dams"? In a paper, recently published in Environmental Challenges, the authors present a decision-support tool for dam-removal planning in California. It is designed as a multi-criteria evaluation framework that considers the broad suite of economic, environmental, and social factors that influence dam removal decisions.

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2024 | Terrestrial | Planning | Science | Publications & Reports

Climatically robust multiscale species distribution models to support pronghorn recovery in California

William T. Bean, H. Scott Butterfield, Jeanette K. Howard, Thomas J. Batter

In this paper, the authors used a variety of habitat suitability modeling approaches to begin to understand where pronghorn may exist in the future in California under different climate change scenarios. This work directly informs The Nature Conservancy's Water for Wildlife projects in and around…


2024 | Terrestrial | Marine | Science | Publications & Reports

Spatial Patterns of Vegetation Change in a Fire-Suppressed Coastal California Landscape

Lucy Genua, Brad Anderson, Meghan Bowen, Genelle Ives, Owen Liu, Thomas Paschos, H. Scott Butterfield, Kelly Easterday, Mark Reynolds, James H. Thorne

In this paper, the authors used historical vegetation data, from both aerial photographs and field transects, to assess the change in major vegetation types at the Dangermond Preserve over the last approximately 80 years. They found that as grazing and fire have decreased across this landscape,…


2024 | Marine | Economics | Science | Publications & Reports

Advancing fisheries sustainability and access through community fisheries trusts

Kate Kauer, Lyall Bellquist, Jenn Humberstone, Vienna Saccomanno, Dwayne Oberhoff, Sherry Flumerfelt, Mary Gleason

This 2024 paper by TNC staff and partners represents the first U.S.-wide synthesis of fisheries trusts – which are community-based entities that acquire and manage fishery privileges with the goal of sustaining community access to locally important fisheries. These entities have emerged following the implementation…


2024 | Freshwater | Terrestrial | Science | Publications & Reports

Potential Impacts to Biodiversity from Proposed Lithium Extraction in Nevada and California

Michael J. Clifford, Sophie S. Parker, Laurel Saito, Brian S. Cohen, Naomi S. Fraga

Lithium batteries are important for the clean energy transition in the United States because they are used in electric vehicles and for grid power storage. However, lithium extraction may have impacts on biodiversity. The authors use data from a previous TNC study to analyze…


2024 | Terrestrial | Planning | Science | Publications & Reports

Quantitative methods for integrating climate adaptation strategies into spatial decision support models

Nicholas A. Povak, Patricia N. Manley, Kristen N. Wilson

This study presents a methodology to integrate spatial assessments of current and future forest conditions to understand the potential to achieve desired conditions under climate change with ongoing disturbances. The output is a strategic (where to go) and tactical (what to do) map to improve…


2024 | Freshwater | Terrestrial | Publications & Reports

Potential impacts of proposed lithium extraction on biodiversity and conservation in the contiguous United States

Sophie S. Parker, Michael J. Clifford, Brian S. Cohen

To address climate change, the United States is incentivizing the production of electric vehicles containing domestically derived lithium batteries. Extracting this lithium may have environmental impacts, including impacts on biodiversity. To reveal what these impacts could be, the authors mapped 72 proposed lithium extraction…


2024 | Terrestrial | Science | Publications & Reports

Oren Pollak Memorial Research Fund - 2024 RFP

Brynn Pewtherer

The Oren Pollak Memorial Research Fund was established in 2000 in memory of Dr. Oren Pollak, a leading grassland ecologist and restoration pioneer, as well as an ardent champion and mentor for grassland ecology students. As The Nature Conservancy’s lead ecologist in California in the…


2024 | Freshwater | Terrestrial | Publications & Reports

Expert bioblitz on the Atwood Preserve

Michael Clifford, Sophie Parker, Matt Rader, Lydia Bailey, Naomi Fraga, Chris Hass, Estella Hernandez, Jan Kempf, Lois Merkler, Michael Swink

The Amargosa River supports one of the most outstanding suites of endemic and imperiled species in the world. In 2019, TNC acquired the Atwood Preserve in the river’s headwaters, the management of which could impact river flows, condition, and biodiversity. With the support of the…


2023 | | Planning | Science | Publications & Reports

Quantifying the smoke-related public health trade-offs of forest management

Claire L. Schollaert, Jihoon Jung, Joseph Wilkins, Ernesto Alvarado, Jill Baumgartner, Julien Brun, Tania Busch Isaksen, Jamie M. Lydersen, Miriam E. Marlier, Julian D. Marshall, Yuta J. Masuda, Charles Maxwell, Christopher W. Tessum, Kristen N. Wilson, Nicholas H. Wolff, June T. Spector

By modeling six scenarios of forest management, wildfire, and health impacts from smoke from 1981-2020, we found that moderate amounts of prescribed fire can decrease harmful particulate matter exposure and reduce asthma related hospitalizations and emergency department visits. This case study from the Tahoe Central…


2023 | Terrestrial | Planning | Science | Publications & Reports

Contrasting management paradigms for pronghorn in the arid Southwest and their northern range: a review

William T. Bean, H. Scott Butterfield, Craig Fiehler, David Hacker, Jeanette K. Howard, Russell Namitz, Brandon Swanson, Thomas J. Batter

TNC launched a Water for Wildlife project motivated by understanding the importance of standing free water across the season for wildlife in general, but most importantly for those species sensitive to water availability during times of the year when water is typically limiting in California,…


2023 | Terrestrial | Science | Publications & Reports

Mojave Desert land-use change: revisiting conservation values after a decade of growth and development

Michael J. Clifford, Sophie S. Parker, Brian S. Cohen, Elaine York, Joel Tuhy

This paper provides an assessment of changes in the conservation value of lands in the Mojave Desert of Nevada and Utah resulting from renewable energy and other development between 2010 and 2018. The authors use conservation value as determined by the Mojave Desert Ecoregional…


2023 | Terrestrial | Economics | Publications & Reports

Wildfire Resilience Insurance: Quantifying the Risk Reduction of Ecological Forestry with Insurance

The Nature Conservancy with Willis Towers Watson, Sarah Heard

California has the highest wildfire risk in the US, and climate change will continue to exacerbate the risk, at least in the foreseeable future. As a result, California is facing an insurance crisis, as insurers are finding it harder and harder to write insurance in…


2023 | Terrestrial | Planning | Science | Publications & Reports

Interstate 15 Wildlife Crossing Design Considerations for Focal Wildlife Species. Santa Ana-Palomar Mountains Linkage Southern California

Trish Smith, Cheryl Brehme, Jill Carpenter, Nancy Frost, Megan Jennings, Barbara Kus, Scott Quinnell, Spring Strahm, T. Winston Vickers

The Nature Conservancy and the California Department of Transportation are planning 3 wildlife crossing infrastructure projects along a 3-mile stretch of Interstate 15 (I-15) in the Santa Ana-Palomar Mountains Linkage in southern California. While wildlife crossings are becoming more common, optimal designs that meet the…


2023 | Freshwater | Terrestrial | Science | Publications & Reports

Statistical evaluation of the similarity of characteristics in springs of the California Desert, United States

Adam H. Love, Andy Zdon, Naomi S. Fraga, Brian Cohen, Maura Palacios Mejia, Rachel Maxwell, Sophie Parker

This paper presents results from the Mojave Desert Springs research project. The authors present a comprehensive statistical analysis of similarities between California desert springs. An observed lack of correlation between the springs’ hydrologic and ecological parameters suggests that each spring represents a somewhat unique…


2023 | Terrestrial | Science | Publications & Reports

Supporting the “virtuous cycle” in urban ecosystems: how research can inform plans, policies, and projects that impact urban resilience

Michele Romolini, Sophie S. Parker, Gregory B. Pauly, Eric M. Wood

This editorial introduces a group of 11 articles published as part of an organized research topic in the Urban Greening section of the journal Frontiers in Sustainable Cities. In contrast with the abundance of literature that describes the negative impacts of humans and anthropogenic change,…


2023 | Marine | Economics | Science | Publications & Reports

Static management presents a simple solution to a dynamic fishery and conservation challenge

Christopher M. Free, Lyall F. Bellquist, Karin A. Forney, Jenn Humberstone, Kate Kauer, Qui Lee, Owen R. Liu, Jameal F. Samhouri, Jono R. Wilson, Darcy Bradley

Dynamic ocean management frameworks can be a useful approach to fisheries management under climate change. In the oceans, marine heatwaves are increasingly common symptoms of climate change that can impact ecosystems, economies, and communities. The recent 2014-2016 marine heatwave in the NE Pacific resulted in…


2023 | Freshwater | Science | Publications & Reports

A decision‐support framework for dam removal planning and its application in northern California

Suman Jumani, Lucy Andrews, Theodore E. Grantham, S. Kyle McKay, Jeffrey Duda, Jeanette Howard

California has a dam problem. Since the start of the 20th century, the state has built thousands of dams on its rivers and streams. Now, more than 75% of the largest dams are greater than 50 years old. This means that a significant proportion of…


2023 | Terrestrial | Planning | Science | Publications & Reports

Exploring interacting effects of forest restoration on wildfire risk, hydropower, and environmental flows

Benjamin P. Bryant, Tessa Maurer, Phillip C. Saksa, John D. Herman, Kristen N. Wilson, Edward Smith

The authors of this study analyzed how wildfires and forest restoration, specifically thinning and prescribed fire being implemented in the French Meadows Project in the central Sierra Nevada, could impact streamflow, hydropower generation, and ecological flows for a threatened frog (Foothill yellow legged frogs). By…


2023 | Freshwater | Terrestrial | Planning | Science | Publications & Reports

A resilient and connected network of sites to sustain biodiversity under a changing climate

Mark G. Anderson, Melissa Clark, Arlene P. Olivero, and D. Richard Cameron

In response to biodiversity loss, scientists have called for the protection of well-connected systems of protected areas covering 30 to 50% of the planet. However, as climate change drives shifts in species, conservation plans based on current biodiversity patterns will become less effective. The authors…