Seth P. D. Riley, Trish Smith, T. Winston Vickers
Freeways are barriers to wildlife passage and gene exchange. In Southern California, mountain lion movement has been severely restricted due to this infrastructure. As a result, the mountain lions in the Santa Ana and Santa Monica Mountains have become severely inbred, threatening their long-term health and viability. Additional wildlife crossings are needed to improve connectivity across the region. This assessment uses landscape characteristics and wildlife data to evaluate and prioritize possible locations and concepts for wildlife crossings along two major freeways that bisect regional wildlife movement, Interstate 15 at the Riversided-San Diego County border and U.S. 101 in northern Los Angeles County. By combining expert opinion and connectivity science, the authors aim to bridge the gap between science and conservation practice.
Michael J. Paul, Ben Jessup, Larry R. Brown, James L. Carter, Marco Cantonatie, Donald F. Charles, Jeroen Gerritsena, David B. Herbst, Rosalina Stancheva, Jeanette Howard, Bill Isham, Rex Lowe, Raphael D. Mazor, Patina K. Mendez, Peter R. Ode, Alison O'Dowd, John Olson, Yangdong Pan, Andrew C. Rehn, Sarah Spaulding, Martha Sutula, Susanna Theroux
Water resource agencies assess stream water quality by determining the bugs and algae present to develop biotic indices. Yet translating these technical measures into meaningful language is difficult. This study finds that by placing technical numerical measures/indices into categories of condition allows resource manages to…
Dr. Winston Vickers, Karen C. Drayer, Trish Smith, Brian Cohen
Highways across the greater San Diego region in southern California are major barriers and causes of mortality for mountain lions and are contributing to the species’ genetic restriction and threat of extirpation. Due to their large territories, mountain lions must regularly cross highways in this…
This article appears in the Desert Report, a news publication of the Sierra Club California/Nevada Desert Committee. The article introduces the Mojave Springs Research Project, led by The Nature Conservancy, that involves a research collaboration with UCLA, the California Botanic Garden, and Partner Engineering and…
Grace C. Wu, Emily Leslie, Douglas Allen, Oluwafemi Sawyerr, D. Richard Cameron, Erica Brand, Brian Cohen, Marcela Ochoa, Arne Olson
California has ambitious climate and energy policies that call for the development of significant amounts of new zero-carbon energy by midcentury. The Power of Place study looks at multiple pathways to meet California's clean energy demand in alignment with decarbonization goals while limiting the impacts…
Rodd Kelsey, Scott Butterfield, Abigail Hart, Ruthie Redmond, Hope Bigda-Peyton
This Policy Brief summarizes the results of a study on the potential for strategic habitat restoration in the San Joaquin Valley of California as an important part of reducing overall water demand to achieve groundwater sustainability under the Sustainable Groundwater Management Act (SGMA). It also provides policy recommendations…
Ray Hilborn, Ricardo Oscar Amoroso, Christopher M. Anderson, Julia K. Baum, Trevor A. Branch, Christopher Costello, Carryn L. de Moor, Abdelmalek Faraj, Daniel Hively, Olaf P. Jensen, Hiroyuki Kurota, L. Richard Little, Pamela Mace, Tim McClanahan, Michael C. Melnychuk, Cóilín Minto, Giacomo Chato Osio, Ana M. Parma, Maite Pons, Susana Segurado, Cody S. Szuwalski, Jono Wilson, Yimin Ye
Does fisheries management work at improving the status of fish stocks? The answer is a resounding, yes. This article compiles estimates of the status of global fish stocks, comprising roughly half of the world’s fish catch. Findings suggest that on average, fish stocks are increasing…
Butterfield, H.S., M. Katkowski, J. Cota, O. Sage, C. Sage, K. Easterday, D. Zeleke, L. Riege, S. Gennet, K. Lin, B. Leahy, M. Bell, M. Reynolds
Cattle grazing is the dominant land management tool TNC has to manage biodiversity and reduce the threat of catastrophic wildfire at the TNC's Jack and Laura Dangermond Preserve. This Rangeland Management Plan, intended to guide rangeland management through 2025, details the adaptive management approach TNC…
Gavin M. Jones, H. Anu Kramer, Sheila A. Whitmore, William J. Berigan, Douglas J. Tempel, Connor M. Wood, Brendan K. Hobart, Tedward Erker, Fidelis A. Atuo, Nicole F. Pietrunti, Rodd Kelsey, R. J. Gutierrez, M. Zachariah Peery
This study examined spotted owl habitat selection after the King Fire in California using satellite tracking of 26 different owls . The authors found that whether severe fire was "good" or "bad" for owls depended on patch size and configuration: owls selected smaller but avoided…
Butterfield, H.S., M. Reynolds , M.G. Gleason, M. Merrifield, B.S. Cohen, W.N. Heady, D. Cameron, T. Rick, E. Inlander, M. Katkowski, L. Riege, J. Knapp, S. Gennet, G. Gorga, K. Lin, K. Easterday, B. Leahy, M. Bell
This Plan frames the biological and cultural significance and provides the short- and long-term goals, objectives, and priority actions for the Jack and Laura Dangermond Preserve.
Sara M. Kross, Breanna L. Martinico, Ryan P. Bourbour, Jason M. Townsend, Chris McColl, T. Rodd Kelsey
Agriculture-dominated landscapes harbor significantly diminished biodiversity. Woody vegetation along field margins can provide farmers with ecosystem services and benefit biodiversity. However, when crops are damaged by the biodiversity harbored in such vegetation, farmers are reluctant to incorporate field margin habitat onto their land and may…
Brian Cohen, Kelsey Jessup, Sophie Parker, John Randall, Jill Sourial
Cities across Southern California are investing in new infrastructure to address the challenges of stormwater management. We promote the useof nature-based solutions to ensure projects both treat stormwater and yield multiple additional benefits. TNC’s spatial analysis tool, SALSA, summarized in this poster, helps prioritize…
H.J. Walker Jr., Philip A. Hastings, John R. Hyde, Robert N. Lea, Owyn E. Snodgrass, Lyall F. Bellquist
In response to anomalously warm sea-surface temperatures, poleward shifts in the geographic range of hundreds of marine organisms worldwide have been documented. This paper reports on the unusual occurrences of 36 fish species recorded from the Southern California Current System (SCCS) during the period of…
Christopher J. Lortie, Jenna Braun, Michael Westphal, Taylor Noble, Mario Zuliani, Emmeleia Nix, Nargol Ghazian, Malory Owen, H. Scott Butterfield
This paper evaluates how endangered species with highly restricted habitat needs and increasingly small population sizes (using blunt-nosed leopard lizard as our example), select and use available habitat. The paper paired a novel experimental – telemetry and remotely-sensed data – and analytical – resource selection…
Sally Liu, Megan Webb, Jeanette Howard, Jennifer Carah
Chinook, coho and steelhead were once tremendously abundant in most of California’s major rivers and streams. As recently as the 1960s, salmon and steelhead were so plentiful in streams that horses would get spooked trying to cross. Due to water damming and diversions, habitat degradation and…
Matt Merrifield, Sue Pollock
Conservation needs to harness technology to meet the complex challenges of today’s world. The Technology Catalyst Fund provides early stage resources to investigate and prototype technologies that have high potential for impact and have effectively disrupted the status quo in other sectors. The Fund empowers…
The Nature Conservancy deploys science to help overcome major challenges facing people and nature. In today’s fast-paced world, turning threats to nature into opportunities for conservation requires agility. The Conservation Science Catalyst Fund enables our science team to mobilize quickly — and produce the information…
Sarah M. Yarnell, Eric D. Stein, J. Angus Webb, Theodore Grantham, Rob A. Lusardi, Julie Zimmerman, Ryan A. Peek, Belize A. Lane, Jeanette Howard, Samuel Sandoval-Solis
The authors of this paper are engaged in developing flow criteria for California Streams through California Environmental Flows Framework (CEFF) collaboration. The effort is funded by the State Water Resources Control Board. This collaboration is a working group within the California Water Quality Monitoring Council. This…
Melissa M. Rohde, Mark Reynolds, Jeanette Howard
In this article, the authors provide an example of how dynamic multi-benefit solutions used to provide “pop-up” wetland habitat for migratory birds also replenishing depleted aquifers to create environmental and water supply benefits and broadens it to the global scale. Additionally, this article outlines six…
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…
Samuel C. Zipper, Jennifer K. Carah, Christopher Dillis, Tom Gleeson, Ben Kerr, Melissa M. Rohde, Jeanette K. Howard, Julie K.H. Zimmerman
Using a newly developed tool for estimating streamflow depletion from groundwater pumping, this study examined the impacts of ongoing groundwater pumping on streamflow and aquatic ecosystems in the Navarro watershed in rural, coastal California. The study found that common uses of groundwater in the watershed,…
