Nearly half of California is protected in some land status that prevents most kinds of intensive human land uses.  These lands support extensive natural habitats, and for many species, are a critical stronghold in an increasingly human-dominated world.

Yet, changes in the landscape in and near these places have left many in a degraded and precarious condition. Catastrophic wildfire, invasive species, and climate change threaten vast swathes of the state. Protected lands are becoming increasingly isolated by urban and agricultural development, roads, and other infrastructure. Such obstacles can limit a species’ ability to move to across the landscape and adapt to climate change.

Conservancy scientists are working to enhance the resiliency of protected lands in the face of rapid change, and to maintain the landscape connections necessary for plants and animals to adapt over time. 

Science in Action

Terrestrial | Science

Island Fox

How do we bring the endemic island fox back from the brink of extinction?

Terrestrial | Science

Invasive Ant Removal

How can we eliminate a large-scale infestation of invasive ants – and how would we know when we have?

2020 | Terrestrial | Planning | Science | Publications & Reports

Santa Ana Mountains to eastern Peninsular Range Conservation Connectivity Infrastructure Planning Project for Interstate 15 and Closely Associated Roadways

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…


2020 | Freshwater | Terrestrial | Technology | Science | Publications & Reports

Mojave Desert Springs: setting an ecological baseline

Sophie S. Parker

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…


2020 | Terrestrial | Planning | Science | Publications & Reports

Roadmap to Restoration

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…


2020 | Terrestrial | Planning | Technology | Science | Publications & Reports

Jack and Laura Dangermond Preserve Rangeland Management Plan

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…


2020 | Terrestrial | Science | Publications & Reports

Habitat selection by spotted owls after a megafire reflects their adaptation to historical frequent-fire regimes

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…


2020 | Terrestrial | Technology | Science | Publications & Reports

Shrub and vegetation cover predict resource selection use by an endangered species of desert lizard

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…


2019 | Terrestrial | Planning | Publications & Reports

Green Light Study: Economic and Conservation Benefits of Low-Impact Solar Siting in California

Stephanie Dashiell, Mark Buckley, Dustin Mulvaney

In an effort to address climate change, California enacted a clean energy energy standard that is driving a market for significant amounts of renewable energy. To explore the economic benefits of developing utility-scale solar energy on low biodiversity value land, the authors conducted an analysis…


2019 | Terrestrial | Technology | Science | Publications & Reports

Parched pines: a quantitative comparison of two multi-year droughts and associated mass mortalities of bishop pine (Pinus muricata) on Santa Cruz Island, California

Annalise Taylor, Tanushree Biswas, John M. Randall, Kirk Klausmeyer, Brian Cohen

In Western North America, droughts are expected to increase in frequency and intensity as the region’s climate changes. Over past decades, land managers on Santa Cruz Island, California witnessed mass mortality of conifer forest dominated by bishop pine (Pinus muricata). These pines play a key role within…


2019 | Terrestrial | Science | Publications & Reports

Plant species natural abundances are determined by their growth and modification of soil resources in monoculture

Sophie S. Parker, W. Stanley Harpole, Eric W. Seabloom

This paper furthers our understanding of what makes some species rare, and others more common. The authors grew monocultures of 18 California grassland plant species and measured their growth and ability to alter soil properties such as moisture and nutrients. Then they related these metrics…


2019 | Terrestrial | Planning | Technology | Economics | Science | Publications & Reports

Power of Place: Land Conservation and Clean Energy Pathways for California

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…


2019 | Terrestrial | Planning | Publications & Reports

Restoring Forests through Partnership: Lessons Learned from the French Meadows Project

David Edelson, Angel Hertslet

There is an urgent need to increase the pace and scale of forest restoration in the Sierra Nevada and throughout the West to reduce the risk of high-severity wildfire and promote more resilient forest conditions. This report, based on The Nature Conservancy's experience with the…


2019 | Freshwater | Terrestrial | Science | Publications & Reports

The dark side of facilitation: native shrubs facilitate exotic annuals more strongly than native annuals

Jacob E. Lucero, Taylor Noble, Stephanie Haas, Michael Westphal, H. Scott Butterfield, Christopher J. Lortie

Previous work at the Carrizo Plain by this team in 2018 showed that native shrubs facilitated endangered blunt-nosed leopard lizard populations, and should be considered part of plans for habitat restoration in the San Joaquin Valley. This paper shows that shrubs have a dark…


2019 | Terrestrial | Planning | Science | Publications & Reports

Making habitat connectivity a reality

Annika T. H. Keeley, Galli Basson, D. Richard Cameron, Nicole E. Heller, Patrick R. Huber, Carrie A. Schloss, James H. Thorne, Adina M. Merenlender

Connectivity conservation must move more rapidly from planning to implementation. We provide an evidence‐based solution composed of key elements for successful on‐the‐ground connectivity implementation. We identified the social processes necessary to advance habitat connectivity for biodiversity conservation and resilient landscapes under climate change.


2019 | Terrestrial | Marine | Science | Publications & Reports

Globally important islands where eradicating invasive mammals will benefit highly threatened vertebrates

Holmes ND, Spatz DR, Oppel S, Tershy B, Croll DA, et al.

Restoring islands by eradicating damaging, non-native invasive mammals such as rats, cats, goats, and pigs has repeatedly proven to be a high impact conservation action. New research published in PLOS ONE shows this conservation action can have a major contribution towards stemming the global extinction…


2019 | Terrestrial | Marine | Science | Publications & Reports

Future Directions in Conservation Research on Petrels and Shearwaters

Rodríguez A, Arcos JM, Bretagnolle V, Dias MP, Holmes ND, Louzao M, Provencher J, Raine AF, Ramírez F, Rodríguez B, Ronconi RA, Taylor RS, Bonnaud E, Borrelle SB, Cortés V, Descamps S, Friesen VL, Genovart M, Hedd A, Hodum P, Humphries G, Le Corre M, Lebarbenchon C, Martin R, Melvin EF, Montevecchi WA, Pinet P, Pollet IL, Ramos R, Russell JC, Ryan PG, Sanz-Aguilar A, Spatz DR, Travers M, Votier SC, Wanless RM, Woehler E, Chiaradia A

Seabirds are amongst the most engaged species on our planet. Among these are petrels and shearwaters: species characterized by long ocean journeys for migration and feeding, and a dependence on islands to safely breed and raise young. This dual lifestyle places them at risk from…


2019 | Terrestrial | Science | Publications & Reports

Wildfires and Forest Resilience: the case for ecological forestry in the Sierra Nevada

Rodd Kelsey

Forests of the Sierra Nevada and across the western U.S. are experiencing an unprecedented increase in the size and severity of wildfire along with widespread tree mortality due to drought and insect outbreaks. These developments not only threaten lives and communities but also seriously compromise…


2019 | Freshwater | Terrestrial | Planning | Science | Publications & Reports

Habitat restoration opportunities, climatic niche contraction, and conservation biogeography in California's San Joaquin Desert

Joseph A. E. Stewart, H. Scott Butterfield, Jonathan Q. Richmond, David J. Germano, Michael F. Westphal, Erin N. Tennant, Barry Sinervo

Due to limited water resources, there is a global trend toward the retirement of farmland, especially in the San Joaquin Valley in California where the Sustainable Groundwater Management Act could necessitate the retirement of more than 500,000 acres. This paper helps identify where, across the…


2019 | Terrestrial | Planning | Science | Publications & Reports

New concepts, models, and assessments of climate-wise connectivity

Annika T H Keeley, David D Ackerly, D Richard Cameron, Nicole E Heller, Patrick R Huber, Carrie A Schloss, James H Thorne, Adina M Merenlender

As climate change impacts wildlife and plants, species may need to access new habitats. Various approaches exist to plan to climate-driven habitat connectivity needs. We summarize the literature of connectivity planning that accounts for climate change, and suggest guidance for preferred approaches given various objectives.