Export 46 results:
Filters: First Letter Of Title is E  [Clear All Filters]
2024
Iknayan, K.; Heath, S.; Terrill, S. B.; Wenny, D. G.; Panlasigui, S.; Wang, Y.; Beller, E. E.; Spotswood, E. 2024. Patterns in bird and pollinator occupancy and richness in a mosaic of urban office parks across scales and seasons. Ecology and Evolution 14 (3).

Urbanization is a leading cause of global biodiversity loss, yet cities can provide resources required by many species throughout the year. In recognition of this, cities around the world are adopting strategies to increase biodiversity. These efforts would benefit from a robust understanding of how natural and enhanced features in urbanized areas influence various taxa. We explored seasonal and spatial patterns in occupancy and taxonomic richness of birds and pollinators among office parks in Santa Clara County, California, USA, where natural features and commercial landscaping have generated variation in conditions across scales. We surveyed birds and insect pollinators, estimated multi-species occupancy and species richness, and found that spatial scale (local, neighborhood, and landscape scale), season, and urban sensitivity were all important for understanding how communities occupied sites. Features at the landscape (distance to streams or baylands) and local scale (tree canopy, shrub, or impervious cover) were the strongest predictors of avian occupancy in all seasons. Pollinator richness was influenced by local tree canopy and impervious cover in spring, and distance to baylands in early and late summer. We then predicted the relative contributions of different spatial scales to annual bird species richness by simulating “good” and “poor” quality sites based on influential covariates returned by the previous models. Shifting from poor to good quality conditions locally increased annual avian richness by up to 6.8 species with no predicted effect on the quality of the neighborhood. Conversely, sites of poor local and neighborhood scale quality in good-quality landscapes were predicted to harbor 11.5 more species than sites of good local- and neighborhood-scale quality in poor-quality landscapes. Finally, more urban-sensitive bird species were gained at good quality sites relative to urban tolerant species, suggesting that urban natural features at the local and landscape scales disproportionately benefited them.

2021
Spotswood, E.; Beller, E. E.; Grossinger, R. M.; Grenier, L.; Heller, N.; Aronson, M. 2021. The biological deserts fallacy: Cities in their landscapes contribute more than we think to regional biodiversity. BioScience 71 (2) . SFEI Contribution No. 1031.

Cities are both embedded within and ecologically linked to their surrounding landscapes. Although urbanization poses a substantial threat to biodiversity, cities also support many species, some of which have larger populations, faster growth rates, and higher productivity in cities than outside of them. Despite this fact, surprisingly little attention has been paid to the potentially beneficial links between cities and their surroundings.

We identify five pathways by which cities can benefit regional ecosystems by releasing species from threats in the larger landscape, increasing regional habitat heterogeneity and genetic diversity, acting as migratory stopovers, preadapting species to climate change, and enhancing public engagement and environmental stewardship. Increasing recognition of these pathways could help cities identify effective strategies for supporting regional biodiversity conservation and could provide a science-based platform for incorporating biodiversity alongside other urban greening goals.

 (781.56 KB)
 (204.95 MB) (21.97 MB)
2018
Beller, E. E.; Spotswood, E.; Robinson, A.; Anderson, M. G.; Higgs, E. S.; Hobbs, R. J.; Suding, K. N.; Zavaleta, E. S.; Grenier, L.; Grossinger, R. M. 2018. Building Ecological Resilience in Highly Modified Landscapes.

Ecological resilience is a powerful heuristic for ecosystem management in the context of rapid environmental change. Significant efforts are underway to improve the resilience of biodiversity and ecological function to extreme events and directional change across all types of landscapes, from intact natural systems to highly modified landscapes such as cities and agricultural regions. However, identifying management strategies likely to promote ecological resilience remains a challenge. In this article, we present seven core dimensions to guide long-term and large-scale resilience planning in highly modified landscapes, with the objective of providing a structure and shared vocabulary for recognizing opportunities and actions likely to increase resilience across the whole landscape. We illustrate application of our approach to landscape-scale ecosystem management through case studies from two highly modified California landscapes, Silicon Valley and the Sacramento–San Joaquin Delta. We propose that resilience-based management is best implemented at large spatial scales and through collaborative, cross-sector partnerships.

 (4.93 MB)
Safran, S. M.; Baumgarten, S. A.; Beller, E. E.; Bram, D. L.; Crooks, J. A.; Dark, S. J.; Grossinger, R. M.; Longcore, T. R.; Lorda, J.; Stein, E. D. 2018. The Historical Ecology of the Tijuana Estuary & River Valley (Restore America's Estuaries 2018 Conference Presentation).

This talk was given at the 2018 Restore America's Estuary Conference in Long Beach, CA as part of a special session titled "Restoration Perspectives from the Tijuana River National Estuarine Research Reserve." It is based on information from the Tijuana River Valley Historical Ecology Investigation, a report published in 2017.


Though many areas of the binational Tijuana River watershed remain relatively undeveloped, land and water use changes over the past 200 years have resulted in significant ecological impacts, particularly in the more urbanized areas of the lower watershed. Drawing upon a diverse set of historical data, we reconstructed the ecological and hydrogeomorphic conditions of the lower Tijuana River valley prior to major Euro-American modification (ca. 1850) and documented major changes in habitat distribution and physical processes over this time. The river corridor, which was historically dominated by riparian scrub, today instead supports dense stands of riparian forest. The valley bottom surrounding the river corridor, which historically supported extensive seasonal wetlands, has largely been converted to drier habitat types and agricultural uses. The estuary, which historically supported large expanses of salt marsh and mudflat as well as seasonally dry salt flats, has retained much of its former extent and character, but has been altered by increased sediment input and other factors. The new information about the historical landscape presented here is relevant to a number of issues scientists and managers are dealing with today, including the conservation of endangered species, the fate of the valley’s riparian habitats after the recent invasion of invasive shot-hole borer beetles, and the effects on groundwater levels on native plant communities. We will also draw from other historical ecology studies conducted in Southern California to illustrate how the information about the past has been utilized to improve the functioning and resilience of nearby coastal ecosystems.

Presentation recording: available here.

 (14.16 MB)
2017
Baumgarten, S.; Grossinger, R. M.; Beller, E. E.; Trowbridge, W.; Askevold, R. A. 2017. Historical Ecology and Landscape Change in the Central Laguna de Santa Rosa. SFEI Contribution No. 820. San Francisco Estuary Institute - Aquatic Science Center: Richmond, CA.

This study synthesizes a diverse array of data to examine the ecological patterns, ecosystem functions, and hydrology that characterized a central portion of the Laguna de Santa Rosa during the mid-19th century, and to analyze landscape changes over the past 150 years. The primary purpose of this study was to help guide restoration actions and other measures aimed at reducing nutrient loads within this portion of the Laguna de Santa Rosa watershed.

 (94.51 MB) (39.07 MB)
Spotswood, E.; Grossinger, R. M.; Hagerty, S.; Beller, E. E.; Grenier, J. Letitia; Askevold, R. A. 2017. Re-Oaking Silicon Valley: Building Vibrant Cities with Nature. SFEI Contribution No. 825. San Francisco Estuary Institute: Richmond, CA.

In this report, we investigate how re-integrating components of oak woodlands into developed landscapes — “re-oaking” — can provide an array of valuable functions for both wildlife and people. Re-oaking can increase the biodiversity and ecological resilience of urban ecosystems, improve critical urban forest functions such as shade and carbon storage, and enhance the capacity of cities to adapt to a changing climate. We focus on Silicon Valley, where oak woodland replacement by agriculture and urbanization tells a story that has occurred in many other cities in California. We highlight how the history and ecology of the Silicon Valley landscape can be used as a guide to plan more ecologically-resilient cities in the Bay Area, within the region and elsewhere in California. We see re-oaking as part of, and not a substitute for, the important and broader oak woodland conservation efforts taking place throughout the state.

 (65.64 MB) (31.88 MB)
Safran, S. M.; Baumgarten, S. A.; Beller, E. E.; Crooks, J. A.; Grossinger, R. M.; Lorda, J.; Longcore, T. R.; Bram, D. L.; Dark, S. J.; Stein, E. D.; et al. 2017. Tijuana River Valley Historical Ecology Investigation. Prepared for the State Coastal Conservancy. A Report of SFEI-ASC’s Resilient Landscapes Program. SFEI Contribution No. 760. San Francisco Estuary Institute - Aquatic Science Center : Richmond, CA. p 230.

The Tijuana River Valley Historical Ecology Investigation addresses a regional data gap by reconstructing the landscape and ecosystem characteristics of the river valley prior to the major modifications of the late 19th and 20th centuries. The research presented here, funded by the California State Coastal Conservancy, supplies foundational information at the regional and system scale about how the Tijuana Estuary, River, and valley looked and functioned in the recent past, as well as how they have changed over time. The ultimate goal of this study is to provide a new tool and framework that, in combination with contemporary research and future projections, can support and guide ongoing restoration design, planning, and management efforts in the valley.

 (232.2 MB) (73.63 MB)
2016
Cloern, J. E.; Barnard, P. L.; Beller, E. E.; Callaway, J.; Grenier, J. Letitia; Grossinger, R. M.; Whipple, A.; Mooney, H.; Zavaleta, E. 2016. Estuaries: Life on the edge. In Ecosystems of California. Ecosystems of California. University of California Press: Berkeley, CA. pp 359-388.
Beller, E. E.; Downs, P. W.; Grossinger, R. M.; Orr, B. K.; Salomon, M. 2016. From past patterns to future potential: using historical ecology to inform river restoration on an intermittent California river. Landscape Ecology 31 (3), 20.

Context  Effective river restoration requires understanding a system’s potential to support desired functions. This can be challenging to discern in the modern landscape, where natural complexity and heterogeneity are often heavily suppressed or modified. Historical analysis is therefore a valuable tool to provide the long-term perspective on riverine patterns, processes, and ecosystem change needed to set appropriate environmental management goals and strategies.

Objective In this study, we reconstructed historical (early 1800s) riparian conditions, river corridor extent, and dry-season flow on the lower Santa Clara River in southern California, with the goal of using this enhanced understanding to inform restoration and management activities.

Method Hundreds of cartographic, textual, and visual accounts were integrated into a GIS database of historical river characteristics.

Results We found that the river was characterized by an extremely broad river corridor and a diverse mosaic of riparian communities that varied by reach, from extensive ([100 ha) willow-cottonwood forests to xeric scrublands. Reach-scale ecological heterogeneity was linked to local variations in dry-season water availability, which was in turn underpinned by regional geophysical controls on groundwater and surface flow.

Conclusions Although human actions have greatly impacted the river’s extent, baseflow hydrology, and riparian habitats, many ecological attributes persist in more limited form, in large part facilitated by these fundamental hydrogeological controls. By drawing on a heretofore untapped dataset of spatially explicit and long-term environmental data, these findings improve our understanding of the river’s historical and current conditions and allow the derivation of reach-differentiated restoration and management opportunities that take advantage of local potential.

 (47.38 MB)
Safran, S. M.; Clark, E.; Beller, E. E.; Grossinger, R. M. 2016. Mission Bay Historical Ecology Reconnaissance Study: Data Collection Summary (Technical Report). SFEI Contribution No. 777.

The goals of the Mission Bay Historical Ecology Reconnaissance Study were to collect and compile high-priority historical
data about the Mission Bay landscape, identify sources that could help to develop a deeper understanding of early
ecological conditions, and to identify future possible research directions based on the available data. This technical
memorandum is intended to document the archives consulted during the reconnaissance study, summarize the collected
and compiled data, and to identify potential next steps. A separate technical presentation to project staff and advisors will
summarize the preliminary findings and questions generated from a review of the historical dataset. Ultimately, this
research is intended to support the San Diego Audubon Society’s Mission Bay Wetlands Conceptual Restoration Plan (CRP)
and the ReWild Mission Bay project.

 (3.44 MB)
2015
Yarnell, S. M.; Petts, G. E.; Schmidt, J. C.; Whipple, A.; Beller, E. E.; Dahm, C. N.; Goodwin, P.; Viers, J. H. 2015. Functional Flows in Modified Riverscapes: Hydrographs, Habitats and Opportunities. BioScience.

Building on previous environmental flow discussions and a growing recognition that hydrogeomorphic processes are inherent in the ecological functionality and biodiversity of riverscapes, we propose a functional-flows approach to managing heavily modified rivers. The approach focuses on retaining specific process-based components of the hydrograph, or functional flows, rather than attempting to mimic the full natural flow regime. Key functional components include wet-season initiation flows, peak magnitude flows, recession flows, dry-season low flows, and interannual variability. We illustrate the importance of each key functional flow using examples from western US rivers with seasonably predictable flow regimes. To maximize the functionality of these flows, connectivity to morphologically diverse overbank areas must be enhanced in both space and time, and consideration must be given to the sediment-transport regime. Finally, we provide guiding principles for developing functional flows or incorporating functional flows into existing environmental flow frameworks.

Beller, E. E.; Robinson, A.; Grossinger, R. M.; Grenier, J. Letitia. 2015. Landscape Resilience Framework: Operationalizing Ecological Resilience at the Landscape Scale. SFEI Contribution No. 752. San Francisco Estuary Institute - Aquatic Science Center: Richmond, CA.
 (5.18 MB)
Baumgarten, S.; Beller, E. E.; Grossinger, R. M.; Askevold, R. A. 2015. Mt. Wanda Historical Ecology Investigation. SFEI Contribution No. 743. San Francisco Estuary Institute - Aquatic Science Center: Richmond, CA. p 51.
 (20.92 MB) (57.9 MB)
Salomon, M.; Baumgarten, S.; Dusterhoff, S. D.; Beller, E. E.; Askevold, R. A. 2015. Novato Creek Baylands Historical Ecology Study. SFEI Contribution No. 740. San Francisco Estuary Institute - Aquatic Science Center: Richmond, CA.

Project Background

Over the past century and a half, lower Novato Creek and the surrounding tidal wetlands have been heavily modified for flood control and land reclamation purposes. Levees were built in the tidal portion of the mainstem channel beginning in the late 1800s to convey flood flows out to San Pablo Bay more rapidly and to remove surrounding areas from inundation. Following levee construction, the wetlands surrounding the channel were drained and converted to agricultural, residential, and industrial areas. These changes have resulted in a considerable loss of wetland habitat, reduced sediment transport to marshes and the Bay, and an overall decreased resilience of the system to sea level rise.
In addition to tidal wetland modification, land use changes upstream in the Novato Creek watershed have resulted in several challenges for flood control management. Dam construction and increased runoff in the upper watershed have resulted in elevated rates of channel incision, which have increased transport of fine sediment from the upper watershed to lower Novato Creek. Channelization of tributaries and construction of irrigation ditches have likely increased drainage density in the upper watershed, also potentially contributing to increased rates of channel incision and fine sediment production (Collins 1998). Downstream, sediment transport capacity has been reduced by construction of a railroad crossing and loss of tidal prism and channel capacity associated with the diking of the surrounding marsh. As a result of the increased fine sediment supply from the watershed and the loss of sediment transport capacity in lower Novato Creek, sediment aggradation occurs within the channel, which in turn reduces the flood capacity of the channel, necessitating periodic dredging.

Currently, the Marin County Department of Public Works (MCDPW) is coordinating the Novato Watershed Program, which includes Marin County Flood Control and Water Conservation District, Novato Sanitary District, and North Marin Water District. Within lower Novato Creek, the Program is seeking to implement a new approach to flood control that includes redirecting sediment for beneficial use, reducing flood channel maintenance costs, restoring wetland habitat, and enhancing resilience to sea level rise. Included as part of this goal is the re-establishment of historical physical processes that existed before major channel modification, which in turn will re-establish historical ecological functions and help to create a tidal landscape that is resilient to increasing sea level.

 (27.13 MB)
 (4.19 MB)
 (21.78 MB)
2013
 (335.05 MB) (163.08 MB)
Beller, E. E.; Salomon, M.; Grossinger, R. M. 2013. An Assessment of the South Bay Historical Tidal-Terrestrial Transition Zone. SFEI Contribution No. 693. San Francisco Estuary Institute: Richmond, CA.
 (7.87 MB)
2011
 (17.71 MB) (123.69 MB) (149.82 MB) (193.36 MB)
 (17.09 MB) (201.86 MB)
Grossinger, R. M.; Beller, E. E. 2011. Oak Landscapes in the Recent Past. In Oaks in the Urban Landscape: Selection, Care, and Preservation. Costello, L. R., Hagen, B. W., Jones, K. S., Eds.. Oaks in the Urban Landscape: Selection, Care, and Preservation. University of California Agriculture and Natural Resources: Richmond, CA.
 (15.59 MB) (59.08 KB)
 (47.1 KB) (2.42 MB)