Location: Sustainable Agricultural Water Systems Research
2023 Annual Report
Objectives
The USDA California Climate Hub program will enable climate-informed decision-making through the successful development of science-based, region-specific syntheses, information products, decision support tools and technologies for agricultural, forestry and natural resource managers, and where possible provide assistance to enhance adoption and implementation of the same. The aforementioned will be accomplished through investments via three primary pathways: (i) data and information syntheses; (ii) tool and technology development, curation and implementation support; and (iii) convening to support technical assistance, training and information exchange. The work will be conducted as the California USDA Climate Change Hub (CACH) and will be coordinated with ARS, NRCS, USFS broadly and locally, and other USDA and non-USDA organizations in accordance with guidance found in the USDA Climate Change Hubs Charter, and Terms of Reference. The focus of these activities will be the regions natural and working lands, inclusive of all farms, ranches, forests and other production and natural systems however with special attention to agro-climate applications in specialty crop and forestry contexts.
Objective 1: Enable climate-smart decision-making by developing science-based, region-specific information, tools and technologies for agricultural and natural resource managers, and provide assistance where possible to enhance adoption and implementation of the same.
Objective 2: Expand and enhance each Hub’s research and communication capacity and ensure integration of ARS research outcomes from across the region into Hub outreach assets.
Objective 3: Provide capacity to expand and enhance the hub’s climate-science, social-science, and economic-science resources and tools via enhanced collaboration with ARS research teams and other research partners to ensure impactful integration of ARS research outcomes from across the region into Hub outreach assets.
Approach
The CACH program will co-develop and produce science-based syntheses to elucidate expected climate impacts, stressors and/or disturbances using largely readily available climate and weather data. These outputs will lead to products to report and communication climate-linked impacts to natural and working land interests and assets that are place- and/or resource-based including climate scenarios (forecasts) and vulnerability assessments. Efforts will also include the translation of climate and weather data to communicate current conditions, extreme events and lookout forecasts. The program will also support and/or co-develop products resulting from novel frameworks, stakeholder need (or barrier) assessments, technologies or techniques leading to the advancement of practices founded in climate adaptation and mitigation science. Products may include but are not limited to peer reviewed, government, trade or technical assistance papers, reports, bulletins or articles.
Investments and products that result from synthesized information sets or tools leading to an improved interpretation of and/or new understanding of changing natural and working land management systems in context of climate change in the form of decision support tools, toolkits, dashboards, factsheets, agriculture or forestry alerts will remain a core program focus. Generally speaking, this can include outputs akin to agro-climate or other climate informed agriculture or forestry decision support systems or web-based applications. These products will provide a better understanding of climate change information (literacy), facilitating improved management practices to both adapt and mitigate the effects associated with climate change.
Designing, developing and organizing opportunities for information exchange, content appropriate/specific conferences, workshops, symposia, dialogs, field days, site demonstrations, trainings through convening of focused groups of managers, practitioners, scientists, technical assistance provider’s etc. Additionally, we will regularly produce, develop and disseminate information products in the form of newsletters, blogs, etc. using a variety of media including social, trade and popular outlets. CACH staff will contribute and serve on advisory and steering committees, give lectures, webinars, presentations to audiences that support the broader mission and function of the USDA Climate Hub program and needs and requests of stakeholders. We will also continually evaluate (assess) and communicate the needs of producers and managers to the science community as well as sharing science-based knowledge and applications to those that can act on that information.
Progress Report
This is the final report for project 2032-12610-001-000D, which has been replaced by project 2032-12610-002-000D. For additional information, see the new project’s report.
In support of Element I of Objective 1 (Research and scientific review/syntheses), research was conducted by ARS scientists at Davis, California, to understand climate adaptation practice adoption barriers by farmers and technical assistance providers in support of California agriculture. Farmers noted adoption of climate smart practices that confer both adaptation and mitigation outcomes were driven primarily by on-farm characteristics, information sources and a general limited understanding around the potential benefits the practices considered could provide. The technical assistance providers surveyed cited limited capacity in terms of time and money for themselves and farmers as well as insufficient information and messaging around climate-adaptive practices as key barriers to practice adoption by farmers.
Research was conducted by scientists at Davis, California, to evaluate agroclimate metrics over the two most recent normal periods (1981 to 2010 and 1991 to 2020), focusing on specialty crop production regions in California. Most metrics showed small changes between the two periods. During the latter period, the last spring freeze occurred about five days earlier as compared to the former period, contributing to a greater then six days longer frost-free period in the Sacramento and Salinas Valleys. A complementary trend analysis of the agroclimate metrics over the latter period showed significant increases in growing degree days across all agricultural regions, while significant increases in heat exposure were found for the Salinas and Imperial Valleys and over the Central Coast region. Observed changes in agroclimate metrics were largely consistent with broader global warming trends. Quantifying the shifts in these agroclimate metrics between the two most recent 30-year normal periods and the accompanying 40-year trends provides context for understanding and communicating around changing climatic baselines and underscores the need for adaptation to meet the challenge that climate change poses to agriculture both in the future and in the present.
Research was conducted by scientists at Davis, California, to understand linkages between the large-scale teleconnections and winter chill accumulations for specialty crops in California. This understanding will enable a more effective and dynamic adaptation to climate variability and change. Three large-scale teleconnection indices were used: Oceanic Nino Index (ONI), Pacific-North American teleconnection pattern (PNA), and Pacific Decadal Oscillation (PDO) index. Three major crop-producing regions, including Central Coast, Sacramento Valley and San Joaquin Valley, are used as the focused regions. The correlations between chill accumulation and teleconnections are generally weaker during the summer than other seasons, and the strongest correlation can be observed two to 10 months before the start of the chilling season. Among the three teleconnection indices, ONI is most weakly correlated to chill accumulation in focused regions, while PDO shows the strongest positive correlation and explains up to 39 percent (%) variability of chill portion (CP). PNA presents the most widely spread negative correlation with chill accumulation. This research provides insights on early-season chill prediction and the feasible management and adaptation strategies.
Research was conducted by scientists at Davis, California, on the projected impact of climate change on the incidence of frost temperatures during those coldest winters, defined as the 98th percentile of cool season (November to April) frost hours, under both early- and mid-century time periods, as compared to contemporary conditions, across a range of threshold temperatures. The focus was on three high-value perennial orchard crops– almonds, avocados, and oranges– to assess the effects of climate change on the incidence of temperatures below crop-specific threshold temperatures and for crop-specific critical development phases, and what these temporal changes in frost exposure may mean for the water and energy requirements for mitigating damages. Across both early- and mid-century periods, and across temperature thresholds, frost exposure declines in California's agricultural regions, with an average reduction in frost exposure of 63% by the mid-21st century. This reduction in frost exposure yielded attendant reductions in water use and energy costs, and may save almond, avocado, and orange growers in the highest acreage counties more than 50,000-acre feet of water and $4.2 million in electricity costs for water pumping per year, collectively.
Research was conducted by scientists at Davis, California, using climate models and projected plant water stress to assess which California counties are expected to be most impacted by future climate change impacts. The counties that have the most land area classified as rangelands and also the counties that have the highest beef production are highlighted to evaluate impacts to both rangeland-based ecosystem services, like biodiversity and the beef production industry. Approaches for land and range managers to adapt to a changing future to buffer potential effects have also been considered.
In support of Element II of Objective 1 (Science-based decision support tools, technical products), a workbook was developed by scientists at Davis, California, for California specialty crops on adaptation strategies, approaches and practices for specialty production systems in California. The workbook allows users to articulate specific and general operation goals and objectives, consider and understand the effects of climate change to their unique agricultural production system, consider on farm or operation approaches and practices that would reduce the impacts of climate change and design a monitoring and evaluation system to assess the degree to which the adaptation practices selected were effective at reducing or minimizing climate change related stress or disturbance.
ARS scientists at Davis, California, co-authored a handbook published by the U.S. Forest Service (USFS) for small parcel forest landowners in the Sierra Nevada/Cascade region to assist private forest landowners with developing a site assessment and determining appropriate management strategies to increase fire resilience or adaptive capacity for climate change.
A reforestation prioritization tool was designed by scientists at Davis, California, to help locate where to reforest based on the level of tree mortality and other user-defined variables. The post-drought stand condition tool was designed to allow users to explore newly changed conditions on their National Forest area of interest. And finally, to help guide planting techniques, we have compiled a brief best management practices (BMPs) summary. These tools can be used along with site visits, local knowledge, and individual management goals to aid project planning. Specifically, we hope this tool will help communicate manager’s reforestation ideas and also interactively calculate different scenarios with interested stakeholders, facilitating their input.
The CalAgroClimate web-based decision support system was designed by scientists at Davis, California, that translates high resolution gridded weather data and forecast information into decision support tools designed to provide crop-specific information for managing risks. The tools are designed to be user-friendly and are based on the needs and priorities of agricultural stakeholders. The goal was centered around developing crop-specific, science-based, locally relevant decision-support tools that align with the priorities of agricultural stakeholders in California.
Scientists at Davis, California, developed a menu of climate adaptation strategies, approaches and practices for private, federal/state and industrial forest managers or landowners to understand the potential impacts to forested ecosystems in California and what activities or practices can be considered and applied to yield increased system adaptive capacity.
In support of Element III of Objective 1 (Convening, climate literacy, outreach), scientists at Davis, California, conducted eight roundtable dialog sessions focused on assessing opportunities and barriers leading to the advancement of region appropriate nature-based solutions on natural and working lands for California. The information gained from those events has been synthesized in a report. We developed and conducted eight workshops for the USFS focused on advancing climate science literacy and climate adaptation science understanding for mid-level leadership. We co-led two climate adaptation planning workshops for two individual USFS districts in Region 5 and one such workshop for curators and managers of national and international public gardens. A co-hosted workshop focused on reforestation in context of large fires and climate change in the Southern Sierra Nevada ecosystem. We participated in over 50 workshops, 20 special sessions, 50 oral talks, and 75 meetings. We also visited with over 15 international delegations to share information around the USDA Climate Hub program, impacts of climate change to California natural and working lands and/or provided detailed and technical support to USDA and non-USDA partners. The California Climate Hub develops and publishes a monthly newsletter for over 3,500 recipients and regularly maintains content on the official USDA Climate Hubs website. The Program Director serves on the Governor of California’s Wildfire and Forest Resilience Task Force and provides scientific briefings for state and federal decision makers and regularly moderates scientific and expert panels for large audiences.
Accomplishments
1. New workbook helps specialty crop producers in California develop climate-informed adaptation plans. Climate change is projected to challenge agricultural production in California, bringing more frequent and intense droughts and heatwaves to the state punctuated by extreme precipitation and flooding. The state’s specialty crop industry may be uniquely vulnerable to warming winters and increasing water demands. To help producers cope with the effects of climate change, ARS scientists at the USDA California Climate Hub in Davis, California, created the Adaptation Resources Workbook for California Specialty Crops. The details within the workbook provide science-based information and a multi-step process for developing a farm management plan that explicitly incorporates climate adaptation. Throughout the workbook, resources such as Cooperative Extension guides, Natural Resources Conservation Service technical documents, and scientific literature offer a scientific basis for the workbook’s adaptation menu, which offers a non-exhaustive list of climate-adaptive actions that producers can use to adapt their operations to the effects of climate change.
2. Elucidating barriers of climate smart farm practice adoption. Climate adaptation practice adoption barriers experienced by farmers and technical assistance providers. Research was conducted by ARS scientists in Davis, California, to understand climate adaptation practice adoption barriers by farmers and technical assistance providers working in support of California agriculture. Farmers noted that adoption of climate smart practices (practices that confer both adaptation (resilience) and mitigation (carbon sequestration) outcomes) were driven primarily by on-farm characteristics, information sources and a general limited understanding around the potential benefits that the practices could provide. Technical assistance providers cited limited capacity in terms of time and money both for themselves and farmers, as well as insufficient information and messaging around climate-adaptive practices, as key barriers to practice adoption by farmers. These results can be used to better hone the focus of activities such as trainings or workshops for farmers and farm managers and/or the audiences that support those individuals including USDA Natural Resources and Conservation Service and University of California Cooperative Extension staff.
3. Observed changes in agroclimate metrics relevant for specialty crop production in California. Understanding how agroclimate normals change over time can be important for farm management decisions. This research conducted by ARS scientists at Davis, California, calculated 12 agroclimate metrics across California for the two most recent normal periods (1981-2010 and 1991-2020) and determined the change between these two periods. The results showed that heat exposure is more frequent and that growing seasons are longer in the new normal period (1991-2020) as compared to the previous normal period (1981-2010). Similarly, the 40-year trends in agroclimate metrics were consistent with what we would expect given global warming. The changes in agroclimate normals and the 40-year trends provide observational evidence of a changing climate. These changes underscore the need for adaptation in order to maintain agricultural production. The results of this research are being used to develop a web-based viewer of trends for the agroclimate metrics across California that farmers, farm consultants or extension staff can better appreciate the nature of the changes at the spatial unit of inquiry that may affect their production system.
4. New handbook helps small-parcel forest landowners in the Sierra Nevada and Southern Cascade Range make informed decisions. Contemporary forests in the Sierra Nevada and Southern Cascades are stressed by a number of factors that put them at risk. High severity wildfire, drought stress, insect outbreaks, disease, and a backdrop of changing climate all pose a threat to the persistence of these forests. A significant portion of these forests are owned and managed by nonindustrial private landowners who typically own small parcels (e.g., 10 to 50 acres). ARS scientists at Davis, California, prepared a guidebook structured in a step-by-step manner that walks the small parcel forest landowner through the process of objective-setting for their property, site inventory, a basic risk assessment, potential management options and an outline of available resources. The intent of the publication is to enable decision making that is both informed by scientific information and yet easy to understand by all forest landowners.
5. Supporting the USDA priority of enhancing climate literacy for Department employees. Considering climate change and associated impacts in forest management is critical for sustaining these ecosystems and the benefits they offer. ARS scientists at Davis, California, designed and facilitated a series of interactive trainings to increase U.S. Forest Service (USFS) employees’ climate literacy. The trainings focused on understanding how climate change will impact forests and offered an opportunity to practice using freely available tools (Cal-Adapt and Climate Toolbox) to generate their own climate projections. The scientists offered a training for each USFS zone in the state (Southern California, Southern Sierra, Central Sierra, and Northern) and tailored content to each area’s priority issues.
6. Monthly newsletters provide information on climate, agriculture, and natural resources in California. Information sharing with stakeholders and the public is an important facet of the USDA Climate Hub program. One mechanism for disseminating information are regular newsletters, written for and sent to a wide audience via email. The USDA California Climate Hub in Davis, California, produces such newsletters monthly, highlighting newsworthy issues on topics relevant to the readership, including climate extremes, variability, and change; agriculture; forest ecology and wildfire; water; and the nexus of many combinations of these topics. The newsletters also provide brief syntheses of emerging research on these topics, climate outlook information from the National Oceanic and Atmospheric Association Climate Prediction Center, notices on upcoming events and opportunities, and updates on Hub accomplishments when applicable.
7. Regional Profiles inform socioecological priorities to achieve wildfire resilience across California. Wildfire poses an increasing threat to many communities and ecosystems across California, but the context of how this is occurring varies significantly across the state. USDA California Climate Hub researchers in Davis, California, led the development of publicly available resources called Regional Profiles to inform state decision-makers and regional stakeholders on the key issues and opportunities related to community and ecosystem resilience to wildfire. Each Regional Profile summarized relevant scientific literature into non-technical language accessible for a public audience, and it also presented findings from expert interviews and a public survey about stakeholder priorities and concerns. Regional Profiles were released in conjunction with regional California Wildfire and Forest Resilience Task Force meetings and are publicly available online at https://wildfiretaskforce.org/regional-resource-kits-page/.
8. USDA reforestation strike team produces an all-lands department-wide strategy. A USDA reforestation strategy will help the department realize planting targets. Climate change and the associated impacts of large and intense wildfires across the western United States has increased the already great need to reforest large areas of disturbed forestlands. As part of a USDA interdepartmental team, ARS scientists at Davis, California, co-authored a Reforestation Strategy for the USDA Office of the Secretary. This strategy identified a comprehensive list of potential recommendations and actions, that if carried out by participating agencies and programs, could help realize the administrations reforestation and tree planting targets.
9. 4th California Climate Assessment. ARS scientists at Davis, California, co-authored a report in the most recent state climate assessment for the Sacramento Valley region. In this report, the author team reviewed and synthesized the best available science to report the direct and indirect impacts to the region's communities and natural and working lands from climate change. Impacts covered ranged from compromised air quality due to increased wildland fire smoke and dust impacts due to sustained drought to water storage and related reductions to hydroelectrical energy generation.
10. 5th National Climate Assessment. ARS scientists at Davis, California, are co-authors on the Southwest Chapter of the National Climate Assessment. In this congressionally mandated report, this chapter reviewed and synthesized the best available science, largely from the last 5 years, on the climate impacts and potential solutions to societally critical issues including water scarcity, agricultural production, sea-level rise and wildfire to name a few. A researcher at Davis, California, is also lead author on a special feature in the National Climate Assessment on Western Wildfires. In this feature the authors outline impacts from wildfires that range from public health, water security, critical infrastructure to biodiversity as well as potential applications to reduce such impacts.
Review Publications
Johnson, D., Almaraz, M., Rudnick, J., Parker, L.E., Ostoja, S.M., Khalsa, S.S. 2023. Farmer adoption of climate-smart practices is driven by farm characteristics, information sources, and practice benefits and challenges. Sustainability. 15(10). Article 8083. https://doi.org/10.3390/su15108083.
Johnson, D., Parker, L., Pathak, T., Crothers, L., Ostoja, S.M. 2023. Technical assistance providers identify climate change adaptation practices and barriers to adoption among California agricultural producers. Sustainability. 15(7). Article 5973. https://doi.org/10.3390/su15075973.
