Legalization of cannabis production has daylighted a unique and highly valuable crop in California agriculture. State and regulatory agencies must now address the ecological, social and agricultural effects of cannabis production, but little is known about how growers produce this crop. Using an online survey, we gathered information from growers in July 2018 on their production practices. According to responses from about 100 growers, most cannabis was produced outdoors or in greenhouses, relied primarily on groundwater and used biologically based inputs for pest management. Many farms employed seasonal workers paid at fixed piece rates. Regulatory compliance varied according to farm size. Beginning to document growing practices will help scientists formulate key environmental, social and agronomic questions and develop relevant research and extension programs to promote best management practices and minimize negative environmental impacts of production.
Editorial Note
Cannabis producers in California can now participate in a regulated supply chain — but little is known, despite considerable speculation, about which types of producers are likely to seek legal status. Growers' decisions about joining the legal market are central to questions about how formalization will transform cannabis production in California, and in particular whether small farms, which were encouraged under Proposition 64, can remain part of the industry. We combine data on the location and characteristics of cannabis farms in 2012 and 2016 with applications for cultivation permits from 2018 to investigate farm characteristics associated with cannabis formalization in Humboldt County. We find strong evidence that the farms most likely to start the permit process are larger, existed in 2012 prior to the start of the “green rush” and expanded at greater rates between 2012 and 2016. The evidence is consistent with concerns that formalization of the cannabis industry may lead to industry consolidation, as has been the trend in California's agricultural and timber industries more broadly.
Land ownership is one of the primary determinants of how agricultural land is used, and property size has been shown to drive many land use decisions. Land ownership information is also key to understanding food production systems and land fragmentation, and in targeting outreach materials to improve agricultural production and conservation practices. Using a parcel dataset containing all 58 California counties, we describe the characteristics of cropland ownership across California. The largest 5% of properties — with “property” defined as all parcels owned by a given landowner — account for 50.6% of California cropland, while the smallest 84% of properties account for 25% of cropland. Cropland ownership inequality (few large properties, many small properties) was greatest in Kings, Kern and Contra Costa counties and lowest in Mendocino, Napa and Santa Clara counties. Of crop types, rice properties had the largest median size, while properties with orchard trees had the smallest median sizes. Cluster analysis of crop mixes revealed that properties with grapes, rice, almonds and alfalfa/hay tended to be planted to individual crops, while crops such as grains, tomatoes and vegetables were more likely to be mixed within a single property. Analyses of cropland ownership patterns can help researchers prioritize outreach efforts and tailor research to stakeholders' needs.
Purchases of private land for conservation are common in California and represent an alternative to regulatory land-use policies for constraining land use. The retention or enhancement of ecosystem services may be a benefit of land conservation, but that has been difficult to document. The InVEST toolset provides a practical, low-cost approach to quantifying ecosystem services. Using the toolset, we investigated the provision of ecosystem services in Sonoma County, California, and addressed three related questions. First, do lands protected by the Sonoma County Agricultural Preservation and Open Space District (a publicly funded land conservation program) have higher values for four ecosystem services — carbon storage, sediment retention, nutrient retention and water yield — than other properties? Second, how do the correlations among these services differ across protected versus non-protected properties? Third, what are the strengths and weaknesses of using the InVEST toolset to quantify ecosystem services at the county scale? We found that District lands have higher service values for carbon storage, sediment retention and water yield than adjacent properties and properties that have been developed to more intensive uses in the last 10 years. Correlations among the ecosystem services differed greatly across land-use categories, and these differences were driven by a combination of soil, slope and land use. While InVEST provided a low-cost, clearly documented way to evaluate ecosystem services at the county scale, there is no ready way to validate the results.
Water use by cannabis cultivators represents an emerging threat to surface flows in Northern California's sensitive watersheds. To date, however, no data has been available to formally assess where cannabis sites source their water. This study analyzed data from annual reports, covering the year 2017, submitted by 901 cannabis cultivators enrolled in the Cannabis Waste Discharge Regulatory Program administered by the North Coast Regional Water Quality Control Board. The analysis identified cannabis cultivators' most common sources for water extraction, monthly patterns for each water source and differences between sites compliant and not compliant with the cannabis program. The most commonly reported source of water was wells (58% of sites), with most extraction from wells occurring during the growing season (April through October). Surface water diversions (22% of sites) and spring diversions (16% of sites) were the most common sources after wells, with extractions from these sources distributed much more evenly across the year. Although nearly one-third of noncompliant sites (33%) used wells, this source was more than twice as frequently reported among compliant sites (68%), indicating that wells may become increasingly common as more sites become part of the regulated cannabis industry.
Maintaining and enhancing soil organic carbon storage can mitigate climate change while promoting forage growth. California has adopted incentive programs to promote rangeland practices that build soil organic carbon. However, there is no standard framework for assessing the baseline level of soil organic carbon at the ranch scale. Here, we use the Ecological Site Description — a land-type classification system — to help ranch managers set priorities about where to implement practices to increase soil organic carbon. We measured baseline carbon stocks at 0 to 15 and 15 to 30 centimeters' depth across three ecological sites and two vegetation states (shrubland and grassland) at Tejon Ranch, California. We discovered increased levels of soil carbon at ecological sites in higher elevations, and more soil carbon in shrublands as compared to grasslands. Slope, elevation, and soil texture, as well as plant litter and shrub cover, were significant predictors of soil carbon. The Ecological Site Description framework can serve as an important tool to help range managers keep carbon in the soil and out of the atmosphere.
The 2004 Sierra Nevada Forest Plan Amendment adopted by the U.S. Forest Service called for using adaptive management — management through deliberate experimentation — to carry out treatments to improve forest health and reduce fire severity. The Sierra Nevada Adaptive Management Project (SNAMP), begun in 2005 and ending this year, has developed, implemented and evaluated participatory adaptive management processes in two national forests for applying fuels management treatments based on strategically placed patterns of tree thinning. SNAMP participants include federal and state agencies, the University of California and many members of the public. UC Cooperative Extension staff members have played an important role in facilitating the participation of public stakeholders. In 2010, a survey showed that stakeholders valued the learning opportunities of the project, especially appreciating the open discussions, public input and face-to-face contact with scientists. Despite the institutional limits to sharing decision making, an environment conducive to the social learning characteristic of collaborative adaptive management projects was created. The SNAMP process may lead to long-term relationships and knowledgeable stakeholders who can support the Forest Service's use of the project findings after UC's role ends.
Remote-sensing methods are being used to study a growing number of issues in the San Francisco Estuary, such as (1) detecting the optical properties of chlorophyll-a concentrations and dissolved organic matter to assess productivity and the nature of carbon inputs, (2) creating historical records of invasive aquatic vegetation expansion through space and time, (3) identifying origins and expansions of invasions, and (4) supporting models of greenhouse-gas sequestration by expanding restoration projects. Technological capabilities of remote sensing have likewise expanded to include a wide array of opportunities: from boat-mounted sensors, human-operated low-flying planes, and aerial drones, to freely accessible satellite imagery. Growing interest in coordinating these monitoring methods in the name of collaboration and cost-efficiency has led to the creation of diverse expert teams such as the Remote Imagery Collaborative, and monitoring frameworks such as the Interagency Ecological Program Aquatic Vegetation Monitoring Framework and Wetland Regional Monitoring Program. This paper explores the emerging technologies and applications of various methods for studying primary producers, with an emphasis on remote sensing.
Cannabis is often grown on agricultural and forest lands in California, but little is known about the adjustments that traditional agriculture and timber producers are making to their livelihoods as cannabis becomes legal under state law. Our goal in this research was to better understand how larger landowners, whose families have often produced timber and cattle for generations, are experiencing increased cannabis production in their areas — and also to better understand these landowners' perceptions of the impacts of cannabis, whether positive or negative, on their communities. To accomplish this, we surveyed landowners who owned at least 500 acres in Humboldt County, an area that — more than 40 years ago — became one of the first California counties to begin experiencing expansive cannabis cultivation. Of the 211 landowners we invited to complete a survey, 71 responded, providing insights into their experiences with and perceptions of cannabis production. Many survey respondents reported illegal cultivation on their properties, problems with shared roads and other direct negative effects of cannabis production. Most landowners also reported that cannabis production has increased the cost of labor, though they acknowledge that it has increased the value of their property as well. Survey respondents, however, have not changed their views of cannabis with legalization. The findings of this study illustrate some of the challenges involved in developing land use ordinances and other policies that can support multiple industries whose interests may be in competition.
