The center’s ongoing research includes a multi faceted project to assess specific aspects of Northern California’s cannabis farms, including the number and size of non-compliant cultivation sites; the environmental effects of non-compliant sites ; and the challenges to regulatory compliance that cannabis cultivators encounter. According to a grant proposal associated with the research, the project is motivated by an urgent need to understand the environmental threats posed by non-compliant farms and the reasons that some farms successfully navigate state regulations while others fail. The researchers are combining high-resolution satellite images with local and state permitting data to identify permitted and non-permitted cultivation sites. In parallel, the researchers are combining permit specifications with water use models to estimate the effects on stream flows of non-permitted versus permit ted cultivation. Additionally, they are determining which factors associated with cannabis cultivation are most closely linked to compliance — whether parcels are large or small, old or new — and, through writ ten grower surveys and in-person interviews, they are seeking to understand what stands in the way of cultivator compliance. Ultimately, the work will yield a policy report outlining ways in which state and local governments can decrease the harm of non-compliant cannabis cultivation while increasing rates of compliance. The research is supported by a grant from the Campbell Foundation, provided through the Resource Legacy Fund. In another example of CRC research focused on cannabis and the environment, last year Butsic, Jennifer Carah and additional co-authors published the results of their work on “agricultural frontiers” . These are places where,plants rack due to increased profit potential for agricultural activity, land is newly cultivated — frequently resulting in environmental impacts such as forest fragmentation and threats to sensitive species.

Such transformations, the authors write, occur when economic circumstances are altered by some new mechanism — such as, in the case of cannabis, a new legal status. The researchers, documenting the emergence of such a frontier, studied cannabis cultivation sites in Humboldt and Mendocino counties from 2012 to 2016. Using satellite imagery to develop a database of cultivation sites, the research ers correlated site characteristics such as remoteness and erosion potential with the spread of agricultural frontiers. They report that, over the study period, cannabis cultivation sites in the study area nearly doubled in number, with total acreage under cultivation likewise nearly doubling, and that a significant portion of the new cultivation occurred in areas such as sensitive watersheds. They found, for example, that nearly 90% of the areas newly developed for cannabis cultivation had been covered in natural vegetation as late as 2006. The researchers argue that agricultural frontiers can develop “almost anywhere institutions fail to prevent” them — and note that, for 18 years after medicinal cannabis use became legal in California with the 1996 Compassionate Use Act, the state devoted no funds to regulating cannabis cultivation and production. In this issue of California Agriculture, Grantham and four co-authors from the North Coast Regional Water Quality Control Board present the results of their research into cannabis cultivators’ patterns of water use in several Northern California countries. For the research that resulted in “Watering the Emerald Triangle: Irrigation sources used by cannabis cultivators in Northern California” , Grantham and his colleagues analyzed reports submitted to the board by cannabis cultivators. The researchers determined how many cultivators sourced their water from wells, surface water diversions, spring diversions and other sources; how water sourcing behavior changed over the course of a year; and how water use patterns varied ac cording to whether growers operated within the state’s legal cannabis market.

The researchers determined that cannabis growers rely on well water to a greater degree than is generally supposed — and that their reliance on well water may increase as more growers join the legal market because of well water’s less restrictive permit ting requirements. In separate research, Michael Polson — a post doctoral researcher in UC Berkeley’s Department of Environmental Science, Policy, and Management — has investigated the environmental dimensions of cannabis from an anthropological perspective. In a paper published earlier this year, Polson shows how cannabis has been identified as an environmental problem that requires public intervention . On the basis of participant observation and more than 70 interviews with subjects across the cannabis spectrum — from park rangers to environmentalists to “criminalized people” — Polson demonstrates how cannabis production has been defined as pollution — “dovetail[ing] with [cannabis] prohibition’s history of marking people and substances as socially polluting.” Polson argues, as he highlights the legacy of cannabis prohibition in environmental debates, that policy making is at its most innovative when it includes a broad range of cultivators and when stigmas are explicitly addressed. Research into the environmental aspects of cannabis is also underway at UC Davis, where Mourad Ga briel is a research associate member in UCD’s School of Veterinary Medicine. In 2018, Gabriel and co-authors, including Robert Poppenga — a professor of molecular bio-sciences at the California Animal Health and Food Safety Lab at UC Davis — published the results of their research on the effects of rodenticides on owls in northwestern California forests . The researchers, working on privately owned timberland in Humboldt and Del Norte counties, investigated the prevalence of anticoagulant rodenticides in areas char acterized by illegal cannabis cultivation. Anticoagulant rodenticides, used by some cannabis cultivators to control pests, are known to affect non-target species in urban areas and recently have been shown to affect carnivores in California’s remote forest areas as well. Gabriel and his co authors undertook to deter mine whether the northern spotted owl, a threatened species, is exposed to anti coagulant rodenticides in the study area — and also to determine if barred owls, a common species, can be used as a surrogate to determine exposure levels in northern spotted owls.

The researchers analyzed liver samples from 84 barred owls and 10 northern spotted owls. Within the study area, 70% of northern spotted owls and 40% of barred owls tested positive for anticoagulant rodenticides. The researchers hypothesize that cannabis cultivation in the area is the main source point for the presence of dangerous rodenticides. They also determined that barred owls are a suitable surrogate for determining rodenticide levels in the threatened northern spotted owl. Gabriel, in his capacities as a UC researcher and as executive director of the Integral Ecology Research Center, a nonprofit organization based in Humboldt County, is currently carrying out reclamation projects at illegal cannabis cultivation sites in California and Oregon. In a project conducted this May in the Shasta-Trinity National Forest, a team representing 11 governmental and nongovernmental entities worked at 16 cultivation sites within eight large cultivation complexes, removing 6,000 pounds of trash, which included rodenticides and more than 5 miles of irrigation lines. Mourad estimates that removal of the irrigation lines restored more than 500,000 gallons of water — daily — into affected watersheds. Agencies including the California Department of Fish and Wildlife and the Law Enforcement and Investigations arm of the U.S. Forest Service have provided grant funding for 170 such projects, 112 of which have already been completed. In an entirely different vein, UC Davis–based cannabis research has been conducted since 2016 at the UC Agricultural Issues Center , a UC Agriculture and Natural Resources statewide program operating since 1985. The center’s broad mission is to provide research based information on the economic dimensions of emerging issues in agriculture. Cannabis, then, is right in the center’s wheelhouse. Dan Sumner, the center’s director,plant growing trays reports that AIC began pursuing cannabis-related work after the 2015 passage of a set of laws known collectively as the Medical Marijuana Regulation and Safety Act. This legislation laid the groundwork for state regulation of medicinal cannabis and ultimately of the recreational cannabis industry. The lead agency in regulating commercial cannabis licenses for distributors and retailers, among other business types, is the Bureau of Cannabis Control — for which, between 2016 and 2018, the AIC prepared a Standardized Regulatory Impact Analysis . In the process, the AIC advised the BCC on the economic dimensions of various regulatory scenarios — and the bureau used the center’s analysis to inform the final cannabis regulations that it issued on Jan. 16 of this year. According to Sumner, a principal insight that the AIC furnished to the BCC was that, since illegal cannabis continues to be attractive to retail buyers because it is cheaper than cannabis from regulated retailers, “much of the cannabis sold in California [after legalization] would remain in the illegal segment.” Moreover, regulations that generate benefits for consumers at lower costs will help sustain the legal marketplace. In this issue of California Agriculture, three AIC researchers — Pablo Valdes-Donoso, a postdoctoral scholar; Robin S. Goldstein, principal economic counselor; and Sumner — present their research on California’s rather stringent system for testing cannabis that enters the legal market . All cannabis sold legally in the state is tested for more than 100 contaminants. Of those contaminants, 66 are pesticides — and tolerance for 21 of those pesticides is set at zero. In many cases, allowable levels of cannabis contaminants are lower than those established for food sold in the state. The researchers, drawing on data provided by testing laboratories and manufacturers of testing equipment, estimated how much it costs to test a pound of cannabis under California’s regulatory regime, as well as the cost of collecting samples. They concluded that the need to destroy batches of cannabis that fail testing accounts for a large share of testing costs. The research ers argue that, though the availability of certifiably safe and legal cannabis products may prompt some customers to join the regulated market, other customers will remain in the cheaper illegal market.

They speculate that, over time, increased availability of data about cannabis testing and sales will allow for greater certainty about the effect of the testing regime on cannabis prices and demand for legal cannabis. Meanwhile, UC Davis is establishing a dedicated center for research into psychoactive cannabis and industrial hemp — the Cannabis Research Initiative. According to Cindy Kiel, executive associate vice chancellor for research administration at UC Davis, the initiative will draw on the comprehensive strengths of UC Davis faculty in areas ranging from agricultural and environmental impacts to legal, economic and policy outcomes to human and animal health. In particular, the initiative will benefit from UC Davis’s strong emphasis on agricultural issues such as soils, water, genomics and plant science and from faculty interest in two-way interactions such as those between cannabis and the environment. Funding is envisioned to flow from the UC Davis budget, from research funds established in Proposition 64 and from outside sources such as industry partners. The initiative will be headed by co-directors representing the agricultural and medical sides of cannabis research. In May, UC Davis faculty members including Chemistry Professor Mark Mascal, along with col leagues from the University of Reading in the United Kingdom, published an article demonstrating that a synthetic analogue of cannabidiol is as effective as CBD in controlling seizures in rats — and that it provides several benefits in comparison to CBD. The synthetic analogue is cheaper than herbal CBD, cannot be converted into psychoactive tetrahydro cannabinol and is not restricted by the Drug Enforcement Administration’s “scheduling” apparatus. Meanwhile, the UC Davis–affiliated Western Center for Agricultural Health and Safety is studying issues such as workplace safety for cannabis workers, who face risks that include unhealthy pesticide exposure. For students, UC Davis has offered cannabis courses including the graduate-level Cannabis sativa: The Plant and Its Impact on People — and, for undergraduates, Physiology of Cannabis.A brand-new entrant into UC cannabis research is the UC Nicotine and Cannabis Policy Center at UC Merced , established just last year to study tobacco- and cannabis-related issues in public health and public policy, especially in the San Joaquin Valley. The center, partnering with local public health departments and organizations such as the American Heart Association, aims to produce tobacco and cannabis research that places special emphasis on the San Joaquin Valley’s diverse population of teens and young adults and in forms policy decisions that affect the region. The center’s flagship research initiative is a long term, survey-based effort to understand issues surrounding cannabis, tobacco and e-cigarettes.