Posts Tagged: cannabis
The Camp Fire started on federal land. This rule would make PG&E clean up its power lines
(Sac Bee) Emily Cadei, Sept. 30
…“In California, it is fairly clear that PG&E did not keep an up-to-date inventory and accomplishment schedule on vegetation clearance on all of their power lines,” William Stewart, director of the Berkeley Forests program at UC Berkeley, said in an email. “ I think the Forest Service wants to make sure that they are sending the same signals to their staff and partners that judges are now sending to PG&E — do proper power line clearance or some entity (or entities) is going to be on the hook for billions of dollars of damages.”
UC ANR Takes In-Depth Look at the Cannabis Industry
(AgNet West) Brian German, Sept. 27
Following the passage of Proposition 64 which legalized recreational cannabis, there was significant excitement surrounding the potential for a legal and regulated cannabis industry in California. However, the development of the guidelines for cannabis cultivation has undergone significant delays as the state works to build infrastructure for a commodity which is still federally prohibited. The July-December 2019 issue of the research publication from UC Agriculture and Natural Resources, California Agriculture, highlights multiple components for the development of legal cannabis in California. The special issue details the history of cannabis in the state, as well as some of the research being conducted on various aspects of cannabis.
Industry advocates weigh in on California's proposed rodenticide ban
(Pest Management Professional) Diane Sofranec, Heather Gooch and Marty Whitford, Sept. 26
…Dr. Niamh Quinn, Human-Wildlife Interactions Advisor University of California Cooperative Extension, Irvine, Calif.
There have been several iterations of bills in California over the past four years. Most of them are targeting anticoagulant rodenticides, although they morphed along the way; they started with all of the rodenticides, and now they're particularly focused on SGARs. As it was written, AB 1788 proposed serious restrictions on the use of SGARs, with some fairly limited applications throughout the state. In essence, it would have been an almost total ban of SGARs for structural pest control.
California farm region faces furry new threat: swamp rodents
(AP) Samantha Maldonaldo and Terry Chea, Sept. 26
…Damage to the region's soil or water infrastructure would be devastating to the economy and diet.
“It would mean no more sushi because the alternative would be to buy rice from Japan or Korea, where the price is five times higher,” said Daniel Sumner, director of the Agricultural Issues Center at the University of California-Davis. “Kiss off carrots, or live without table grapes in the summertime.”
New California lab seeks cure to deadly citrus disease
(Washington Post) Amy Taxin, Sept. 26
RIVERSIDE, Calif. — In a lab southeast of Los Angeles, researchers are opening a new front in the yearslong battle against a tiny pest that has wreaked havoc on citrus groves around the world.
California citrus growers and packers and the University of California, Riverside on Thursday marked the opening of an $8 million lab dedicated to finding a solution to the tree-killing disease known as Huanglongbing that has ravaged groves in Florida, Brazil and China.
…Georgios Vidalakis, director of the Citrus Clonal Protection Program at University of California, Riverside, said citrus boomed in California in the late 1800s. In the decades that followed, researchers in Riverside started a citrus breeding program, which helped develop new varieties, and a citrus collection, which now has more than 1,000 kinds of trees, he said.
Vidalakis, a plant pathologist, oversees a program aimed at ensuring trees don't introduce diseases into the region. But without the ability to study the illness, research was hampered, he said, until experts and growers joined together to build the lab.
“This disease is like nothing we have ever faced as plant pathologists,” he said. “We need all hands on deck.”
These Big Plans to Protect California Homes From Wildfire Fell Short in the Legislature
(KQED) Lauren Sommer, Sept. 26
…While Cal Fire has a goal of inspecting 33 percent of structures in its jurisdiction each year, a KQED investigation found the agency only did half that in 2018. In some parts of the state, only 6 percent of homes in risky areas were inspected.
“It's becomes really clear that our defensible space has been insufficient to protect homes from embers,” said Yana Valachovic, a fire expert with UC Cooperative Extension. “What's immediately adjacent to a structure affects the probability of a structure's survival.”
…“The science has been clear for quite a while, but it's been slow to incorporate into codes, standards and practices,” said Valachovic.
… “There's no single solution that's going to solve the fire problem,” said Valachovic. “It takes an all-hands-on-deck approach.”
Lindcove dedicates conference center to Exeter man
(Sun Gazette) Sept. 25
A late Exeter man who donated most of his fortune to local agriculture and educational institutions, will soon have his name affixed to University of California research facility.
The Lindcove Research and Extension Center, part of the UC Agriculture and Natural Resources system, will rename its conference center after the late Ray Copeland. The Ray Copeland Citrus Center will be dedicated during the Lindcove Citrus Gala on Oct. 4.
Participating in Agricultural Meetings Creates Long-Term Benefits
(AgNet West) Brian German, Sept. 24
…“It's an all-encompassing benefit for everyone,” said Brooke Latack, Cooperative Extension Livestock Advisor serving Imperial, Riverside and San Bernardino Counties. “Not just the farmers, but the people putting the workshops on also benefit a great deal from it.”
A Healthy Agriculture Approach
(CSU Stanislaus Signal) Aliyah Stoeckl, Sept. 23
UCCE Vegetable and Irrigation Advisor Dr. Zheng Wang held an insightful lecture at Stan State among students and faculty discussing the values of vegetable grafting.
… “Grafting conveys a lot of merits in terms of disease resistance and yield maintenance, it enriches the production practices by introducing more variety. And by making impossible things become possible,” said Wang.
UC Cooperative Extension Survey Results on Cannabis Cultivation
(Sierra Sun Times) Jeannette Warnert (news release) Sept. 23
A UC Cooperative Extension survey of California registered and unregistered marijuana growers will help researchers, policy makers and the public better understand growing practices since cannabis sales, possession and cultivation first became legal for recreational use.
“This survey is a starting point from which UC scientists could build research and extension programs, if possible in the future,” said lead author Houston Wilson, UC Cooperative Extension specialist with UC Riverside. A report on the survey results was published in the July-December 2019 issue of California Agriculture journal, the research publication of UC Agriculture and Natural Resources.
In a Race Against the Sun, Growers Try to Outsmart Climate Change
(New York Times) Marla Cone, Sept. 21
…“We can't continue to do the exact same thing we are doing now,” said Katherine Jarvis-Shean, a University of California researcher who advises orchardists on how to cope with climate change. “There are a lot of solutions to the anticipated problems. We just have to get on top of them, testing them and making them available to growers.”
…“For the most part, the world gets fed by row crops,” said Pat J. Brown, an associate professor at the University of California-Davis, referring to wheat, corn and other staples. “But a lot of the stuff that makes life really worth living comes from trees. Think of the world without chocolate or wine or coffee.”
…The Agriculture Department has repositories that store genetic material from every type of tree on earth. Dan Parfitt, a now-retired University of California-Davis plant geneticist, started breeding pistachios using tissue from those repositories more than 30 years ago in an effort to help growers economize their harvest.
As the climate changed, Dr. Parfitt got the idea to plant a few hundred of the trees in the California desert. “The Coachella Valley is the closest to the warmer winters and drier conditions that we will see in the San Joaquin Valley in 20 to 30 years,” he said.
Cannabis findings presented in Mendocino County by Berkeley's Cannabis Research Center
(Ukiah Daily Journal) Carole Brodsky, Sept. 21
One knows times have changed when California Agriculture, the official magazine for the University of California's Agriculture and Natural Resources Division features High Times-worthy photos of cannabis flowers on the front cover. In fact, cannabis is the sole focus of the quarterly, peer-reviewed publication.
Since 2017, the University of California's Cannabis Research Center (CRC) has been hard at work. A 12-person research team, supported by 50 undergraduates, has been conducting groundbreaking research, some of which was presented to the public on Sept. 15 at the Hopland Research and Extension Center.
Team members presented their findings, including the results of a cannabis production survey, which was taken by 350 California cannabis farmers largely located in the Emerald Triangle region. Dr. Van Butsic, assistant cooperative extension specialist and co-director of the Cannabis Research Center, acted as presenter for the event.
Butte County suffers two more human cases of West Nile
(Chico Enterprise Record) Brody Fernandez, Sept. 20
…Maurice Pitesky, is a researcher medical professional for the Veterinary Medicine Extension at the UC Davis School of Veterinary Medicine. Pitesky specializes in poultry health and food safety epidemiology — the study of diseases and large populations.
“The reason chickens are ‘sentinels', are because they don't really get sick,” Pitesky said. “Chickens are the canaries in the coal mine for the West Nile virus. We use them to determine if certain areas contain infected mosquitoes and if they've contracted the virus themselves. It's also a good way to put chickens in strategic places and check to see if they are producing the appropriate antibodies to the virus. From a preventative health perspective, they do serve a beneficial service.”
Chickens can not transmit the virus, they are only carriers, Pitesky said.
A tiny beetle has decimated hundreds of SoCal trees. Now experts are worried about Sacramento
(Sac Bee) Michael Finch II, Sept. 19
…The shot hole borer is not a strong flier so it's unlikely to move far on its own. It can, however, move faster when hiding in firewood and other green waste or landscaping equipment, said Akif Eskalen, a plant pathologist and professor at UC Davis.
Eskalen is one of many investigators looking for ways to naturally eradicate the beetle. Eskalen's work focuses on using native plants, but there is an ongoing trial with pesticides and another using natural predators. The studies, he said, “may take several years to complete.”
… Once inside a tree, the female produces offspring that mate with each other when they grow up and the death-dealing cycle repeats. This sequence happens as many as four times a year, or more if the weather is hotter, said Beatriz Nobua-Behrmann, a researcher studying the insect for the UC Cooperative Extension in Irvine.
They're believed to have arrived in wood packing materials made with infested wood from Taiwan and Vietnam, she said. Climate change could make it worse since the beetle thrives in warm weather. Its reproductive cycle accelerates as the temperature rises.
“Knowing that they can travel in wood or in green waste or in equipment that makes it a little bit more dangerous,” Nobua-Behrmann said. “It could easily make it to the northern counties with people moving firewood because they find it for cheap or for free.”
CBD oil price likely factor in $100 million payoff predicted for Ventura County hemp crop
Kathleen Wilson, Ventura County Star, Sept. 18
…More than 25,000 products can be made from industrial hemp, said Oli Bachie, a UC Cooperative Extension farm adviser in Imperial County who is studying hemp production. The plant can be used for fiber, feed, textiles and oils, but most if not all of the strains of hemp being planted in the county are for CBD, apparently because of the large profits that are expected.
Bachie would not be surprised to see that happen around the state.
"There is a huge interest in this because people want to grab the first economic benefit out of it," Bachie said.
Federal Government Approves Release Of Non-Native Weevil In California To Combat Invasive Thistle
(CapRadio) Drew Sandsor, Sept 18
…The U.S. Department of Agriculture said Tuesday it will permit use of the weevil native to Europe and western Asia to control yellow starthistle, which is from the same areas.
Brad Hanson, UC Cooperative Extension weed specialist at UC Davis, says yellow starthistle thrives in part because of its prickly spines.
"So it's not very palatable to any livestock, especially once it's started to flower, and it's toxic to horses. So often times the other grasses and more palatable plants are grazed and the starthistle persists and is sort of the only thing left,” he said.
California farms, ranches strive to adapt as climate warms - it's a matter of survival
(San Francisco Chronicle) Peter Fimrite, Sept 18
…Josué Medellín-Azuara, the associate director of the UC Agricultural Issues Center at UC Merced, said the biggest issue will be irrigation. Decreases in the Sierra snowpack mean less melting in the summer, so more rainwater will need to be stored in the winter. Hotter temperatures would also mean crops and orchards will retain less moisture.
“Plants may actually lose water more quickly because of the heat, so they may actually need more water than they need now to survive,” Medellín-Azuara said. This at a time when California is expected to experience more droughts.
…Frank Mitloehner, a professor in the UC Davis animal science department, said that is why sensors are being installed to monitor water use, and more ranchers are adopting regenerative farming and grazing techniques that ensure the land sequesters more carbon than it emits.
Drought tolerant crop being studied in the Valley
(ABC 30) Cristina Davies, Sept. 17
Big research is happening at the Kearney Agriculture and Extension Center in Fresno County.
Sorghum, a crop that looks similar to corn, is under a microscope.
Jeff Dahlberg, director of the center, said that sorghum is very drought tolerant.
"What we are looking for is the mechanism behind the drought tolerance in sorghum and if we can elucidate the genetics behind that, what we believe is we can use those genetics to see if the genetics in corn, or in rice, or in wheat," he said.
UC Pot Researchers Working with 'Gray Literature'
(East Bay Express) Dan Mitchell, Sept. 17
… The problem was brought into sharp relief last week when the Cannabis Research Center at UC Berkeley made its first formal presentation of the work that it's been doing. The center began operating at the beginning of the year to "promote interdisciplinary scholarship on the social and environmental dimensions of cannabis production." Every one of the five researchers who spoke during the presentation addressed the often-ridiculous restrictions under which they still operate. As Chronic Town reported recently, researchers in public universities all over the state aren't even allowed to be around pot plants, thanks to the federal ban — a mighty hurdle for people studying health effects, cultivation methods, pest-management techniques, and the like.
"It's a tricky problem," observed center Co-Director Van Butsic, an adjunct professor who specializes in land use. "We don't want our researchers to stay in the academy."
Here's a talk about creating sustainable landscapes in Redlands, sponsored by Redlands Horticultural and Improvement Society
(Redlands Daily Facts) Sept. 17
Janet Hartin, an area environmental horticulture adviser for San Bernardino, Riverside and Los Angeles counties, will present a program on “Beautiful Sustainable Landscapes for Redlands” when the Redlands Horticultural and Improvement Society meets 7 p.m. Thursday, Sept. 19, at Redlands Church of the Nazarene, 1307 E. Citrus Ave.
Sept. 18 meeting to explore prescribed burning
(Taft Midway Driller) Sept. 17
The SRWC's meeting will begin with an introduction from Etna Fire Chief Alan Kramer, after which Lenya Quinn-Davidson and Jeffery Stackhouse, advisors with UC Cooperative Extension and co-founders of the Humboldt County Prescribed Burn Association, will share the story of how their PBA got started two years ago. They'll talk about their PBA's work – more than a thousand acres of prescribed fire through 18 different projects – and they'll talk more generally about options for prescribed fire on private lands, permitting and regulations, project costs, and the benefits of prescribed fire on rangelands, forests, and woodlands.
In 1953, amid reports that cannabis was growing around San Mateo County, the local sheriff's office and the UC Agricultural Extension Service in Half Moon Bay issued a booklet entitled Identify and Report Marihuana. The booklet envisioned “total eradication” of cannabis. The authors couldn't have imagined that, in 2017, the San Mateo County Board of Supervisors would pass an ordinance allowing greenhouse cultivation of cannabis in the county's unincorporated areas.
A lot can happen in 60-plus years — such as voter approval of Proposition 64, the 2016 ballot measure that altered California law to allow the recreational use of cannabis by adults.
page 106). A sense of momentum has begun to suffuse cannabis research.
That said, federal restrictions still inhibit many aspects of research (see page 104 for more detail). Cannabis research is also inhibited by funding constraints. The $10 million in annual research funding that Proposition 64 allocated to California universities has not begun to flow, and the Bureau of Cannabis Control — the entity responsible for disbursing the money — reports that it is still establishing guidelines for doing so.
Despite these obstacles, UC cannabis research in the legalization era is well underway, as attested by this special issue of California Agriculture. The research articles presented here fall into three broad categories — research into cannabis production, into the economics of the cannabis industry in California and into the social and community impacts of cannabis. The three articles focused on cannabis production include the results of the first known survey of California cannabis growers' production practices, by Wilson et al. (page 119). In the article “Characteristics of farms applying for cannabis cultivation permits” (page 128), Schwab et al. combine data on cannabis farms with information about applications for cultivation permits, establishing that, of farms within the dataset, those seeking permits tended to be larger and to have expanded faster than other farms. And on page 146, Dillis et al. analyze data submitted to the regional water quality control board to characterize the water sources used by cannabis cultivators in the Emerald Triangle region (Humboldt, Mendocino and Trinity counties).
Articles focused on the economics of the cannabis industry include a study by Goldstein et al. (page 136) analyzing online retail prices for cannabis flower and cannabis-oil cartridges as changes in regulation and taxation have taken effect in recent years. Valdes-Donoso et al. (page 154) analyze data from sources including California's cannabis testing laboratories to estimate the cost per pound of testing under the state's regulatory framework.
Four articles explore the social and community impacts of cannabis production. On page 161, Valachovic et al. report the results of a survey of timberland and rangeland owners in Humboldt County, who shared their experiences with the rapid expansion of cannabis production in their region and its attendant social, economic and environmental challenges. LaChance (page 169) interviewed noncannabis farmers, ranchers and others across Humboldt, Mendocino and Sonoma counties, eliciting their views on issues such as increased land prices amid cannabis legalization. For the article “Growers say cannabis legalization excludes small growers, supports illicit markets, undermines local economies” (page 177), Bodwitch et al. surveyed cannabis growers to gain insight into their experiences with the state's system for regulation of commercial cultivation. Finally, on page 185, Polson and Petersen-Rockney employed ethnographic methods to study cultivation regulations in Siskiyou County and their effects on the county's Hmong-American community. The special issue was conceived by Van Butsic and Ted Grantham — UC Cooperative Extension (UCCE) specialists based at UC Berkeley — and Yana Valachovic — a UCCE forest advisor and director for Humboldt and Del Norte counties. Butsic, Grantham and Valachovic developed the issue in collaboration with Daniel Sumner, a UC Davis professor of agricultural economics and director of the UC ANR Agricultural Issues Center, and with the staff of California Agriculture.
California has legalized marijuana, but commercial cannabis growers have been slow to obtain the required state and local permits. To find out what deters them from complying with new laws, University of California scientists are asking cannabis growers to participate in a survey about their experiences with the regulated market.
“The majority of cannabis farmers are not joining the legal market and we want to know why,” said Van Butsic, UC Cooperative Extension specialist in the Department of Environmental Science, Policy & Management at UC Berkeley. “The objective is to identify barriers to joining the legal market.”
The researchers plan to share the results with policymakers as well as with the cannabis farming community and other researchers.
“Cannabis growers will have an opportunity to tell us what's wrong with the regulatory system so we can advise policymakers on changes they could make to improve compliance,” Butsic said.
Butsic estimates that less than one-third of cannabis growers in Humboldt County have completed the permit process. He says it's difficult to estimate statewide how many cannabis growers are operating illegally because laws vary from county to county and in many parts of the state, local governments don't allow cannabis growing.
One impact from cannabis growers not joining the regulated market is the state receives lower revenues from cultivation taxes.
Beginning on Jan. 1, 2018, two taxes went into effect: a cultivation tax on harvested cannabis that enters the commercial market and a 15% excise tax on purchases of cannabis and cannabis products.
Prop. 64, approved by voters in 2016, stated: “The revenues will provide funds to invest in public health programs that educate youth to prevent and treat serious substance abuse, train local law enforcement to enforce the new law with a focus on DUI enforcement, invest in communities to reduce the illicit market and create job opportunities, and provide for environmental cleanup and restoration of public lands damaged by illegal marijuana cultivation.”
Legalization was projected to create $1 billion annually in new state revenue, but initial tax revenue has been significantly lower. In the Governor's May 1 budget revision, cannabis cultivation and cannabis retail salesrevenues were projected at $288 million in 2018-19 and $359 million in 2019-20.
Compliance is important not only for tax revenue, but also for the environment, Butsic said. Research has shown that illegal cannabis production causes environmental damage, including rodenticide poisoning of forest wildlife.
“We know there are environmental impacts from non-permitted farms,” Butsic said. “The more growers are able to comply, the better off our environment will be.”
The survey can be anonymously filled out online at https://ucanr.edu/sites/compliance until Aug. 1. Cannabis growers who wish to provide more information can volunteer to give the researchers an interview.
Cannabis is unlike any other agricultural crop. Because of its circuitous history — once illegal to grow, and now legal but heavily regulated — cannabis has cast a unique footprint on the environment and the communities of farmers who grow it.
UC Berkeley's new Cannabis Research Center, announced today by a multidisciplinary team of faculty, will explore how cannabis production impacts the environment and society, and how these impacts will evolve under new regulations set in place by legalization.
While other research groups in the University of California are focusing on the individual and public health ramifications of cannabis, the center will be the first in the UC system to explore oft-overlooked dimensions of cannabis growth.
Berkeley News spoke with center co-directors Van Butsic and Ted Grantham, both assistant cooperative extension specialists in UC Berkeley's Department of Environmental Science, Policy and Management, to learn more about the state of cannabis production in California and the center's goals.
Ted Grantham: My research primarily focuses on the impacts of water use. These farms are taking water directly from streams or from groundwater wells connected to streams. Most farms are located in smaller watersheds, so even though the total amount of water taken can be small, it can have a big impact on streams that support sensitive species, such as salmon. Other potential ecological impacts relate to the use of pesticides and fertilizers, and habitat fragmentation from building roads and clearing trees.
The social scientists in the center are also concerned about equity and the sustainability of growing communities. Historically many growers would be characterized as small-scale, and there is concern that through this process of legalization, there is going to be a consolidation of cannabis production following models of industrial agriculture. We are trying to understand if there is a way to have cannabis cultivation continue to sustain local economies and rural communities, while limiting impacts to the environment.
How have legalization and associated regulations affected cannabis production so far?
Van Butsic: We're about a year into the formal legalization of recreational cannabis production and it has been a rocky start. There have been fewer participants in the market — producers — than were anticipated. Some growers appear to have gone out of production, many appear to remain in black market production and a relatively small subset of growers have gone through the process of compliance. And the grower community that has pursued legal production are very vocal about the issues and challenges facing their group. We have been trying to better understand what are the barriers to compliance and, ultimately, if there can be changes made in policies that can really help to catalyze this transition.
Van Butsic: This is a great system to study really big sustainability problems. How do we develop an agricultural system that's good for the environment and good for farmers? And cannabis is a really interesting spot to look at it because the regulations enforcing cannabis are totally different than in the rest of agriculture, so it would be really interesting to see if we get different outcomes.
How do regulations differ between cannabis production and the rest of agriculture?
Van Butsic: Cultivators need to be permitted by the state water board, by local government and by state government to grow cannabis legally, and there are environmental regulations in all three of those levels that they need to comply with that require a higher order of environmental performance than most other agricultural crops.
So you think that understanding these regulations might help you apply them to other types of agriculture?
Van Butsic: Exactly. Agriculture has been notoriously difficult to regulate in the past, and this is a system where the regulators got the upper hand, and so it will be interesting to see how the producers respond, and if cannabis producers can be profitable and meet these super-high environmental performance measures, then perhaps there is knowledge and technology that can transfer from the cannabis industry to the rest of agriculture that can improve environmental performance of food production.
We are working on a big project right now where we are mapping where all the farms are after the latest regulatory changes. We want to know, if we could take down these barriers and everybody became compliant, what would that mean for local water budgets, environmental health and for the amount of cannabis that would be produced?
Ted Grantham: This is a rapidly changing industry, and no one really knows where it is headed. Everyone is playing catch up to a certain extent, and we believe researchers have an important role in bringing independent scientific information to conversations around cannabis policy./span>
Planting cannabis for commercial production in remote locations is creating forest fragmentation, stream modification, soil erosion and landslides. Without land-use policies to limit its environmental footprint, the impacts of cannabis farming could get worse, according to a new study published in the November issue of Frontiers in Ecology and the Environment.
“Despite its small current footprint, the boom in cannabis agriculture poses a significant threat to our environment,” said co-author Van Butsic, a UC Cooperative Extension specialist in UC Agriculture and Natural Resources and the UC Berkeley Department of Environmental Science, Policy and Management. “To mitigate the anticipated environmental impacts, now is the time for policymakers and land-use planners to set regulations to manage the spatial pattern of cannabis expansion before crop production becomes established.”
Earlier studies have shown that cannabis production causes environmental damage, including rodenticide poisoning of forest mammals and dewatering of streams due to improper irrigation.
Cannabis, as either a medicinal or recreational drug, is now legal in more than 30 U.S. states and in several countries. In California, where medicinal marijuana has been legal since 1996, voters in November approved the sale and possession of one ounce of marijuana for recreational use. As a result, cannabis production is ramping up.
Effective policymaking for a new crop can be challenging without scientific data. In this study, Butsic and Ian J. Wang, assistant professor in the Department of Environmental Science, Policy and Management at UC Berkeley, and Jacob C. Brenner, associate professor in the Department of Environmental Studies and Sciences at Ithaca College in New York, present an approach for early assessment of landscape changes resulting from new agricultural activities.
Their approach uses per-unit-area analysis of landscape change. To study forest fragmentation in northern California, the scientists compared the effects of cannabis cultivation to those of timber harvest from 2000 to 2013 in Humboldt County.
Based on the size, shape and placement of the cannabis grows among 62 randomly selected watersheds, they quantified the impacts relative to those of timber harvest.
“We found that although timber has greater landscape impacts overall, cannabis causes far greater changes in key metrics on a per-unit-area basis,” Butsic said.
On a per-unit-area basis, the cannabis grows resulted in 1.5 times more forest loss and 2.5 times greater fragmentation of the landscape, breaking up large, contiguous forest into smaller patches and reducing wildlife habitat.
“The results show how important it is to consider environmental impacts at different scales,” Brenner said.
Current California law caps the size of outdoor cannabis production to 1 acre per parcel, to prohibit the development of industrial-scale cannabis operations outdoors. An unintended consequence of this law may be small dispersed cannabis grows that edge out wildlife.
While the long-term effects of cannabis cultivation on the environment are unknown, the researchers concluded that land management and agricultural policy informed by further research may reduce these threats in California and in other states and countries where cannabis production can be regulated.
“Studies like this one have the potential to directly inform local land-use policy and state environmental regulation,” Brenner said. “It's exciting to be a part of this research because it is capturing a human-environment phenomenon at the moment of its emergence.”