Today as we witness the international shift in cannabis policy away from prohibition toward a patchwork of incongruent regulatory schemes, cannabis genetic resources are critically threatened around the world by both the legacy and remnants of prohibition as well as the regulatory and market forces shaping the emerging industry. Now, more than ever, the preservation and dissemination of heirloom and landrace cannabis varieties is absolutely essential to the continuation of our traditional cannabis cultures and the Green Renaissance.
Since the 1970s there has been increasing awareness and concern among academics, policy makers, and international organizations, regarding the loss of genetic resources (Frankel and Bennett 1970, Harlan and de Wet 1971, Hammer 2004, Hammer 2008). One of the fundamental concepts to emerge from international conservation literature is what’s known as ‘genetic erosion’ defined as:
“• loss of genetic diversity (e.g. evolutionary potential), lineages, traits, populations or metapopulations, breeds, varieties, landrace or similar, in situ or ex situ; and/or
- the disruption of processes maintaining genetic resilience such as genetic connectivity; and/or
- high levels of hybridization; and/or
- other threats to genetic diversity such as high inbreeding.”
Over the last decade cannabis researchers and academics have increasingly begun raising the alarm about the threat of genetic erosion in cannabis (Clarke and Merlin 2013, Welling 2016, McPartland and Small 2020).
Historically prohibition has been the primary contributing factor interfering with the preservation and improvement of cannabis germplasm driving genetic erosion of cannabis genetic resources (Welling 2016).
Over the last 80 years prohibition has significantly impacted academic and international efforts to study, catalogue, and preserve cannabis genetic resources, indirectly resulting in genetic erosion due to ignorance and neglect.
Prior to federal prohibition the US Dept of Agriculture regularly produced reports and research papers on the subject of hemp. Lyster Dewey ran the USDA’s Office of Fiber Investigations working extensively with hemp. Dewey coordinated research with farmers and universities and conducted breeding experiments of his own at the USDA’s Arlington Experimental Farm. Dewey’s work resulted in the creation of the first commercial hybrid hemp varieties.
After federal prohibition was adopted in the late 1930s Dewey’s work with hemp ended. Arlington Experimental Farm, where Dewey grew and bred his hemp varieties, was replaced by the Pentagon. Eventually all hemp production ceased and the varieties bred by Lyster Dewey and the USDA were lost completely.
Since the passage of the Controlled Substance Act in 1970 the DEA has determined the priorities and funding for scientific cannabis research at best significantly hindering understanding and preservation of cannabis genetic resources at worst pursuing research into eradication strategies specifically designed to cause genetic erosion. Despite recent legal reforms national and international prohibition of cannabis continues to block efforts to comprehensively catalogue, characterize and preserve cannabis genetic resources (Welling 2016).
Cannabis prohibition has resulted in the direct confiscation, eradication and destruction of billions of individual cannabis plants (and seeds). According to government statistics between 1984-2005, the period for which these statistics were kept, over 4.7 billion feral cannabis plants were eradicated by the DEA Domestic cannabis eradication/suppression program. At the same time (1984-2005) the DEA DCE/SP eradicated roughly 4.2 million cultivated cannabis plants. One of the DEAs most well known Special Enforcement Operations, Operation Green Merchant, specifically targeted seed banks, grow shops and magazines to identify, investigate and prosecute cannabis growers and distribution networks. The DEA DCE/SP continues to operate to this day and over the last decade (2011-2019) 37,994,000 cannabis plants have been destroyed.
Eradication programs had significant impacts on cannabis genetic resources causing genetic erosion by forcing breeders to work with smaller populations, pushing cultivators indoors and driving selection pressures determined by the economics and necessity created by prohibition. Cannabis prohibition has been an internationally coordinated state funded assault on the genetic resource of the most useful and versatile crop species on the planet.
In addition to the remnants of prohibition that continue to erect barriers to understanding, utilizing and preserving cannabis genetic resources; the emerging regulatory framework and market forces of the green rush increasingly threaten cannabis genetic resources.
Historically the Industrial Agricultural Model has contributed to the genetic erosion of essentially every agricultural crop species. As shown in the Infographic, below, between 1903-1983 every major crop species declined from 100s of varieties to a few dozen at most.
It is estimated that 75% of global crop diversity was lost in the previous century (Hammer 2004). These trends have only intensified in recent years as the global seed trade has increasingly consolidated under what is now the Big-4 agri-chemical companies (Bayer, BASF, Chem-China, and Corteva).
We have seen the consequences of the Industrial Agricultural Model on the genetic resources of every major food crop, critically threatening crop biodiversity and the long term sustainability of global food supply. We have also witnessed the consequences of this economic model on farmers and communities rights and sovereignty.
Landrace and Heirloom Varieties Critically Endangered and Threatened Cannabis Genetic Resources
Today distinct cannabis landraces are the most at risk cannabis populations. The introduction of foreign gene pools (particularly modern hybrids) into traditional cultivation regions and centers of diversity threatens the genetically distinct diverse populations in these regions (Wiegand, 1935, Rhymer and Simberloff 1996, Merlin and Clarke 2013).
In 2020 John McPartland and Ernest Small and John co-authored a paper describing landrace populations of cannabis in south and central Asia as critically endangered and in need of immediate conservation action warning “[w]orldwide introgressive hybridization…threatens the agro-biodiversity of C. sativa.” Specifically, “Central and South Asian landraces face extinction through introgressive hybridization.” They argue, “…formal recognition of indigenous Central and South Asian varieties…may help prevent their extinction.” Concluding, “collection and conservation of germplasm of indigenous populations of Central and South Asian landraces in their centers of diversity is urgently needed.” The findings of McPartland and Small echo a common concern emerging in the literature on cannabis genetic resources (Clarke and Merlin 2013, Welling 2016).
Existing heirloom cannabis varieties are also important sources of genetic diversity critically threatened by genetic erosion. We have already witnessed the disappearance of specific traits and varieties that were once ubiquitous though are no longer readily available driven largely by the forces described above in the section on prohibition. Going forward if decisions regarding genetic resources of heirloom and landrace cannabis varieties are left in the hands of government regulators and licensed commercial farms, as market forces and consumer trends increasingly determine what is or is not commercially viable within the regulated markets heirloom and landrace varieties will be increasingly subject to the whims of the market with all of the attendant consequences.
Today, all around the world, cannabis genetic resources are critically endangered. Instead of acknowledging the inherent value of cannabis genetic resources and the threat of genetic erosion policy makers, bureaucrats, law enforcement officials and commercial interests have actively adopted policies and practices that exacerbate the problem and contribute to genetic erosion. In the absence of coherent coordinated international efforts to protect and preserve cannabis genetic resources the urgency of the present moment calls for those of us in the grassroots cannabis movement to organize around concrete strategies to preserve cannabis genetic resources. This column will provide a space for exploring and mobilizing around these concrete strategies to preserve and improve cannabis genetic resources into the future.