Eradications We call locale-specific varieties of cannabis “landraces”, and they are the backbone of modern commercially-bred cannabis seeds. But these landraces are under threat from habitat loss, government eradication programs, and invasion of foreign varieties. Let’s take a look at how this occurs, and what we can do to preserve our remaining landrace genepool.
Throughout the world, humans cultivate cannabis and hemp – and in many cases, they have done so for hundreds or even thousands of years. Humans live in a range of habitats, and as such, we need crops that can grow in a wide variety of different environmental conditions.
Cannabis is an incredibly useful crop for humans, and a big part of that usefulness is its ability to adapt to an incredible variety of different environmental conditions, from near-Arctic cold, through the parched deserts, to the sweltering tropics.
Over centuries, people working in diverse conditions have selected, cultivated and nurtured cannabis plants that are most fit for the local environment – and during this time, local varieties of cannabis, with particular characteristics, usage and cannabinoid profile, have become established.
What Exactly Is A Landrace?
Landrace crop varieties are those that have adapted over time to local environmental conditions, in isolation from other populations of the same species, to a point where they have developed a degree of inbreeding – and typically, a range of unique characteristics.
This process is generally assisted by some selective breeding and management by humans – but unlike cultivars, landraces are generally more diverse and variable in their expression of traits, and a lot more is left up to natural selection.
Landraces are not just limited to plant species. There are plenty of different landrace dog, cat, rabbit, pig, sheep and cattle varieties across the world, just as there are landrace varieties of apple, wheat, maize, rice, and of course, cannabis.
Landraces may have developed over millennia from ancient lineages that survived in isolation, but may also develop from semi-feral populations of cultivars that have escaped from cultivation sites. Via the latter route, it may take just a hundred years or so for a landrace to develop.
Features That Characterize a Landrace
- Specific and recognisable traits, but with considerable variation between individuals
- Adapted to local environmental conditions, including climate, pathogens and pests
- Not arising from formal breeding programs
- Maintained, selected and improved less rigorously than a cultivar
- Historically isolated from other populations
- Originating in a specific geographic area, with a local name and traditional methods of usage
- May significantly alter in expression when grown in a new environment
- Usually deliver yields that are relatively consistent, but relatively low compared to cultivars
Pros & Cons of Crop Uniformity
Landraces are of crucial importance to crop-breeding programs the world over, and have been for centuries. However, modern agriculture depends far too heavily on uniform crop varieties, and due to their encroachment onto vast areas of arable land, biodiversity the world over is threatened.
The benefits of crop uniformity are obvious to farmers and breeders alike – consistent yields, appearance, flavour and growing requirements, for example. To some extent, uniform crops are expected by consumers too – most Western consumers would expect a Gala apple to taste like Gala and not Pink Lady, for example.
However, crop uniformity also brings with it great disadvantages, which often may be initially disguised. The Gros Michel banana, which was the world standard prior to the current standard Cavendish, is an excellent example.
Bananas are propagated via cuttings and not seeds. In the 1950s, large-scale banana plantations throughout Latin America began to use Gros Michel to the exclusion of all other cultivars. The Gros Michel was favourable in appearance, flavour and taste compared to other varieties, and producers rushed to replace their traditional crops with this more popular and valuable variety.
As they were propagated from clones, there was practically zero genetic variation between different plantations. Then, a fungus known as Panama disease began to take hold, to which the Gros Michel variety had no resistance. Vast swathes of plantations were wiped out in just a few years.
Now, the banana industry relies far too heavily on another genetically uniform cultivar, the Cavendish – and it may just be a matter of time before a new pathogen wipes out swathes of plantations once more.
Landrace Populations Provide a Buffer Against Disease
Cultivars are very often bred directly from landraces. In fact, this process is the backbone of commercial cannabis breeding. Cannabis seed breeders have repeatedly drawn from pools of landrace cannabis varieties the world over, and hybridised them to create unique cultivars. The more effort is put into multiple generations of careful crossing and backcrossing, the more stable and true-breeding the final variety will prove to be.
Again, this stability and uniformity has many benefits, and consumers certainly expect it within this particular industry! Most growers will praise the qualities of a well-stabilised variety while bemoaning the unreliable variation found in one that is poorly-stabilised.
However, when a disease emerges, having a diverse gene pool means there is more chance that individuals with genes for resistance exist among the population. If all individuals are identical, and are susceptible to a particular pathogen, all individuals in the population are equally at risk. As cannabis is often propagated by clones, this is a very real concern for growers the world over – but because there are literally thousands of cultivars out there, we’re a vast distance from the kind of uniformity seen in the banana industry.
Why We Must Preserve Landrace Varieties
Thus, the sheer variation that can be found within the world of cannabis is greatly important and must be preserved as well as possible. Due to this variation, breeders have been able to develop cultivars with a wide range of useful traits. For example, growers in damp parts of the world can choose varieties that are well-adapted to resist mould, those in very hot locations can choose varieties that resist high temperatures, and so on.
Given that all these useful traits found in commercial cultivars ultimately derive from landrace parents, it makes a great deal of sense to preserve landrace genepools all over the world. Not only will we therefore preserve buffers against disease, pests and so on – we may also be yet to discover variations and traits that could prove highly useful for development into new cultivars, for use in medicine, research and industry.
Thus, allowing our arable crop varieties to be reduced and reduced down to a few dozen “global” varieties is almost suicidally insane. This is not looking likely or imminent with cannabis – we have thousands of varieties and there is practically no large-scale monoculture of cannabis that compares to that of corn, wheat, cotton and so on. But nonetheless, cannabis landraces varieties do seem to be disappearing from their home environments at an alarming rate.
Where Has Cannabis Developed Into Landraces?
Wherever humans have gone in our millennia-long diaspora throughout the world, cannabis has followed. The cannabis genus is now present in every continent save Antarctica, and everywhere it has gone, it has established landraces.
The cannabis genus appears to benefit from a great deal of phenotypic plasticity – this is the quality of exhibiting a great deal of possible variation within a species or genus. Added to this, cannabis has various obvious benefits to humanity, and has been a crop of measurable importance to various world cultures over the millennia of recorded history. Thus, cannabis can express new variations in response to environmental and human pressures, and can do so with relative ease and rapidity.
Cannabis has successfully adapted to habitats in Africa, Europe, and the Americas, as well as establishing dozens of different and unique populations in its native continent of Asia. In Africa, famous landrace varieties include Malawi Gold, Durban Poison, and Swazi Gold; less well-known varieties can be found in Kenya, Tanzania, Congo and Mozambique.
In Latin America, there have been several landraces of fundamental importance to the commercial breeding industry. Panama Red, Acapulco Gold and Oaxacan are three notable strains; however, the former two are all but unknown in today’s cannabis circles.
In Europe, most cannabis landraces are fibre and seed varieties rather than high-cannabinoid varieties. As Europe is mostly in the cool temperate zones, with cold winters and mild summers, cannabinoid production is less than it is in the subtropics and tropics. However, some drug-type landraces do apparently exist, such as the Kalamata from the Peloponnese region of Southern Greece.
Where Do Threats to Landrace Varieties Come From?
The main threats to cannabis landrace populations across the world seem to be introduction of foreign genetics, government eradication programs, and habitat loss in general. Currently, threats to landrace cannabis varieties from climate change are not well evidenced, but in future, this may be another concern to consider.
There is not a great deal of research specific to the question of cannabis landrace loss. However, there is strong evidence of biodiversity loss in plant and animal kingdom in general, which has occurred in response to human activity. Furthermore, there is abundant anecdotal evidence from locals in traditional landrace habitats pointing to the degradation of local types in response to the introduction of foreign varieties.
Meanwhile, eradication programs across the world have not ceased despite the global trend towards cannabis legalisation. In the US and Australia, the federal authorities continue to conduct annual eradication programs – although there is increasing opposition to this practice from many corners.
In South Africa, government spraying programs are targeting the country’s substantial illicit cannabis fields, sometimes causing injury to local people. In the midst of the current situation unfolding around ex-President of Gambia Yahya Jammeh, Senegalese armed forces are targeting crops believed to be a source of income to Jammeh’s rebel loyalists in the conflict zone of Casamance.
In Kazakhstan, government officials are still unsure whether to utilise their vast natural cannabis resources in ways that could benefit the economy, or to continue eradication programs that are arguably an outdated remnant of the Soviet era. Kazakhstan has the largest wild-growing area of cannabis in the world, and may even be the evolutionary home of the cannabis genus – to lose this precious natural genepool would be a tragic loss both to the Kazakh ecosystem but also the humanity in general.
Fortunately, it seems that eradications have not been conducted for several years – and even in peak years, authorities found it impossible to eradicate the tenacious crop.
What Can We Do About It?
Preservation efforts for traditional landrace varieties (not specific to cannabis) are ongoing, such as those conducted by organizations such as Biodiversity International and the UK’s National Institute of Agricultural Botany. As well as this, seed repositories such as the Svalbard Institute are a crucial means of preserving seed varieties in case of future need. Furthermore, there are even some organizations dedicated to preserving cannabis varieties, such as the Vavilov Institute in Russia. Lastly, some cannabis breeders and growers have maintained extensive libraries of landrace genetics, and due to this, certain varieties can be preserved even if they are threatened in the wild.
It is wise to avoid taking foreign varieties, particularly commercial hybrids, to regions that are home to historic landraces. The preservation and maintenance of landraces depends greatly on their isolation to other populations from the same species, and although the short-term benefits of introducing uniform, high-yielding cultivars may be appealing, the long-term harm to ecosystem and biodiversity may far outweigh any advantages.