Echoes from the soil help identify poached cycads
In poaching circles, cycads are for the plant community what rhinos are for wildlife. As the illegal trade continues apace, conservationists are adding isotopic analysis to the toolkit of measures to protect trees whose lineage goes back to the time of the dinosaurs.
Written by: Leonie Joubert
Photographs by: Sam Reinders
A trained eye can spot a wild-grown cycad without much difficultly. A blackened stem is the telltale sign that it has survived many natural veld fires. A twisted stem is typical of those that have grown in stoney terrain or up a cliff face. Scarring could suggest that porcupines have fed on the plant’s tough hide.
Finding a specimen of a slow growing species which has a long stem, like the Eastern Cape blue cycad (Encephalartos horridus), will almost certainly suggest that the plant has been taken from the wild.
‘If you find someone with a two-metre-long plant, which might have taken about 600 years to grow, it’s quite questionable, right?’ says Zwelakhe Zondi.
Zondi is a zoologist by training, and now works as a technician with the South African National Biodiversity Institute (SANBI) biodiversity research assessment and monitoring (BRAM) unit which does scientific research and monitoring of traded species and those that occur in the wild, amongst other things.
Zondi’s work involves auditing cycads at nurseries as part of the international permitting system, for trading in such plants, and also surveys certain priority populations in the wild.
Cycad poaching continues apace. In the past 10 years — about the time Zondi has been working in the cycad conservation, and almost a quarter of the 38-year-old’s life — one more South African cycad species has joined the list of cycads that are classified as extinct in the wild. This means that the only living individuals or populations of a species are either growing outside of their natural distribution after being established at a non-native site through human intervention or are in private collections and nurseries.
Conservation agencies and government are using two new technologies to respond to the threat of cycad poaching. The first is the use of micro-dot paint, something developed by the security industry as an anti-theft method for vehicles and is usually applied to car parts as a tracing mechanism.
This involves spraying wild cycads in the field with a substance that is invisible to the naked eye, and which becomes visible if a certain kind of light is applied. If law enforcement seizes a plant specimen that’s suspected of being poached, they can scan it for signals of the paint. If found, the micro-dot information will say precisely where the plant was tagged in its wild location.
But now, looking at the isotopes in a plant can help with the sleuthing necessary to determine if a cycad has been poached, and from where, in order to build an even stronger criminal case against a suspected poacher.
Keeping and transporting any kind of cycad is a restricted activity in South Africa, no matter how common the species. Even plants that are private- or nursery-grown and bought are subject to strict permitting conditions. Sometimes people operating in the illicit trade will try to pass off a poached cycad as being a legally obtained nursery plant.
How the element of strontium helps build a criminal case
Zondi says there are a few ways that law enforcement can compile evidence in a cycad poaching case. Identifying the species is the first starting point. For instance, if the seized plant is an Eastern Cape giant cycad (Encephalartos altensteinii), law enforcement will know that it’s from a specific region of the Eastern Cape where it is endemic. Although, if a plant doesn’t have leaves, identification is tricky. Should law enforcement find micro-dot paint, this will allow them to link a plant back to a wild location, and most likely a vulnerable population as these are the plants that have been prioritised for micro-dot marking.
Isotope analysis is a new relatively technology that can add another layer of evidence — and in this case, law enforcement can turn to the element of strontium on the periodic table for help.
Strontium occurs naturally in soils, and the kinds of strontium isotopes will vary across the country, depending on the makeup of the rock and geological processes at play.
As plants growing in an area, they draw nutrients and chemicals up from the surrounding soils, which will show up as specific isotopic fingerprints in the plant’s tissues. This is like a marker pin on map. By looking at the kind of strontium isotope present in a seized cycad, scientists can match the plant with a likely area of origin.
‘It is particularly helpful for plants that have been poached years or even decades ago, as the old tissue in a plant will always carry the strontium signature from the wild,’ explains Michele Pfab, scientific co-ordinator at SANBI’s BRAM division.
This kind of information can also help authorities identify poaching hotspots and adjust anti-poaching methods accordingly.
For strontium isotopes to be an effective forensics tool, though, authorities need to know what the lay of the land is: they need a comprehensive strontium isotopic map that spans natural cycad country, and researchers are working on that. A map is expected to be completed in late 2025.
In the meantime, Pfab says that they have made good headway on building a strontium isotope forensic database for all South African cycads occurring in the Eastern Cape, Kwa-Zulu Natal, Gauteng, Mpumalanga, and Limpopo.
Even though this map and database aren’t yet complete, what researchers have can be enough to help build a criminal case.
‘Provided we have around five samples for a wild cycad population we can link a cycad back to the population it came from. In one case we could even link it back to the slope it was growing on. It all depends on the variability of the strontium isotopes in the site,’ she says.
In 2013, law enforcement seized Lebombo and Alexandria cycad plants (Encephalartos lebomboensis and E. arenarius) which the owner claimed were legally obtained specimens. The prosecuting case was built by first establishing the age of the plants using carbon dating technology, which looks at the carbon-14 isotopes in the plant tissue.
Samples were then taken from the trunk ‘scars’, the stubs left on the stem after a plant has shed its old leaves. Isotopes from the top of the stem clearly showed that the plant had grown in a domesticated location in the years preceding its confiscation, but that it had grown in a very different location prior to that, and most certainly in the wild.
Strontium isotope fingerprinting is a relatively new technology for tackling cycad poaching, but Zondi is hopeful that it will add to successful conviction rates in future.
Conservationists are now also exploring how the same technology can be used to address the poaching of succulents in the Richtersveld, in the drier western part of the country, where theft of plants from the wild has increased dramatically in recent years.
After his years in this work, Zondi says there are clearly three kinds of people behind cycad poaching.
‘You've got the dodgy nursery owners who want specific plants,’ says Zondi.
Then there’s the shady collector, who wants a plant for the bragging rights. The rarer a plant, the better the trophy value.
‘Then there’s the naive person who might buy a cycad from someone on the side of the road,’ says Zondi. ‘They think they’re contributing to the conservation of cycads, when actually they’re not. The seller will just go out and collect more to sell, so they’re perpetuating the trade.’