title: Can stable isotopes and radiocarbon dating provide a forensic solution for curbing illegal harvesting of threatened cycads?
abstract: Cycads in South Africa are facing an extinction crisis due to the illegal extraction of plants from the wild. Proving wild origin of suspect ex situ cycads to the satisfaction of a court of law is difficult, limiting law enforcement efforts. We investigated the feasibility of using multiple stable isotopes to identify specimens removed from the wild. Relocated and wild specimens from two species in the African genus Encephalartos (E. lebomboensis and E. arenarius) were sampled. (14) C analysis indicated that a ± 30-year chronology could be reliably obtained from the cycads. For E. arenarius, pre-relocation tissue was consistent with a wild origin, whereas tissue grown post-relocation was isotopically distinct from the wild for (87) Sr/(86) Sr and δ(15) N. For E. lebomboensis, δ(34) S, δ(18) O, and (87) Sr/(86) Sr were different between relocated and control plants, consistent with the >30 years since relocation. Our findings demonstrate the potential for a forensic isotope approach to identify illegal ex situ cycads.
authors.affiliation: Department of Biological Sciences, University of Cape Town, Private Bag X1, Rondebosch, Cape Town, South Africa.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Retief
authors.forename: Adam G
authors.initials: AG
authors.lastname: West
authors.forename: Michèle F
authors.initials: MF
authors.lastname: Pfab
mesh_terms: D001901:Botany; D002250:Carbon Radioisotopes / Q000032:analysis; D003132:Commerce; D003415:Crime; D056727:Endangered Species; D044707:Forensic Sciences; D007856:Lead Radioisotopes; D009590:Nitrogen Radioisotopes; D018515:Plant Leaves / Q000737:chemistry; D025341:Principal Component Analysis; D013326:Strontium Radioisotopes; D013462:Sulfur Radioisotopes; D032481:Zamiaceae / Q000737:chemistry*
chemical_list: D002250:Carbon Radioisotopes; D007856:Lead Radioisotopes; D009590:Nitrogen Radioisotopes; D013326:Strontium Radioisotopes; D013462:Sulfur Radioisotopes
keywords: Encephalartos; South Africa; conservation; forensic science; illicit trade; poaching; provenance; radiocarbon dating; stable isotope analysis; strontium