Dorjee1, Tony Buckmaster2, Stephen Johnson3 and Paul Downey2
1National Plant Protection Centre, Bhutan
2University of Canberra, Australia
3Department of Primary Industries, New South Wales, Australia
Very few alien plants were recorded in the ancient historical texts and publications in Bhutan prior to the end of the country’s self-imposed isolation until the early 1960s. Those species that were recorded were for sustenance (cereals and pulses) and nutrition (fruits and vegetables). The Bhutanese Government introduced many alien plants with the launch of modern economic development in 1961, however, a baseline inventory on which alien plant species were introduced and their status (i.e. cultivated, casual, naturalized or invasive) has not been created. A preliminary assessment, after reviewing the literature and consultation with government officials, revealed that the available data and information on alien plants introduced into the country were scattered across different sectors. It was also apparent that many old records would be lost if an effort was not made to collate the alien plant species data into one repository.
The baseline inventory of the alien flora of Bhutan was collated from many sources including herbarium records, published and unpublished documents, as well as global online botanical databases. I verified the data from non-scientific and unpublished reports (e.g. annual or project reports) using other published scientific papers and global online databases to minimise epistemic and linguistic ambiguities in the listing of alien plant species in Bhutan. My aim was to provide a reliable and comprehensive list of alien plant species for research, to support policy decisions and to prioritise management of potentially invasive alien plant species. I found that there was an unprecedented increase in alien plant species introduced into Bhutan, from 94 species before 1961 to 964 in 2016 (more than a ten-fold increase in alien flora). Importantly, it was noted that 88% of the alien plants in the database were intentionally introduced, indicating the potential for implementing pre-border screening and post-border management activities to minimise socio economic and environmental impact from invasive alien species in Bhutan.