Musa nanensis

Due to the limited locality information around the species, it is difficult to infer the specific impact of threats, especially for the subpopulation in Lao PDR, for which there is limited information. In both the Amphoe Bo Kluea area in Thailand and Kasi district in Lao PDR, the species is threatened by deforestation and habitat fragmentation (Swangpol et al. 2015). Across Dong Phaya, approximately 21% of tree cover has been lost since the species was last collected in 2012, and in Kasi district, 10% of tree cover was lost between 2001 and 2020. Additionally, the species has only been recorded between 679–835 m asl, and most of this deforestation has taken place below 1,000 m asl (GFW 2020). Within the Bo Kluea district, the majority of land is dedicated to cultivating maize or rice for sustenance. Often this cultivation occurs on steep gradients, increasing the likelihood of soil erosion. In combination with low PH and low fertility of soil, the harvested fields are commonly subjected to slash-and-burn agriculture in order to increase the fertility and productivity of crops. Pastoral agriculture also contributes to degradation of forest habitat (Kitchaicharoen et al. 2015). Additionally, this species is susceptible to diseases (Swangpol et al. 2017), which may be a consequence of limited genetic variation due to its small population size. However, the specific impact of deforestation on members of the Musa genus is somewhat difficult to quantify: while clear-felling or land conversion is likely to be detrimental to the species, wild bananas spring up in transient, often man-made, habitats and thus may benefit from human disturbance to some extent (Simmonds 1962). A better understanding of the ecological requirements of this species are necessary to infer the extent to which the species is tolerant of disturbed habitat.

The genus Musa is listed in Annex I of the International Treaty on Plant Genetic Resources for Food and Agriculture (ITPGRFA) which aims to guarantee sustainable agriculture and food security through the conservation and sustainable use of plant genetic resources for food and agriculture, as well as ensuring the fair and equitable sharing of the benefits arising out of their use (FAO 2009). The species is not known to be represented in formal ex situ conservation (BGCI 2020, Genesys Global Portal on Plant Genetic Resources 2020), although it has been observed growing ex situ in Chiang Mai (S. Swangpol pers. comm. 2021). The species occurs within the protected area of the Khun Nan national park, therefore, passive conservation is presumed (UNEP-WCMC and IUCN 2020). Swangpol et al. (2015) recommended that the species be categorised as Critically Endangered using IUCN Red List Criteria; however, additional subpopulations have been identified since this recommendation was made. Given the precarious status of the wild population, conservation measures including habitat protection and the banking of seed germplasm are recommended.