Endemic Prunus species in the high Himalayas, Eastern Nepal, seeking conservation

Abstract

Prunus species play an important role in preserving the Nepal's unique identity; such as three endemic species of Prunus, Prunus topkegolensis, Prunus jajarkotensis, and Prunus taplejungnica, represent the country's local area. An ecological and social survey of P. topkegolensis and P. taplejungnica was conducted. To analyze these species' regeneration status and population structures, the density of seedlings, saplings, and adult trees were compared, and created a diameter size class diagram. The Wilcoxon signed-rank test was used to compare the average values of seedlings, saplings, and adult trees between two species. To determine the ethnobotanical importance of a species, the relative frequency of citation (RFC) was calculated for various use categories. We classified both species as trees as the average diameter at breast height (DBH) of P. topkegolensis was 19.55 ± 14.66 cm with an average height 5.05 ± 2.28 m, while that of P. taplejungnica was 14.5 ± 7.93 cm with an average height of 4.89 ± 1.66 m. P. topkegolensis had an average 32 ± 31 adult trees, 16 ± 15 saplings, and 21 ± 18 seedlings per 0.1 ha, while P. taplejungnica had 12 ± 5 adult trees, 2 saplings, and 6 ± 4 seedlings per 0.1 ha. The number of seedlings and saplings at the plot level differed significantly between species (W = 75.5, p- = 0.05, and W = 84, p = 0.01, respectively). Both had humped-shaped diameter at breast height size class distribution. However, P. taplejungnica had a more apparent hump-shaped diameter at breast height distribution than P. topkegolensis, indicating that P. taplejungnica has more unsustainable regeneration issues. P. taplejungnica was locally recognized as a separate species from P. rufa, whereas P. topkegolensis was not. P. topkegolensis have seven different use categories, with wood and fuel wood being the most frequently cited, with RFC value 1. Rapid vulnerability assessment (RVA) showed both species are having high conservation threats. In situ conservation measures are suggested to address the issue of poor regeneration and disturbances.