Invasive alien plant species and their effect on the habitat utilization of mammal species in Shuklaphanta National Park, Nepal

Abstract

The introduction and colonization of invasive alien plant species (IAPS) is one of the most serious threat to the conservation of native flora and fauna. Such threats are noted in the various protected areas including lowlands of Nepal with negative impacts on the species and ecosystem services. The impacts of IAPS on threatened mammal species especially on their occurrences is little known. This study identified the effects of IAPS on the occurrence and habitat utilization of threatened mammal species at Shuklaphanta National Park (ShNP), Nepal from 11 November 2020 to 11 June 2021. During the study period, ShNP was categorized into IAPS invaded and non-invaded habitats. The occurrence of threatened mammal species was recorded from 210 plots of 10 m X 10 m along the line transect. Altogether 11 IAPS were recorded among seven families during this study. Among them Blue Billygoat Weed (Ageratum houstonianum) was abundant species in the study area. Altogether 25 mammal species were recorded in the study area, whereas 11 mammal species were threatened. Among the threatened mammal species, 10 species were in IAPS invaded habitat and all 11 species in IAPS non-invaded habitat. In IAPS invaded habitat, the sign of Fishing Cat (Prionailurus viverrinus) was recorded only from IAPS non-invaded habitat. The higher occurrence of threatened mammal species was recorded nearer the forest as the abundance of IAPS decreased with decreasing distance to the forest. In addition, the higher occurrence of mammal species was found with increasing the distance to water source, distance to road, distance to human settlement and distance to agricultural land as the abundance of IAPS decreased with increasing distance to water source, road, human settlement and agricultural land. The threatened mammal species utilizes the IAPS noninvaded habitat rather than the IAPS invaded habitat. For providing suitable habitat for threatened mammal species, the removal or control of the invasive alien plant species from ShNP is recommended.