# Diversity and Distribution Patterns of Invasive Alien Plant Species Along Dispersal Corridors in Parsa National Park, Central Nepal

## TL;DR

This study explores how invasive plant species spread in Nepal's Parsa National Park, finding that roadsides and riversides are most affected, with open canopies promoting their growth.

## Contribution

The study identifies road verges and riversides as key dispersal corridors for invasive plant species in Parsa National Park.

## Key findings

- Road verges and riversides were invaded by 70% of the recorded invasive species.
- Chromolaena odorata was the most prevalent invasive species.
- IAPS richness increased significantly with tree canopy openness.

## Abstract

Protected areas are vital for preserving native biodiversity, yet invasive alien plant species (IAPS) pose significant threats to their conservation. This study investigates how IAPS diversity varies across their dispersal corridors, such as road verges, riversides, seasonal springs, fire lines, and trekking trails, and examines the relationship between tree canopy openness and IAPS richness. We sampled 156 plots (2 m × 5 m) along these corridors in Parsa National Park (PNP), ensuring a minimum distance of 100 m between plots. Out of 10 IAPS recorded during the study, road verges and riversides were invaded by 70% of the recorded species, while the walking trail had the lowest number of IAPS (30%). The most prevalent IAPS was
Chromolaena odorata
, followed by
Mikania micrantha
and
Ageratum conyzoides
. One‐way ANOVA indicated significant differences in IAPS richness among dispersal corridors (p < 0.001). Furthermore, IAPS richness increased with increasing tree canopy openness (R = 0.8, p < 0.001). Given that road verges and riversides appeared to be the major dispersal corridors of IAPS in the context of PNP, it is imperative to prioritize these corridors for IAPS monitoring, early detection, eradication, and control. Such efforts can reduce the establishment probability of new IAPS and mitigate the impacts of the widespread IAPS on the native species and ecosystems.

Protected areas face growing pressure from invasive alien plant species (IAPS), whose distribution differs across dispersal corridors. This study reveals that road verges and riversides were the most heavily invaded areas (70% of recorded species), with
Chromolaena odorata
being the most dominant IAPS. Additionally, richness increased significantly with increasing canopy openness. These results underscore the importance of prioritizing road verges and riversides for focused IAPS monitoring, early detection, and management to safeguard native biodiversity.