Status and impacts of invasive alien plant species in Parsa National Park, central Nepal

Any plant species that are native to one region but have been introduced into an area outside their natural distribution range where they colonize and threaten biological diversity, ecosystems and human well-beings are considered as the invasive alien plant species (IAPS), and the processes are known as biological invasions (CBD, 2002). The IAPS can display strong allelopathic properties (Rai and Tripathi, 1982), rapid vegetative growth, prolific seed production capacity (Norbu, 2004), long-lived seeds, early maturation to sexually reproductive stage, phenotypic plasticity and ability to survive in a wide range of environmental conditions (Tiwari et al., 2005). The IAPS can display several negative impacts in wide range of field such as biodiversity, ecosystems, human health and livelihood, agriculture and aquaculture, and can cause economic losses (Rai and Singh, 2020). Invasion by IAPS is often associated with out-competing native species and homogenizing ecosystems, changing hydrological characteristics, degrading gene pools through hybridization with native species resulting biodiversity loss (Miththapala, 2007; Richburg, 2008; Hui et al., 2011). These damages are aggravated by climate change (Kriticos et al., 2003), pollution, habitat loss and human-induced disturbances (Norbu, 2004; Kohli et al., 2009). The IAPS can break the plantconsumer interactions, drive population declines and species extinction (Donlan et al., 2003; Reaser et al., 2007; Dangermond et al., 2010). Status and impacts of invasive alien plant species in Parsa National Park, central Nepal