Diversity of naturalized and invasive plant species across land use types in an inner Tarai Valley of Central Nepal

Abstract

Diversity of naturalized and invasive plants often vary across land use types. However, empirical studies analysing such patterns are mostly lacking at local level where management intervention are implemented. In this study, we aimed to understand if (i) the diversity of naturalized and invasive plants differ across land use types and (ii) the diversity of native species affects diversity of naturalized and invasive species. Vascular plants across five land use types were sampled in southern lowland of Nepal. Species richness was compared across land use types by one-way analysis of variance; and variations of alien species richness with natives by generalized linear model. Ordination was used to visualize the relationship between species composition and land use types. Out of 193 species of vascular plants recorded in the study area, 30 were naturalized and 13 invasive. Species richness varied significantly across the land use types. Disturbed and highly modified land use types (Shrubland, Agricultural land) had a higher number and cover of naturalized and invasive species than in relatively undisturbed Sal (Shorea robusta) forest. The richness of naturalized and invasive species declined with an increase in native species richness. Species composition varied across land use types, and a higher frequency of invasive species was found in disturbed land use types. The results suggest that regular monitoring and control of invasive species in highly invaded and disturbed land uses may help for early detection of new invasive species and prevent previously established invasive species from spreading into new habitats.