PLANT INVASION: DYNAMICS AND HABITAT INVASION CAPACITY OF INVASIVE SPECIES IN WESTERN INDIAN HIMALAYA

Abstract

Understanding the factors that intensify the invasion patterns across the geographic ranges is an important challenge in the effort to conserve biodiversity. In the present study we tried to establish a correlation between the exotic invasive richness with different habitat types. To achieve the goal we used Importance value Index for biodiversity assessment and established linear regression alongwith spearman’s rank correlation to testify the significant relationship between chosen habitat types and dependent variables, including exotic species richness and cover. Invasive cover from all three habitats was positively correlated with the invasive species number but negatively correlated with the total species richness and the native richness. Invasive species richness, however, was neither correlated with native richness nor the total species richness. In riparian areas a significant positive correlation was observed between invasive species richness and areas away from direct water sources than areas near water sources. Our results highlight that riparian areas despite having high native richness are more prone to plant invasion than forest periphery and highway roadsides. However, areas with increased feral cattle activity alongwith scattered cattle dung from all three habitats were also found promoting plant invasions. Our result from riparian areas thus rebuff the widespread hypothesis (rich biodiversity less invasion) proposing that migration and establishment of invasive species are likely to be based primarily on changes in propagule pressure, availability of nutrients and light and not exclusively on habitat richness.