Impact of invasive plants on the structure and composition of natural vegetation of Timli range, Dehradun.
Invasive species are a major component of changing patterns of biodiversity around the world. The species that modify the habitat in a major way by preventing the establishment of other species over the long term will themselves generate major shifts in biodiversity. If not checked at this juncture, will affect not only the biodiversity alone but the whole ecosystem. During the past three decades, because of increased pace of development and interference of humans through introduction of invasive exotics, the ecology of the Timli range has changed tremendously. Ragweed (Parthenium hysterophorus), goat weed (Ageratum conyzoides) and lantana (Lantana camara) - the three exotics from South America have caused much harm in the area, because of their invasive potential. A study conducted to assess the changes in the structural composition and dynamics of the vegetation shows that density and diversity of the native flora were adversely affected because of invasion by these exotics. As all the three exotic weeds are known to exhibit allelopathy, it might be one of the major non resource based hypothesis for the successful invasion by these exotic species.