Invasiveness traits help Amaranths to invade Kashmir Himalaya, India

Abstract

Several alien plant species have been introduced into Kashmir Himalaya from different regions of the world and subsequently some of these have been able to colonize and become invasive. Why only some species among the alien species pool establish as strong invaders represents a fundamental question for invasion ecologists. Trait comparisons of invasive with less/non-invasive congeners help in understanding the role of various trait differences in invasion success. In this study, we investigated the differences in various phenological, physiological and morphological traits in three alien plant congeners (Amaranthus blitum Linn., A. caudatus Linn. and A. spinosus Linn.) which differ in their invasion status, and attempted to relate the trait differences to their differential invasion potential in Kashmir Himalaya. The results revealed that the more aggressive behavior of A. caudatus in contrast to other two congeneric species is more likely explained by its early and longer germination period, shorter pre-reproductive period, early and extended flowering period, shorter generation time, early life cycle completion, fast growth, high reproductive allocation, more height, inflorescence length and higher seed production. We expect this knowledge to yield theoretical as well as practical information, about the possible adaptive traits employed by the three alien species, to target their long term management in the Kashmir Himalaya.