Distribution and ecological impact of invasive aliencalyptocarpus vialis less along an altitudinal range in north western Himalayas of Himachal Pradesh and investigating its allelopathic interference

Abstract

The invasion potential of Calyptocarpusvialis Less. was investigated in terms of its actual and predicted distributional ecology, adaptive functional biology, and allelopathy. The studies indicated that C. vialis is not only rapidly expanding its niche along an altitudinal range in the north-western Himalayas of Himachal Pradesh but also has potential to expand further in the event of climate change. The distributional studies using modeling tool revealed that ~5.6 percent of the state area can be very suitable for its occupancy. The present study also showed that the invasion of weed along an altitudinal gradient directly/indirectly affect the associated vegetation through changes in soil nutrient and chemical composition. It reduced diversity, evenness, and richness of associated species compared to uninvaded areas. The reduction in native species of the area may have serious socio-economic implications. The growth patterns of C. vialis in different types of soils indicated its strong adaptability and phenotypic plasticity which possibly aided in its invasion into new regions. Furthermore, C. vialisalso exhibited allelopathic potential which may also have contributed towards its rapid spread. The aqueous leachates and plant residues-incorporated in soil reduced the growth of test crops (Brassica nigra, Triticumaestivum, and Avenasativa) in a dose-dependent and species-specific manner. Different types of phenolic compounds were identified in the plant which may be regarded as the putative allelochemicals. Overall, the study showed that plant traits and allelopathy both facilitate the invasion of C. vialis along an altitudinal gradient as well as in different habitats. newline