ORNAMENTAL PLANTS FOR ENVIRONMENTAL MANAGEMENT AT ROADSIDES IN KATHMANDU VALLEY, NEPAL

Abstract

Plant species growing along roadsides in Kathmandu gives the development which is necessities of the good environment. This study determines plantation, coverage, leaves condition of important ornamental species at different sites of Kathmandu. Many Plant species are growing and applicable for bio-indicator and maintaining greenery. Bougainvillea glabra, Callistemon citrinus, Duranta erecta, Euphorbia pulcherrima, Jasminum mesnyi, Lagerstroemia indica, Malvaviscus penduliflorus, Nerium oleander and Rose indica are documented. The heavily polluted sites shows dominance of C. citrinus 73.33±2.08 and  N. oleander has 73.7±1.6. The coverage of C. citrinus, D. erecta, J. mesnyi, L. indica and N. oleander has been observed as excellent along the roadside. However B. glabra, E. pulcherrima, M. penduliflorus and R. indica are seen at some places. These trees have the capacity to absorb carbon dioxide and reduce pollution levels. The study sites are heavily, moderately and less polluted sites. Plants in the period of study (2017 to 2022) from the observation and comparison are in further development. Elements analysis of soil and leaves are from ICP-OES (Inductively coupled plasma-optical emission spectrometry) were done. Subsequently, following elements Aluminium, Barilium, Cadmium, Cobalt, Chromium, Copper, Iron, Manganese, Nickel, Lead, Vanidium and Zinc were determined. The dust deposition on plants, chlorophyll content and anatomy of N. oleander was with less deposition of dust and chlorophyll values is increased (0.001547±0.000788 and 2.397±0.299). The stomata and stomatal index of C. citrinus are calculated (33.607± 4.509 and 15.699± 0.898). Evergreen and broad leaf trees have advantageous in environment. The summer in Kathmandu is gorgeous with L. indica flowers while flowers of C. citrinus and N. oleander observed in all seasons of the year. The success programs are recommended from the authority that is evaluated and continued for long term benefit.