Effect of Elevation and Latitude On Spring Phenology Of Rhododendron at Kanchenjunga Conservation Area, East Nepal

Mountainous terrain in the East corner of Nepal is a good location for phenological studies. Spring phenology in Rhododendron arboreum Sm. was monitored around the Ghunsa river valley in Kanchenjunga Conservation Area of Nepal. Observations were carried out following
the crown density method; flowering events of the selected species were recorded in 15-days interval. Flowering activity including duration
of flowering and synchrony were determined. In addition, expected difference in flower onset time in two consecutive monitoring plots was
determined. Elevation, latitude and longitude were regressed against the flower onset to determine the effect of each variable on flower onset.
Delay in flower onset along with rise in elevation, North latitude and West longitude was found in the results of the regression. Full bloom
phase was found highly synchronized throughout the elevation gradient with contraction of flowering duration. High synchrony also
indicates that the reproductive timing might plastic enough to cope with short-term change in environment.