Willow trees, the life line of people in Lahaul valley, will have to be replaced with fresh stocks of superior quality of plants. The present willow wealth has been dying up in valley for about five years. Fresh seedlings are the only mantra to help grow and survive this variety forest wealth. The recommendation in this direction the Himachal Pradesh state Forest Department, has come from the Himalayan Forest Research Institute (HFRI). A team of scientists comprising pathologists, entomologists and ecology of the HFRI visited the valley in different seasons to make a study and to investigate the causes of drying up of the trees and aphid and pest attacks. In the report, which had been submitted recently, it was said that though massive attack of aphids were the main cause of drying up of the willows but global warming and planting stocks in the region had aged and their resistance to disease and pest attacks had diminished.