The following are useful measures for conserving forest except

Encouraging the use of charcoal for industrial and domestic purposes is not a useful measure for conserving forests. Charcoal production involves cutting down trees and burning them in the absence of oxygen, which releases carbon dioxide and other harmful gases into the atmosphere. This process contributes to deforestation and greenhouse gas emissions, which are major environmental issues. In contrast, the other measures listed are useful for conserving forests. Preventing and controlling accidental forest fires, combating and preventing plant diseases, reafforestation of depleted forests, and protecting young growing trees are all important strategies for maintaining the health and vitality of forest ecosystems. By reducing the loss of forest habitat and preserving biodiversity, these measures help to ensure the long-term survival of forest ecosystems and the many species that depend on them. Therefore, the correct option is encouraging the use of charcoal for industrial and domestic purposes.