In a major shift, the ecological health of national forests would be given precedence over logging and other commercial uses of the forestland in regulations proposed yesterday by the Clinton administration. The proposed rules would likely lock in or reduce the relatively low logging levels of recent years, down significantly from the astronomical logging levels in the 1980s. They also call for more public input in drawing up management plans for forests, as well as greater reliance on scientific information about the land. Enviros were generally pleased with the rules, though they were disappointed by new restrictions on appealing land-use plans. The rules will now undergo a three-month public comment period.