LICHEN DIVERSITY AND STAND CONTINUITY IN THE NORTHERN HARDWOODS AND SPRUCE-FIR FORESTS OF NORTHERN NEW-ENGLAND AND WESTERN NEW-BRUNSWICK

The continuity of 33 northern hardwoods and spruce-fir stands in Maine, New Hampshire, Vermont, and western New Brunswick is assessed using indices of ecological continuity (IEC) that are based upon the percentage occurrence of ancient forest indicator lichen species found at each site. Stands are ranked according to decreasing IEC value, with results confirming the ancient forest status of 12 of the 15 previously investigated old-growth forest sites included in the investigation. The data also show that epiphytic lichen floras become richer over time, with older stands harboring more rare species, and suggest that the total number of Caliciales species collected at a site may, in itself, be an indicator of continuity.