Longevity of tall tree species in temperate forests of the northern Japanese Archipelago

ABSTRACT The longevity of tall tree species is an essential variable for understanding the dynamics and structure of forest ecosystems. However, it is difficult to accumulate sufficient observations on the mortality of mature individuals in natural populations to obtain a general longevity index. Therefore, we applied a statistical method based on annual ring-count data for approximately 1,700 large-diameter trees from 42 tree species to estimate an age limit for each species. The estimated attainable age varied widely among species, with the longest-living group (approximately 700 years) that included Aesculus turbinata, Kalopanax septemlobus, and Quercus crispula reaching seven times the lifespan of the shortest-living group that included Populus suaveolens, Betula platyphylla, and Cornus controversa. Fagus crenata, the dominant climax species in the region, had moderate longevity. Longevity was not necessarily linked to the regeneration strategy of pioneer species, which are highly shade intolerant during seedling establishment, as many long-lived species also exhibited pioneer-species-like regeneration. Although longevity varied greatly within some genera such as Betula, we detected a phylogenetic influence on longevity across a wide range of taxa. A comparison of longevity among common taxa in the northern Japanese Archipelago and North America showed that each taxon had similar longevity in both regions. These findings imply that the longevity of the tree species examined in this study is phylogenetically fixed, and that the longevity of each component species has similar effects on forest dynamics in forest communities in both regions, each of which contains many closely related species and has similar species compositions.