DOI: 10.5061/dryad.tx95x6b3q
title: Grow or die: A 49-year growth history of a Japanese warm-temperate tree species

description: The growth trajectories of trees are not fully understood due to their
 long lifespan. We characterized the population dynamics of the canopy tree
 Castanopsis cuspidata (Thunb.) Schottky in a Japanese warm-temperate
 forest over 49 years (1966–2015). Our study was initiated approximately 50
 years after our study site was clear-cut. The forest had a closed canopy
 for the first 23 years of the study. Strong typhoons in 1991 and 1993
 seriously damaged the forest, and since then the forest has been
 recovering from these disturbances. The diameter distribution of this
 species was bell-shaped in 1966, suggesting that the trees emerged
 simultaneously after the clear-cut in the 1910s, and the recruitment of
 trees has remained unchanged since then. The lack of recruitment of C.
 cuspidata before the typhoon disturbance supports this conclusion.
 Assuming that the C. cuspidata trees in 1966 were cohorts that were
 established soon after the clear-cut, the size differences reflect
 differences in growth rate, with small trees corresponding to slow growers
 and large trees corresponding to fast growers. Before the typhoon, slow
 growers had low survival, and the mortality rate of fast growers was low.
 Many fast growers were uprooted or snapped by strong winds by the
 typhoons. However, their mortality rate did not differ from that of slow
 growers because many slow growers were killed by large fallen trees. The
 growth of some slow-growing survivors increased after the typhoon, which
 allowed them to rapidly reach the canopy. Therefore, the typhoon altered
 the distribution of canopy trees among slow and fast growers. Survivors
 experienced faster growth than trees that died during the census period,
 suggesting that growth rate provides a robust indicator of future
 survival. Before the typhoon, the survival of fast growers was higher than
 that of slow growers. This suggests that fast growers disproportionally
 contribute to reproduction compared with slow growers. However, no
 recruited tree was observed in this subperiod, suggesting that fast
 growers made no contribution to reproduction. Fast growers might not play
 a more significant demographic role than slow growers in this species.
description: This study was performed in a
 warm-temperate evergreen forest in Minamata, Kyushu, Japan (33°19’ N,
 130°80’ E, 400 to 637 m above sea level). A 33-ha secondary forest at our
 study site was designated as a forest reserve for the conservation of
 genetic resources for timber trees by the Japanese government. The forest
 is dominated by the evergreen broad-leaf trees
 <em>Castanopsis cuspidata</em>, <em>Quercus acuta</em> (Thunb. ex
 Murray), <em>Q. salicina</em> (Blume), and <em>Machilus
 thunbergii </em>(Sieb. et Zucc.), which regenerated after the
 clear-cut between 1910 and 1920 for charcoal production. Therefore, the
 trees in the forest were established after the clear-cut from coppices,
 dispersed seeds, or soil seed banks. <em>Castanopsis
 cuspidata</em> is a
 common evergreen broad-leaved tree species in Japanese warm-temperate
 forests. <em>Castanopsis cuspidata</em> grows to approximately
 20 m tall and over 100 cm in dbh. Within the forest, a permanent plot of 40 m × 40
 m was established in 1966 approximately 50 years after the clear-cut for
 studies of the International Biological Program, and it has been monitored
 since then. Thus, 49 years of data were collected. All tree stems with
 dbh ≧ 4.5 cm were monitored in the plot. These stems
 were tagged, mapped, and identified, and dbh measurements were taken.
 Instances in which trees had multiple stems because of coppice
 regeneration were noted. All trees inventoried in previous censuses were
 remeasured to estimate growth and mortality rates. Trees were recorded as
 recruits, and their size was measured when new trees reached dbh
 ≧ 4.5 cm during the census period. Censuses were
 conducted in 1966, 1989, 2001 and 2015.
description: # Grow or die: A 49-year growth history of a Japanese warm-temperate tree
 species --- ## Description of the data and file structure File name:
 dynamics.xlsx Column headers: year Rows: The diameter of the stem at
 breast height (dbh, 130 cm from the ground) in 1966, 1989, 2001, and 2015
 are shown in cm. dead = trees that died