The spatio-temporal forest patch dynamics inferred from the fine-scale synchronicity in growth chronology

Abstract

Question: Abrupt increments in tree radial growth chronology are associated with gap formations derived from disturbances. If a forest has been primarily controlled by fine‐scale disturbances such as single tree‐fall, do these release events spatio‐temporally synchronize at a fine scale such as 10 m and 5 years? Is it possible to quantify spatio‐temporal patterns of synchronicity from tree rings and long‐term inventories, and associate them with spatial forest patch dynamics? How and to what extent can we reconstruct the fine‐scale synchronized growth and spatio‐temporal forest patch dynamics from currently available information? Location: Cores were taken from Abies sachalinensis trees in a coniferous/deciduous mixed forest in the Shiretoko Peninsula, Hokkaido, northern Japan. Methods: We first eliminated short‐term fluctuations and highlighted growth trends over the mid‐term using a time‐series smoothing technique. This helped identify release events, we then conducted fine‐scale spatial analyses on released A. sachalinensis primarily with cluster analysis. Results: We specified the unit scale of synchronicity at 10 m, and classified released A. sachalinensis trees into spatially separated regions. Only once during the recent 50 years was extensive synchronicity over 40 m found. Most of the released A. sachalinensis were isolated, with non‐released A. sachalinensis present in nearby, implying imperfect synchronization. The ambiguous 20–30 m A. sachalinensis patches present in the current forest were the result of connected and overlapping patches smaller than 10 m associated with different disturbances and different responses of understorey trees. Conclusion: Tree‐ring series, long‐term census and fine‐scale spatio‐temporal analyses revealed that this forest community has been controlled by two types of disturbance: frequent small disturbances such as single tree‐fall and less frequent multiple tree‐falls.

Individual‐based approach to the detection of disturbance history through spatial scales in a natural beech‐dominated forest

“…The limitation of noise that resulted from different responses of neighbouring trees to disturbance was resolved by Shimatani & Kubota (). They used 386 tree cores on 2.25 ha (Japanese).…”

Local range boundaries vs. large‐scale trade‐offs: climatic and competitive constraints on tree growth

“…Conversely, asynchronous growth suggests that local factors (pathogen attack, mechanical damage, changes in competitive environment) drive growth fluctuations for individual trees (Ettinger et al . ; Shimatani & Kubota ; Shestakova et al . ).…”

“…Synchronous growth fluctuations across all trees in a population suggest that broad-scale factors, likely climate, drive growth fluctuations. Conversely, asynchronous growth suggests that local factors (pathogen attack, mechanical damage, changes in competitive environment) drive growth fluctuations for individual trees (Ettinger et al 2011;Shimatani & Kubota 2011;Shestakova et al 2016). Other broad-scale factors that may influence all trees in a population, such as soil parent material and nutrient availability, should influence mean growth without synchronising growth year to year across trees.…”

What Happens after the Gap?— Size Distributions of Patches with Homogeneously Sized Trees in Natural and Managed Beech Forests in Europe

“…In addition, it requires huge resources to determine the age of trees on such large areas, while tree sizes provide sufficient guidance for the management of uneven-aged forests (Schütz, 2001). Nevertheless, the probability of finding neighbour trees of the same size with precisely the same age in uneven-aged forest is not high, especially in older stages (Shimatani & Kubota, 2011). Therefore, a group of trees of the same size class is not equal to a cohort sensu Oliver and Larson (1996) or others.…”