Basal area growth and mortality of Betula maximowicziana affected by crown dieback in a secondary forest in Hokkaido, northern Japan

Abstract

Since the late 1990s, decline of B. maximowicziana Regel has been observed in mature secondary forests in various parts of Hokkaido, northern Japan. To develop a method of thinning for large-timber production of B. maximowicziana, we measured basal area growth and the mortality of 217 trees during a four-year period (1999)(2000)(2001)(2002)(2003) in a 90-year-old secondary forest with serious tree damage. We analyzed growth and mortality in relation to the degree of crown dieback (DC), symmetric and asymmetric competition from neighbors, and initial tree size. Individual basal area growth decreased with increasing DC, with increasing symmetric (two-sided) competition, and with decreasing initial tree size. During the four-year period, 4.1% of the observed trees died. Logistic regression analysis revealed that mortality rate increased with increasing DC and with increasing symmetric competition. These results suggest that both growth and mortality rates were affected by the same factors (i.e., DC and symmetric competition). We concluded that the resource for which individuals were competing at the study site was underground, most likely water. Modeled growth and mortality rates can be used to improve the management of damaged forests. A management plan for the damaged study site is proposed.

Competition as a predisposing factor of crown dieback in a secondary forest of Betula maximowicziana in Hokkaido, northern Japan

“…Our results, along with those of Ohno et al (2009), demonstrate a process of monarch birch crown dieback to death in the study stands as follows:…”

“…Since the late 1990s, considerable mortality has been observed following development of crown dieback symptoms in canopy trees of 90 to 100-year-old Betula maximowicziana Regel (monarch birch)-dominated secondary forests in parts of Hokkaido (Hon-ami et al 2000;Terazawa et al 2001;Watanabe et al 2002;Ohno et al 2009). These losses have caused serious management problems because monarch birch is a commercially important tree (Mukaide 1985;Hatakeyama 2004); accordingly, since the late 1960s, many of these forest stands have been managed through repeated thinning to produce large timbers (Hokkaido Government 1979).…”

“…Based on stem analysis data from 29 trees, Hon-ami et al (2000) found that monarch birch in another region of Hokkaido underwent growth reduction 40 years before the occurrence of crown dieback, but they did not analyze quantitatively the relationship between crown-dieback probability and growth rate. We previously analyzed the effect of crown dieback on subsequent growth and survival (Ohno et al 2009); here, we examine the relationship between basal area growth rates prior to crown dieback and crown-dieback probability.…”

Climate change and oak growth decline: Dendroecology and stand productivity of a Turkey oak (Quercus cerris L.) old stored coppice in Central Italy

“…It is likely that coppices are characterized by a closer link between stems, for instance through root connections (anastomosis), making growth-climate relationships more homogeneous over a region. Furthermore, competition for water is symmetric (see the case of declining Betula maximowicziana, Ohno et al, 2009), hence it can synchronize growth rates among size classes and population cohorts. In our study, this mechanism would also explain the ∼30% reduction in productivity (about 2-3 m 3 ha −1 y −1 ) experienced by stems of different size, age, and sociological status during the drought of the last decade.…”

Indicadores del decaimiento en bosques de Nothofagus pumilio en el norte de la Patagonia, Argentina

“…A su vez, estos procesos incrementan la susceptibilidad al ataque de plagas, enfermedades u otros factores que contribuyen o inducen la muerte de los árboles, tal como lo indica el modelo en espiral de eventos en cascada propuesto por Manion (1981Manion ( , 2003. Si bien el deterioro sanitario de las copas de los árboles ha sido asociado con ritmos lentos de crecimiento, son pocos los estudios que relacionan en forma comprensiva la condición externa de los árboles con los patrones de crecimiento radial (Dobbertin, 2005;Ohno et al, 2008). Por un lado, es necesario conocer estas relaciones para comprender mejor los procesos de decaimiento y mortalidad, pero, a su vez, resulta útil y práctico poder establecer cuáles son los indicadores externos más confiables para estimar la intensidad del decaimiento de un rodal.…”