Regeneration of a Coastal Pine (Pinus thunbergii Parl.) Forest 11 Years after Thinning, Niigata, Japan

Abstract

To examine the effects of thinning intensity on wind vulnerability and regeneration in a coastal pine (Pinus thunbergii) forest, thinning with intensities of 20%, 30% and 50% was conducted in December 1997; there was an unthinned treatment as the control (total 8 stands). We re-measured the permanent sites to assess the regeneration characteristics 11 years after thinning. In the 50% thinned stand, seedlings aged from 2 to 10 years exhibited the highest pine seedling density and growth. The age composition ranged from 1–3 years with densities of 9.9 and 5.1 seedlings m−2 in 30% and 20% thinned stands; only 1-year-old seedlings with a density of 6.1 seedlings m−2 in the unthinned stand. Similar trends were found for the regeneration of broadleaved species such as Robinia pseudoacacia and Prunus serrulata. We speculate that the canopy openness and moss coverage contributed to the regeneration success in the 50% thinned stand, while the higher litter depth and lack of soil moisture induced the regeneration failure in the unthinned stand. The stands thinned at 20% or 30% were less favourable for pine regeneration than the stands thinned at 50%. Therefore, thinning with less than 30% canopy openness (20% and 30% thinned stands) should be avoided, and thinning at higher than 30% canopy openness (50% thinned stand, approximately 1500 stems ha−1 at ages 40–50 years) is suggested for increasing regeneration in the coastal pine forest. The implications of thinning-based silviculture in the coastal pine forest management are also discussed. The ongoing development of the broadleaved seedlings calls for further observations.

Effects of Age and Stand Density of Mother Trees on EarlyPinus thunbergiiSeedling Establishment in the Coastal Zone, China

“…Due to few thinnings which lead to high stand density and low light intensity in the forest, the natural regeneration of the light demanding species P. thunbergii becomes very difficult [29–31]. Litter demonstrates negative effects on the regeneration [30, 31], which was similar to P. pinea natural regeneration [33]. Grass cover did not affect the survival and growth of the seedlings [30].…”

Effects of sand burial and overstory tree age on seedling establishment in coastal Pinus thunbergii forests in the northern Shandong Peninsula, China

“…Determining how to regenerate coastal P. thungergii forests without altering current forest structure and composition and interrupting its protective function is crucial in coastal forest management (Zhu et al 2003(Zhu et al , 2012. Dense canopies, low soil moisture and thick litter and duff on the ground have long been believed to be the primary factors that hamper the regeneration of P. thungergii (Zhu et al 2012).…”

“…Dense canopies, low soil moisture and thick litter and duff on the ground have long been believed to be the primary factors that hamper the regeneration of P. thungergii (Zhu et al 2012). However, recent studies found that few seedlings were found in stands near the shoreline, despite having greater light intensity (Zhang et al 2009).…”

“…forests are the most important coastal protection forests in the Japanese islands and Shandong peninsula, China. They provide multiple benefits in mitigating the effects of natural disasters, stabilizing shorelines and sustaining biodiversity (Taniguchi et al 2007, Hayasaka et al 2009, Zhu et al 2012. Because of the harsh environment, coastal forests are vulnerable to disturbances.…”

PCR-Mediated Detection of Endophytic and Phytopathogenic Fungi from Needles of the Japanese Black Pine, <i>Pinus thunbergii</i>

“…), an evergreen species, is distributed along the seacoasts of Japan and South Korea. In addition, the Japanese black pine has been planted not only along seacoasts as a windbreak (Zhu et al, 2012) and to prevent soil erosion due to its resistance to salt (Townsend & Kwolek, 1987) and various environmental stresses (Tsukahara et al, 1985), but also in public parks and gardens due to its beautiful appearance and toughness. Japanese black pines have been popular in Japan as both garden trees and bonsai (Chan, 2014).…”