Establishment and growth of coniferous seedlings in an altered forest floor after long-term exclusion of deer

Abstract

We evaluated differences between the forest floors and the establishment and growth of coniferous seedlings in fenced (13 years) and unfenced plots on Mt Ohdaigahara where the sika deer (Cervus nippon) population density is high. Large coniferous seedlings (height > 0.05 m) were less abundant in the unfenced plot, as a result of deer browsing. Small coniferous seedlings (height < 0.05 m), however, were more abundant in the unfenced plot, where most seedlings of Abies homolepis were found on bare ground and those of Picea jezoensis var. hondoensis were found on buttresses and fallen logs. The large area of bare ground in the unfenced plot was caused by deer browsing. Deer therefore have an indirect effect on the emergence and growth of small coniferous seedlings by modifying the forest floor.

Effects of sika deer (Cervus nippon) and dwarf bamboo (Sasamorpha borealis) on seedling emergence and survival in cool-temperate mixed forests in the Kyushu Mountains

“…These findings differed from those reported by Kumar and Shibata (2007), who found that Sasa nipponica covered the forest floor and remained in its dwarf form (less than 20 cm in height) after heavy browsing by sika deer on Mt. Ohdaigahara in central Japan.…”

“…Sika deer can reduce the biomass and height of sasa (Takatsuki 1980;Yokoyama and Shibata 1998). The decrease in sasa biomass that results from sika deer browsing could facilitate seedling survival (Ito and Hino 2005), emergence, and growth (Kumar and Shibata 2007). However, such positive indirect effects of sika deer on seedlings are not always observed (Nomiya et al 2002;Ito and Hino 2004).…”

“…Previously, the effects of sika deer on sasa and seedling regeneration were investigated in forests with a low abundance of sasa and high densities of sika deer (Nomiya et al 2002;Ito and Hino 2004;Kumar and Shibata 2007). There are no reports on seedling regeneration in forests with abundant sasa and low densities of sika deer.…”

“…At high densities, deer can affect tree generation and forest understory communities both directly and indirectly (Horsley and Marquis 1983;Rooney and Walter 2003;Ito and Hino 2005;Kumar and Shibata 2007). Deer are keystone herbivores in whole ecological communities (Rooney 2001;Côté et al 2004).…”

Effects of deer browsing on the survival and growth of Abies homolepis and Picea jezoensis var. hondoensis seedlings after fencing on Mt. Ohdaigahara

“…hondoensis were found mostly on tree buttresses and fallen logs in the fenced and unfenced plots (Kumar and Shibata 2007). This is thought to depend on differences in the forest floor rather than the presence or absence of deer (Kumar and Shibata 2007;Kawatani 2006). Fig.…”