Environmental Factors Affecting Growth of <I>Cerasus jamasakura</I> and <I>Padus grayana</I> in a Sub-urban Secondary Forest

Abstract

Cerasus jamasakura and Padus grayana are wild cherry species indigenous to Japan. These wild cherries have high values in secondary forests. However, their population declines due to forest degradation are concerned recently in suburban areas. To collect fundamental information on forest ecology, we conducted an assessment on all woody stems in a 2.21 ha research plot in a secondary forest of the suburban area of Nara, Central Japan in 2006 and 2011. Basal area increment (BA) during 2006 2011, was calculated for each wild cherry species, based on the measurement of stem diameter at breast height in 2006 and 2011. Through the development of growth prediction models using BA and its natural logarithm as objective variables, we examined the growth of the wild cherries as affected by environmental factors such as indices of neighborhood competition and topography (index of convexity, slope position and slope azimuth). The decrease in stem density and sum of basal area of C. jamasakura and P. grayana decreased from 2006 until 2011 and the highest frequency of both species in the smallest BA class suggest that the population decline of these species in this site. Our results indicate that a model with a competition index used as an explanatory variable predicted the C. jamasakura growth well (R 2 0.54) and that their growth are significantly affected by the neighboring competitive trees. In contrast, a model developed for P. grayana didn t perform well (R 2 0.17), while suggests that there are other factors that affect the P. grayana growth.

Comparing Rates of Rock Weathering and Soil Formation between Two Temperate Forest Watersheds Differing in Parent Rock and Vegetation Type

“…This estimation error may be attributed largely to the vegetation effect which has not been assessed in this study; neither has it been done in the previous studies (Wakatsuki & Rasyidin 1992, Wakatsuki et al 1993, Rasyidin & Wakatsuki 1994, Huang et al 2013. Although the vegetation in MKW has most likely been a steady state thanks to the protection from logging and hunting over the centuries, the one in YHW might be still in transition because it had been maintained under anthropogenic disturbance and exploitation (e.g., collection of fuel wood) until around 1970 (Tabata et al 2016(Tabata et al , 2017. The larger estimation error indicated by the larger difference between RMS and TAE in YHW than that in MKW might be derived from vegetation.…”

“…The vegetation type at MKW is a primary evergreen broadleaf forest consisting predominantly of Castanopsis cuspidate, Quercus salicina, Q. acuta, Q. sessilifolia, and Q. glauca (Shimoda et al 1994, Maesako et al 2007. On the other hand, YHW is covered by a secondary semi-deciduous forest, a mixed stand of deciduous broadleaf trees, e.g., Q. serrata, Q. acutissima, and Clethra barbinervis, and coniferous trees, e.g., Cryptomeria japonica and Chamaecyparis obtusa (Tabata et al 2016(Tabata et al , 2017. This vegetation type is often referred to as Satoyama forest in Japan, which indicates a semi-natural forest or a wooded hill nearby a village or residence (Takeuchi et al 2002).…”