Effects of thinning on leaf-fall and leaf-litter nitrogen concentration in hinoki cypress (Chamaecyparis obtusa Endlicher) plantation stands in Japan

Leaf Photosynthetic Responses to Thinning

“…For example, Blanco et al (2008) found that thinning seems to affect nutrient returns mainly by reducing aboveground biomass and litterfall in Pinus sylvestris L. forests in northern Spain. Inagaki et al (2008) reported that net nitrogen mineralization in the surface soil and fresh-leaf nitrogen concentration in thinned plots was significantly greater than in control plots in two Chamaecyparis obtusa plantations in southern Japan. The increase in nitrogen mineralization rate after thinning is considered to be related to soil microbial activity, caused by changes in soil temperature and soil water content (see next section), and increases in the pool of soil inorganic nitrogen and other nutrients due to reduced plant uptake.…”

“…In contrast, stand transpiration decreases because of the reduction in number of trees per ground area (Jiménez et al, 2008;Morikawa et al, 1986). Less water consumption at the stand level results in increased soil water availability (Bréda et al, 1995;Inagaki et al, 2008;Jiménez et al, 2008;Lagergren et al, 2008). The improvement in tree water status is more significant at dry sites, in dry climates, and for species that are sensitive to soil water availability (Moreno & Cubera, 2008).…”

Stem productivity in relation to nitrogen concentration and carbon isotopic composition (δ13C) in leaves of hinoki cypress (Chamaecyparis obtusa Endlicher) plantations in Shikoku district, Japan

“…Previous studies have shown diverse relationships between soil nitrogen availability and stem productivity: positive (Pastor et al 1984;Reich et al 1997), no significant relationship (Binkley et al 2003;Zushi 2003), and high stem productivity despite low soil nitrogen availability (Joshi et al 2006;Inagaki et al 2004Inagaki et al , 2008. The reason for the absence of a clear relationship between soil nitrogen availability and stem production is not known, but the difference in soil water conditions may affect the nitrogen-productivity relationship.…”

Carbon and nitrogen status in litterfall of a red pine stand with varying degrees of damage from pine wilt disease

“…However, the inputs of C and N by litterfall depend on several ecological factors and forest management activities such as forest type, climate, site quality, stand increment, stand age, stand density, fertilization, thinning (Pedersen and Bille-Hansen 1999, Berg and Laskowski 2006, Inagaki et al 2008, Kim et al 2009, and forest disturbances such as fire and the incidence of insect pests and disease (Morehouse et al 2008, Clark et al 2010, Lorenz and Lal 2010. Disturbances such as defoliation or the killing of trees by forest insects or disease may result in changes in litterfall input to the forest floor because of reduced litter production from trees (Morehouse et al 2008).…”