Stand structure and composition of a 60-year-old larch (Larix kaempferi) plantation with retained hardwoods

Abstract

Tree retention is understood as a key practice in creating complexity, leading to heterogeneity in resources and habitats in managed stands. In this article, we clarify the long-term effects of tree retention on stand structure and tree-species composition in a 60-year-old Larix kaempferi plantation in central Japan. In our study plot (1.5 ha) there were 18 stems/ha of retained trees (determined by tree-ring analysis), mostly Quercus crispula. We conducted spatial analyses and tested the hypothesis that tree abundance, size structure, and species composition and diversity change with distance from the retained trees. Near the retained trees, L. kaempferi showed a reduction of 40%-60% in basal area, due presumably to the shading effect. In contrast, the nearby area showed greater species diversity in the canopy layer. The retained trees created patches of different species composition in the understory. The spatial gradient of shade and colonization opportunity provided by retained trees greatly affect the distribution of the colonized species, according to their shade tolerance and seeddispersal ability, which resulted in the stand structure with a heterogeneous shrub-layer vegetation. Retention proved particularly important for the enhancement and long-term maintenance of structural and compositional complexity in L. kaempferi plantations.

Broad-leaf species composition in Cryptomeria japonica plantations with respect to distance from natural forest

“…Sapling diversity, on the other hand, did not show any significant trend. Species diversity in forest plantations has been shown to be affected by several factors such as stand age, herbivory, soil moisture, insolation, gap formation/size, and community assemblage (Battles et al, 2001;Kodani, 2006;Sakai et al, 2006;Utsugi et al, 2006;Yoshida et al, 2005). Sapling diversity in the sites we studied may be more dependent on one or more of these factors and not just simply distance from source.…”

“…Many plantations are even-aged monocultures that have low value for wildlife (Hansen et al, 1991;Nagaike, 2000) and present problems such as soil surface runoff (Kajihara et al, 1999), snow damage (Masaki et al, 2004), high soil acidity (Yamashita et al, 2004), and susceptibility to pests (Kamata, 2002). As such, although different plantation management approaches have been undertaken, the consensus is that they should evaluate, conserve, and enhance species diversity and composition (Kodani, 2006;Masaki et al, 2004;Nagaike, 2000;Sakai et al, 2006;Utsugi et al, 2006;Yoshida et al, 2005).…”

How many broadleaved trees are enough in conifer plantations? The economy of land sharing, land sparing and quantitative targets

“…Yoshida et al . () examined the stand structure of a 60‐year‐old larch Larix kaempferi plantation with retained broadleaved trees (mostly Quercus crispula ) in central Japan. Retained trees (larger than 40 cm d.b.h.)…”

“…The major additional costs would be shading effects of the retained trees on the planted coniferous trees (Rose & Muir 1997). Yoshida et al (2005) examined the stand structure of a 60-year-old larch Larix kaempferi plantation with retained broadleaved trees (mostly Quercus crispula) in central Japan. Retained trees (larger than 40 cm d.b.h.)…”

Estimating the distribution characters of Larix kaempferi in response to climate change

“…The successful introduction and cultivation of plant species depends on the availability of environmental conditions suitable for its growth (Huang et al 1996). In recent years, studies on L. kaempferi forests have been conducted on the physical and chemical properties of soil (Kotani et al 2019), the growth processes and structural fea-tures of stands in different areas (Yoshida et al 2005, Fukatsu & Nakada 2018, the characteristics of the understory plant diversity (Li et al 2016), and the productivity and ecological adaptability (Chen et al 2015). However, the effects of climate change on the distribution of L. kaempferi have not been documented.…”