Root System Development of Larch Trees Growing on Siberian Permafrost

Abstract

Below-ground processes have been highlighted in the studies of carbon flux, nutrient cycling, and biodiversity in many terrestrial ecosystems under changing climates (e.g., Chapin and Ruess 2001; Schulze 2006). So far, as tree roots are concerned, much attention has recently been paid to the study of fine roots rather than coarse roots (Brunner and Godbold 2007), since fine roots are more important biologically, such as in resource uptake and mycorrhizal association (Vogt et al. 1996; Read and Perez-Moreno 2003). This trend is aided by improvements in observation techniques and/or devices (i.e., minirhizotron, digital image analyzer) that enable us to monitor fine root dynamics (e.g., Vogt and Persson 1991; Hendrick and Pregitzer 1996; Majdi 1996; Vogt et al. 1998; Johnson et al. 2001). In contrast, individual-based root observation (i.e., root system excavation), which requires laborious and time consuming work, seems outdated today, although many classical studies indicated advantages of this approach. For example, measurement of coarse root mass is essential in the estimation of stand-level below-ground biomass and production (e.g., Karizumi 1974; Santantonio et al. 1977; Deans 1981). Also, quantitative description of the spatial patterns of root systems (e.g., rooting map) tell us characteristics of species-specific strategies under local or microscale soil conditions in natural habitats (e.g., McMinn 1963; Eis 1974; Fayle 1975a, b; Karizumi 1979; Coutts 1983; Reynolds 1983; Kuiper and Coutts 1992; Drexhage and Gruber 1998).