Publications by authors named "Toko Tanikawa"
Pyrola japonica, a member of the family Ericaceae, is a mixotroph that grows on forest floors and obtains carbon (C) from both its photosynthesis and its mycorrhizal fungi. Its mycorrhizal community is dominated by Russulaceae. However, the mechanism of its C acquisition and its flexibility are not well understood.
View Article and Find Full Text PDFLeachate from decaying root and leaf litter plays crucial roles in soil biogeochemical processes in forest ecosystems. Unlike for leaf litter, however, the chemical composition and microbial community of root litter leachate are poorly understood. We hypothesized that both leachate nitrogen (N) composition and microbial communities differ between plant organs and decomposition stages and that leachate composition affects microbial community composition.
View Article and Find Full Text PDFArticle Synopsis
- Developed algorithms to reconstruct tree root systems using only root point coordinates and diameters, allowing analysis without excavating roots.
- The study focused on creating a three-dimensional model of root system architecture (RSA) for Cryptomeria japonica by systematically collecting data on root locations and sizes.
- Findings revealed that root diameters decrease with distance from the stump and that certain roots have shorter segments and narrower angles, leading to a model that can estimate total volume and length with decent accuracy.
- This model offers potential for broader applications in assessing root functions without intrusive methods.
Some tree species increase fine root production under soil acidification, thus changing the balance of litter input from leaves and roots. Litter leaches a significant amount of acidic materials during its decomposition, which might facilitate soil acidification. In this context, we focused on dissolved organic matter (DOM) as the major component of acidic materials.
View Article and Find Full Text PDFArticle Synopsis
- Recent studies have utilized the net sheet method to track fine root growth in forests by inserting net sheets into the soil to observe roots as they grow through them.
- This study focused on a hinoki cypress stand in Japan, aiming to refine calculations for estimating fine root production rates based on the data collected from these net sheets, converting measurements of root number and area into dry mass values.
- Results indicated fine root production rates of approximately 80-100 g m-2 year-1 using empirical formulas compared to 40-50 g m-2 year-1 using theoretical models, suggesting non-random root orientation in the specific study area and validating the effectiveness of the new calculation procedures.
Article Synopsis
- Soil nitrogen (N) fertility impacts how fine roots allocate carbon belowground, but the specific responses of these roots to varying N levels in their natural environment are not fully understood.
- A study conducted in a 100-year-old coniferous forest measured fine root respiration rates, nitrogen content, and morphological traits, revealing that higher soil N fertility led to increased root respiration rates, nitrogen concentration, and specific root length while decreasing root tissue density.
- The findings indicate that as soil N fertility rises, fine root traits adapt by improving nutrient and water uptake efficiency, showing distinct relationships between respiration rates, nitrogen content, specific root length, and tissue density across varying soil N levels.