Faculty Profiles - TANIKAWA Toko

Papers - TANIKAWA Toko

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Sulfur accumulation in soil in a forested watershed historically exposed to air pollution in central Japan Reviewed

Toko Tanikawa, Hiroyuki Sase, Sei Fukushima, Yoshiaki Ito, Michiru Yamashita, Naoyuki Yamashita, Masato Kamisako, Akifumi Sugiyama, Akihiro Imaya, Takuya Ishida, Chisato Takenaka, Masamichi Takahashi

Geoderma Vol. 407 page： 115544 - 115544 2022.2

スギ根系が抱きかかえている土壌の量はどれくらい？－台風21号が地上に残した根鉢の解体－ Open Access

谷川東子, 池野英利, 藤堂千景, 山瀬敬太郎, 大橋瑞江, 岡本透, 溝口岳男, 中尾勝洋, 金子真司, 鳥居厚志, 稲垣善之, 中西麻美, 平野恭弘

水利科学 Vol. 383 page： 1 - 35 2022.2

Can ground-penetrating radar detect adjacent roots and rock fragments in forest soil? Reviewed

Toko Tanikawa, Hidetoshi Ikeno, Keitaro Yamase, Masako Dannoura, Kenji Aono, Yasuhiro Hirano

PLANT AND SOIL Vol. 468 ( 1-2 ) page： 239 - 257 2021.11

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER

Aim Ground-penetrating radar (GPR) has been used for estimating root biomass, estimating pull-out resistance force of roots, and reconstructing root system architecture. Although GPR can estimate the diameter of a single root, it has not yet been verified whether it can successfully estimate the diameters of adjacent roots or whether rock fragments occurring in the soil matrix can be misidentified as roots. This study aimed to (1) evaluate the visual properties of GPR images of root bundles and rock fragments, and (2) clarify whether they have the potential to create non-negligible errors in GPR surveys. Methods Root bundle samples buried in a sandy soil bed were scanned using 900 MHz and 1500 MHz antennas. Sole roots of Cryptomeria japonica and rock fragments in the bed were also scanned. Results A bundle of root formed one hyperbola with an apex in the radar profile, like a sole root. However, the contrast of the hyperbolas was weak and GPR indices relating to diameter were reduced compared to those of the comparably sized sole root. Stones did not form clear images, but boulders were faintly visible with non-negligible GPR indices. Conclusions For evaluation of root biomass, adjacent roots had the potential to lead to significant errors. Similarly, in reconstructions of root system architecture, adjacent roots might lead to incorrect modelling of root point connections, because of incorrect diameters. For pull-out resistance force, adjacent roots could lead to only underestimation, i.e., safe-side error. Misidentification of rock fragments as roots depends on their sizes.

DOI： 10.1007/s11104-021-05116-3

Web of Science

Scopus

Colonization status and community structure of arbuscular mycorrhizal fungi in the coniferous tree, Cryptomeria japonica, with special reference to root orders Reviewed

Yosuke Matsuda, Kohei Kita, Yudai Kitagami, Toko Tanikawa

PLANT AND SOIL Vol. 468 ( 1-2 ) page： 423 - 438 2021.11

Authorship：Last author Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER

Aims Arbuscular mycorrhizal (AM) fungi are intimately associated with fine roots and are involved in nutrient acquisition. However, little information is available on the links between roots of individual orders and fungus colonization and community structure. Our aim was to elucidate AM fungal communities in the fine root systems of the temperate coniferous tree species, Cryptomeria japonica (Cupressaceae). Methods We characterized the morphological traits of AM fungi microscopically and determined the community structure of AM fungi using metabarcoding with an Ion Torrent Personal Genome Machine (PGM) focusing on lower-order roots from first to third order roots. Results Paris-type and Arum-type AM morphologies were both generally more prevalent on first-order roots than on second- or third-order roots, but the colonization rates by the Paris type were higher than those by the Arum type. We found a total of 48 fungal operational taxonomic units dominated by Glomeraceae, and all the AM taxa detected on third order roots were also found on first and/or second order roots. In the case of the second and third orders, AM fungal communities were affected by soil conditions: electrical conductivity, pH, and N concentration. Conclusion These results suggest that the abundance and species richness of AM fungi vary among lower root order systems, and that the AM community is sensitive to soil conditions and turns over as roots age.

DOI： 10.1007/s11104-021-05147-w

Web of Science

Scopus

秋田県の海岸砂丘に生育するクロマツおよび植栽広葉樹数種の根系分布 Reviewed Open Access

新田響平，野口宏典，太田敬之，小野賢二，萩野裕章，野口享太郎，大谷達也，宇川裕一，小森谷あかね，谷川東子，平野恭弘，鈴木覚.

森林総合研究所研究報告 Vol. 20 page： 169 - 184 2021.10

海岸防災林造成を目的として植栽された広葉樹とクロマツの土壌特性に基づく成長と根系発達. Reviewed Open Access

太田敬之, 新田響平, 宇川裕一, 小野賢二, 萩野裕章, 谷川東子, 大谷達也, 平野恭弘, 小森谷あかね, 野口宏典.

森林総合研究所研究報告 Vol. 20 page： 195 - 204 2021.10

Root system of the giant Cryptomeria japonica tree collapsed at Shinmei shrine in Okute town, Gifu, in July 2020. Reviewed Open Access

HIRANO Yasuhiro, NANKO Kazuki, DOI Ryuusei, NISHIMURA Rei, IRIYAMA Tetsuya, TANIKAWA Toko

Root Research Vol. 30 ( 3 ) page： 65 - 75 2021.9

Authorship：Last author Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Japanese Society for Root Research

On the night of July 11, 2020, the giant Cryptomeria japonica tree collapsed during the heavy rainfall event in Okute Town, Gifu. The purpose of this study is to clarify the characteristics of the root system of the fallen tree together with the weather conditions such as heavy rainfall at the time. In July 2020, there were few sunshine hours which could induce higher water contents of the tree and soils. A large area of decay was observed in the root system close to the center of the stem and roots remaining in the soil showed signs of stripping. Using a laser scanner, the three-dimensional structure of the tree was digitally reproduced, and the volume of root system was estimated to be 43.2 m3. The diameter of the root-soil plate and the volume ratio to the aboveground part suggested that the root system of the tree was relatively small compared with those of other C. japonica trees. Based on the evaluation of the root system and weather conditions, the soil reinforcement by roots could be reduced due to decay during the long-term growth periods, and the balance between the above- and below-ground parts of the tree might be disrupted by the increase in the water contents of the tree and soils caused by prolonged rainfall and lack of sunlight.

DOI： 10.3117/rootres.30.65

Open Access

CiNii Research

Reconstruction of Conifer Root Systems Mapped with Point Cloud Data Obtained by 3D Laser Scanning Compared with Manual Measurement Reviewed Open Access

Chikage Todo, Hidetoshi Ikeno, Keitaro Yamase, Toko Tanikawa, Mizue Ohashi, Masako Dannoura, Toshifumi Kimura, Yasuhiro Hirano

FORESTS Vol. 12 ( 8 ) 2021.8

Language：English Publishing type：Research paper (scientific journal) Publisher：MDPI

Three-dimensional (3D) root system architecture (RSA) is a predominant factor in anchorage failure in trees. Only a few studies have used 3D laser scanners to evaluate RSA, but they do not check the accuracy of measurements. 3D laser scanners can quickly obtain RSA data, but the data are collected as a point cloud with a large number of points representing surfaces. The point cloud data must be converted into a set of interconnected axes and segments to compute the root system traits. The purposes of this study were: (i) to propose a new method for easily obtaining root point data as 3D coordinates and root diameters from point cloud data acquired by 3D laser scanner measurement; and (ii) to compare the accuracy of the data from main roots with intensive manual measurement. We scanned the excavated root systems of two Pinus thunbergii Parl. trees using a 3D laser scanner and neuTube software, which was developed for reconstructing the neuronal structure, to convert the point cloud data into root point data for reconstructing RSA. The reconstruction and traits of the RSA calculated from point cloud data were similar in accuracy to intensive manual measurements. Roots larger than 7 mm in diameter were accurately measured by the 3D laser scanner measurement. In the proposed method, the root point data were connected as a frustum of cones, so the reconstructed RSAs were simpler than the 3D root surfaces. However, the frustum of cones still showed the main coarse root segments correctly. We concluded that the proposed method could be applied to reconstruct the RSA and calculate traits using point cloud data of the root system, on the condition that it was possible to model both the stump and ovality of root sections.

DOI： 10.3390/f12081117

Open Access

Web of Science

Scopus

Dynamics of soil reinforcement by roots in a regenerating coppice stand of Quercus serrata and effects on slope stability Reviewed

Keitaro Yamase, Chikage Todo, Nobuyuki Torii, Toko Tanikawa, Tomonori Yamamoto, Hidetoshi Ikeno, Mizue Ohashi, Masako Dannoura, Yasuhiro Hirano

ECOLOGICAL ENGINEERING Vol. 162 2021.4

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER

Regeneration by sprouting in secondary forests is a necessary technique not only for the utilization of forest resources, but also for maintaining forest health by regrowth and avoiding slope instability caused by over-sized aboveground biomass. The strength of soil reinforcement by roots generally decreases during the tree death process in deforestation, such as clear-cutting, whereas root system strength temporarily decreases in trees that regenerate sprouting after cutting. However, quantitative evaluation of decreasing soil reinforcement by roots and slope stability has not been conducted during regeneration. In this study, we evaluated changes in the number of roots and root distribution up to 3 years after cutting in the regeneration process of Quercus serrata, a major dominant species of secondary forests in warm and cool temperate zones in Japan. We also estimated soil reinforcement by roots: additional cohesion from roots using the root bundle model, and slope stability based on a factor of safety by dividing the effect of the tree root system into vertical and horizontal cohesion with soil physical properties. After cutting at the height of approximately 0.2 m, the aboveground sprouting branches immediately regenerated, whereas the belowground root system gradually decayed. The additional cohesion from roots in trees before cutting was calculated as 34.6 kPa, whereas it decreased significantly to 21.7 kPa in living stumps 3 years after cutting. The value for the factor of safety with a saturated soil thickness of 0.7 m was calculated as 1.20 in soil under trees before cutting, whereas it decreased significantly to 1.11 in soil under living stumps in the 3 years after cutting. The safety factor?s value to 0.99 in soil under dead stumps, which did not regenerate sprouts within 3 years after cutting. We concluded that the probability of slope failure was significantly greater in the dead stumps than in the living stumps and could vary depending on the dynamics of above and below-ground parts, including fine roots.

DOI： 10.1016/j.ecoleng.2021.106169

Web of Science

Scopus

A quantitative evaluation of soil mass held by tree roots Reviewed

Toko Tanikawa, Hidetoshi Ikeno, Chikage Todo, Keitaro Yamase, Mizue Ohashi, Toru Okamoto, Takeo Mizoguchi, Katsuhiro Nakao, Shinji Kaneko, Atsushi Torii, Yoshiyuki Inagaki, Asami Nakanishi, Yasuhiro Hirano

TREES-STRUCTURE AND FUNCTION Vol. 35 ( 2 ) page： 527 - 541 2021.4

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER HEIDELBERG

Key message Tree roots hold soil that is dramatically heavier than the tree biomass, wet or dried. This soil might compensate for the imbalance between above- and belowground mass. Root-soil plates are recognized to play an important role in root anchorage of plate-like root system, however, actual measurements of their mass have rarely been reported. Even though the root-soil plate mass is often estimated using aboveground allometric indices, no research confirms the validity. Seven root-soil plates of Cryptomeria japonica fallen by Typhoon Jebi were divided into roots and soil, and their weights were directly measured. Mass of the seven plates ranged from 251 to 3070 kg on a dry basis. Roots accounted for 8% of total plate mass and soil for 92%. The mass of the soil held in the plates was 2.8 times greater than tree biomass. The root-to-shoot biomass ratio was 0.26, whereas the ratio of root-soil plate mass to shoot biomass was 3.9, meaning that the root-soil plate mass was much greater than aboveground biomass. These results suggest that the soil mass held in the plate is the main component of whole-tree mass including the plate. The root system holds soil weighing as much as 13 times the root system's mass. The soil might balance the aboveground weight of the tree by adding mass. Aboveground allometric indices are good indicators of root-soil plate mass and allow the belowground mass to be estimated to understand tree anchorage without soil disturbance.

DOI： 10.1007/s00468-020-02054-y

Web of Science

Scopus

人工林で営まれる植物-土壌-微生物間相互作用がもたらすもの Invited

谷川東子

生物資源 Vol. 15 ( 1 ) page： 12 - 24 2021

Washing methods for Moso bamboo (Phyllostachys pubescens) leaf litter and effects on elemental components. Reviewed

Umemura, M, Tanikawa, T

Bamboo Journal Vol. 32 page： 37 - 47 2021

Effects of microhabitats and soil conditions on structuring patterns of nematode communities in Japanese cedar (Cryptomeria japonica) plantation forests under temperate climate conditions Reviewed

Yudai Kitagami, Toko Tanikawa, Yosuke Matsuda

SOIL BIOLOGY & BIOCHEMISTRY Vol. 151 page： 108044 2020.12

Language：English Publishing type：Research paper (scientific journal) Publisher：PERGAMON-ELSEVIER SCIENCE LTD

The effect of biotic factors impacted by abiotic conditions on nematode communities is not fully understood in forest ecosystems. Monoculture forests with low understory diversity would provide an ideal model system to investigate the relationship between nematode community structure and environmental factors in forest ecosystems. The aim of this study was to clarify the determinant environmental factors shaping community structures of soil nematodes in Japanese cedar (Cryptomeria japonica) forests. Nematodes collected from litter and soil samples were morphologically identified at the family or genus level and divided into trophic groups. Nematodes were discriminated into a total of 40 (including 2 unique taxa) and 52 (including 14 unique taxa) taxa in litter and soil samples, respectively. Variation in microhabitat substrates created contrasting nematode assemblages between litter and soil samples. Moreover, nematodes identified from litter habitats were a subset of those from soil samples. Bacterivorous and fungivorous nematodes were present in high proportions in both sample types. Herbivorous nematodes were the third most abundant trophic group in soil samples, but were rare in litter samples. The nematode community structure in soils was significantly ordinated by water, C, N, hyphae, and soil pH. The pH is most likely to affect ecological function of soil nematodes indirectly by altering microbial biomass. Our results showed that microhabitat substrates, that is, soil and litter, have a crucial effect on nematode assemblage patterns in temperate coniferous forests. Moreover, soil nematode assemblages were diversified due to the high spatial heterogeneity of proximate soil environments.

DOI： 10.1016/j.soilbio.2020.108044

Web of Science

Scopus

Morphological traits of Chamaecyparis obtusa fine roots are sensitive to soil acid buffering capacity Reviewed

Ryuusei Doi, Toko Tanikawa, Ryusei Wada, Yasuhiro Hirano

PLANT AND SOIL Vol. 452 ( 1-2 ) page： 73 - 85 2020.7

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER

Aims The purpose of this study was to clarify how the morphological traits of Chamaecyparis obtusa (Sieb. & Zucc.) Endl. roots vary with soil acid buffering capacity (ABC), i.e., along a gradient in soil acidification. We used an order-based root classification system instead of a diameter-based root classification system, as the former relates better to root function. Methods We sampled 210 intact fine root systems up to the fourth order and measured the morphological traits of a total of 16,657 individual branch-order roots in three C. obtusa stands with high soil ABC and four stands with low soil ABC. Results We found significant differences in the morphological traits of the first- to fourth-order roots between the soil ABCs. In the low-ABC soils, the fine root systems consisted of more and thinner roots than in the high-ABC soils. The diameter of the second-order roots was positively correlated with the soil pH and the concentration of base cations, but negatively with soil aluminum. Conclusion Morphological traits of fine roots are sensitive indicators of soil acidification in C. obtusa forests.

DOI： 10.1007/s11104-020-04561-w

Web of Science

Scopus

Detection of Tree Roots Using Ground Penetrating Radar for Disaster Mitigation Open Access

Vol. 64 ( 3 ) page： 87 - 112 2020

Estimating slope stability by lateral root reinforcement in thinned and unthinned stands of Cryptomeria japonica using ground-penetrating radar Reviewed

Yamase K, Tanikawa T, Dannoura M, Todo C, Yamamoto T, Ikeno H, Ohashi M Aono K, Doi R, Hirano Y

Catena Vol. 183 ( 183 ) page： 104227 2019.12

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER

Tree root diameter and root distribution are crucial factors for root reinforcement in forest soils and can be estimated using nondestructive ground-penetrating radar (GPR). However, no studies on estimating root reinforcement have been performed using GPR. The aim of this study was to evaluate root reinforcement using GPR in thinned and unthinned stands of Cryptomeria Japonica in Andisols. Roots in each stand were detected using a 900 MHz GPR and the diameter and horizontal distribution of roots were estimated. Roots were also excavated to compare their GPR estimates. The relationships between root diameter and tensile force were established through field pullout tests. Finally, root reinforcements in each stand were estimated using the recently proposed root bundle model (RBM). There were no significant differences in the diameter frequency distribution of roots estimated between thinned and unthinned stands, determined using either the GPR or excavation methods. The detection frequency of the number of roots > 5 mm in diameter using GPR was 27.2%, but it increased to 58.7% for roots > 10 mm. The waveform indexes, determined using the sum of time intervals between zero crossings (ET) of all reflection waveforms of GPR, had a significant linear relationship with the diameters of excavated roots, indicating that waveform index could be used to estimate root diameter using the GPR index in these stands. Furthermore, the relationship between the root tensile force (F) and- root diameter (d) was estimated as F = 15.69 d(1.75) (R-2 = 0.87). The root reinforcements at the center of gaps between individual trees were estimated to be 23.4-32.9 kPa in the thinned stand and 8.8-23.9 kPa in the unthinned stand using GPR. These values ranged from 31.9% to 170.7% of those obtained by using the excavation method. There were no significant differences in root reinforcement between thinned and unthinned stands, regardless of the method used. This study revealed that GPR, together with diameter-tensile force relationships, can nondestructively estimate root reinforcement in managed forests. This protocol can be applied to manage forests to evaluate the effects of management on belowground roots.

DOI： 10.1016/j.catena.2019.104227

Web of Science

Scopus

Variation in the morphology of fine roots in Cryptomeria japonica determined by branch order-based classification Reviewed

Wada R, Tanikawa T, Doi R, Hirano Y

Plant and Soil Vol. 444 ( 1-2 ) page： 139 - 151 2019.11

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER

Aims This study assessed intraspecific variation in morphological traits of the fine root branch orders of Cryptomeria japonica, and identified variation in the diameter of the first three-order roots among species types with mycorrhiza, and the diameter of first-order roots at the family level. Methods Diameter, length, and specific root length of branch order roots (up to the fourth-order) were measured in intact fine root systems collected in four C. japonica stands. Relationships between soil chemical properties and morphological traits of the first- to fourth-order roots were investigated. The diameter of roots of 52 tree species reported in previous studies was compared at species types with mycorrhiza and at family level. Results The diameter of first-order roots in C. japonica varied by 1.2 times among stands. Negative correlations between soil NH4+ content and specific root length of the second- and third-order roots were observed in C. japonica. The diameter of first- and second-order roots forming arbuscular mycorrhiza in coniferous trees were significantly higher than those of roots forming ectomycorrhiza in coniferous and broadleaf trees. The diameter of first-order roots in Cupressaceae were significantly larger than those of Pinaceae, Sapindaceae, Betulaceae, and Fagaceae. Conclusions Clarifying intraspecific variation in morphological traits of C. japonica lower-order roots may contribute to understanding their responses to different site conditions such as soil inorganic nitrogen contents.

DOI： 10.1007/s11104-019-04264-x

Web of Science

Scopus

Free-living nematodes associated with pine cones of Pinus thunbergii and P. taeda at Japanese coastal and inland forest sites. Reviewed

Kitagami,Y., Kanzaki, N., Tanikawa, T., Matsuda, Y.

Nematology Vol. 21 ( 4 ) page： 389 - 400 2019.4

Reconstruction of root systems in Cryptomeria japonica using root point coordinates and diameters. Reviewed

Ohashi, M, Ikeno, H, Sekihara, K, Tanikawa, T, Dannoura, M, Yamase, K, Todo, C, Tomita, T, Hirano, Y

Planta Vol. 249 ( 2 ) page： 445 - 455 2019.2

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER

Main conclusionWe developed simple algorithms for reconstructing tree root system architecture using only the root point coordinate and diameter, which can be systematically obtained without digging up the root systems.Root system architecture (RSA) is strongly related to various root functions of the tree. The aim of this study was to develop a three-dimensional (3D) RSA model using systematically obtained information on root locations and root diameters at the locations. We excavated root systems of Cryptomeria japonica and systematically obtained XYZ coordinates and root diameters using a 10-cm grid. We clarified the patterns of the root point connections and developed a reconstructed root system model. We found that the root diameters farther from the stump centre are smaller. Additionally, we found that the root lengths of the segments running between the base and the connected root point were smaller than those of other root segments, and the inner angle between the base and the stump and between the base and the connected root point was narrower than for the other pairs. The new RSA model developed according to these results had average accuracies of 0.64 and 0.80 for estimates of total volume and length, respectively. The developed model can estimate 3D RSA using only root point data, which can be obtained without digging up root systems. This suggests a wide applicability of this model in root function evaluation.

DOI： 10.1007/s00425-018-3011-x

Web of Science

Scopus

PubMed

Response of river water chemistry to changing atmospheric environment and sulfur dynamics in a forested catchment in central Japan Reviewed

Hiroyuki Sase, M. Takahashi, K. Matsuda, K. Sato, T. Tanikawa, N. Yamashita, T. Ohizumi, T. Ishida, M. Kamisako, R. Kobayashi, S. Uchiyama, T. Saito, M. Morohashi, H. Fukuhara, S. Kaneko, T. Inoue, T. Yamada, C. Takenaka, I. Tayasu, T. Nakano, T. Hakamata, S. Ohta

Biogeochemistry Vol. 142 ( 3 ) page： 357 - 374 2019.2

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Papers - TANIKAWA Toko