Masamichi Takahashi

Japan International Forestry Promotion and Cooperation Center(JIFPRO)

Forest soils that have accumulated anthropogenic sulfur (S) as a result of historical air pollution may gradually or suddenly release inorganic sulfate either by desorption of inorganic sulfate or by mineralization of organic S, even after mitigation of previous air pollution. The release of inorganic sulfate from soil to surface water leads direct...

Geographic information on soil organic carbon (SOC) is important for climate change research and understanding the global carbon cycle. At present, this information is limited for forest soils in mountainous regions that have complex topographies and are affected by tephra deposition. This study predicted the SOC concentration (OC), bulk density (B...

Excess inputs of reactive nitrogen (Nr) from the atmosphere will cause disturbances to forest ecosystems, including soil and stream water acidification, plant nutrient imbalances, alterations of species compositions (such as biodiversity losses), and nitrogen (N) leaching into stream water. Central Japan (or Chubu region) has experienced both domes...

Nutrient storage in the forest floor is regulated through litter decomposition and nutrient cycling. Stoichiometry of nutrients can provide characterization of the forest floor. To quantify nutrient storage in the forest floor and to determine stoichiometry among different forest types, available data on nutrients were meta-analyzed. The data on nu...

Air pollution and atmospheric deposition have adverse effects on tree and forest health. We reviewed studies on tree and forest decline in Northeast and Southeast Asia, Siberia, and the Russian Far East (hereafter referred to as East Asia). This included studies published in domestic journals and languages. We identified information about the locat...

Radiocesium is well-known to be stabilized by clay minerals in soils, while volcanic soils could typically be poor in micaceous clays that fix ¹³⁷Cs effectively. We investigated ¹³⁷Cs fixation potentials [radiocesium interception potential (RIP)] and depth distribution of ¹³⁷Cs stocks in volcanic soils to analyze effects of clay content and mineral...

Reduction of atmospheric sulfur (S) deposition and recovery of terrestrial ecosystems from acidification are matters of concerns in Asia. The Lake Ijira catchment (IJR) is located in the downwind region of the Chukyo Industrial Area in central Japan and has historically experienced large-scale deposition of S and nitrogen (N) from the atmosphere. L...

The pattern of soil carbon stock is atypical along the slope position in a seasonally dry tropical forest; the mean stock values increase from the lower, middle, to upper slopes, at 11.5, 13.2, and 15.5 kg m−2, respectively. In sloping landscapes, soil organic carbon tends to accumulate in lower slopes, but our previous soil respiration study sugge...

The amendment of soil with superabsorbent polymers (SAPs) has been gaining interest in agriculture and forestry, in both dry and semi-dry lands since the late 1970s. Here, we review studies on the characterization, application, and evaluation of SAPs in forestry and revegetation fields worldwide. SAPs usually absorb amounts of pure water several hu...

Soils have an important role as a reservoir of essential elements for forest ecosystems. Although previous chronosequence studies have determined accumulation rates of several elements in soils, they have not focused on sulfur (S), a secondary macronutrient. We investigated S accumulation rates in five volcanic soils, dated by the use of tephras fr...

Underground community assemblies have not been studied well compared with aboveground communities, despite their importance for our understanding of whole ecosystems. To investigate underground community assembly over evolutionary timescales, we examined terrestrial earthworm communities (Oligochaeta: Haplotaxida) in conserved mountainous primary f...

This research was conducted in radiologically contaminated forests at Fukushima Prefecture from 2011 to 2014 to reveal the contribution for air dose rate at a height of 1 m in the forests from the various forest compartments, by calculating air dose rates from radiocesium inventories in leaves and branches, the litter layer, the mineral soil layers...

To elucidate uptake via the roots and the dynamics of cesium (Cs) in Japanese cedar (Cryptomeria japonica D. Don), we measured the stable cesium (¹³³Cs), rubidium (Rb), and potassium (K) content in the needles and wood of Japanese cedar harvested from four sites: 1) Kawauchi; 2) Kamikawauchi; 3) Otama; and 4) Tadami in Fukushima Prefecture, Japan....

International Union of Forest Research Organization (IUFRO) is united more than 15,000 scientists in over 110 countries to construct "the" global network for forest science cooperation. IUFRO held XXIV IUFRO World Congress in Salt Lake City, United State of America, during 5 - 11 October, 2014. We proposed a technical session entitled as "Radioacti...

In contaminated forest, it is essential to measure the temporal variation of air dose rate because forests constitute a major part of the land use in the contaminated area by Fukushima Daiichi nuclear power plant accident. In this study, we examined the temporal variation of air dose rate from 2011 to 2014 at heights 1 m and 10 cm at Japanese cedar...

After the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, information about stand-level spatial patterns of radiocesium initially deposited in the surrounding forests was essential for predicting the future dynamics of radiocesium and suggesting a management plan for contaminated forests. In the first summer (approximately 6 months after th...

We examined the dynamics of radiocesium in the forest ecosystems which were contaminated by the Fukushima Daiichi Nuclear Power Plant Accident. Field measurement and sampling were conducted in eight stands; plantations of Japanese cedar (Cryptomeria japonica, n = 4), Hinoki cypress (Chamaecyparis obtusa, n = 2), Japanese red pine (Pinus densiflora,...

In forest soils contaminated by radiocesium (134Cs and 137Cs), deposition from the Fukushima nuclear accident, clay minerals might play important roles in long-term cesium (Cs) dynamics through sorption. To determine whether radiocesium can be retained within the organic layer and the upper mineral soil layers in the Fukushima region, we investigat...

To understand the contribution of upbuilding pedogenesis to the accumulation of sulfur (S) in Melanudands, we investigated the vertical distribution of S species using K-edge X-ray absorption near-edge structure (XANES) spectroscopy of S species and vertical variation of δ34S values of total S in two Japanese Melanudands developed above tephra Nt-S...

To understand the organic sulfur (S) stabilization in volcanic soils, we investigated organic S transformation rates and their relationships to soil properties in incubation experiments using forest soils from the Nikko volcanic region, central Japan. We hypothesized that carbon (C)-bonded S would first be transformed into ester sulfate-S and then...

Pedotransfer functions (PTFs) for estimating bulk density (BD) of forest soils in Japan affected by volcanic ash were developed using 3513 stone-free soil data. We found that 29 existing PTFs of five empirical types and one physical type generally overestimated the BD. This occurred because volcanic soil with the unique physical and chemical proper...

Many studies have elucidated the possible effects of air pollution/acid deposition on East Asian forest ecosystems. Consequently, in addition to monitoring wet and dry deposition, the Acid Deposition Monitoring Network in East Asia (EANET) has been monitoring soil, vegetation, and inland water in forest areas since 2001 as part of its regular-phase...

To predict the behavior of radiocesium derived from the Fukushima Daiichi Nuclear Power Plant accident in a forest ecosystem, soil survey and sampling were performed in five experimental plots at three sites in Fukushima prefecture, Kawauchi-mura, Otama-mura and Tadami-machi, and the physicochemical properties of the soils were examined. The humus...

The carbon (C) stocks of dead wood, litter, and soil are the basic data for evaluating the C sink function in the forest sector in Japan. We estimated the C stocks of dead wood, litter, and soil at 0-30 cm in the forest sector in Japan and clarified the spatial distribution of those C stocks according to region units. Data were collected in 2438 su...

High concentrations of organic C and Al/Fe oxides, and low bulk density are responsible for the accumulation of large amounts of S compounds in volcanic soils. The purpose of our study was to clarify the spatial distribution of S compounds and determine the factors governing that distribution within the Katsura Headwater Catchment, a small drainage...

The aims of this study were to report the C stocks of dead wood, litter, and soil at 0–30 cm in the forest sector of Japan, to clarify the spatial distribution of those C stocks according to prefecture units and to determine the ratio of soil C stock at 0–30 cm to that at 0–100 cm. To achieve these objectives, data collected by the National Forest...

The carbon (C) stocks of dead wood, litter, and soil are the basic data for evaluating the C sink function in the forest sector in Japan. We estimated the C stocks of dead wood, litter, and soil at 0–30 cm in the forest sector in Japan and clarified the spatial distribution of those C stocks according to region units. Data were collected in 2438 su...

Estimating carbon (C) and nitrogen (N) stocks in deadwood in forests nationwide is required for understanding large-scale C and N cycling. To do so requires estimated values of wood density and C and N concentrations. Additionally, parameters that show variation should be examined. In this study, we clarified the estimated values and the variation...

Teak has been a popular tree species for timber production in commercial and private farmland and remains a promising species for carbon sequestration in the seasonally dry tropics. A carbon cycling scheme obtained in teak (-gmelina) plantations showed a high rate of carbon accumulation in the soil of Alfisols in western Thailand which has high cal...

Aims Nitrogen deposition affect fine-root dynamics, a key factor in forest carbon and nutrient dynamics. This study aimed to elucidate the effects of increased soil inorganic nitrogen (N) levels on the fine-root dynamics of Cryptomeria japonica, which is tolerant to excess N load. Methods An ammonium nitrate solution (28 kg ha−1 month−1) was appli...

The tissue structure of a bamboo stem (culm) differs from that of woody species, exhibiting a large cavity in the internode surrounded by a cortex with high silica concentration. Thus, to obtain an accurate estimation of the necromass, as well as carbon (C) and nitrogen (N) stocks in dead bamboo culms, we examined the basic characteristics of culm...

Coefficient of explanatory variable in general linear model (Formula 1′–4′). The coefficient means “b” in each formula. Asterisk shows significant difference from 0 (*, p ≦ 0.05; **, p ≦ 0.01)

Results of linear and non-linear regressions with Gaussian errors. No random effect was incorporated into the linear and non-linear regressions

Fine roots play a key role in carbon and nutrient dynamics in forested ecosystems. Fine-root dynamics can be significantly affected by forest management practices such as thinning, but research on this topic is limited. This study examined dynamics of fine roots <1mm in diameter in a 10-year-old stand of hinoki cypress (Chamaecyparis obtusa) for 3y...

Most of litter returned by non-commercial thinning was existed without contact onto the forest floor. We discussed nitrogen dynamics with decomposing litter after thinning with a focus on the site difference of litter existence in this study. The amount of nitrogen returned by thinning was 84kg ha^<-1> and 67% of them were existed in the air withou...

Soil respiration is a carbon flux that is indispensable for determining carbon balance despite variations over time and space in forest ecosystems. In Kanchanaburi, western Thailand, we measured the soil respiration rates at different slope positions—ridge (plot R), upper slope (plot U), and lower slope (plot L)—on a hill in a seasonal tropical for...

Emissions and uptake of soil greenhouse gases (GHG) are controlled by soil biogeochemical processes. We developed simple models, which were termed SG models, for soil CO2 efflux, CH4 uptake, and N2O efflux in forest soils. We described each gas flux in terms of three functions: soil physiochemical properties (C/N ratio for CO2 and N2O, bulk density...

Nitrogen fixation during litter decomposition was studied for 34months using litterbags containing newly fallen litter of coniferous species Cryptomeria japonica and Pinus densiflora and that of deciduous species Quercus serrata. Litterbags were set in contact with the forest floor in a deciduous broad-leaved forest near the top of a slope and in a...

To establish accuracy criteria for measurements of carbon and nitrogen concentrations in forest litter and mineral soil, we examined the change in the coefficient of variance (CV) with the number of measurement repetitions, the distribution of CVs and the effect of analytical error on the variation of CV to suggest a threshold for detecting outlier...

To determine the rates of increase in C and N stocks in the soil and organic layers following afforestation in Andisols, we measured C and N densities in the organic and soil layers at depths of 0–5, 5–15 and 15–30 cm, together with a chronosequence analysis of 4-year-old, 14-year-old and 23-year-old Japanese cedar (Cryptomeria japonica) and 4-year...

Rapid industrialization in East Asia is causing adverse effects due to atmospheric deposition in terrestrial and freshwater ecosystems. Decreasing stream pH and alkalinity and increasing NO3 − concentrations were observed throughout the 1990s in the forested Lake Ijira catchment in central Japan. We investigated these changes using data on atmosphe...

Estimation of carbon sequestration in the forest sector should take into consideration changes in carbon stock in all carbon pools, including above-ground and below-ground biomass, litter, deadwood and soil. In this review, we discuss current knowledge of carbon stocks in litter, deadwood and soil in Japan’s forest sector. According to data from pu...

We clarified the differences in root-tip diameter (RTD) among tree and shrub species in an Abies forest. To evaluate the effects of sampling month and tree size on RTD, we measured the root-tip diameters of mature individuals of nine woody species and sapling individuals of two Abies species in a subalpine Abies forest on Mount Shimagare in central...

Soil respiration is a crucial carbon flux for determining carbon balance in the forest ecosystem. In Kanchanaburi, western Thailand, we measured soil respiration at different stand ages (1, 6 and 21 year-old) of teak (Tectona grandis) plantations. There were no significant differences in soil respiration among plots of different ages. Soil respirat...

To understand sulfur (S)-accumulating systems of Andisols in Japanese forests, this study examined the contributions of inorganic sulfate and organic S to S accumulation. The profiles showed high total S concentrations of 540 to 2240 mg S kg− 1. These high concentrations resulted in large pools of total S, ranging from 3370 to 8520 kg S ha− 1 to 1...

To clarify the reason for the higher CH4 uptake rate in Japanese forest soils, twenty-seven sites were established for CH4 flux measurement. The first order rate constant for CH4 uptake was also determined using soil core incubation at 14 sites. The CH4 uptake rate had a seasonal fluctuation, high in summer and low in winter, and the rate correlate...

Decay rates of dead wood after non-commercial thinning, i.e., fallen logs, stumps, and snags, in plantation forests were estimated from changes in wood density over time. Decay rates were compared using the decay constant k of the exponential function (D = a exp (-kt), where D : wood density, a : a constant, t : time, k : decay constant). The plots...

For a general assessment of the nitrogen status of sugi plantations in Japan, we measured nitrogen content in the needles of sugiCryptomeria japonica D. Don) trees growing at 531 sites across the country. We attempted to find local pockets with high or low needle N and to ascertain the relationships between needle N and temperature, the rainfall en...

Effects of drought stress on the fine roots (diameter up to I mm) and root tips were studied in a 28-year-old Japanese cedar tCryptomeria japonica D. Don) plantation in the Kanta Plain, eastern Japan. To simulate drought stress, four rain shelters were constructed. The shelters blocked all throughfaIl to C. japonica root systems between mld-April a...

To evaluate the influence of excessive N deposition on the water consumption of a Japanese plantation forest, 1-year-old seedlings of major plantation trees, Cryptomeria japonica (Japanese cedar) and Chamaecyparis obtusa (Hinoki cypress), were treated with combinations of two N levels (Moderate N and High N) and two soil water conditions (Dry and M...

Field incubation was conducted by resin core method to determine rate and amounts of nitrogen mineralization of top soil under the forest along the climatic zone in Japan. Annual rate of mineralized nitrogen were high in the soils of warm and cool temperate and low in those of to sub arctic and sub tropical. Rate of mineralized nitrogen by laborato...

This paper presents results of regional application of the CENTURY ecosystem model to Japanese forests. Global and regional evaluation of organic carbon stored in forest soil and greenhouse gases emissions from forest soils are important (e.g., the Kyoto protocol). Our goal is to develop a biogeochemical model that can simulate carbon dynamics in J...

We measured methane (CH4) emissions from the stem surfaces of mature Fraxinus mandshurica var. japonica trees in a floodplain forest. Flux measurements were conducted almost monthly from May to October 2005, and positive CH4 fluxes were detected throughout the study period, including the leafless season. The mean CH4 flux was 176 and 97μgCH4m−2h−1...

To determine the means and variations in CH4 uptake and N2O emission in the dominant soil and vegetation types to enable estimation of annual gases fluxes in the forest land of Japan, we measured monthly fluxes of both gases using a closed-chamber technique at 26 sites throughout Japan over 2 years. No clear seasonal changes in CH4 uptake rates wer...

We discussed rate of mineralized nitrogen changing through soil profile and their seasonal changes in the soil of small catchments under Sugi (Cryptomeria japonica) and broad leaved forest at North Kanto region. We determined rate of nitrogen mineralization in the soil under field condition using resin core method. Rate of mineralized nitrogen in t...

Many pathways have been proposed for including land use in a post-2012 climate agreement. Several involve new accounting structures which are quite different from the rules established in the Marrakech Accords and related decisions. However, a mechanism based largely on the structure agreed for the first commitment period also has its benefits. Thi...

Anthropogenic Pb affects the environment worldwide. To understand its effect on forest ecosystem, Pb isotope ratios were determined in precipitation, various components of vegetation, the forest floor, soil and parent material in a Japanese cedar (Cryptomeria japonica D. Don) forest stand. The average 206Pb/207Pb ratio in bulk precipitation was 1.1...

In determining the soil and ecosystem carbon balance, it is necessary to distinguish between autotrophic respiration and heterotrophic respiration. We attempted to measure the contribution of CO2 emissions from plant roots (RRHI), from soil organic matter (RSOM), and from litter (RL) to CO2 emissions from the forest floor (soil respiration; RS) in...

We have examined the surface (0–10cm) soil characteristics of sites after bamboo (Cephalostachyum pergracile) mass flowering and death (DB sites) in comparison with sites with living bamboo (Bambusa tulda) (LB sites) in a seasonal tropical forest in Thailand. One year after bamboo flowering the DB sites were acidic with lower concentrations of exch...

Drought stress was simulated in a 28-year-old Japanese cedar plantation (Kanto Plain, Japan) between April and October 2004 by removing throughfall using rain shelters. Changes in fine-root parameters caused by this drought treatment were examined by sequential soil coring. Drought effects on fine roots were analyzed separately for particular soil...

To better understand the control of fine-root dynamics in Japanese forests, we reviewed studies conducted in Japan on fine-root biomass and production. Most of the data on fine-root biomass were obtained for conifer plantations in limited regions; the average fine-root biomass of dominant trees ranged from ∼50 g m−2 for Pinus species (n = 3) to ∼60...

Root biomass and root distribution were studied in Entisols derived from the thick deposition of volcanic pumice on Hokkaido Island, Japan, to examine the effect of soil conditions on tree root development. The soil had a thin (<10 cm) A horizon and thick coarse pumiceous gravel layers with low levels of available nutrients and water. Two stands we...

Since 1983, the Ministry of the Environment of Japan has conducted nation-wide acid deposition surveys. To investigate the effects of acid deposition on surface water, we used the nonparametric Mann–Kendall test to find temporal trends in pH, alkalinity, and electrical conductivity (EC) in more than 10years of data collected from five lakes and the...