ACG30-01

Room:301B

Time:May 25 09:00-09:15

Quantifying warming effect due to urbanization based on comparative measurements ofthe surface energy budget
ANDO, Tomoyoa1∗ ; UEYAMA, Masahito1 ; KOSUGI, Yoshiko2
1

Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 2 Graduate School of Agriculture, Kyoto
University
Land use changes from natural ecosystems to urban built-up have strong influence on local climates. The urban heat island hasreceived much attention as an important environmental problem. However, detailed mechanisms have not be clear enough. In
this study, we conducted comparative measurements of the surface energy balance at an urban built-up and a forest, and evaluatedfactors contributing surface warming due to the land use change based on a methodology called temperature decomposition.
We measured the energy balance at the urban built-up in Sakai,Osaka and at a cypress plantation (Kiryu Experimental Watershed ) in Shiga. Sensible and latent heat fluxes were measured using the eddy covariance method. The ground heat flux for theurban area was estimated using the objective hysteresis model with relevant plot-scale experiments. In this study, we evaluatedthe urbanization effect from the forest plantation to the urban in terms of changes in surface temperatures associated with surface
albedo, aerodynamic resistance, Bowen ratio, and ground heat flux.
In daytime, the urbanization increased net surface temperatures by 5.5 K in the summer (June to August 2014) and 3.8 K in thewinter (January, February, and December 2014). The daytime warming was mostly contributed by increased surface resistancedue to the urbanization in the summer (4.4 K) and the winter (3.7 K). In the urban built-up, the decreased surface roughness
due to a high building density restricted the heat transfer redistribution into the atmosphere. Consequently, we found that thedecreased surface resistance was the most effective factor to warm the urban surface temperatures in daytime. In nighttime, theurban surface temperature was higher than those in the forest in the summer (1.9 K) and the winter (2.5 K). Change in groundheat flux most strongly contributed to the nighttime warming in the summer (4.2 K) and the winter (5.2 K). In the urban built-up,
a lot of incoming energy was stored in buildings and impervious roads in daytime. This energy was radiated and warmed up theurban surface in nighttime. The estimated net increases in the surface temperature were lower than those estimated using the bulk
model in daytime and nighttime. The discrepancy could be caused by uncertainties associated with estimated radiative fluxes,
energy imbalance of turbulent fluxes, and no consideration of anthropogenic heat in the urban built-up.

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ACG30-02

Room:301B

Time:May 25 09:15-09:30

A decline of a Japanese oak by sulfuric acid of an air pollutant, and reproduction bycharcoal
OMORI, Teiko1∗
1

FOMER TOHO UNIVERSITY

A fossil fuel generates sulfuric acid by combustion.Sulfuric acid becomes an air pollutant, moves by wind and adheres totrees.Sulfuric acid which adhered to trees is dropped on a root by rain, and acidifies soil.If soil acidifies, a metal ingredient
will dissolve.The dissolved metallic ion is absorbed into the trees.The phosphoric acid in trees combines with metallic ion.The
combined phosphoric acid becomes inactivate and trees wither.The combined phosphoric acid becomes inactivate and trees
wither.If the tannin contained in trees combines with a metal ion,it loses the insect control effect.Rain water becomes alkaline
solution by charcoal.An alkaline solution changes metal ion into hydroxide.Trees cannot absorb metal hydroxide.As a result,
trees are saved.If charcoal is scattered on the tree of the declined Japanese oak, it dropped a seed after 3 years and budded after
4 years.
Keywords: air pollutant, acidifies soil, acidifies soil, tannin, metallic phosphate

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ACG30-03

Room:301B

Time:May 25 09:30-09:45

Long-term warming effect on soil respiration in warm-temperate evergreen broad-leaved
forest in Kyusyu
TERAMOTO, Munemasa1∗ ; LIANG, Naishen1 ; TAKAGI, Masahiro2 ; ZENG, Jiye1
1

Center for Global Environmental Research, National Institute for Environmental Studies, 2 Faculty of Agriculture, University ofMiyazaki
Soil respiration is composed of heterotrophic respiration and plant root respiration, and is the second largest carbon flux in theterrestrial ecosystem. As the heterotrophic respiration increases exponentially with soil temperature, its positive feedback to theglobal warming has become a concern.
In the middle of December 2008, a multi-channel automated chamber measurement system was installed at the Tano forest
science station of Miyazaki University, which is a warm-temperate broad-leaved forest site in Kyusyu. We prepared 10 trenchedplots with 5 of them artificially warmed by +2.5o C by infrared heaters 1.6 m above the surface for long-term measurement ofwarming effect on soil respiration.
The average value of soil respiration in control and warmed plots were, respectively, 3.45 µmol CO2 m−2 s−1 and 3.53 µmol
CO2 m−2 s−1 in 2009, 3.81 µmol CO2 m−2 s−1 and 4.07 µmol CO2 m−2 s−1 in 2010, 3.31 µmol CO2 m−2 s−1 and 3.81 µmol
CO2 m−2 s−1 in 2011, 3.02 µmol CO2 m−2 s−1 and 3.79 µmol CO2 m−2 s−1 in 2012, 3.08 µmol CO2 m−2 s−1 and 3.33 µmol
CO2 m−2 s−1 in 2013. The annual warming effect increased soil respiration by 5.4% in 2009, 9.9% in 2010, 18.4% in 2011,29.5% in 2012, and 11.5% in 2013. The warming effect showed an increasing trend until 2012, but decreased in 2013 due tofewer amount of rainfall in summertime, which caused a much lower moisture in soil.

Keywords: soil respiration, global warming, chamber, forest soil

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ACG30-04

Room:301B

Time:May 25 09:45-10:00

Control of Soil Carbon Dynamic of Southeast Asian Ecosystems
LIANG, Naishen2∗ ; TERAMOTO, Munemasa2 ; TANG, Zhenghong3 ; FLETCHER, Christine D.4
1

NIES, 2 NIES, 3 XTBG, 4 FRIM

The tropical ecosystems have been estimated to be a large carbon source (1.3 Pg C yr−1 ) due to deforestation and forest
degradation, even the global terrestrial carbon sink has been large (1.1 Pg C yr−1 ) in recent decades. Reducing Emissions from
Deforestation and Forest Degradation (REDD) is an effort to create a financial value for the carbon stored in forests, offering
incentives for tropical region to reduce emissions from forested lands and invest in low-carbon paths to sustainable development.
The ultimate goal of this study is to update REDD mechanism through improved forest management by evaluation of effectsof logging and land-use change on soil carbon emission of tropical forests. This study was conducted in a lowland primary
forest at Pasoh Forest Reserve (2o 58’N, 102o 18’E; 75˜150m a.s.l.) and a mountainous tropical forests at Temenggor concession
area (5o 33’N, 101o 36’E; 800˜900m a.s.l.) in Peninsular Malaysia. About 50˜65% biomass was harvested and soil temperature
increased about 3oC with SMS, resulting value of the carbon stock lost about 2,577 US$ ha−1 following the first year of logging.
On the other hand, under low-impact harvest condition, only about 1,773 US$ ha−1 was lost following the first year of logging.
Result suggests that this low-impact harvest system would achieve about 804 US$ ha−1 of REDD credit partially contributed
from mitigating soil degradation of about 169 US$ ha−1 .
Keywords: Automated chamber, LULUC, moisture, soil carbon, tropical ecosystem

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ACG30-05

Room:301B

Time:May 25 10:00-10:15

Spatial variations in larch and soil nitrogen isotope ratio along forest-grassland gradientin northern Mongolia
FUJIYOSHI, Rei1∗ ; TSUJIMURA, Maki2 ; LOPEZ, Larry c.m.3 ; SUGIMOTO, Atsuko4
1

Graduate School of Environmental Science, Hokkaido University, 2 Faculty of Life and Environmental Sciences, University ofTsukuba, 3 Faculty of Agriculture, Yamagata University, 4 Faculty of Environmental Earth Science, Hokkaido University
The underlying processes that affect the Nitrogen isotope ratio of plant and soil,which is known as a good indicator of N
dynamics and shows dependency on climate, is not yet clearly understood.
In this study, we compare the nitrogen isotope ratio of single plant species (Larix sibirica Ledeb.) and soils along the forestgrassland gradient of a forest-steppe ecotone in Mongolia. Larch needles and soils were sampled during the growing season(May- August) from 2004-2012 at several sites in seven study areas.
The results showed the clear spatial pattern in needle, soil nitrogen isotope ratios, and its difference (∆δ 15 N)along forestgrassland gradient and the pattern corresponded to humus type (mor/mull). ∆δ 15 N also had significant correlations with needleδ 13 C and C/N ratio of bulk soil, suggesting the ∆δ 15 N change relates to water, light conditions and soil N availability. Isotope
mass-balance model was applied to investigate the processes affecting the spatial pattern of ∆δ 15 N.
Keywords: ecotone, Mongolia, nitrogen isotope ratio, plant and soil

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ACG30-06

Room:301B

Time:May 25 10:15-10:45

Seasonal variation in ratio of soil respiration to ecosystem respiration at Takayama estimated from d18O measurement
MURAYAMA, Shohei1∗ ; SAWADA-TAKAMURA, Chikako2 ; SAIGUSA, Nobuko3 ; ISHIDOYA, Shigeyuki1 ;WATANABE, Tsutomu4 ; ITO, Akihiko3 ; MORIMOTO, Shinji5 ; KONDO, Hiroaki1 ; MAEDA, Takahisa1 ;MURAOKA, Hiroyuki6 ; USAMI, Tetsuyuki1 ; AOKI, Shuji5 ; NAKAZAWA, Takakiyo5
1
6

AIST, 2 AORI, The University of Tokyo, 3 NIES, 4 ILTS, Hokkaido University, 5 Graduate School of Science, Tohoku University,
River Basin Research Center, Gifu University

Forest ecosystems are one of the important reservoirs in the global carbon cycles. However, environmental factors governing
variation in carbon dioxide (CO2 ) flux between the atmosphere and the forest ecosystems have not been fully understood, whichleads to very large uncertainty in future predictions of response of forest ecosystems to climate change. For more precise prediction of the future global carbon budgets, better understandings of each process in the carbon cycle in the ecosystem are necessary.
A stable oxygen isotopic ratio (δ 18 O) in CO2 is a unique tracer reflecting not only the carbon cycle but also the hydrologicalcycle. Using difference of isotopic fractionation in 18 O between photosynthetic and respiratory processes and between soil andleaf respiratory processes, gross CO2 fluxes in each of the processes have been estimated in some previous studies at relatively
short time scales from diurnal to a few months. In this study, isotopic measurements of not only CO2 in the atmosphere and soil
air but also soil water and atmospheric water vapor were made at a cool-temperate deciduous forest, Takayama (TKY; 36o 08’N,
137o 25’E, 1420 m a.s.l.) in the growing seasons during 2006-2009. From the obtained data, δ 18 O values in CO2 emitted due
to soil (Rs ) and leaf respirations and total ecosystem respiration (Rec ) during the nighttime were calculated. Then, seasonalvariation in relative contribution of Rs to Rec was estimated form mass balance equations. The obtained result was comparedwith variation in the ratio of Rs to Rec estimated from soil chamber and eddy covariance flux measurements. The result from theδ 18 O measurements showed that the ratio of Rs to Rec increased from about 0.5 in late spring to almost 1 in early autumn though
the estimated ratios were very scattered. Such a seasonal pattern was similar to that estimated from the flux measurements. In
our presentation, factors governing the seasonal variation will also be discussed by comparison with the results simulated for
TKY using a process-based ecosystem model (VISIT) and a multi-layer canopy model (MINCER).
Keywords: oxygen isotope, forest ecosystem, ecosystem respiration, soil respiration

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ACG30-07

Room:301B

Time:May 25 11:00-11:15

Long-term observation of CO2 flux over a larch forest in northern foot of Mt. Fuji
TAKAHASHI, Yoshiyuki1∗ ; SAIGUSA, Nobuko1 ; IDE, Reiko1 ; HIRATA, Ryuichi1
1

Center for Global Environmental Research, National Institute for Environmental Studies

Larch forest is representative vegetation type of widespread region in northeast Eurasia where vulnerability to climate change
is expected to be significant. Since length of growing season of the vegetation is affected by temperature, evaluation of climatechange feedback in the carbon exchange process in the ecosystem has great importance. National Institute for Environmental
Studies has been operating long-term observation of CO2 flux over a larch plantation at the Fuji Hokuroku flux observation site
in northern foot of Mt. Fuji since 2006. We have accumulated 9-year records of observational data set. The observation is to becontinued until 2025. In this presentation, we will investigate year-to-year variation of CO2 exchange and its relationship withenvironmental factors based on the observational data.
Keywords: carbon dioxide, flux, forest ecosystem, climate change, long-term monitoring, micrometeorology

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ACG30-08

Room:301B

Time:May 25 11:15-11:30

Effects of waterlogging on carbon isotope discrimination of Larix gmelinii during photosynthesis
LI, Fang1∗ ; SUGIMOTO, Atsuko1
1

Graduate school of environmental science, Hokkaido university

The carbon isotope discrimination during photosynthesis reflects various environmental factors, such as VPD, solar radiation,soil moisture, salinity, air pollution and so on. It has been used to estimate environmental condition, or calculation of carbon
isotope mass balance equation to know a flow of carbon. It is well known that soil moisture is one of the major factors controllingcarbon isotope discrimination: discrimination decreased under drought condition due to a decrease of stomatal conductance. On
the other hand, there is almost no research on carbon isotope discrimination under extremely wet condition. Larix gmelinii is
one of the major species of larch trees, which constitute eastern Siberian Taiga. In 2007, extreme wet event has been reported
near Yakutsk. In this research, pot experiment with Larix gmelinii saplings was conducted to obtain carbon isotope discrimination during photosynthesis under waterlogging condition which may happen more frequently in the future. Under waterlogging
condition, both photosynthesis rate and stomatal conductance of all three larch saplings used for experiment decreased, while
only one sapling among three showed clear decrease in carbon isotope discrimination. Although the decrease in carbon isotope
discrimination was not so clear, needles on current year stem, which seemed to be formed with C fixed during the experiment,
showed slightly higher δ 13 C in waterlogging treatment than that in control. This result suggests that waterlogging condition
makes stomatal conductance decreased.
Keywords: carbon isotope discrimination, photosynthesis, stomatal conductance, waterlogging, larch, experiment

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ACG30-09

Room:301B

Time:May 25 11:30-11:45

Effects of the expansion of vascular plants in Sphagnum-dominated bog on carbon balance
HIRANO, Takashi1∗ ; YAMADA, Hiroyuki1 ; TAKADA, Masayuki2 ; FUJIMURA, Yoshiyasu3 ; FUJITA, Hiroko4 ;TAKAHASHI, Hidenori5
1

Research Faculty of Agriculture, Hokkaido University, 2 Faculty of Humanity and Environment, Hosei University, 3 Nippon
Koei, 4 Field Science Center for Northern Biosphere, Hokkaido University, 5 Hokkaido Institute of Hydro-Climate
Peatland ecosystems have accumulated a huge amount of soil organic carbon for millennia. However, it is reported that the soil
carbon has become vulnerable because of global warming and land-use change. Such disturbances potentially enhance oxidative
peat decomposition, and consequently a large amount of CO2 is emitted into the atmosphere. In Sarobetsu Mire in northern
Hokkaido, which has the largest Sphagnum -dominated bog in Japan, vascular plants, Sasa , have invaded into Sphagnum bog
because of the change of the hydrological environment, which was due to drainage for agriculture. To understand the effects ofthe expansion of Sasa -dominated area in Sphagnum bog on carbon balance, we measured CO2 flux using the eddy covariancetechnique at a Sphagnum -dominated area (B site) and a Sasa -dominated area (T site) and compared CO2 balance between thetwo sites.
Flux measurement was conducted during the four snow-free seasons from mid-April through early November in 2007 to 2010.
Eddy sensors of CO2 (LI7500, Licor) and wind speed (CSAT3, Campbell) were installed at the heights of 2.0 and 2.3 m, respectively, at B and T sites. The outputs from the sensors were recorded with a datalogger (CR1000, Campbell) at 10 Hz. Net
ecosystem CO2 exchange (NEE) was calculated on a half-hourly basis as a sum of eddy CO2 flux and CO2 storage change calculated from CO2 concentration measured by LI7500. NEE was partitioned into gross primary production (GPP) and ecosystem
respiration (RE) using an empirical conventional method.
Both GPP (gross ecosystem photosynthesis) and RE were larger at T site than B site. In 2008 with dry summer, cumulative
NEE for 6.5 months of the snow-free season was -129 and -179 gC m−2 , respectively, at T site and B site. The negative NEE
values indicate that the two peatland ecosystems functioned as CO2 sinks in the season. In addition, sink strength was higher
at T site. In 2010 with hot, wet summer, however, cumulative NEE was -238 and -159 gC m−2 , respectively, at T site and B
site. Although NEE increased largely at B site, it decreased at T site. Sphagnum moss grew more under the hot and moist
environment, which increased GPP more than RE. In contrast, although growth and resultant GPP also increased at T site, RE
increased more than GPP because of high temperature. This result suggests that net CO2 uptake will decrease by the invasion of
Sasa plants under the warming environment in the near future.

Keywords: Peatland, CO2 flux, Eddy covariance technique, Global warming

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ACG30-10

Room:301B

Time:May 25 11:45-12:00

Detection of vegetation phenology across Japan by using digital time-lapse cameras
IDE, Reiko1∗ ; OGUMA, Hiroyuki1 ; NAKAJI, Tatsuro2 ; NASAHARA, Kenlo3 ; ICHII, Kazuhito4 ;NAGAI, Shin4 ; ISHIDA, Akito5 ; NAKAMURA, Kazuhiko6 ; FUJIWARA, Akio6 ; WATANABE, Ryuichi7
1

National Institute for Environmental Studies, 2 Hokkaido University, 3 University of Tsukuba, 4 Japan Agency for Marine-Earth
Science and Technology, 5 Kyoto Prefectural University, 6 University of Tokyo, 7 Shinsyu University
Many recent studies have reported earlier timings of leaf flush and later timings of leaf fall around the world with progress ofrecent global warming. Seasonal change (phenology) of vegetation is an indicator for the climate change, and also is one of theimportant parameters for terrestrial ecosystem models to estimate the carbon balance. For detection of the long-term changes invegetation across wide areas, remote sensing technique is expected as a useful tool. However, due to the limitations of spatial
resolution and observing frequency, it is difficult to detect the species specific environmental responses by satellite. Therefore,
we collected high temporal and spatial resolution images by using digital time-lapse cameras. The purpose of this study is todetect phenology at a community or a species level for various types of vegetation across Japan, and to analyze the relationships
between phenology and temperature.
We used the images of live camera archives such as ”Phenological Eyes Network (PEN)”, ”Internet Nature Information System” of the Ministry of the Environment, ”Mt. Hiei live camera” of Kyoto Prefectural University, ”Cyberforest” of Tokyo
University and so on, which were taken in 2002-2014. Images of approximately 120 site·year at 20 sites across Japan were analyzed. The areas of interest for vegetation a community or a tree within the images were selected for analysis. RGB digital counts
in each pixel in the areas were extracted and Green Ratio Index (GR= G/ (R + G + B)), which varies seasonally reflecting leaf
greenness, was calculated at daily step. The time series of GR showed the maximum rate of change on the timings of leaf flush
and leaf coloring, consequently, the dates of start/end of green leaves (SOG/EOG) were estimated. Furthermore, we investigated
the relationships of the inter-annual variations between SOG/EOG and the temperature at each site.
The estimated SOG/EOG showed large variations across both years and areas, although earlier or later phenological trend
during 2002-2014 was not recognized so far. Nationwide earlier SOG in 2002, 2004 and 2009, and later EOG in 2005, 20102012 were found. When the green leaved season started earlier than other years, it tended to end relatively later. Vice versa, when
the green leaved season started later than other years, it tended to end relatively earlier. Such tendency of earlier or later SOG
sometimes differed from the districts even in the same year. SOG or EOG of each community or species had high correlations
with the mean temperature during respectively March-April or September at each sites. The impact of the climate change wasdiscussed from the view point of species-specific and site-specific temperature sensitivities of the estimated SOG/EOG.
For assessment of the impact of climate change on vegetation, we need to observe the phenology at more sites for longer term.
We plan to install more cameras and to analyze much more data including the uploaded images on the Internet. In addition, it isnecessary to keep updating the existing camera systems and to administrate the observation networks sustainably.
Keywords: Time-lapse camera, Phenology, RGB, temperature sensitivity

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ACG30-11

Room:301B

Time:May 25 12:00-12:15

Development of Above Ground Biomass estimation method using satellite data in Japan
BORJIGIN, Habura1∗ ; HAYASHI, Masato1 ; SAIGUSA, Nobuko1 ; YAMAGATA, Yoshiki1
1

National Institute for Environmental Studies

As a measurement method of Forest Above Ground Biomass, getting basic information of tree category, height and DBH fromfieldwork, then calculate the volume, multiply expansion factor and wood density to get the result is widely used. This method
can measure the forest above ground biomass correctly, however it is hard for us to make wall-to-wall map when monitoringlarge area of land. Satellite Remote Sensing is an effective way to estimate large area of forest distribution. In this study, ourpurpose is to investigate forest above ground biomass in the whole terrestrial land of Japan using ground truth data (fieldwork
data from forest above ground biomass) and satellite data. We mainly used MODIS reflectance data from 2000 to 2009, Land
Surface Reflectance data, Vegetation Index, LAI then using Random Forest method to estimate biomass.
We divided ground truth data to two groups, one group (90%) used as building Random Forest learning model. After thelearning model was built, another group of data (10%) was used for estimating above ground biomass. Then we did the regression
analysis between the estimation result and ground truth data. Accuracy assessment was carried out by calculation of coefficient ofdetermination and RMSE from regression analysis. The results showed R2 is 0.6, RMSE is 26.37 (t ha-1). Estimation accuracy
from deciduous forest and evergreen forest, R2 is 0.4 and 0.53, RMSE is 24.29 (t ha-1) and 27.34 (t ha-1), respectively. Evergreen
forest showed an higher accuracy. Also, we found out that low biomass (<100 t ha-1) and high biomass (>200 t ha-1) showedbigger estimation error. We compared the estimation result (acquired from forest above ground biomass of whole Japan) toprefectural data and forest registration, the comparison results showed coefficient of determination is 0.95, slope is 1.68 times,
which is much lower than verification result (1.86 times) from Forestry and Forest Products Research Institute.
In this study, we confirmed that combine satellite data and fieldwork data, using Random Forest machine learning model, thelarge area of forest above ground biomass can be effectively estimated. In future study, compare the Random Forest to othermodels then get more accurate estimation is one of our goals. Also, carbon emission from deforestation, typhoon and otherdisturbance caused forest biomass change should be considered as well.

Keywords: Satellite data, MODIS, Above Ground Biomass, RandomForest

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ACG30-12

Room:301B

Time:May 25 12:15-12:30

Forest resources monitoring using spaceborne LiDAR over Borneo
HAYASHI, Masato1∗ ; BORJIGIN, Habura1 ; SAIGUSA, Nobuko1 ; YAMAGATA, Yoshiki1 ; HIRANO, Takashi2
1National Institute for Environmental Studies, 2 Research Faculty of Agriculture, Hokkaido University

Forests serve as a primary reservoir of terrestrial carbon. Recently, the technology for forest resources monitoring at large-scaleis required for the purpose of understanding the global carbon cycle or supporting REDD+ scheme. Satellite remote sensing canprovide the most practical mean for the large-scale observation, and spaceborne LiDAR is particularly expected. This sensor
transmits a laser pulse from space to the Earth’s surface, and records the time-varying return signal intensity as a waveform.
The waveform makes it possible to analyze vertical structure near the surface. ICESat/GLAS was the only spaceborne LiDAR
so far, which was operated by NASA from 2003 to 2009. However, there are some future plans of spaceborne LiDAR, such as
ICESat-2, GEDI, and MOLI, and they are expected to be used for forest monitoring. This study aims to clarify the potentialof spaceborne LiDAR to quantitatively observe forest biomass at large-scale. We targeted Borneo as a study area, where is oneof the most important areas for REDD+ because the forest area in the island has been rapidly decreasing in recent years. First,
we measured above-ground biomass (AGB) by the Bitterlich method at 37 plots, where corresponded with the GLAS footprints.
And, we used the field measured data as the training data to develop an empirical model for estimating AGB from the GLAS
waveform parameters. As a result of cross-validation, the accuracy of this model (root-mean-square error) was 32.1 Mg ha−1 .
Next, we applied the developed model to the 127,862 points GLAS data over Borneo to assess the forest resources in the island.
As a result, some features were found as follows: (1) the average AGB in Borneo was 183.1 Mg ha−1 , (2) the AGB of evergreen
broadleaved forest was nearly two times larger than that of mangrove forest or shrub land, and (3) the total AGB in Borneo
was 9.81 Gt. Next, we developed a wall-to-wall map of forest biomass over Borneo using MODIS satellite image (see figure),
because GLAS observed at only discrete points. These results indicate that spaceborne LiDAR is a suitable sensor for forest
resources monitoring at large-scale.
Keywords: Forest biomass, Spaceborne LiDAR, ICESat/GLAS, Borneo

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ACG30-13

Room:301B

Time:May 25 14:15-14:30

Development of Sun-Induced Chlorophyll Fluorescence database based on ecosystem
tower measurement
KATO, Tomomichi1∗ ; TSUJIMOTO, Katsuto2 ; NASAHARA, Kenlo3 ; AKITSU, Tomoko3 ; NAGAI, Shin4 ;ONO, Keisuke5 ; SAITOH, Taku M.6 ; MURAOKA, Hiroyuki6 ; NODA, Hibiki7 ; SAIGUSA, Nobuko7 ;IDE, Reiko7 ; TAKAHASHI, Yoshiyuki7
1

Research Faculty of Agriculture, Hokkaido University, 2 School of Agriculture, Hokkaido University, 3 Faculty of Life and Environmental Sciences, University of Tsukuba, 4 Japan Agency for Marine-Earth Science and Technology, 5 National Institute forAgro-Environmental Sciences, 6 River Basin Research Center, Gifu University, 7 National Institute for Environmental Studies
Terrestrial ecosystems, forest, grassland and so on, absorbs atmospheric CO2 as a greenhouse gas by photosynthesis, and arethought to mitigate global warming. Estimation of geographical extent of their photosynthesical activity is very crucial for theunderstanding of global climate change in future. However, conventional vegetation indices (for ex, NDVI, EVI, etc.) representing the greenness of ecosystem, reduce the accuracy for photosynthesis estimation in the particular situations: for ex., theoverestimation in evergreen forest in winter and in drought.
Chlorophyll fluorescence is emitted from chloroplast to release the overflown energy of incident sunlight (so-called as SunInduced Fluorescence; SIF). Recently, Several studies proved that SIF could be utilized for photosynthesis estimation at theecosystem spatial scale (Zarco-Tejada et al., 2013, AFM, etc.) as shown by the strong correlationship between SIF and gross primary production (GPP). On the other hand, the availability of SIF is reduced due to small number of ground-based measurement
thought highly evaluated potential of them.
This study compiles the SIF derived at five different ecosystems at tower-based flux stations in Japan: paddy field in Mase,
grassland in Tsukuba university, deciduous broad-leaf and evergreen needleleaf forests in Takayama, deciduous needleleaf forest
in Fujihokuroku. The SIF is calculated in the O2-A band around the wavelength of 760 nm by Fraunhofer line depth (FLD)
method. We will compare the SIF to eddy GPP flux during 2005-2013 and show the preliminary analysis on the availability of
the SIF for the estimation of ecosystem photosynthesis.

Keywords: Ecosystem Photosynthesis, Remote Sensing, Flux measurement, Satellite measurement

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ACG30-14

Room:301B

Time:May 25 14:30-14:45

Estimation of water storage and evaporation at seasonal wetlands in Namibia by satellite
remote sensing
MIZUOCHI, Hiroki1∗ ; NASAHARA, Kenlo2
1

University of Tsukuba, 2 University of Tsukuba

North-central Namibia, classified as a semi-arid region, forms vast seasonal wetlands during the rainy season. Especially theseasonal ponds near the local farmers’ house (ondombe ) are assumed as important water resources for agriculture. Local farmers
mainly have cultivated only pearl millet (Pennisetum glaucum ), but nowadays they require the introduction of rice cropping inthe seasonal ponds to mitigate the risk of poor harvests.
To introduce sustainable rice cropping, evaluation of available water resource and water budget in the seasonal ponds is required. However, there has been few such researches due to the difficulty of the hydrological monitoring because the seasonal
ponds are distributed widespread area, and the water storage in the seasonal ponds fluctuate even during a few days. Thus we
utilized satellite remote sensing together with field measurement to estimate the chronological water storage and evaporation in
the seasonal ponds.
Study site covers north-central Namibia and the part of southern Angola (16:29:43S-19:05:20S, 14:24:59E-17:00:53). Also
we set three test sites (each site is 5.4 km by 5.4 km) in the study site for field measurement. First we prepared three different
types of satellite data (AMSR-E and AMSR2, MODIS, Landsat ETM+) from 2002 to 2013. We integrated these data by new
data fusion technique (database unmixing; Mizuochi et al ., 2014, Remote Sensing ) to detect water covered area with temporally
and spatially high resolution. Second, we made a field laser measurement in 11 typical seasonal ponds to generate regression
model between water covered area and water storage in the seasonal ponds. Then we translated water covered area detected bysatellite remote sensing into water storage based on the regression model. Finally, we estimated evaporation from seasonal ponds
derived from satellite data, comparing with precipitation data obtained by field observation to reveal the hydrological features inthis region.
As the result of database unmixing, the spatial resolution was improved from original resolution of AMSR-E and AMSR2(25 km) to Landsat ETM+ resolution (30 m). Temporal resolution was also dramatically improved: original Landsat ETM+
provided only 1.8% available data through the study period, whereas database unmixing provided 88.5% available Landsat-likedata through the study period. The laser measurement provided 110 samples which shows the relationship between water covered area and water storage in seasonal ponds. Based on these samples we generated regression model, and eventually translated
water covered area detected by database unmixing into chronological water storage data from 2002 to 2013. Both the integral
water storage and maximum value of water storage for each year reflected the precipitation situation of each year. For example,
in the rainy season between 2012 and 2013, which was reported as the severe drought once in 30 years, the water storage wassignificantly less than the other year’s water storage. While in the rainy season between 2008 and 2009, during which the flooding
occurred in the surrounding rivers, both the annual integral water storage and maximum water storage were high. By comparing
evaporation estimated by the satellite data with the precipitation data in three test sites, it was shown that the evaporation fromthe seasonal ponds was several to ten percent of the amount of water input by the precipitation. This result shows that both water
infiltration into the ground and evaporation from the soil surface are important process to express this region’s water budget.
This study not only revealed this region’s water storage and water evaporation but also proposed new approach for hydrological monitoring with high spatiotemporal resolution in seasonal wetlands. Further researches should be done in the future on
improvement of the algorithm or validation of these result.
Keywords: semi-arid, seasonal pond, database unmixing, laser measurement

1/1

ACG30-15

Room:301B

Time:May 25 14:45-15:00

Process-based modeling for mountain pasture dynamics in unusual warm and long snowfree wintertime
KATATA, Genki1∗ ; GROTE, Ruediger2 ; ZEEMAN, Matthias2 ; MAUDER, Matthias2 ; OTA, Masakazu3 ;LU, Haiyan2 ; KIESE, Ralf2
1

Karlsruhe Institute of Technology (KIT-IMK/IFU)/Japan Atomic Energy Agency, 2 Karlsruhe Institute of Technology (KITIMK/IFU), 3 Japan Atomic Energy Agency
Alpine plant ecosystems are known as a carbon source mainly in colder periods when soil respiration is exceeding grossprimary productivity. However, there is still little information about the specific impact of snow cover and thus the responseof these ecosystems to climate warming and accompanying snow cover shortening is unclear. Here, we coupled a multi-layer
atmosphere-SOiL-VEGetation model (SOLVEG) with a detail snow scheme, a grass growth scheme, and a soil microbiology
scheme to investigate managed grassland-snowcover dynamics. The employed grass growth module can simulate key processes
under cold environment such as leaf formation, elongation and death, tillering, carbon allocation, and acclimation on temperatureon photosynthetic activity and frost damages. We applied the modified SOLVEG to pre-alpine grassland sites in TERestrial
ENvironmental Observatories (TERENO) networks in Germany for a year with an exceptional small amount of snowfall (20132014). The modified model reproduced temporal changes in observations of surface energy and CO2 fluxes, soil temperature andmoisture, and aboveground biomass. Our simulations and measurements demonstrate that grasses at lower elevation continuously
assimilate atmospheric CO2 even in the middle of winter season. On the other hand, dead leaf biomass increases due to frosts
over cold snow-free days. As a result, snow-free wintertime carbon uptake was not as large as expected (13% of the annual carbon
uptake), and it almost balanced with wintertime soil respiration. However, under temperature rise conditions, grass ecosystems
act as a strong sink of CO2 from winter to early spring (25% of the annual carbon uptake) due to a decrease of frost damages offoliage. Future climate developments may enhance the importance of wintertime carbon uptake of typical mountain grass species
in the world.
Keywords: managed grassland dynamics, snow-free period, land surface model, photosynthesis, frost damage, European Alps

1/1

ACG30-16

Room:301B

Time:May 25 15:00-15:15

Model-Aided Analysis of FACE Effects on Rice Canopy Photosynthesis, Transpiration,and Water Use Efficiency
IKAWA, Hiroki2∗ ; OUE, Hiroki1 ; YOSHIMOTO, Mayumi2 ; KOBAYASHI, Kazuhiko3 ; OKADA, Masumi4
1

Faculty of Agriculture, Ehime University, 2 National Institute for Agro-Environmental Sciences, 3 Graduate School of Agricultural and Life Sciences, The University of Tokyo, 4 National Agricultural Research Center for Tohoku Region, 5 Faculty ofAgriculture, Iwate University
Sustainable agricultural practice requires promising crop productivity with efficient water use. Given the projected increase inatmospheric CO2 concentration [CO2 ], our understanding on the CO2 effects on rice productivity (i.e., photosynthesis) and wateruse (i.e., transpiration) on a leaf scale improved in the last few decades, particularly with Free-Air CO2 Enrichment (FACE) experiments that enable a simulation of a future agricultural field with high [CO2 ]. However, very few information is yet available
as to how the investigation on a leaf-level response of photosynthesis and transpiration to [CO2 ] is translated to the whole canopy
photosynthesis and transpiration (Shimono et al., Glob. Change Biol., 2013; Yoshimoto et al., Agric. For. Meteorol., 2005).
This is partly due to the limited size of a FACE ring where it is difficult to apply top-down measurements, such as the eddy
covariance technique. In this study, we quantified the effect of [CO2 ] on rice canopy photosynthesis, transpiration and water use
efficiency, using a multi-layer model with the model parameters obtained from single-leaf photosynthesis and transpiration measurements. With the model parameters carefully determined, we delineated the effects of [CO2 ] on the canopy photosynthesis
and transpiration through the changes in physiological and micrometeorological conditions for a better understanding on future
rice productivity and water use.

1/1

ACG30-17

Room:301B

Time:May 25 15:15-15:30

Improving the soil sub-model of the process-based terrestrial ecosystem model to apply
tropical swamp forests
HIRATA, Ryuichi1∗ ; ITO, Akihiko1 ; HIRANO, Takashi2 ; SAIGUSA, Nobuko1
1

National Institute for Environmental Studies, 2 Research Faculty of Agriculture, Hokkaido University

We applied conventional model (Vegetation Integrative Simulator for Trace Gases; VISIT) to tropical peat forest data obtained
from Palangkaraya (PDF) site in Kalimantan but it cannot simulate carbon balance accurately. Especially, ecosystem respiration(RE) showed opposite seasonal variation with observed RE because of misunderstanding of soil respiration process. Soil respiration process in conventional ecosystem model is controlled by only soil temperature and soil water content. In contrast, CO2
release from peat is regulated by not only these components but also water table. Soil respiration data obtained from PDF site
shows that the response of soil respiration to wetness is also different from that in conventional model. In order to improve theresponse of soil respiration, we modify soil submodel of the model. Ground water level is simulated by tank model. We modify
soil respiration function using the relationship between ground water level and soil respiration.
Keywords: carbon balance, ground water level, Central Kalimantan

1/1

ACG30-18

Room:301B

Time:May 25 15:30-16:00

Global estimation of soil nitrous oxide emission using a semi-empirical model
HASHIMOTO, Shoji1∗
1

Forestry and Forest Products Research InstituteNitrous oxide (N2 O) flux is one of the major greenhouse gas fluxes from terrestrial ecosystems. N2 O is generally released fromsoil surface to the atmosphere. In this study, a semi-empirical model was developed through modifying a model for soil CO2
flux (Raich et al. 2002), and the global distribution of N2 O flux from soil was examined. The model consists of the functionsof nitrogen, air temperature, and precipitation and the parameters of the functions were determined using a global dataset of
N2 O emission (Stehfest and Bouwman 2006). The model was applied at a spatial resolution of 5-minute and at a monthly time
resolution.
The preliminary calculation revealed that the total amount of N2 O emission was 14 Tg N yr−1 , and the monthly flux showeda clear seasonality, and was highest in August and lowest in February. The dry natural land is the major source of N2 O emission
while the dry cultivated land was the second major source. Latitudinally, the flux was high around 30 ̶ 40 degreeN and 10
degreeS ̶ 10 degreeN. These results were still based on limited data, especially for wet ecosystems, and will be updated infuture.

Keywords: soil, nitrous oxide, model, nitrogen

1/1

ACG30-19

Room:301B

Time:May 25 16:15-16:30

Variability in aboveground woody biomass in miombo woodland under fire disturbances
SAITO, Makoto1∗ ; LUYSSAERT, Sebastiaan2 ; POULTER, Benjamin3 ; WILLIAMS, Mathew4 ; CIAIS, Philippe2 ;BELLASSEN, Valentin5 ; RYAN, Casey4 ; YUE, Chao2 ; CADULE, Patricia2 ; PEYLIN, Philippe2
1

NIES, 2 LSCE, 3 Montana State University, 4 University of Edinburgh, 5 INRA Dijon

Miombo woodland is a savanna that spreads extensively over Africa, but it subjects to frequent fires (fire return intervals of
1-3 years) that are probably caused by human activities, such as cultivation, deforestation, and fuel wood collection. These
activities result in degradation of miombo woodland. The degradation of large areas of miombo woodland involves the risksof rapid change in the current stable state of ecosystems to an alternative state and of increasing fire frequency and intensity.
This study combined a process-based ecosystem model ORCHIDEE-FM with a fire regime model SPITFIRE to quantify the
relative importance of fire regime and climate change in regulating aboveground woody biomass in miombo woodland undercurrent and near-future climate conditions. The model was developed based on observations of resprouting and tree topkill rates
in individual tree size classes for varying fire intensity. The model demonstrated that fire has a large impact on abovegroundwoody biomass and vegetation structure in miombo woodland. Aboveground woody biomass in miombo woodland significantly
varies with fire regime with fire intensity and fire return interval. A shorter fire return interval and higher fire intensity results
in a greater reduction of aboveground woody biomass by reducing the mean tree size. Although fire return interval in miombo
woodland depends on human activities, fire intensity depends on the amount of grass fuel and on the season. For the current
fire regime in miombo woodland, adaptive fire management is necessary to maintain today’s aboveground woody biomass bycontrolling moderate fire intensity and frequency under current climate conditions. Under near-future climate with elevated CO2
concentration and warmer climate, miombo woodland is perhaps more tolerant of fire disturbances by increase in the resprouting
capacity and growth rate of woody plants.
Keywords: savanna, miombo, fire, aboveground woody biomass

1/1

ACG30-20

Room:301B

Time:May 25 16:30-16:45

Arctic terrestrial model intercomparison and its site-specific difference - physical process
and biogeochemical cycle.
MORI, Junko1∗ ; SAITO, Kazuyuki2 ; MIYAZAKI, Shin1 ; YAMAZAKI, Takeshi3 ; ISE, Takeshi4 ;ARAKIDA, Hazuki5 ; HAJIMA, Tomohiro2 ; IIJIMA, Yoshihiro2 ; MACHIYA, Hirokazu1 ; SUEYOSHI, Tetsuo1 ;YABUKI, Hironori2 ; GTMIP, Group6
1

National Institute of Polar Research, 2 Japan Agency for Marine-Earth Science and Technology, 3 Tohoku University, 4 Kyoto
University, 5 RIKEN, 6 GTMIP group
GRENE-TEA Model Intercomparison Project (GTMIP) is one of the modeling group’s activities in the terrestrial research
project of the GRENE Arctic Climate Change Research Project (GRENE-TEA). One of the challenges for Arctic model development is scarcity of site observation data available for validation of the models. GTMIP stage 1, site simulations at GRENE-TEA
observation sites using the common driving data which was elaborately combining reanalysis and site observation data, assesses
the inter-model variations and the site-specific differences, investigates their attributions to the implemented processes and theircomplexity of the models, and propose possible improvement of physical and biogeochemical processes for modeling of the
Arctic terrestrial (excl. glaciers and ice sheets).
So far, 16 terrestrial process models participate in GTMIP stage 1: a permafrost model (FROST), physical snow models (SMAPand SNOWPACK), land surface models (2LM, HAL, JULES, MATSIRO with several versions, and SPAC-Multilayer), physicaland biogeochemical soil dynamics model (PB-SDM), terrestrial biogeochemical models (BEAMS, Biome-BGC, STEM1 and
VISIT), dynamic global vegetation models (LPJ and SEIB-DGVM coupled with a land surface model (Noah-LSM) or standalone), and a coupled hydrological and biogeochemical model (CHANGE). Driving and validation data were produced for thefour GRENE-TEA observation sites; Fairbanks (USA), Kevo (Finland), Tiksi (Russia) and Yakutsk (Russia), which have different characteristics in snow accumulation, permafrost condition, vegetation and continentality. The 30plus-year forcing data is
primarily prepared from reanalysis data to compensate missing values and limitation in the coverage period of the observation
data. First, we made 30 minutes-interval forcing dataset (level 0.2) based on ERA-Interim. Air temperature and precipitation are
corrected with CRU and GPCP respectively. Then, the site specific data (level 1.0) was created by fitting the level 0.2 data to
the observation data at a site to inherit the characteristics of the site with enough temporal coverage for driving models. Target
period was set from 1980 to 2013 (34 years). Model outputs are compared and evaluated in terms of the metrics in the fivecategories: energy budget, snowpack (annual maximum snow depth, snowpack duration etc.), phenology, subsurface thermal andhydrological condition (ground temperature profile, active layer/seasonal freezing thickness etc.) and carbon budget.
Physical models reproduced mean annual latent heat flux better, especially at Fairbanks and Yakutsk, than biogeochemical
models that tend to show larger values than the observed, and great inter-model variability at Kevo. While dedicated snow models are good at reproducing maximum snow depth except for Tiksi, those models with invariant snow density show relatively
lower value than the observation. At Tiksi, a tundra site on an Arctic coast, all the models overestimate snow depth. Annual
gross primary production is reproduced well at Yakutsk. However at Fairbanks, the inter-model variation is large. Annual net
ecosystem production (NEP) does not have such large inter-model variation at all sites examined. However, at Fairbanks, model
outputs relatively overestimate to the observation value. On the contrary, NEP is underestimated at Yakutsk. Causes and attributions of the variability in reproducibility of the models will be discussed further.
Keywords: Circum-Arctic region, Terrestrial process model

1/1

ACG30-21

Room:301B

Time:May 25 16:45-17:00

A design for the new Earth System Model with terrestrial carbon/nitrogen cycle processes
HAJIMA, Tomohiro1∗ ; WATANABE, Shingo1 ; KAWAMIYA, Michio1 ; WATANABE, Michio1 ; NOGUCHI, Maki1 ;OKAJIMA, Hideki1 ; TATEBE, Hiroaki1 ; ITO, Akinori1 ; YAMAZAKI, Dai1 ; TACHIIRI, Kaoru1 ;KATO, Etsushi2 ; SUGIYAMA, Masahiro3 ; ITO, Akihiko4 ; OHGAITO, Rumi1
1

Japan Agency for Marine-Earth Science and Technology, 2 The Institute of Applied Energy, 3 UTokyo Policy Alternatives Research Institute, 4 National Institute for Environmental Studies
Changes in the natural environment that are the result of human activities are becoming evident, and these changes are interrelated and can not be investigated without interdisciplinary collaboration between scientific fields. In order to understandthe interrelated mechanism within the Earth’s environment and to evaluate/project the anthropogenic impact on it, Earth system models (ESMs) have been developed by incorporating the biogeochemical processes of terrestrial/marine ecosystems into
atmosphere-ocean general circulation models. These models have joined the Coupled Model Intercomparison Project (CMIP)
and contributed to the assessment report of IPCC. We finished a process of reviewing our modeling and scientific activities up
to the IPCC 5th assessment report, and we have started to design a new generation of ESMs. In this presentation, we briefly
summarize the scientific/modeling tasks with ESM, and illustrate the design of the new ESM we are now developing.
Keywords: terrestrial ecosystems, carbon cycle, nitrogen cycle, Earth system models, Climate change projection, Biogeochemistry1/1

ACG30-P01

Room:Convention Hall

Time:May 25 18:15-19:30

Estimation of carbon cycle in a cool-temperate coniferous forest by continuous monitoring of carbon isotopic ratio
TAKANASHI, Satoru1∗ ; DANNOURA, Masako2 ; NAKANO, Takashi3 ; KOMINAMI, Yuji1 ; MIYAMA, Takafumi1
1

Forestry and Forest Products Research Institute, 2 Kyoto Universitiy, 3 Mount Fuji Research Institute, Yamanashi

In recent years, carbon assimilation has been estimated at various vegetation and forests are expected as carbon reservoir for
the future climate changes. In a forest ecosystem, gas-exchange processes are complicated and difficult to estimate carbon flows
because leaf, trunk, root and soil have distinctive gas-exchange characteristics and are interactively affected by environmental
factors within a canopy. Fluxes and concentrations of 12 CO2 isotope compositions provide information about ecosystem physiological processes and their response to environmental variation. We continuously measured the concentrations of 12 CO2 and
13
CO2 inside the automated closed dynamic soil chambers and the surrounding atmosphere of a cool-temperate coniferous forest
near Mt. Fuji in Japan (AsiaFlux site code:FJY) using a tunable diode laser spectrometer (TDLS: G2101i, Picarro Inc.). The
δ13C of the atmospheric CO2 were fluctuated according the changes of CO2 concentration and fluctuations of the carbon isotope
signal from soil respired CO2 (δ 13 CRs ) was not detected, although Keeling plots to estimate δ 13 CRs were very sensitive and theresults were very scattered.
To understand carbon flows in a tree, we carried out in situ 13 C pulse-labelling experiments for a mature pine tree (Pinus densiflora ,Tree height: 20m) at the FJY site. The experiments were carried out September 2012, December 2012, and July 2013, covering
the canopy of the tree by a plastic film chamber and introducing 13 CO2 into the labelling chamber. The internal 12 CO2 and13
CO2 was monitored by the TDLS to calculate a carbon assimilation by the tree during the labelling experiments. Carbon efflux
from a trunk surface were monitored by the TDLS using four closed dynamic trunk chambers installed in different heights (15.5,
11.1, 7.3 and 3.8m height) of the tree. The carbon flow speed were estimated from the arriving time of 13 CO2 pulse to the trunk
chambers. The pattern of labelled 13 CO2 efflux in winter was different from other seasons. The speeds ranged from 0.04 to 0.24
m/hr and relatively slow in winter. The amount of carbon respired from the trunk surface were ranged 14-20% of the assimilated
carbon. In winter, the tree respired carbon from relatively upper trunk surface and lower in other seasons.

Keywords: forest, carbon cycle, isotope, laser spectrometry, carbon dioxide, respiration

1/1

ACG30-P02

Room:Convention Hall

Time:May 25 18:15-19:30

Methane dynamics in a temperate forest revealed by plot-scale and ecosystem-scale flux
measurements
SAKABE, Ayaka1∗ ; KOSUGI, Yoshiko1 ; TAKAHASHI, Kenshi2 ; ITOH, Masayuki3 ; UEYAMA, Masahito4 ;IWATA, Hiroki5 ; ATAKA, Mioko1
1

Graduate School of Agriculture, Kyoto University, 2 Research Institute for Sustainable Humanosphere, Kyoto University, 3 Center
for Southeast Asian Studies, Kyoto University, 4 Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 5 Faculty of Science, Shinshu University
Soils play important roles as CH4 sources and sinks. CH4 is produced in anoxic environments, including submerged soils,
by methanogenic bacteria. On the contrary, CH4 is oxidized by methanotrophic bacteria in upland soils. In general, forest soils
are recognized as the efficient sinks for atmospheric CH4 , because of their CH4 oxidation capacity in water-unsaturated soil
(Le Mer and Roger, 2001). However, we hypothesized that forest ecosystems, especially in wet warm climates such as Asianmonsoon climate, are not always CH4 sink. In this study, we examined the CH4 dynamics in a temperate Asian monsoon forest(Kiryu Experimental Watershed: 35o N, 136o E), which included wet areas along riparian zones within the watershed. In order toreveal the spatio-temporal variations of CH4 fluxes, we combined multi-point plot-scale CH4 flux measurements using chamber
methods and ecosystem-scale CH4 flux measurements using a micrometeorological method, relaxed eddy accumulation (REA)
method (Businger and Oncley, 1990; Hamotani et al., 1996, 2001).
Intensive manual chamber measurements of CH4 fluxes at 60 points in the wet areas and within the water-unsaturated forest
floor, respectively, showed that the wet areas had a greater spatial and temporal variability of CH4 fluxes than the forest floor. This
indicates that accurate consideration of CH4 fluxes from any wet areas is important in order to evaluate the CH4 budget within
the forests. From biweekly continuous manual chamber measurements of CH4 fluxes at 9 points in the wet areas and the forest
floor, respectively, hotspots of CH4 emissions were observed during summer and fall immediately after intensive precipitation in
the wet areas. On the other hand, in the forest floor, seasonal variations of CH4 fluxes were not simply associated with temperature variations. In contrast, CH4 absorption increased at some measurement plots in spring before intensive summer rainfall.
In addition to the manual chamber measurements, we observed the environmental responses of CH4 fluxes at a half-hourly time
resolution, by using automated chamber measurements at three plots on the water-unsaturated forest floor. We found that theCH4 absorption flux was greatly weakened by summer intensive rainfall, but recovered and peaked after rainfall as the soil watercontent decreased. The responses of CH4 fluxes to rainfall were different for each plot. In a dry soil plot with a thick humus
layer, CH4 fluxes decreased abruptly at the peak of rainfall intensity, and it increased gradually after rainfall. In a wet soil plot
and a dry soil plot with a thinner humus layer, such abrupt decreases in CH4 fluxes were not observed, and CH4 fluxes graduallyswitched from a sink to neutral following rainfall. Simultaneous measurements of CO2 fluxes provided useful information when
considering the controlling factors affecting complex CH4 fluxes in terms of gas diffusivity and microbial activity.
The ecosystem-scale CH4 flux measurements revealed that the Japanese cypress forest switched seasonally between being asink and source of CH4 , and the pattern differed year by year. CH4 fluxes tended to be a source during summer and fall, andswitched to a sink during dry period. At hourly to daily timescales, the CH4 fluxes were sensitive to rainfall; rain events increased
CH4 emission, decreased CH4 absorption, or shifted CH4 absorption to CH4 emission. The results show that the temperate forest containing riparian zone acted as a CH4 source seasonally, through the increased CH4 emission in the wet areas and/or thedecreased CH4 absorption on the water-unsaturated forest floor in response to changing soil temperatures and/or the soil water
status. The Asian monsoon rainfall was found to strongly influence temporal variations in CH4 fluxes at both plot-scale andecosystem-scales.

1/1

ACG30-P03

Room:Convention Hall

Time:May 25 18:15-19:30

Response of Siberian larch in Mongolia to environmental variability for the last century
KITAYAMA, Asami1∗ ; SUGIMOTO, Atsuko2 ; YONENOBU, Hitoshi3 ; MIJIDSUREN, Byambasuren4 ;LOPEZ, Larry5
1

Graduate school of environmental Science, Hokkaido University, 2 Faculty of Earth Environmental Science, Hokkaido University, 3 College of Education, Naruto University of Education, 4 Plant Protection Research Institute, Mongolian state university ofAgriculture, 5 Faculty of Agriclture, Yamagata University
Mongolian forest locates the southern boundary of Siberian Taiga forest. Patchy forests are observed only on the permafrost
in moisture area in Mongolia where annual precipitation exceeds about 300mm. Therefore, this means moisture condition is amajor factor controlling forest distribution. Recently, increase in temperature and decrease in precipitation have been reported inlarge area of Mongolia (Batima, 2006), and that these environmental changes may be a potential trigger tree mortality, change
in forest distribution and future thaw of permafrost. In this study, we selected five areas showing different moisture condition
and growth environment, Terelj (47N, 107E) in Khenty mountain region, Tsagaannuur (51N, 99E) and Hatgal (50N, 100E) near
Khuvsgul Lake in the northern forest area, and Tariat (48N, 100E) and Uyanga (51N, 102E) in Hangayn mountain region respectively. Tree-ring cores were collected from Siberian larch and tree-ring width was measured for each areas. Carbon isotope ratio
in tree-rings were analyzed to understand tree response to environmental variability for two areas of these.
Tree-ring width at Terelj negatively correlated with temperature and positively correlated with precipitation, and carbon isotope ratio positively correlated with temperature and negatively correlated with precipitation of previous and current summer.
Especially, tree-ring width shows more clear correlation with precipitation in previous summer than that in current summer,
whereas carbon isotope ratio shows more good correlation with precipitation in current summer than that in previous summer.
These results suggest that stem growth depends on the moisture condition in previous year, while tree-ring is formed with carbon
assimilated in the current year. Siberian larch showed very narrow ring width in recent years (after 1997) with very high carbon
isotope ratio at Terelj, suggesting severe drought stress. On the other hand, tree-ring width and carbon isotope ratio in northern
forest area did not show clear correlation with climate parameters. This results imply that trees in Tsagaannuur and Hatgal growunder relatively wet condition compared to trend at Terelj. Narrow ring width and high carbon isotope ratio found for Terelj was
not observed trees in northern forest area.

Keywords: Monoglia, Larch, Tree-ring, Carbon isotope ratio, Drought stress

1/1

ACG30-P04

Room:Convention Hall

Time:May 25 18:15-19:30

In situ measurement of soil carbon monoxide flux in temperate forest
KAWAI, Amy1∗ ; TAKAHASHI, Kenshi2 ; SAKABE, Ayaka3 ; KOSUGI, Yoshiko3
1

Faculty of Agriculture, Kyoto University, 2 Research Institute for Sustainable Humanosphere, Kyoto University, 3 Graduate
School of Agriculture, Kyoto University
Carbon monoxide plays an important role in the tropospheric chemistry via its reaction with the OH radical. Soil uptake of
CO is a sink of secondary importance, except for the chemical reaction with the OH. However, no reports are available on soil
CO flux continuously measured in the field of forest. Therefore, it is still unknown about the dynamics of CO in the temperate
forest ecosystem, especially the response to the micrometeorological and soil environmental change. In this study, we intended
to clarify the effects of the differences of the soil environment by measuring soil CO flux with the closed-chamber method and alaser spectrometer.
Soil CO flux was observed in Kiryu hydrological study site (KEW), in Shiga Prefecture, Japan. KEW has 55-year-old cypress
forests. Priority species of the forest floor is Eurya japonica growing sparsely. CO fluxes between soil surface and the atmosphere
were measured using the closed chambers, in which changes in CO concentration during the chamber closure were monitoredin-situ with the laser spectrometer. Three chambers were set up in three locations under different soil environment. Also, the soil
moisture content and soil temperature in the three plots were measured.
We found a significant absorption of atmospheric CO by soil surface. Focusing on the differences with the plot, less absorption
was found in the plot of less humus layer. More CO absorption was observed when the CO concentration of surrounding area
was high.

1/1

ACG30-P05

Room:Convention Hall

Time:May 25 18:15-19:30

Application of three sap flow techniques for Japanese cedar: attempting to estimate thecharacteristics of sap movement
IIDA, Shin’ichi1∗ ; TAKEUCHI, Shin’ichi2 ; SHIMIZU, Takanori1 ; TAMAI, Koji1
1

Forest Hydrology Laboratory, Forestry and Forest Products Research Institute, 2 Minami Kyushu University

Forests cover about 66% of land area of Japan, and Japanese cedar (Cryptomeria japonica ) occupies 18% of total forested area.
Recently, the water balance of a stand of Japanese cedar has been made clear quantitatively by using eddy-covariance method
and sap flow technique in Kyushu Island, Japan (Kumagai et al., 2014; Shimizu et al., 2015). Although Japanese cedar is one of
the most representative planted species in Japan, few studies have been carried out except in Kyushu Island. The most common
technique of sap flow is thermal dissipation method (TDM, Granier, 1985) in Japan. Heat ratio method (HRM, Burgess et al.,2001) and heat field deformation method (HFD, Nadezhdina et al., 2012) have been widely used among foreign countries, andadvantages and disadvantages of these techniques were described (e.g., Vandegehuchte and Steppe, 2013). However, HRM and
HFD have not been applied for Japanese cedar in Japan. In this study, we applied TDM, HRM and HFD for a tree of Japanesecedar, and carried out preliminary comparison among three techniques. Based on field measurements, we attempted to estimate
the sap flow characteristics within the target tree by three techniques.
We conducted measurements in a mature stand of Japanese cedar, whose age is 62, within Tsukuba Experimental Watershedlocated in southern part of Mt. Tsukuba, Japan. We picked up a tree of Japanese cedar whose height is 24.9 m and diameter at
breast height is 40.4 cm, and applied sensors of TDP, HRM and HFD. We used handmade sensors for TDM (e.g., Iida et al., 2013)
and sensors for HRM and HFD manufactured by ICT international Pty Ltd (type SFM1 and HFD8, respectively). Japanese cedar
has white zone, in which water movement stops, near the sapwood area. We injected acid fuchsin into a stem, and determinedcolored area as sapwood. The length of TDM sensor was 20 mm, and sap flux density, which is mean value along the sensor
length, was computed by the calibration equation by Granier (1985). The width of sapwood was 44 mm, and additional TDM
sensor was inserted into the sapwood at the depths from 20 to 40 mm. On the other hand, the length of HRM sensor was 35 mm,
and the sap flow movement was detected at the depths of 12.5 and 27.5 mm. For HFD, the sensor length was 96 mm, and thedepths of sap flow detecting were 20, 30, 40, 50, 60, 70, 80 and 90 mm.
The sap flux densities measured at the depth from 20 to 40 mm with TDM was larger than that at the depth from 0 to 20 mm.
Similar trend was found in the outputs of HRM and HFD. The results of measurements by three techniques show that active sap
flow movement occurred up to the depth of 40 mm of sapwood. The diurnal variations in sap flow movement measured by threetechniques were almost same, suggesting the applicability of these techniques to evaluate the characteristics of sap flow for a
Japanese cedar. However, additional measurements including thermal diffusivity of wood are necessary to obtain sap flux density
by HRM and HFD (e.g., Vandegehuchte and Steppe, 2013): in current stage, we have only qualitative comparisons among threetechniques. Moreover, to compare the sap flux densities measured by TDM, HRM and HFD, we have to make clear the azimuthalchanges in sap flux density within the target tree: three sensors inserted into different part of a stem in this study. We will present
the results including these topics.
Cited paper
Burgess, 2001. Tree Physiol., 21:589-598.
Granier, 1985. Ann. Sci. For., 42: 193-200. [English translation, in Evaporation, Benchmark Papers in Hydrology 2. Gash
JHC, Shuttleworth, WJ (eds). IAHS Press: Oxfordshire; 61-63].
Iida et al., 2013. JARQ, 47: 319-327.
Kumagai et al., 2014. J. Hydrol., 508: 66-76.
Nadezhdina et al., 2012. Trees, 26:1439-1448.
Shimizu et al., 2015. J. Hydrol., 522: 250-264.
Vandegehuchte and Steppe, 2013. Function. Plant Biol., 40: 213-223.

Keywords: Thermal dissipation probe, Heat ratio method, Heat field deformation

1/1

ACG30-P06

Room:Convention Hall

Time:May 25 18:15-19:30

Seasonal change in photosynthetic function of cedar and cypress forest estimated by
tower-based chlorophyll fluorescence
TSUJIMOTO, Katsuto1∗ ; KATO, Tomomichi2 ; HIRANO, Takashi2 ; SAITOH, Taku M.3 ; NAGAI, Shin4 ;AKITSU, Tomoko5 ; NASAHARA, Kenlo N.5
1

Graduate School of Agriculture, Hokkaido University, 2 Research Faculty of Agriculture, Hokkaido University, 3 River Basin
Research Center, Gifu University, 4 Japan Agency for Marine-Earth Science and Technology, 5 University of Tsukuba
Estimating the carbon cycle in terrestrial ecosystem is very important for predicting the climate change in future. Remote sensing observation with vegetation indices (VIs, for ex., Normalized Differential Vegetation Index: NDVI) has contributed greatly
to estimate terrestrial carbon budget. Because conventional VIs represent generally the greenness of ecosystem, however, there
has been the less accuracy especially for winter time in evergreen forest where the VIs tend to overestimate the photosynthesicalactivity due to its nearly constant greenness.
Chlorophyll fluorescence is emitted from the chlorophyll a and b to release the excess sun-light energy, and has been used for
detecting the photosynthesis stress in numerous ecophysiological studies so far. Recently, the chlorophyll fluorescence has beenutilized to represent the gross primary production (GPP), ecosystem photosynthesical activity, by the satellite remote sensing
studies (e.g. Frankenberg et al ., 2011, GRL). However, small number of chlorophyll fluorescence observation on the ecosystemscale at the ground reduces its availability despite its highly expected usefulness.
The aim of this study is to clarify the relationships between chlorophyll fluorescence, and photosynthesis and light use efficiency (LUE) by the ground based measurement in coniferous evergreen forest. The observations were carried out in theplantation forest consisting of mature Japanese cedar and Japanese cypress in Takayama, Japan, from 2007 to 2008. Downward
and upward spectral radiances were measured with hemispherical spectroradiometer (MS-700, Eko Instruments, Japan) mounted
at 30m-high above the ground surface. We calculated the Sun-Induced fluorescence (F S ) around the O2 -A band from the spectral
data with the Fraunhofer Line Depth method. The GPP was calculated from the carbon fluxes measured with eddy covariance atthe top of the tower (Nagai et al ., 2012). Both F S and GPP were averaged for 30 minutes.
F S showed the strong correlation to GPP linearly in the diurnal course (sunny day (2007/08/10): r 2 = 0.81, cloudy day(2007/07/24): r 2 = 0.87) and logarithmically in the seasonal change (2008 (half-hour): r 2 = 0.68, 2008 (daily): r 2 = 0.87). The
GPP was fitted against the F S for each month by the following rectangular hyperbolic curve:
GPP = αGPPSAT F S / (GPPSAT + αF S ),where α is the initial slope of the F S -GPP curve and GPPSAT is the saturated GPP at high F S emission. These two parameters showed the clear seasonal change. The root-mean-square error (RMSE) calculated for 2008 was 4.56 µmolCO2 m−2 s−1 .
We also investigated the relationship between F S and LUE in daily averages. The F S -LUE relationship could be regressed bylogarithm curve for each month (r 2 = 0.46 ˜0.95). The seasonal changes in the regression coefficients for F S -GPP and F S -LUE
curves were thought to be induced by the seasonal variation in the temperature-dependency of photosynthesis and the phenology.
We conclude that F S can be utilized to estimate GPP and LUE in evergreen forest, and that relationship between F S and GPP
is influenced by environmental factors such as air temperature.
Keywords: Remote sensing, Light use efficiency, Eddy covariance, Carbon cycle

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ACG30-P07

Room:Convention Hall

Time:May 25 18:15-19:30

Year-to-year variability in the timing of start and end of growing season in deciduous
forests in JapanNAGAI, Shin1∗ ; SAITOH, Taku2
1

Japan Agency for Marine-Earth Science and Technology, 2 Gifu University

Accurate detection of the spatio-temporal variability in the timing start (SGS) and end of growing season (EGS) is importantbut challenging task to evaluate the ecosystem functioning and service in deciduous forests under meteorological and climatechanges. Here, (1) we detected the spatio-temporal variability in the timing of SGS and EGS in Japan from 2001 to 2013 byanalysing Terra/Aqua MODIS satellite-observed daily green-red vegetation index (GRVI) with a 500-m spatial resolution; (2) we
examined the spatio-temporal variability in the timing of blooming of cherry, leaf-flushing of ginkgo, leaf-colouring of ginkgo
and maple, and leaf-fall of ginkgo and maple based on dataset of in situ phenological observation; and (3) we evaluate therelationship between year-to-year variability in the timing of satellite-observed SGS and EGS and those of in situ -observed SGS
and EGS. We found that (1) the year-to-year variability in the timing of SGS, EGS, blooming, leaf-flushing, -colouring, and-fall showed characteristics along vertical and/or horizontal gradients; and (2) the year-to-year variability in the timing of SGS
correlated with those of blooming of cherry and leaf-flushing of ginkgo in Hokkaido and Tohoku.
Keywords: satellite data, biometeorological data, deciduous forest, Japan, phenology, year-to-year variability

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ACG30-P08

Room:Convention Hall

Time:May 25 18:15-19:30

Differences in inter-annual variation in flowering and budding dates at two different climatological sites in JapanINOUE, Tomoharu1∗ ; NAGAI, Shin1
1

Japan Agency for Marine-Earth Science and Technology

To investigate the relationship between the inter-annual variability of the flowering and budding phenology and their geographical characteristics in Japan, we analysed the first flowering and budding dates of various plant species during winter and spring(Japanese camellia, persimmon, ginkgo, mulberry, narcissus, cherry, Japanese apricot, rhododendron, dandelion, Japanese wisteria, and Japanese lawn grass) from 1953 to 2011 at two different climatological study sites (Takayama, a northern colder site;
Gifu, a southern warmer site). We found that (1) fewer than half of the species showed a trend of earlier phenology at both sites,(2) mean phenological dates at Gifu were distributed at wider range (DOY [day of year] 21.9 to 145.2) than those at Takayama(DOY 95.5 to 165.5), and (3) the species with earlier flowering or budding at Gifu showed higher variability and advanced phenology compared with plants that had later flowering and budding. These findings (a) suggest the possibility that flowering andbudding phenology in central Japan has a localized response to increasing air temperature and (b) suggest the importance of thelong-term and continuous observation of flowering and budding phenology for a range of plant species at multiple sites (Inoueand Nagai, under review ).
Keywords: phenological observation, flowering date, budding date

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