Management of Water and Land Resources: Studies in Asia and Europe Yamagata University, 19.-23.November 2018

20.November 21. November Session I: Forest Ecology Session III: Carbon and nutrient cycles (Chairs: Larry Lopez & Jordi Voltas) (Chairs: Georg Guggenberger & Shigeta Mori) 9:10-9:20 Layout of the symposium (Larry Lopez) 9:00-9:30 Sustainable management of Siberian steppe agroecosystems (Georg 9:20-9:50 Use of snowmelt water by Japanese cedar inferred from sapflow and Guggenberger) δ18O, Shonai Region (Larry Lopez) 9:30-10:00 Universal scaling of roots/shoot respiration from seeds to giant trees: 9:50-10:10 Spatial and temporal urban pollution development assess by a triple How do roots drive individual growth? (Shigeta Mori) isotope approach inferred from tree-rings (Mika Hayashi) 10:00-10:20 Long-Term Organic Farming on Carbon Decomposition and Nitrogen 10:10-10:30 Nitrogen isotopic composition of plant tissues of Japanese cedar Mineralization in a Paddy Field: A Case Study on Andosol (Valensi (Cryptomeria japonica D.Don) and its implications on nitrogen Kautsar). recycling (Felix Seidel). 10:20-10:30 Coffee break 10:30-10:40 Coffee break 10:30-11:00 Abiotic processes control on organic P cycling in soils (Prof. Luisella 10:40-11:10 Long-term trends in water-use efficiency and relationships with tree Celli) growth in Mediterranean conifers: a synthesis (Jordi Voltas) 11:00-11:30 Biotic and abiotic controls of soil CO2 efflux in an Ethiopian mountain 11:10-11:30 Consistent scaling in whole-shoot respiration between bamboo and forest (Olga Shibistova) trees derived from different constraints. (Wang Mofei) 11:30-12:00 Soil properties modulation of elements biocycling (Eleonora 11:30-11:50 Effects of low light environment to whole plant respiration and Bonifacio) morphological traits of Fagus crenata seedlings (Citra Gilang qur’ani). 12:00-14:00 Lunch break 11:50-12:20 Forest management effects on different ecosystem elements: sustainability or resilience of what to what? (Josu G. Alday) Session IV: Agro-ecosystems (Chairs: Sergio de Miguel Magana & Yuka Sasaki) 12:20-14:30 Lunch break Session II: Mapping and machine learning 14:00-14:30 Impact of forest management and climate change on wild mushroom resources in Mediterranean pine forests: a synthesis (Sergio de Miguel (Chairs: Ching-Ying Tsuo & Jens Gross) Magana) 14:30-15:00 Life among landslides in mountainous terrain (Ching-Ying Tsuo) 14:30-14:50 Influence of Azolla incorporation and dual cropping on rice growth 15:00-15:30 A study in semantic segmentation (Motohisa Fukuda) and greenhouse gas emissions from a flooded rice paddy (Samuel 15:30-15:50 UAV-based tree species classification in combination with object- Kimani) based machine deep learning (Sarah Kentsch). 14:50-15:20 Past, present and future of strawberries in Japan (Takeshi Nishizawa) 15:50-16:00 Coffee break 15:20-15:30 Coffee break 16:00-16:30 Computer vision techniques applied to forestry (Yago Diez) 15:30-16:00 Applicability of water saving irrigation practice for paddy rice 16:30-17:00 Ecosystem services in agricultural landscapes: modeling pollination cultivation in an irrigation scheme of Kenya (Yuka Sasaki) services in Lower Saxony, Germany (Jens Gross) 16:00-16:20 Reduction of Greenhouse Gas Emissions from Paddy Fields in Response to Continuous Irrigation with Treated Wastewater (Luc Phung). 16:20-16:50 New Natural Products from Endophytic Fungi in Tropical Forest (Yoshihito Shiono).

Management of Water and Land Resources: Studies in Asia and Europe Yamagata University, 19.-23.November 2018

22. November 23. November

Session V: Hydrological Processes 9:00-11:30 Discussion about future collaborations (Chairs: Wolfgang Bogacki & Jörg Bachmann)

9:00-9:30 Scenario approach for seasonal forecasting of snowmelt-runoff (Wolfgang Bogacki) 9:30-9:50 Degree-Day Factor, snow characteristics and soil moisture dynamics in the Asahi Mountains of Shonai Region (Alex Brandt). 9:50-10:10 Dynamics of degree-day factor - A case study in German Alps (Fraz Ismail) 10:10-10:30 Water use pattern in different tree species and δ18O variability in the water cycle in Shonai area (Qiqin Zhang). 10:30-10:40 Coffee break 10:40-11:10 Dynamics of nitrate and sulfate inferred from stable isotope techniques in Chikusa river watershed, Hyogo Prefecture (Lei Fujiyoshi). 11:10-11:40 Soil Carbon and Soil Functions: How Solid Interfacial Chemistry and Wettability Control Important Soil-Physical Processes (Jörg Bachmann) 11:40-12:00 Closing Remarks

12:30-17:30 Fieldtrip: Yamagata University Research Forest and Farm

18:30 Joint dinner

Management of Water and Land Resources: Studies in Asia and Europe Session I: Forest Ecology

18 Use of snowmelt water by Japanese cedar inferred from sapflow and δ O, Shonai Region, Japan

M. Larry Lopez C.a*, Takahiro Osonoia, Qiqin Zhanga, Alexander Brandt Aa, Yoshihiro Iijimab, Takeshi Nakatsukac a Faculty of Agriculture, Yamagata University, Tsuruoka, Japan. b Graduate School of Biological Resources, Mie University, Mie, Japan. cResearch Institute for Humanity and Nature, Kyoto, Japan. …..

*Corresponding Author：[email protected]

Forest in heavy snowfall areas in northeastern Japan are characterized by periods of snow cover in spring that extend longer than the onset of transpiration and photosynthesis. In this study we measured sap flow in cedar trees (Cryptomeria japonica) and tree-ring cellulose δ18O. Simultaneous measurements of tree growth, snow depth, soil moisture, soil temperature and environmental parameters were conducted to determine the timing of the start of transpiration and evaluate the contribution of snowmelt on tree transpiration. The results showed that tree sap flow started by mid March when snow depth was approximately 2.2 m. However, based on the ranges of optimum air temperatures for the start of photosynthesis we estimated that transpiration started by mid-April and tree growth started by the end of April when soil temperature increases sharply as snowmelt is complete and there is no limitation for tree water uptake. This was reflected in the cellulose δ18O where the snow δ18O signal was not found at the initial stage of wood growth. Soil moisture showed a drastic increase in April along with the snowmelt rate. Thus, by May, the driest month of the year, soil water, which was is made of previous year rainfall and snowmelt water and it’s the water that contributes to transpiration in May when tree-ring formation started.

Key words: sap flow, snowmelt, snow cover, soil temperature, transpiration

Management of Water and Land Resources: Studies in Asia and Europe 1 Session I: Forest Ecology

Spatial and temporal pollution development asset by a triple isotope approach

inferred from tree-rings

Mika Hayashia*, M. Larry Lopez C.a, Chihiro Katob, Purevsuren Batdelgerc, Yoshihiro Noboria, ToshiroYamanakad, Takeshi Nakatsukae a Faculty of Agriculture, Yamagata University, Tsuruoka, Japan. b Department of Agricultural and Environmental Engineering, Faculty of Agriculture and Life Science, Hirosaki University, Hirosaki, Japan. c Institute of Plant Protection, Mongolian University of Life Sciences, Ulaanbaatar, Mongolia. dDepartment of Ocean and Environmental Sciences, Tokyo University of Marine Science and Technology, Tokyo, Japan. eResearch Department, Research Institute for Humanity and Nature, Kyoto, Japan. …..

*Corresponding Author：[email protected]

Since the 1990s rapid urbanization and land expansion has led to high pollution levels in Ulaanbaatar, Mongolia. Emissions mainly originate from households using local brown coal, especially during winter; the coal fueled thermoelectric power plants and vehicle exhaust. Trees uptake these pollutants via leaves and roots and ‘archive’ it in the tree tissue. Environmental monitoring has a short history in Ulaanbaatar, making it difficult to understand the development of pollution in the city. Therefore, in this study δ15N, δ13C, δ18O and trace elements in soil, needles and tree-rings (Larix sibirica) of the last 40 years were used as a proxy of the development of air pollution. The larch trees growing in different representative locations in Ulaanbaatar were used to estimate temporal and spatial change in pollution for the period 1978-2016. Only the stable isotope ratio for N reflected clearly the pollution development with tree-ring values being enriched for the last 20 years in the city center, ger and industrial area. From the δ15N values in the ger and residential areas, it could be inferred that the main source of pollution was coal and vehicle exhaust respectively, while the city center and industrial area showed a combination of pollution sources. The stable isotope ratios of O and C as well as the trace elements in tree-rings showed mixed results, therefore larch tree-ring δ15N only proved the highest potential as a proxy for the temporal as well as micro-spatial pollution characteristics within cities.

Key Words: stable isotopes; air pollution; heavy metals; Larix sibirica; tree-ring

Management of Water and Land Resources: Studies in Asia and Europe 2 Session I: Forest Ecology

Nitrogen isotopic composition of plant tissues of Japanese cedar (Cryptomeria japonica, D. Don) and its implications on the nitrogen cycle

Felix Seidela*, M. Larry Lopez C.a, Akira Oikawab, Toshihiro Yamanakab

aFaculty of Agriculture, Yamagata University, Tsuruoka, Japan bTokyo University of Marine Science and Technology, Tokyo, Japan

…..

*Corresponding Author：[email protected]

Nitrogen withdrawal from senescing leaves in evergreen trees is assumed to be stored mainly in the remaining leaves at the end of the growing season. However, there seems to be evidence that roots as well as stem tissues play a significant role in the storage of nitrogen and other nutrients. Therefore, the objective of this study is to clarify the seasonal nitrogen cycle in Japanese cedar (Cryptomeria japonica) trees in order to elucidate its N storage strategy. N content, isotope ratio and amino acids content were measured in coarse roots, sapwood, leaves (separated by age), litter and buds along the growing season. N content increased from shoot growth to the post-abscission period with younger leaves storing more nitrogen than older. One-third of N from senescent leaves was returned to root tissues in October and then to the sapwood and the remaining leaves in November. The variation of amino acids in leaf tissues did not match the fractionation of δ 15N during leaf abscission. Finally, Japanese cedar trees reabsorbed N in the pre-abscission period and stored most N in the wooden tissues of the tree followed by the leaves.

Key Words: Amino acids, Cryptomeria japonica, Nitrogen recycling, Nitrogen storage, Stable isotopes

Management of Water and Land Resources: Studies in Asia and Europe 3 Session I: Forest Ecology

Long-term trends in water-use efficiency and relationships with tree growth in Mediterranean conifers: a synthesis

Jordi Voltas

Dep. Crop and Forest Sciences, University of Lleida – Agrotecnio Center (Spain)

Intrinsic water-use efficiency (WUEi, the ratio of net photosynthesis to stomatal conductance of water) is a crucial trait that determines, at least in part, the carbon and water balance of forests and can be estimated from wood α-cellulose carbon isotope composition (δ13C). The magnitude of tree plastic responses determines the spatial and temporal dimensions of the variation of this important functional characteristic. Genetic differentiation at the inter- and intra-specific level adds complexity to the interpretation of WUEi patterns across scales. An increasingly large body of literature is reporting on how climate change and increasing atmospheric CO2 (Ca) are leading to substantial changes in WUEi of forest trees. The realisation 13 that δ C-based WUEi estimates are in close agreement with eddy covariance measurements or modelled ecosystem WUE (the ratio between gross primary productivity and evapotranspiration) supports the inference of vegetation-climate feedbacks grounded in tree-ring information. Disentangling the physiological effects of elevated Ca and warmer and drier climate conditions on long-term WUEi trends is fundamental for this purpose.

The long-term examination of WUEi changes can provide valuable clues on critical physiological thresholds under current warming that may compromise the future persistence of forests. Combined studies of radial growth and WUEi can also provide a better understanding on how trees modulate their water-use strategies to safe survival. In this presentation, I will focus on the interpretation of the patterns of WUEi stimulation observed over the last century in Mediterranean conifers. I will show examples on the nature and magnitude of changes in climate responses linked to increased aridity for an array of (mainly) pine species based on δ13C and ring-width data, as well as their impacts on absolute tree growth. Finally I will discuss whether recent WUEi trends are coupled or decoupled from forest growth dynamics in the Mediterranean region and under which conditions. This information is relevant to understand how climate change is affecting terrestrial carbon and water balances as urgent research priority in ecology and biogeosciences.

Management of Water and Land Resources: Studies in Asia and Europe 4 Session I: Forest Ecology

Convergence in scaling of whole-shoot respiration between bamboo and trees

derived from different constraints

Wang Mofei a,b*, Mori Shigetab, Kurosawa Yokob, Juan Pedro Ferrioc,d a The United Graduate School of Agricultural Sciences, Iwate University, Iwate, Japan b Faculty of Agriculture, Yamagata University, Tsuruoka, Japan c Aragon Agency for research and development (ARAID), E-50018 Zaragoza, Spain d Agrifood Research and Technology Centre of Aragón (CITA), Forest Resources Unit, Avada. Montañana 930, E- 50059 Zaragoza, Spain

*Corresponding Author：[email protected]

Individual metabolic rate, or respiration is evolutionally and ecologically meaningful indicator in the biological processing of energy and materials for all organisms. In general, the metabolic rate (i.e. respiration rate, R) of individual organism scales with body size, and is usually described as the simple power function of body mass (Ｍ): R = aM b, where a is a normalization constant, and b is the scaling exponent (slope on the log-log coordinates). In general, scaling exponent b of whole-individual respiration in trees is explained by the WBE model (Nature, 1997) on the basis of the assumption: “space-filling fractal like geometry”. The equation represents the emergent outcomes of the metabolism of individuals under various constraints. Therefore, to obtain a mechanistic insight into the regulation of scaling of metabolic rate, we need empirical evidence of whole-organism measurements. However, few empirical studies have compared whole-shoot respiration between bamboo and trees. To empirically explore the effects of the determinate and indeterminate growth on whole shoot respiration rates, we measured respiration of 83 growing whole-bamboo sprouts before leaf expansion, and 58 whole-bamboo shoots with leaves, and then compared them with our prior data of 254 tree-shoots from seedlings to giant trees. Astonishingly, we observed unpredicted consistency in scaling exponents b of bamboo sprout: 0.847 (95%CI: 0.814 – 0.881), bamboo-shoots: 0.833 (95%CI: 0.786 – 0.876), and tree shoots: 0.839 (95%CI: 0.818 – 0.857). For understanding the mechanism that the exponent of trees and bamboo shoots converged, we measured respiration rates of whole-leaves, branches, and culms of bamboo shoots. We observed clear isometric relations between mass and respiration rates in leaves, branches and culms, and recognized that the partition of mass in the three organs varied depending on the whole-shoot mass. Thus, in spite of the convergence of scaling exponent b between bamboo and trees, the value of b in bamboo was derived from the shift in partition of mass among organs, not the WBE model that is applicable for trees. Additionally, we recognized ontogenetic change in mechanisms for the converged scaling exponent in bamboo-sprouts and bamboo-shoots. Thus, even in a consistency of scaling exponent, we found the different mechanisms for constraining the exponent by reliable empirical measurements in tree-shoots, bamboo-shoots, and bamboo-sprouts.

Key Words: metabolic scaling; whole-shoot respiration; determinate and indeterminate growth; Phyllostachys pubescens; clonal plants

Management of Water and Land Resources: Studies in Asia and Europe 5 Session I: Forest Ecology

Effects of low light environment to whole plant respiration and morphological traits of Fagus crenata seedlings

Citra Gilang Qur’ani, Kenichi Yoshimura

Faculty of Agriculture, Yamagata University, Tsuruoka, Japan.

*Corresponding Author：[email protected]

In forest understorey, light availability strongly affected by the canopy trees in which creating gap formation and avoid direct transfer of light. Previous studies reported that growth, biomass and photosynthesis performance of Beech exhibited acclimation as light availability changed. We planted Japanese beech seedlings in the pots and placed them in open (max value 1,760 µmol/m2/s) and shaded sites (max value 252 µmol/m2/s). We observed the effect of low light availability to the growth and respiration rate of Japanese beech from seeds to 1-years-old seedlings. The results showed that seedlings in open site has higher value of height, stem diameter, leaf thickness, root-shoot biomass and leaf-stem-root surface area than seedlings in shaded site, but not significantly different in respiration rate for both seedlings at the same mass. Interesting fact that we observed was, root respiration rate was relatively higher than shoot with less biomass allocation than open site. We are currently observing growth rate and respiration rate in this year to see further affection of low light to Japanese beech using of planted materials. The results from this study confirm that light affects the growth of Japanese beech seedlings without affecting the respiration rate especially in the stage of current-year to 1-year old.

Key Words: Respiration rate, growth rate, open and shaded site, Fagus crenata, current- to 1-year -old

Management of Water and Land Resources: Studies in Asia and Europe 6 Session I: Forest Ecology

Forest management effects on different ecosystem elements: sustainability or resilience of what to what?

Josu G Alday*a, Carolina Martínez-Ruíz, Rob H. Marrsc a Departament de Producció Vegetal i Ciència Forestal, Universitat de Lleida-AGROTECNIO, Lleida, Spain. b Ecology Area, Agroforestry Sciences Department, E.T.S.II.AA. University of Valladolid, Spain. c School of Environmental Sciences, University of Liverpool, Liverpool, United Kingdom.

*Corresponding Author：[email protected]

Predicted changes produced by global change might negatively affect Mediterranean forests ecosystems and associated ecosystem processes. Forest management, such as forest thinning or clear-cutting, are traditional management tools that nowadays should be used adequately to manage these forest ecosystems for the long-term. However, studies addressing the combined effects of forest management over different ecosystem compartments such as understory vegetation or soil biome are still scarce. At the same time, different responses to management can be found. For instance, understorey plant species composition being an important part of Mediterranean forest ecosystems suffered both qualitative and quantitative changes with medium to hard management treatments, reducing the frequency and cover of characteristic forest species. In contrast, soil fungal community composition nor fungal species richness and diversity are clearly affected by thinning, indicating that soil fungal communities are resilient to management. Ecological resilience and its link to alternative states is an important concept in forest ecosystems dynamics. Nowadays, there is a need to maintain the forest resilience to respond against current and future disturbances. The difficulty for forestry is that resilience concept is complicated to measure in practice, and hence tend to be discussed in rather abstract terms. Here, we describe a methodology to test resilience in forest ecosystems considering different ecosystem compartments individually and simultaneously.

Key words: understorey vegetation, soil fungi, diversity, composition, harvesting

Management of Water and Land Resources: Studies in Asia and Europe 7  Session II: Mapping and machine learning

Life among landslides in mountainous terrain

Ching-Ying Tsoua*

a Faculty of Agriculture and Life Science, Hirosaki University, Aomori, Japan.

*Corresponding Author：[email protected]

Landslides come in different forms and can hit any area with great loss of life in mountainous terrain. They can be slow or fast-moving and can be triggered by rainfall or earthquake. This presentation presents the geological and geomorphic characteristics of catastrophic landslide disasters in recent years, including the 2008 Typhoon Morakot-induced landslide in Shiaolin Village in Taiwan, 2011 Typhoon Talas-induced landslides in the Kii Mountains in Japan, and 2015 Grokha earthquake-induced landslides in Nepal. Besides, the presentation also presents landslide hazard mapping in order to delineating landslide prone areas.

Key Words: Life loss; mapping; catastrophic landslide

Management of Water and Land Resources: Studies in Asia and Europe 8  Session II: Mapping and machine learning

Introduction to Deep learning

Motohisa Fukudaa* a Faculty of Science, Yamagata University, Yamagata, Japan.

…..

*Corresponding Author: [email protected]

In this talk, we study basic ideas of deep learning, which is a subcategory of machine learning and AI (Artificial Intelligence). Deep learning is now used widely used and yields successful applications, for example, in the field of image analysis. The talk starts with basic ideas about machine learning and then moves on to topics of deep learning. Moreover, we see some of the applications including agricultural ones.

Key Words: deep learning, image analysis, information theory.

Management of Water and Land Resources: Studies in Asia and Europe 9  Session II: Mapping and machine learning

UAV-based tree species classification by using different sensors in combination with object-based machine deep learning

Sarah Kentscha*, M. Larry Lopez C.a, Yago Diezb, Motohisa Fukudab

a Faculty of Agriculture, Yamagata University, Tsuruoka, Japan. b Faculty of Science, Yamagata University, Yamagata, Japan. ….. *Corresponding Author: [email protected]

A low degree of knowledge combined with a complex structure of mixed forests is the reason why researchers still investigate in mixed forest research for getting a deeper understanding. Especially mixed forests in Japan are influenced by the characteristically relief and the climate conditions. There is a high demand on accurate information about tree species of mixed forests. Methods to get accurate information on a large scale with easy access to the desired information are needed. It is possible to use drones for forest investigation. Images taken with a drone offer new methods to get information of forests like distribution, health condition or dendrometric parameters of trees. Also, it should be possible to do automatically classifications of tree species by using drones. The Yamagata Research Forest offers the opportunity to study mixed forests with different conditions in different parts of the forest for doing automatically classifications of tree species. Till now two study sites were defined and image were taken with a camera detecting the visual spectrum of the light. Also, images were taken during different seasons (summer and autumn). After taking the images they needed to be processed. A first step is to generate orthomosaics by merging the images using Photoscan from Agisoft. As a result, DEMs, orthomosaics and 3D models were generated and can be further analyzed. In the next step the segmentation and classification of tree species should be done in an object-based way using feature information of the trees. After processing the images it should be possible to create a model for deep machine learning which will be able to do the classification on its own.

Key Words: tree species classification, UAV, Yamagata research forest, image processing, Photoscan

Management of Water and Land Resources: Studies in Asia and Europe 10  Session II: Mapping and machine learning

Computer Vision techniques and their applications to forestry research

Yago Dieza* a Faculty of Science, Yamagata University, Yamagata, Japan. ….. *Corresponding Author：[email protected]

Computer vision is as research field that aims at achieving understanding of real data by using digital images. Computers are very well suited to process large sets of organized data such as the pixels that conform a digital image. However gaining insights that are useful in real applications is often a very challenging task. In order to meet this challenge, interdisciplinary teams including computer vision researchers as well as experts from the application area are necessary.

In this talk we will present some popular computer vision techniques and explore their past and potential uses in Forestry research. Special emphasis will be given to image classification, segmentation and registration of Drone images.

Key Words: Computer Vision, segmentation, classification, registration, application, Drone image

Management of Water and Land Resources: Studies in Asia and Europe 11  Session II: Mapping and machine learning

Ecosystem services in agricultural landscapes:

modeling pollination services in Lower Saxony, Germany

Jens Gross, Anne Piechulla and Benjamin Burkhard

Institute of Physical Geography and Landscape Ecology, Leibniz Universität Hannover, Hannover, Germany

Ecosystem services are defined as those functions of ecosystems that directly or indirectly benefit humans or enhance social welfare. Within agricultural landscapes, different kinds of ecosystems services provide benefits to society. Among these, pollination by wild pollinators is considered to be one of the key ecosystem services that improve or stabilize yields of crop and maintain biodiversity. In recent decades, structural changes in landscapes due to agricultural intensification, have led to a decreasing floral availability and a shortage of suitable nesting sites for wild pollinators in the agroecosystems of Lower Saxony. The decline in the diversity of habitats has significantly reduced the abundance of pollinating insects, leading to a decrease of ecosystem service supply. To detect pollination deficits and to predict how management activities and ecological enhancement measures will affect pollination potential, we adapted the small-scale spatial pollination model approach ESTIMAP to fit the local conditions of the agricultural landscape of Lower Saxony. The integration of high-resolution landscape structure data and local expert knowledge provided a spatially differentiated large-scale representation of the relative pollination potential. These results will be integrated in a multi-stakeholder approach to support decision making processes at different scales and policy levels and to implement best management practices that minimize the apparent trade-off between agricultural productivity and improved conditions for pollinator species and biodiversity.

Management of Water and Land Resources: Studies in Asia and Europe 12  Session III: Carbon and nutrient cycles

Sustainable Management of Siberian steppe agroecosystems

Georg Guggenberger

Steppes are among the most important ecosystems providing services of utmost importance for mankind. These soils do not only store tremendous amounts of organic matter and are thus significant players in the global carbon cycle, they belong also to the most fertile soils on Earth and are thus under intensive agricultural utilization. Like many steppes, also the Kulunda steppe in Siberia has been used for a few millennia by humans as non-intensive pastoral ecosystems. Already in the late 19th century the Kulunda region became an important agricultural producer, and with the Virgin Lands Campaign 1954-1963 industrialized agriculture was established. Transformation of grassland soils for agricultural use and intensification of formerly used arable land turned out to be successful only during the first few years, while later tremendous soil degradation, particularly erosion, led to declining and variable crop yield. An analysis of the agricultural soils of the Kulunda steppe revealed that they suffer from erosion, salinization, deterioration of soil physical properties and soil organic matter losses. For the whole study area, a quite close relation has been found between the level of soil degradation and the yield depression, being accentuated by the steppe type, i.e. climatic condition. The utmost important issue of soil degradation in this loess soils with establishment of agriculture was loss of aggregate stability. It was directly related to the intensity of soil cultivation, with intensively tilled soils showing the largest loss and no-till soil management the smallest. As both, wind and water erosion is directly related to the aggregate stability, the development and implementation of minimum or no-till management is very relevant to decrease soil erosion. The aggregate stability is strongly related to the loss of soil organic carbon contents and stocks. Throughout the whole study area the soils lost about 30% of their organic carbon. Most of the organic carbon losses occurred within the first 5 years after land use change, quite rapidly developing towards a new, lower, steady-state equilibrium. Expected future soil carbon contents were modeled using the PLJ model. The prognosed changes are spatially heterogenic, and vary depending on the recent land future land use. The LPJmL model simulates a continuing climate-change driven C loss from soil, which corroborates results of soil analysis along the climatic gradient. Based on the space-for-time approach, experimental data suggest that at the predicted drier climate there will be a pronounced organic carbon losses under both, grassland and cropland, due to generally reduced biomass inputs under dry conditions. Converting grassland to cropland under drier conditions will further keep the land use change-induced organic carbon losses at the same critical level as is observed in soils at present. Decreasing intensity of soil tillage and establishment of a proper fertilization regime will help to increase plant production with higher residue input to soil, will increase soil organic carbon storage and improve aggregate stability. Leaving crop residues on the soil surface will further have positive impacts on these parameters and will reduce evaporative water losses. All together this will reduce soil erosion and other types of soil degradation and increase the crop yield.

Management of Water and Land Resources: Studies in Asia and Europe 13  Session III: Carbon and nutrient cycles

Universal scaling of roots/shoot partition in whole-plant respiration

from seeds to giant trees

Shigeta Mori1,Yoko Kurosawa1, Mofei Wang2, Juan Pedro Ferrio3, Keiko Yamaji4

1 Faculty of Agriculture, Yamagata University, Japan 2 The United Graduate School of Agricultural Sciences, Iwate University, Iwate, Japan 3 Aragon Agency for research and development (ARAID), E-50018 Zaragoza, Spain 4 Graduate School of Life and Environmental Sciences, University of Tsukuba, Japan

*Corresponding Author：[email protected]

Plants have evolved from aquatic area and expanded their territory to terrestrial area by development of roots. Further, all terrestrial plants effectively use energy by respiration for acquiring carbon and water at a flexible energy balance in roots/shoot partition at the individual level, i.e. evolutionary important unit of life, under continuously variable terrestrial environments. However, few empirical studies of individual plants have focused on roots/shoot partition in whole-plant respiration of trees. In the present study, we conducted the most comprehensive measurements of respiration in entire roots and shoots using about 1000 individuals from seedlings to giant trees (including various phylogenies from Siberia to Tropical) with custom made chambers from 0.08 to 1200000 L in volume (Fig.1). Astonishingly, spanning about 1011-hold range of individual mass, we observed a converged trend in roots/shoot partition in whole-plant respiration, and it revealed that the larger plants have the smaller roots/shoot ratio in respiration. The size dependence of roots/shoot partition indicates that the larger ones have higher water use efficiency and relatively stable under changing environments. The results may provide a universal rule for all trees indicating a kind of emergent properties independent of phylogenic or biological properties of individual plants. The findings would develop general understanding of roots/shoot partition as an energy flow in terrestrial ecosystems.

Fig1. Measurements of whole-tree respiration including roots at the Yamagata University Forests We used a closed air circulation system (Mori et al. PNAS, 2010).

Key Words: metabolic scaling; whole-plant respiration

Management of Water and Land Resources: Studies in Asia and Europe 14  Session III: Carbon and nutrient cycles

Long-Term Organic Farming on Carbon Decomposition and Nitrogen Mineralization in a Paddy Field: A Case Study on Andosol

Valensi Kautsar a*, Weiguo Chengb, Keitaro Tawarayab, Kazunobu Toriyamac, Kazuhiko Kobayashid a The United Graduate School of Agricultural Sciences, Iwate University b Faculty of Agriculture, Yamagata University c Japan International Research Center for Agricultural Sciences d Graduate School of Agricultural and Life Sciences, The University of Tokyo …..

*Corresponding Author：[email protected]

The purpose of this study is to understand the decomposition of carbon and nitrogen mineralization in Japanese Andisol soil due to long-term organic rice farming. To determine the organic rice farming affected C decomposition and N mineralization in submerged rice paddies, three incubation experiments were carried out in the laboratory on anaerobic condition. The first study was directed to understand changes in topsoil (0-15 cm) and subsoil (15-20 cm) layers. Furthermore, a second study to determine the effect of foxtail (Alopecurus aequalis) as winter fallow grasses with the years of organic practice and lastly to find out the effect of foxtail and milkvetch (Astragalus sinicus) on C decomposition N mineralization potentials. Soil samples were taken from the fields after rice harvested on October 2013. The fields were divided into 4 treatments based on the years after organic farming, which are conventional (0 years), organic 4~5 years, 8~9 years and 12 years. Anaerobic incubation was performed for 2, 4, 6 and 8 weeks and 30°C to measure decomposed C (CO2 and CH4 productions) and mineralized N. The results showed that long-term organic farming increasing C decomposition and N mineralization potentials with the years of organic practice. We also found that application of milk vetch contributed higher N mineralization rate than foxtail, whereas carbon decomposition was not significant.

Keywords: organic farming, rice paddy, Andosols, C decomposition, N mineralization

Management of Water and Land Resources: Studies in Asia and Europe 15  Session III: Carbon and nutrient cycles

Organic P cycling in forest soils: abiotic versus biological reactions

Luisella Celi

Department of Agricultural, Forest and Food Sciences, University of Torino, Italy. …..

*Email：[email protected]

Organic P cycling in soil is strongly controlled by the tight interconnection between Fe/Al and P biogeochemical processes. Abiotic processes are reported to lead to a selective stabilization of inositol phoshates with respect to the other organic P species. This is linked to the high affinity of inositol phosphates for Fe and Al oxide surfaces by adsorption, which hampers their biodegradation and controls their fate in soil. Precipitation and coprecipitation may further contribute to organic P stabilization. Thus, the proportion of different organic P species and their retention by the solid phase are governed by soil evolution and Fe and Al oxide content and characteristics. However, in different chronosequences the most evolved soils did not show the organic P pattern expected from the enrichment in Fe and Al oxides. Combined mechanisms may contribute to change this pattern, such as the stability of Me oxides and the capacity of plants/microorganisms to produce organic acids able to release organic P compounds from minerals. With soil evolution, P becomes the limiting nutrient in many ecosystems, although there are some P poor soils even at the beginning of their formation. In these systems, plants may adopt further strategies for mining organic P, increasing their capacity to utilise also stabilized forms. Thus, if in P rich soils abiotic reactions may control many biologically mediated processes, in P poor systems biocycling drives organic P mobilization and the availability of the nutrient for plants.

Management of Water and Land Resources: Studies in Asia and Europe 16  Session III: Carbon and nutrient cycles

Abiotic and biotic control of carbon exchange rate in Ethiopian Afromontain forest ecosystems

Olga Shibistova

African forests are considered to act as a relevant global carbon sink, but there is still great uncertainty on vulnerability of the African carbon balance, especially with respect to the response on environmental disturbances. Ethiopian highlands contributing more than 50% of the Afromontane forests belt area, potentially represent an important potential source of greenhouse gases due to the ongoing processes of forest degradation caused by anthropogenic pressure (i.g. timber extraction, firewood collection, and in particular forest grazing). As result, structure and composition of pristine forest stands changes in behalf of early successional tree species at the cost of late successional ones. As soil respiration is a decisive component in the carbon exchange between terrestrial ecosystems and atmosphere, knowledge of driving parameters of soil CO2 efflux in Afromontane forests is a key issue in optimizing carbon friendly land management, as well as separating the effects of abiotic and biotic factors is critical to understand the belowground carbon dynamics of forest ecosystem. We evaluated features of seasonal patterns of soil respiration and quantified effect of abiotic factors (soil temperature and soil moisture) as well as influence of tree species on soil CO2 efflux rates and carbon allocation in the atmosphere-tree-soil system. To investigate into the latter topic, using a 13C-labelling technique, we compared the carbon cycling of the late successional gymnosperm Podocarpus falcatus (Thunb.) Mirb. and the early successional (gap filling) angiosperm Croton macrostachyus Hochst. es Del. Since development of forest plantations is one of valuable measures to fulfill ever-increasing demand of forest products and mitigate forest degradation-related carbon emission, we also included in our comparative investigations planted exotic tree (Cupressus lusitanica). Our results show that degradation of Afromontane forests accelerates carbon allocation belowground and increases respiratory carbon losses, in particularly, by autotrophic community (arbuscular myccorhiza). If ongoing disturbance keeps early successional species in dominance, the larger allocation to fast cycling compartments may enhance ecosystem carbon losses and deplete soil organic carbon in the long run. However, promotion of planted coniferous species, like Cupressus lusitanica appeares to be a potential alternative solution to satisfy timber demands without significantly losing soil organic carbon. However, biodiversity losses cannot be precluded.

Management of Water and Land Resources: Studies in Asia and Europe 17  Session III: Carbon and nutrient cycles

Soil properties modulate element biocycling in forest areas

Eleonora Bonifacio

Department of Agricultural, Forest and Food Sciences, University of Torino, Italy.

*Email: [email protected]

Biocycling is essential in preventing losses of nutrients through leaching, and depends both on tree and soil characteristics. The uptake of elements is indeed modulated by plant needs, and its release back to the soil solution is influenced by litter turnover rate. However, biocycling is more effective in nutrient poor-soils, where an active decrease of leaching losses is visible, despite the similarities of element inputs through litter. Beech forests on the Alpine ultramafic complex provided a perfect study area to evaluate fertility- dependent biocycling as soils are more or less Ca-limited depending on the amounts of serpentinitic rocks. Changes in forest cover affect biocycling through variations in litter turnover rate. In case of recalcitrant litter and large amounts of tannins that decrease biological activity, the release of elements from litter mineralization is hampered. American red oak (Quercus rubra L.) has been extensively planted in Northern Italy until the mid of the last century but is now included in the black list of invasive species. Its eradication is mandatory but recolonization by indigenous species is often hampered. The high nutrient demand of red oak, associated with the production of allelopathic substances, uncouples the release of elements from litter and plant needs, dramatically decreasing soil fertility in well developed Luvisols. As the production of tannins and other allelopathic substances is stimulated in low fertility soils, it is likely that the negative effects of red oak on ecosystem restoration are modulated by the soil fertility status, i.e. by soil resilience, which in turn depends on soil development. A comparison of red oak/English oak stands along a soil fertility gradient clearly shows that fertility-poor soils are less resilient and the negative effects of alien species are more evident.

Key Words: Invasive species; nutrients; organic matter dynamics, soil fertility

Management of Water and Land Resources: Studies in Asia and Europe 18  Session IV: Agro-ecosystems

Impact of forest management and climate change on wild mushroom resources in Mediterranean pine forests: a synthesis

Sergio de-Miguel

Department of Crop and Forest Sciences, University of Lleida – Agrotecnio Center, Lleida, Spain. e-mail：[email protected]

Edible mushrooms are one of the most valuable non-wood forest products from Mediterranean forests, not only because of their economic value through harvesting, marketing and consumption (which can be even much higher than the economic benefits from timber production), but also because of the high social value that mushroom picking has as a traditional recreational activity. What are the drivers of edible mushroom productivity? Is this important and valuable forest product endangered within a context of global change? Land use changes such as the progressive abandonment of forest management as a result of profound changes in Mediterranean and European societies and their productive sectors, entail changes in forest ecosystems that can affect the productivity of valuable mushroom species. Can alternative forest management policies contribute to increasing or decreasing mushroom productivity? Moreover, the effects associated with climate change scenarios, which predict a rather generalized increase in temperatures in Mediterranean areas, as well as changes in precipitation patterns, can also affect the productivity of mushrooms since fungal dynamics are largely driven by climatic and weather conditions. This presentation summarizes the results of the main published and ongoing scientific studies carried out in Mediterranean forests of Catalonia region, northeastern Spain, with the aim of providing further insights into the effects of the global change on the production of edible and marketed mushrooms.

Key words: fungi; non-wood forest products; global change; forest harvesting; productivity; yield

Management of Water and Land Resources: Studies in Asia and Europe 19  Session IV: Agro-ecosystems

Past, Present and Future of Strawberries in Japan

Takashi Nishizawaa* a Faculty of Agriculture, Yamagata University, Tsuruoka, Japan. …..

*E-mail: [email protected]

Strawberries were first brought to Japan in the middle of 19th century (“Edo” period) by Netherlanders, and called “Oranda-ichigo” (Holland strawberry). Although other strawberry cultivars were introduced from Europe and USA thereafter, the cultivation was not successful. Commercial production of strawberries in Japan started in 20th century especially in “Kuno” district of Shizuoka Prefecture as “Ishigaki ichigo” (stone-wall) forcing culture, and the production gradually spread to various places. Japan became the biggest strawberry production country in Asia Pacific region at the end of 1,930’s. However, strawberry production in Japan was stopped by the government during World War II, and it was not recovered for a while even after the war. Therefore, the production reached the prewar level in 1,951. However, the production recovered rapidly again with the progress of plastic greenhouse cultivation. In 1,970’s, approximately 200,000 t of strawberry fruit was produced in 14,000 ha that was the 2nd biggest strawberry production in the world next to USA. Strawberry production in Japan, however, is decreasing gradually after 1,980’s because of the aging of strawberry farmers, reduction of consumer income, and so on. On the other hand, strawberry production in many Asian countries is rapidly increasing nowadays, especially in China. As the result, current strawberry production in Asian countries shares almost half of the global output. In this presentation, past, present and future of strawberry production in Japan will be introduced.

Key words: Japan, production, strawberry, yield,

Management of Water and Land Resources: Studies in Asia and Europe 20  Session IV: Agro-ecosystems

Influence of Azolla incorporation and dual cropping on rice growth and greenhouse gas emissions from a flooded rice paddy

Samuel Munyaka KIMANI a*, Putu Oki BIMANTARAa, Weiguo CHENGa, Keitaro TAWARAYAa, Shigeto SUDOb a Faculty of Agriculture, Yamagata University, Tsuruoka, Japan. b Institute for Agro-Environmental Sciences, NARO, Japan.

*Corresponding Author：[email protected]

Azolla filiculoides Lam. is widely used as green manure accompanying rice, but its ecological importance still remains unclear, except for its ability to fix nitrogen in association with cyanobacteria. To investigate the impacts of Azolla cultivation on rice performance and simultaneous methane (CH4) and nitrous oxide

(N2O) emissions in flooded paddy soil, we conducted a pot experiment in Tsuruoka, Yamagata, Japan, in 2017 with six treatments, control (NPK only), Azolla green manure (AGM) (rice plus Azolla incorporation and covering on the flooding water), and AGM+NPK, with and without poultry biochar addition.

The results showed that, compared to conventional NPK treatment, AGM (plus top dressing) significantly increased rice grain yield by 32.7% while combination of AGM with either NPK, biochar, or both, (plus/minus top dressing), showed highly positive and significant synergistic interactions, with AGM+BIO (plus top dressing) significantly increasing grain yield by 30.9% compared to NPK+BIO (plus top dressing). Among the different soil variables studied, results showed improved soil fertility. Increase in soil total C, total N, pH, and phosphorus (P) were consistent with the properties of biochar used in this study. Cumulative CH4 fluxes in AGM treated pots were higher than in the control pots in the order of NPK+AGM > AGM > AGM+BIO > NPK+AGM+BIO > NPK > NPK+BIO. AGM application, plus/minus biochar, however, showed reduced efflux of CH4 per grain ton/yield with NPK+AGM+BIO recording the lowest CH4 efflux values. Cumulative N2O flux followed the order of NPK > AGM > NPK+AGM > NPK+BIO > NPK+AGM+BIO > AGM+BIO. Treatments with biochar significantly reduced initial and cumulative N2O emissions. Green manure, incorporated plus dual, had a positive feedback as a replacement for inorganic N basal application, however, a large positive synergism in terms of yield and N recovery was achieved when combined with inorganic fertilizers, with or without biochar addition. To reduce CH4 and N2O emissions from flooded rice fields, AGM amended with biochar appears to be a promising mitigation option.

Key Words: Azolla; methane; green manure; nitrous oxide; biochar; rice

Management of Water and Land Resources: Studies in Asia and Europe 21  Session IV: Agro-ecosystems

Applicability of water saving irrigation practice for paddy rice cultivation in an irrigation scheme of Kenya

Yuka Sasaki a*, Shota Fukuda a,b, Hiroaki Samejimac, Mayumi Kikutad, John Kimanie, Daniel Mengef, Daigo Makiharaf, Akira Yamauchig a Faculty of Agriculture, Yamagata University, Tsuruoka, Japan. b Zensho Holdings Co., Ltd., Tokyo, Japan. c Graduate School of Agricultural Science, Kobe University, Kobe, Japan. d Applied Social System Institute of Asia, Nagoya University, Nagoya, Japan. e Kenya Agricultural and Livestock Research Organization (KALRO) Mwea, Mwea, Kenya. f International Center for Research and Education in Agriculture, Nagoya University, Nagoya, Japan. g Graduate School of Bioagriculture Sciences, Nagoya University, Nagoya, Japan.

*Corresponding Author：[email protected]

Rice demand in sub-Saharan Africa is increasing. We conducted a research in Mwea irrigation scheme of Kenya, where main rice production area but seasonal and spacial poor distribution of irrigation water limits to increase rice production. The objectives of this research were to know the applicability of water saving practices, alternate wetting and drying (AWD) in Mwea irrigation scheme and the effect of AWD on recovery rate of fertilizer nitrogen by rice plant. The field experiment was conducted in Mar.–Jun. (1st season) and Aug.–Nov. (2nd season) in 2016 on an irrigated paddy field of KALRO Mwea. Treatments were continuous flooding (CF) and AWD reached -10 kPa (AWD-10) and -30 kPa (AWD-30). 15N fertilizer was applied at rooting, early tillering, and panicle initiation (PI) stages to measure recovery rate by rice. Irrigation water was saved in AWD compared with CF, while yield was no difference among treatments in both seasons. Recovery rate of fertilizer nitrogen by rice were lower in AWD than CF at rooting and PI in 1st season and no differences at tillering in 1st season and at three times in 2nd season. From the results of soil redox potential, the follows were estimated: the soil of CF was reductive condition at both surface and middle of plow layer, the soil surface of AWD was oxidized condition which could be nitrified fertilizer nitrogen except at the time of tillering application in 1st season and during after rooting application until tillering application in 2nd season, and the nitrified nitrogen at soil surface of AWD could be denitrified at middle of plow layer of AWD.

Key Words: irrigated paddy field; water saving; rice yield; recovery rate of fertilizer nitrogen

Management of Water and Land Resources: Studies in Asia and Europe 22  Session IV: Agro-ecosystems

Reduction of Greenhouse Gas Emissions from Paddy Fields in Response to

Continuous Irrigation with Treated Wastewater

Luc Duc Phunga*, Dung Viet Phamb, Toru Watanabeb a The United Graduate School of Agricultural Sciences, Iwate University, Morioka, Japan. b Faculty of Agriculture, Yamagata University, Tsuruoka, Japan.

*Corresponding Author：[email protected]

This study evaluated the effects of different continuous irrigation systems on CH4 and N2O emissions from paddy fields irrigated with treated wastewater (TWW) through two consecutive experiments in 2017 and 2018 crop seasons. In the first experiment, two continuous irrigation systems were examined, namely sub- irrigation and surface irrigation in which TWW was continuously supplied into experimental growth chambers at a flow rate of 4.5 L day-1 either through an underground pipe system or on the soil surface, respectively. A control applying manual tap water irrigation and supplementation with synthetic fertilizers was also simultaneously implemented. The treatments for the second season included one control along with three water regimes of the continuous sub-irrigation system: a constant supply rate of 4.5 L day-1 throughout the crop season (R1); a supply rate of either 4.5 (R2) or 6.5 L day-1 (R3) employed from the active tillering stage-30 days after transplanting (DAT) to the hard dough stage-114 DAT with a lower rate of 1.5 L day-1 for the rest growth durations. No chemical fertilizer was supplemented to the examined TWW irrigation systems that were equipped with electronic pumping systems in both seasons.

Results from 2017 experiment showed that the seasonal flux of CH4 averaged from the two TWW irrigation systems (0.23 mg m-2 h-1) was staggeringly lower than that (4.37 mg m-2 h-1) from the control, -2 -1 while their fluxes of N2O emissions averaged 309 and 46.17 µg m h , respectively. The sub-irrigation significantly reduced CH4 and N2O emissions by 37 and 78% compared with the surface irrigation, respectively. The net global warming potential (GWP) of the control was substantially reduced by 48 and 86% by the surface and the sub-irrigation, respectively, which indicated that the sub-irrigation would considerably diminish the radiative forcing of paddy fields. In the follow-up season, accordingly, the different supply regimes (R1, R2, and R3) was examined for minimizing the emissions from the sub- irrigation system. In contrast with the control, the TWW irrigation systems tremendously reduced CH4 but increased N2O emissions by 77 and 62%, respectively. The minimum GWP was measured from the treatment of R2 while the maximum was accounted for the control. Results of grain yield and yield-scaled GWP indicated that there was no significant difference in brown rice yield among the four treatments while the yield-scaled GWP decreased markedly following the order: the control>R1>R3>R2. In conclusion, the continuous sub-irrigation with TWW at a combined supply rates of 4.5 and 1.5 L day-1 (R2) could be an effective option for simultaneously mitigating GHG emissions and maintaining sustainable rice production.

Key Words: Continuous irrigation with TWW; mitigate emissions; sustainable rice production

Management of Water and Land Resources: Studies in Asia and Europe 23  Session IV: Agro-ecosystems

New Natural Products from Endophytic Fungi in Tropical Forest

Yoshihito Shiono1,2, Nanang Rudianto Ariefta2

1Faculty of Agriculture, Yamagata University, Tsuruoka/Japan, 2UGAS, Iwate University, Morioka/Japan

*Corresponding Author：

Microorganisms exhibit a wide range of biological and pharmacological properties, including anticancer, antimicrobial, plant growth inhibition, insecticidal, antioxidant, and antiallergic activities. Endophytes are microorganism living inside tissue of plants without causing any symptom disease toward the host plants and contribute to their hosts as they provide a range of growth, protection, increasing plants survival, and health and defense enhancements. As such, endophytes are one of bio-control agents that can be exploited several different fields of applications such as medicinal and agricultural and industrial purposes. Discovering new novel and biologically active natural products from endophytes has received much research attention in recent years. In our going searching for our ongoing search for new natural products from endophytes, over 200 fungal strains were collected from the twigs and petiols of the tropical plants. In the talk, chemical structures and the biological activities of these compounds produced by the fungi are introduced.

Keywords:

Management of Water and Land Resources: Studies in Asia and Europe 24  Session V: Hydrological Processes

Scenario approach for seasonal forecasting of snowmelt-runoff

Wolfgang Bogackia*, Muhammad Fraz Ismaila a Department of Civil Engineering, University of Applied Sciences Koblenz, Germany.

*Corresponding Author：[email protected]

Snow and glacial melt from the high mountain ranges of the Western Himalaya – Karakoram – Hindu Kush region are the primary sources of spring and summer flows in the large rivers of the Indus Basin. The Indus Basin Irrigation System, which is the backbone of Pakistan’s irrigated agriculture comprising a canal command area of more than 14 million ha, is largely depending on these surface water resources. A reliable forecast of seasonal water availability for the Kharif cropping season (April–September) is therefore of utmost importance for the agricultural production and Pakistan’s peoples welfare. The Snowmelt Runoff Model (SRM) in conjunction with satellite-based remote-sensing data has proven to be a well-suited tool for snow and glacier melt runoff simulation in data-scarce regions. A scenario approach, which like the ensemble streamflow prediction (ESP) uses historic meteorology as model forcings, is used for seasonal (6-month) forecasting of river flows. So far, operational forecasting models using this methodology have been developed for the Upper Jhelum upstream Mangla reservoir, the Upper Indus Basin (UIB) upstream Tarbela reservoir and the Upper Chenab upstream Marala barrage. The forecast accuracy measured by the mean absolute percentage error (MAPE) between observed and hind- /forecasted flow volumes is 6.8% for Mangla, 9.5% for UIB and 8.5% for Chenab model. Percentage bias is -2.5%, -2.0%, and -1.5% respectively. While these values are quite satisfactory, the association between forecasts and observations as well as the skill in predicting extreme conditions is rather weak for UIB and Chenab model, which motivates further research on the selection of a subset of ensemble members according to forecasted seasonal anomalies.

Key Words: Snow- and glacier melt runoff; SRM+G; seasonal forecasting; ensemble streamflow prediction

Management of Water and Land Resources: Studies in Asia and Europe 25  Session V: Hydrological Processes

Degree-Day Factor, snow characteristics and soil moisture dynamics in YU Enshurin

Alexander Brandta*, M. Larry Lopez C.a, M. Fraz Ismailb, Wolfgang Bogackib, Jörg Bachmannc a Faculty of Agriculture, Yamagata University, Tsuruoka, Japan. bHochschule Koblenz, Koblenz, Germany cSoil Institute, Leibniz Universität Hannover, Hannover, Germany. ----- *Corresponding Author：[email protected]

Shonai is located in the North-western part of Yamagata Prefecture, facing the Japanese sea. The Yamagata University Research Forest (Enshurin/YURF) sits in the Asahi Mountains, 30 km south of Tsuruoka (coordinates of the centre of the research forest: 38°33’18.86’’ N, 139°542.63’’ E). With a total snowfall of 1500 mm, which is the half of the total annual precipitation, Shonai is one of the snowiest regions of the world (Asaoka et al, 2013). Snow depth can reach up to 5.2 meters in March before the snow melt finishes in May. The relatively warm air in winter leads to several melting and refreezing processes within the snow column, increasing the snow density to 0.5 g/cm³ (manual measurements, unpublished). Thus, snow melt dynamics as well as soil physical properties like hydraulic conductivity and maximum water content are important for the understanding of water availability and transport, especially in spring. Snow melt can be explained well with the Degree Day Factor. Degree Day Factor (DDF) is a key parameter in modern snow melt runoff modelling (Cui et al., 2013). Variations in DDF result in different melt characteristics and speeds. The higher the DDF the higher in general the snow melt and the less temperature is needed to melt a certain amount of snow. DDFs in this study were calculated as slope of a linear correlation between accumulated daily temperature and accumulated snow melt in the snow melting event of every year. DDFs range between 3 and 6 in the early melting stage and turned smaller after half of the melting period. Underestimation of weight do to the not well calibrated balance in the forest is presumed. The forest and its slopes are dominated by brown forest soils on granodioritic bedrock. The plutonic quartz rich rock induces a sandy texture of the soil. All sampled soils have more than 50% sand and only a little amount of clay. The high amount of sand is indicating a good ability of water movement and a high storage capacity. Hence precipitation is detected with about 3000 mm/a water limitation is no problem in the YURF. Undisturbed soil samples were taken with metal cores. Water retention potential and hydraulic conductivity were measured with the HYPROP system. Maximal water contents of ~50% (vol%) are common in the soils of the YURF. The high content of sand combined with the wet conditions of the soil is leading to a high hydraulic conductivity. Water of snow melt or rain can therefore easily move downhill into the rivers. Measurements of snow density, soil moisture and meteorological conditions will be intensively conducted in the upcoming winter to achieve comparable results for characterizing the snow melt period more in detail.

Keywords: Degree Day Factor, HYPROP, modelling, snow melt, water retention

Management of Water and Land Resources: Studies in Asia and Europe 26  Session V: Hydrological Processes

Dynamics of the Degree-Day Factors - A case study in German Alps

Muhammad Fraz Ismaila,b*, Prof. Dr. –Ing. Markus Dissea, Prof. Dr. –Ing. Wolfgang Bogackib, Prof. Dr. –Ing. Lothar Kirschbauerb a Department of Civil, Geo and Environmental Engineering, Technical University of Munich, Germany. b Department of Civil Engineering, University of Applied Sciences Koblenz, Germany.

*Corresponding Author：[email protected]

Seasonal snowmelt is a pivotal fresh water resource, which is deemed necessary to cater the water needs of a country that is vastly dependent of this important resource. The countries like Germany, where the fresh water resource is present in abundance, there is a sense of concern that how to get the maximum possible benefit from the available water resources as well as catering the floods generated by the combination of snowmelt and rainfall. On the other hand, the paramount importance of the climate change cannot neglected which is effecting more or less every nation around the globe. In this context, the snowmelt runoff modelling has a prime importance in order to know how much water will be generated by the process-based snowmelt. In view of the topographic variability and sparse measuring network density in high mountain areas, simple temperature-index model has been selected which proved to be an adequate approach for modelling the snowmelt behavior in these conditions. The key parameter of these models is the so-called Degree-Day Factor (DDF), which describes the relationship between the mean daily temperature and the resulting snowmelt. Although, the DDF is the essential model parameter of temperature-index models, there are a few physical measurements carried out for this parameter. Mostly, the DDF is calibrated as a model parameter on the observed discharges. This research make use of both the techniques a) calibration on the observed discharges b) estimating the DDFs by considering the change in snow properties with the passage of time. In order to investigate the dynamics of the DDFs in more detail, University of Applied Science Koblenz in collaboration with the Technical University Munich has set up a snow measurement station at the Brunnenkopfhütte (1602m asl) in the Dreisäulerbach catchment from winter 2016/17. In addition to measuring the meteorological data, the snow water equivalent is determined, in particular, using a Snow Scale Ground (SSG). Results from last two years measurement campaign show that the DDF vary in a range from 0.3 to 6.8 mm°C-1 day-1 while the cumulative degree-days are close to 100 which in terms of days are equivalent to 2 to 3 weeks depending upon the year. On the other hand, the DDFs obtained during the initial calibration phase of SRM that made use of MODIS snow cover area as well as RADOLAN precipitation as an input data shows the very similar trend of DDFs, which is very encouraging. The initial results for model calibration for the year 2017 shows a volume difference of -14.5% and the coefficient of determination of 0.54 for the whole year starting from 1st January – 31st December.

Key Words: Snowmelt runoff, Degree-Day factor, Temperature-Index, MODIS, RADOLAN Management of Water and Land Resources: Studies in Asia and Europe 27  Session V: Hydrological Processes

Summer water use pattern in typical Japanese tree species in Shonai region

a b b b Qiqin Zhang , M. Larry Lopez C. , Jordi Voltas , Monica Aguilera

a Faculty of Agriculture, Yamagata University, Tsuruoka, Japan. bUniversity of Lleida, Pl. de Víctor Siurana, 125003 Lleida

*Corresponding Author：[email protected]

Forests are an important component of the global water cycle. Differences in forest types determine the water balance in a given area by these differences in water demand, root depth and their response to environmental conditions. Stable isotopes of water (2H and 18O) have successfully been used to determine the source of water (rainfall, groundwater, soil water) for transpiration and the depth of soil water up taken by trees along the growing season, we can determine this by analyze the xylem water isotopes, but this information also recorded in tree ring cellulose isotopes, but the relationship between xylem water and tree ring cellulose is still unknown. Until now, most of these studies have been conducted in dry areas, while the trees water use pattern in wet areas is not well known. The first objective of this research was to determine the water uptake strategy of different trees species within the growing season of cedar (Cryptomeria japonica), larch (Larix kaempferi) and beech (Fagus crenata) in a humid mountain region of the Asahi Mountainous in Japan, where the annual precipitation is over 3000mm, the second objective is evaluate the relationship between xylem water and tree ring cellulose δ18O. Samples of precipitation, soil and tree xylem water were analyzed for δ18O. The results showed that there was no difference in δ18O between soil depths and months during the growing season, in addition, we found no significant difference in δ18O in xylem water between tree species was found. But xylem water and precipitation δ18O showed a high correlation for all species, and we also found negative correlation between xylem water and tree ring cellulose δ18O. Hence, in heavy rainfall area, the water use pattern does not change among species or months, and is instead more influenced by precipitation. For future work, we will analyze the tree ring cellulose δ18O to determine the relation between soil water, xylem water and tree ring cellulose.

Key Words: δD, δ18O, δ13C, soil water, tree xylem water, tree ring cellulose

Management of Water and Land Resources: Studies in Asia and Europe 28  Session V: Hydrological Processes

Dynamics of nitrate and sulfate inferred from stable isotope techniques in Chikusa river watershed, Hyogo Prefecture

Lei Fujiyoshia*, Ichiro Tayasua, Shiho Yabusakia, Takashi Haraguchia, Chikage Yoshimizua , Kenichi Ohkushib, Fumiko Furukawab, Masayuki Itohb, Yudai Yamamotoc, Tadashi Yokoyamad, Hiromune Mitsuhashie a Research Institute for Humanity and Nature, Kyoto, Japan. b Kobe University, Hyogo, Japan c Nagoya University, Aichi, Japan dHyogo pref. Ako School for Students with Special Needs, Hyogo, Japan e University of Hyogo, Hyogo, Japan

*Corresponding Author：[email protected]

The Chikusa river watershed is located in the southwestern part of Hyogo prefecture. Recent river improvement in the watershed has posed concerns about changes in water quality and river ecosystem. This study aims to clarify dynamics of dissolved ions especially sulfate and nitrate using stable isotope techniques and to contribute the evaluation of water environment in the watershed. Water samples were collected from headwaters to river mouth in August (2015 to 2017) and in February (2018), and measured for ion concentrations, sulfur and oxygen stable isotopes of sulfate, and nitrogen and oxygen stable isotopes of nitrate. Sulfate concentration was lower upstream and higher downstream in all periods, and the nearest point to the river mouth showed topical high concentration (1156 mgl-1). The δ34S and δ18O values of sulfate suggested that sulfate was mainly derived from soil sulfate, and the sulfate near river mouth was derived from the seawater. In contrast, nitrate concentration was higher upstream and lower downstream in August and the trend reversed in February. The δ15N and δ18O values of nitrate imply that the contribution of primary production and/or denitrification in water on the reversed trend of nitrate concentration between in August and February.

Key Words: nitrate; sulfate; sulfur stable isotope; nitrogen isotope; oxygen stable isotope; Chikusa River watershed in Hyogo

Management of Water and Land Resources: Studies in Asia and Europe 29  Session V: Hydrological Processes

Soil Carbon and Soil Functions: How Solid Interfacial Chemistry and Wettability

Control Important Soil-Physical Processes

Jörg Bachmann

Institute of Soil Science, Leibniz Universität Hannover, Germany

Soil as a porous 3-phase system is characterized by a tremendously high surface area to volume ratio. Complex interactions of physical, chemical and biological processes occur mostly at particle interfaces which were formed in soil over time and which might exhibit completely different properties compared to the respective information obtained from bulk soil analysis. One option to assess interfacial properties is the determination of the soil-water contact angle (CA) which controls the energy status of adsorbed water films and connecting water menisci. Energy status as well as spatial distribution of soil water has implications for many physical, chemical and biological soil processes which will be illustrated by special examples of soil hydrology. A special focus lies on the evaluation of spatial variability of soil wettability on different scales. To capture realistic state changes of soil wettability, modifications of contact angle due to environmental conditions like temperature and moisture has to be considered. Capability of X-ray photoelectron spectroscopy (XPS) which has an interfacial analysis depth of about 10 nm is proved to capture ambient conformal changes of the outermost molecular layers. A new FC concept will be presented which allows process evaluation on the mm scale to analyze spatial relations, i.e. between small scale textural changes and corresponding surface properties on small scale transport processes. This new experimental concept has already been proved as a versatile tool to analyze spatial distribution of biological and interfacial soil properties in conjunction with the analysis of complex micro-hydraulic processes which will be shown in the last part of this presentation.

Management of Water and Land Resources: Studies in Asia and Europe 30