The Council of Science and Technology Policy in the Cabinet Office has set out the "Promotion Strategy of Priority Fields" in 2001, in accordance with the "Basic Plan for Science and Technology, " which is now in the second phase in the fiscal years 2001 through 2005. The Council of Science and Technology Policy has organized the "Research Initiatives" in the field of environmental studies to comprehend and integrate the research activities that have been conducted under the auspices and the directions of many ministries and agencies in Japanese government. One of the progressive research initiatives in the field of environmental studies is Global Warming Research Initiatives.

A comprehensive research was initiated in 2002 coordinated by the Research Council of Agriculture, Forestry and Fisheries, MAFF. The title of the research is as shown above, which consists of three research areas of Integrated Monitoring, Predictions and Impact and Mitigation Technique, for the three industrial fields of agricultural, forestry and fishery. Total number of the subjects is 24.

The objective of the present research is to scientifically understand the effect of the anthropogenic emission of the greenhouse gases on productivities in agriculture, forestry and fishery of Japan. At the final stage of this research, we will be able to draw the possible scenario for greenhouse gasses emission within a certain permissible range to stabilize food production.

Twenty-four subjects were proposed for such projection through 2002 to 2006. The comprehension and integration of research activities are particularly significant in this approach since integrated and unified understanding is indispensable to predict future climate, to assess the impact of climate change and to take proper political, economic and technological measures.

Endocrine disruption has become an important public concern, since this action was suspected in the chemicals such as dioxins, pesticides and alkyl phenols. Some of these chemicals are used as agro-materials or transported from other emission sources, and these chemicals are distributed widely in the agro-environment. Furthermore, some toxic chemicals are well known to accumulate in organisms through the food chain.

The objective of this project was as follows: 1) to elucidate the mode of action by endocrine disrupters, the mechanisms of uptake and accumulation of these chemicals by crops and transport in agricultural, forest and aquatic ecosystems, and the fate of chemicals in soil, water and atmosphere; 2) to develop techniques for the decomposition and neutralization of endocrine disrupters and for the control of endocrine disrupter transport in agricultural, forest and aquatic ecosystems.

Field studies were conducted to measure the extent of dioxins transferred into rice, bean, wheat and vegetables. The contamination levels of dioxins in agricultural crops were very low. It was suggested that the possible pathway into edible parts of crops was not uptake from soil via root but mainly atmospheric deposition. The concentration of dioxins in drainage water at the outlet of the experimental paddy fields related closely to that of suspended solids (SS) in puddling and successive transplanting from April until December (Fig. 1). The application of calcium chloride as a flocculating agent was effective in reducing the SS concentration in suspension and the dioxin outflow from the paddy fields. (Research period: 1999-2003)

The project, composed of the following four major topics, started in FY 2002 and would end in FY 2004: 1) Methodology development for the determination of bio-available cadmium in arable soils and its in-situ verification, 2) Determination of soil physico-chemical properties related to cadmium contamination in the mandate staple crops, 3) Elucidation of cadmium budget in farmland, and 4) Differences in cadmium absorption capacity in the cultivars of rice, soybean and spinach.

First, the relationship between cadmium absorption by rice and other relevant field crops and the chemical forms of cadmium existing in arable soils is statistically analyzed, and the relevant soil factors affecting the bio-availability of cadmium are determined. After an on-site verification testing of the method developed, a new method is proposed for the bio-available cadmium determination. Cadmium load to farmland from drainage water, and chemical and organic fertilizers are analyzed to evaluate the cadmium budget in a model area. In addition, the Cd accumulation will be successively surveyed for a long-term application field of chemical as well as organic fertilizers. Finally, the promising cultivars of mandate staple crops possessing a low cadmium absorption capability are to be identified.

The Codex Committee on Food Additives and Contaminants (CCFAC) has been elaborating to set up a new standard of cadmium in foods. To cope with a new standard of Cd under discussion in CCFAC, the Ministry of Agriculture, Forestry and Fisheries (MAFF) has launched a couple of projects to minimize the cadmium contamination to relevant crops, and the National Institute for Agro-Environmental Sciences (NIAES) has organized a research consortium to develop promising technologies for the reduction of Cd contamination in mandate crops.

There are three major topics in this project: 1) Development of promising cultural practices for the reduction of Cd uptake by staple crops, 2) Establishment of soil amendment technology to effectively reduce Cd uptake by staple crops from contaminated soils, 3) On-site verification of the technologies developed for the reduction of Cd uptake by staple crops.

The project started in FY 2000 and finished in FY 2002. Promising technologies have been developed to effectively reduce Cd content in edible parts of staple crops. The Cd content in rice grains could be substantially decreased by water-submergence of the paddy field three weeks before and after the heading time. More than 25 cm-placements of non-contaminated soils on the contaminated soil layer effectively decreased Cd content in rice grains for more than 25 years. Applications of various agricultural materials for the amendment of soil pH, and physical as well as chemical soil properties slightly decreased the Cd content, but this effect could be doubled in combination of with water management.

The present project aims to quantify the spatial and temporal distribution of biospheric sources and carbon sinks on a regional and global scale and to understand the factors that regulate net sequestration of anthropogenic carbon dioxide through biospheric processes especially in East Asia. The present project also coordinates the establishment and operation of a global network through the activities of regional networks. Discussions expected in this research will contribute to the promotion of the Third Conference of the Parties (COP3) agreement that each country can begin consultations on the estimation of all greenhouse gasses budgets and the converted amount in terms of carbon dioxide in various land ecosystems.

Broadleaf deciduous and coniferous forests are the major vegetative constituents in East Asia. The calculated annual value of net ecosystem production (NEP) by the tower flux measurement showed that the variation in the annual NEP seemed to closely relate to the seasonal variations among the years rather than the annual mean of the meteorological elements. Rice paddy fields are also one of the typical agricultural ecosystems in Monsoon Asia. Among them, single rice cropping paddies that dominates in northeastern Asia are characterized by two contrasting periods, a flooded growing period and dry fallowed period which lasts two thirds of a year. From the analyses using stable isotopes of water and carbon, the largest carbon input was CO₂ fixation by photosynthesis of rice, where 64-65% of the fixed carbon was harvested in autumn. Inflow and outflow of dissolved carbon accounted for 5-9% of the total input and output (Fig. 1).

In addition, objectives related to data acquisition and its quality control were arranged to unite the fragmented flux observation activities in East Asian ecosystems, and to promote establishing an integrated database of observation data. The improved Eco-DB was set up at several participating sites and now being operated, which was the first in flux network (FLUXNET) community and showed one of the directions of how to share observation data (Fig. 2). We also collaborated with other database systems and showed the locations for the observation data on the AsiaFlux homepage.