日時：２００６年１０月２５日（水）（大会第１日）１８：００〜２０：００

場所：ウィルあいち特別会議室（大会D会場）「〒461-0016　愛知県名古屋市東区上竪杉町１番地　ウィルあいち」

内容：
　　「統合的陸域圏研究連絡会」においては、陸面を中心とする大気境界層から土壌内に渡る陸域圏を研究の主な対象とし、そ
　　こにおける物理的、生物的諸過程の理解に向けた、広い視野に立った研究のための情報交換、陸域圏を対象とした基礎的な
　　メカニズムの理解と、他の圏との広域的・長期的相互作用システムの解明、直接観測、間接観測、およびモデリングの融合
　　空間的・時間的スケール間ギャップの問題の解決への方向性の探求、正確な現状の認識と、実質的に意味のある手法の開発
　　に向けた努力、およびそれらのための研究協力関係の構築を目的としています。今回は２名の招待講演者による講演を中心
　　に研究会を開催いたします。

講演者：

１．Georgii Alexandrov（国立環境研究所）

Model-data fusion in the studies of terrestrial carbon sink: introduction to the problem and review of the workshop W16 of the Summit on Environmental Modelling and Software.

Abstract;

Terrestrial carbon sink is an indirectly observed natural phenomenon which is not well attributed to known biophysical mechanisms. It is obtained by adding the estimate of net terrestrial uptake to the estimate of emissions from land-use change. The estimate of net terrestrial uptake, in turn, is obtained by subtracting atmospheric and oceanic uptake from carbon emissions resulting from fossil fuel burning and cement production. Therefore, terrestrial carbon sink is more often referred to as “residual terrestrial uptake”. Climate-driven departures may include up to 20% of the terrestrial sink. However, the magnitude and even the sign of climate-driven departure for a given decade is difficult to quantify due to the uncertainty in relative strength of climate impact on productivity, respiration and emission from soil. Data and model validity are two facets of a problem that model-data fusion is expected to resolve. The relative strength of climate impact on plant productivity and respiration can be characterized by using data from the FLUXNET network. This is a network where micrometeorological measurements are performed originally conceived by IGBP and the EUROFLUX project. Flux measurements with chamber and eddy covariance measurements are local and therefore a dedicated measuring network is required to cover a sufficiently varied set of ecosystem types. However, the main purpose of network observations is to improve the understanding of biochemical and physical processes of carbon exchange for different ecosystem types. Subsequently, parameterization allows to scale up local flux estimates to the regional or continental scale. The validity of the scale up methodology can be evaluated in part using atmospheric CO2 concentration measurements.The particular methods of model-data fusion has been discussed at the Summit on Environmental Modelling and Software that was held in Burlington (Vermont, USA) in 2006, July 9-13.  The results of the discussion were formulated in the form of position paper of the W16 workshop.  A draft of this paper is available from the conference website (http://www.iemss.org/iemss2006/wiki/) designed for collaborative writing. Any comments on this draft would be highly appreciated.

２．佐々井崇博　（産業技術総合研究所）

陸域生物圏モデルBEAMSを用いた炭素フラックスの推定
Estimating carbon fluxes using terrestrial biosphere model (BEAMS)

Abstract;

I presents a new biosphere model called the Biosphere model integrating Eco-physiological And Mechanistic approaches using Satellite data (BEAMS). BEAMS provides a new method of calculating the environmental stress affecting plant growth (Stress). Stress is calculated eco-physiologically using a photosynthesis model and stomatal conductance formulation, providing a more realistic result than previous models. Stress values are used to estimate Gross Primary Production (GPP) estimates via the light use efficiency concept. The author used BEAMS, including the new Stress approach, to investigate global spatial and temporal patterns of Net Primary Production (NPP) and Net Ecosystem Production (NEP). BEAMS was run for the years 1982-2000 using global-scale satellite and climate data. Comparison of model results with observational measurements at flux sites revealed that GPP values predicted by BEAMS agreed with measured GPP. Obtained Stress values were compared with those of MOD17 and CASA; the three methods produce contrasting spatial patterns. Upon comparing predicted and observed NPP, the pattern of NPP for each plant functional type can be adequately estimated. In terms of trend analysis, NPP increased for the years 1982-2000 in most regions. Different NPP trends were observed in Europe, Russia, and northeast Canada compared with those proposed by Nemani et al. [2003]; the author attributes these differences to climate-related processes. Simulated inter-annual variations in global NEP are similar to results from inverse modeling. A sensitivity study of obtained NEP shows that the inter-annual variability in NEP is strongly controlled by air temperature, precipitation, CO2, and the fraction of absorbed photosynthetically active radiation.