A review of tower flux observation sites in Asia

Abstract

Aggregating and sharing the metadata of flux observation sites results in a strong collaboration among various fields of study. Such data sharing will also be a part of the future design of a tower flux observation network in Asia. The aim of this review is to comprehend the state of tower flux observation sites in Asia. There are 109 tower flux observation sites in Asia including 51 forest sites. There are more new sites under construction in Asia than in America and Europe. These sites range from the taiga in Siberia to the rainforest in Southeast Asia, and from the equatorial to polar Koeppen climate zones. There are many highly humid areas in Asia, not only at low latitudes but also at middle latitudes. This climate condition has developed unique vegetation such as lucidophyllous (evergreen broadleaf) forest, which is distributed in warm areas with high precipitation in the growing season. However, there are only a few observations taking place in lucidophyllous forest. Rice paddy fields are also unique land cover in Asia. It is important to accumulate long-term data for rice fields with their management records, because plant activity depends highly on both climate conditions and land-use management. Flux data, especially net ecosystem exchange and related elements, are used for widespread studies not only within the flux-research community but also in other fields of study, for example remote sensing. At present, however, both the quantity and quality of the data are not sufficient for these studies. Regarding the quantity, there are many recently established sites that have not published data yet; regarding quality, flux data include uncertainties caused by methodological problems. Flux researchers are required not only to obtain flux data but also to improve their quality. Meanwhile, data users must understand there are still uncertainties in flux data.

Keywords:

• Asia
• Carbon dioxide
• Climate
• Flux observation site
• Vegetation

Acknowledgments

We would like to thank the principal investigators of flux observation sites and many other people, for providing site information, and the network management sub-work group of AsiaFlux (leader: Yasumi Fujinuma) and the database management sub-work group (leader: Takashi Hirano) for supporting our work, especially Naishen Liang, for apprising us of the situation in China, and Yoshikazu Kobayashi, for preparing the format of the site information and contacting many principal investigators of flux observation sites. We would like to also thank Hiromu Daimaru for help in making the GIS map. This work was supported by the Special Coordination Funds for Promoting Science and Technology of the Ministry of Education, Culture, Sports, Science and Technology, Japan.

Notes

Electronic supplementary material The online version of this article (doi:10.1007/s10310-008-0101-9) contains supplementary material, which is available to authorized users.