文献类型：会议论文

英文题名：Methodology for assessment of desertification based on vegetation degradation using net primary productivity (NPP) as a key indicator

作者：Tsunekawa A.[1] Ito T.Y.[1] Shinoda M.[2] Nemoto M.[2] Suhama T.[3] Ju H.[4] Shimizu H.[5]

通信作者：Tsunekawa, A[1]

机构：[1]Tottori Univ, Arid Land Res Ctr, Tottori 6800001, Japan;[2]Tokyo Metropolitan Univ, Grad Sch Sci, Hachioji, Tokyo 1920397, Japan;[3]PASCO Corp, Ctr Geoinformat Technol Integrat, Meguro Ku, Tokyo 1530043, Japan;[4]Chinese Acad Forestry, Inst Forest Resource Informat Technol, Beijing 100091, Peoples R China;[5]Natl Inst Environm Studies, Tsukuba, Ibaraki 3058506, Japan

会议论文集：6th International Symposium on Plant Responses to Air Pollution and Global Changes

会议日期：OCT 19-22, 2004

会议地点：Tsukuba, JAPAN

语种：英文

外文关键词：desertification hotspots; drylands; land degradation; net primary productivity (NPP); vegetation degradation

年份：2005

摘要：Up to now, a "structured informed opinion analysis" based on subjective information has often been used to assess regional desertification and land degradation. Although this might be the most appropriate assessment method given limitations of time, money and labor, the method is neither objective nor quantitative; objectivity and quantitativeness often have a trade-off relationship with efficiency. In the present study, we propose a new methodology for monitoring and assessing regional desertification/land degradation that is both objective and quantitative. This new method relies on net primary productivity (NPP) as a key indicator of biological productivity. We compared the potential NPP (determined from climatological parameters) and actual NPP using a dataset for the 20 years from 1981 to 2000. To estimate the potential NPP, we used the Chikugo model. To estimate the actual NPP, we used a modified Carnegie-Ames-Stanford Approach (CASA) model, a type of Production Efficiency Model (PEM), which is driven by satellite observations. This modified model, the "Dryland-adjusted CASA" (D-CASA) model, was used to estimate the actual NPP of Asian drylands. We identified potential desertification/land degradation hotspots in Asia based on vegetation degradation. Specifically, these were the regions of central Inner Mongolia (China), mid-latitudinal and south Mongolia, northwest India, and the Deccan Plateau (India). We also identified vegetation degradation regions that were not identified by the Global Assessment of Human Induced Soil Degradation (GLASOD) database as being affected by soil degradation in mid-latitudinal Kazakhstan and Betpak-Dala (southwest of Lake Balkhash). Because we were able to assess desertification by objective and reproducible methods and were able to identify desertification hotspots not identified by the existing soil degradation map (GLASOD), we conclude that the new methodology proposed here for desertification assessment is valid and useful.