חיפוש מתקדם
Remote Sensing of Environment
Karnieli, A., Ben Gurion University of the Negev, Beer Sheva, Israel
Shachak, M., Ben Gurion University of the Negev, Beer Sheva, Israel
Tsoar, H., Ben Gurion University of the Negev, Beer Sheva, Israel
Zaady, E., Ben Gurion University of the Negev, Beer Sheva, Israel
Kaufman, Y., NASA / Goddard Space Flight Center, Greenbelt, MD, United States
Danin, A., Hebrew University, Jerusalem, Israel
Porter, W.
The normalized difference vegetation index (NDVI), which is derived from satellite sensor images, is widely used as a measure of vegetation and ecosystem dynamics, change in land use, desertification, and climatic change processes on a regional or global scale. Surprisingly, in semiarid regions, relatively high values of NDVI were measured in landscapes where little, if any, photosynthetic activity of higher plants exists. We tested the hypothesis that the high NDVI values may be caused by the photosynthetic activity of microphytes (lower plants), consisting of mosses, lichens, algae, and cyanobacteria, which cover most of the rock and soil surfaces in semiarid regions. We found that the spectral reflectance curves of lower plants can be similar to those of the higher ones and their derived NDVI values can be as high as 0.30 units. We conclude that, in semiarid environments, the reflectance of lower plant communities may lead to misinterpretation of the vegetation dynamics and overestimation of ecosystem productivity.
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הספר "אוצר וולקני"
אודות
תנאי שימוש
The effect of microphytes on the spectral reflectance of vegetation in semiarid regions
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Karnieli, A., Ben Gurion University of the Negev, Beer Sheva, Israel
Shachak, M., Ben Gurion University of the Negev, Beer Sheva, Israel
Tsoar, H., Ben Gurion University of the Negev, Beer Sheva, Israel
Zaady, E., Ben Gurion University of the Negev, Beer Sheva, Israel
Kaufman, Y., NASA / Goddard Space Flight Center, Greenbelt, MD, United States
Danin, A., Hebrew University, Jerusalem, Israel
Porter, W.
The effect of microphytes on the spectral reflectance of vegetation in semiarid regions
The normalized difference vegetation index (NDVI), which is derived from satellite sensor images, is widely used as a measure of vegetation and ecosystem dynamics, change in land use, desertification, and climatic change processes on a regional or global scale. Surprisingly, in semiarid regions, relatively high values of NDVI were measured in landscapes where little, if any, photosynthetic activity of higher plants exists. We tested the hypothesis that the high NDVI values may be caused by the photosynthetic activity of microphytes (lower plants), consisting of mosses, lichens, algae, and cyanobacteria, which cover most of the rock and soil surfaces in semiarid regions. We found that the spectral reflectance curves of lower plants can be similar to those of the higher ones and their derived NDVI values can be as high as 0.30 units. We conclude that, in semiarid environments, the reflectance of lower plant communities may lead to misinterpretation of the vegetation dynamics and overestimation of ecosystem productivity.
Scientific Publication
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