Patterns in Estonian bogs as depicted in color kite aerial photographs
Aber J., Aaviksoo K., Karofeld E., Aber S. Patterns in Estonian bogs as depicted in color kite aerial photographs.
Tiivistelmä
Kite aerial photography (KAP) was conducted at three bogs in east-central and southwestern Estonia to further investigate the possibilities of this technique for mire research. Color-visible and color-infrared photographs were acquired in all orientations with film and digital cameras. Individual objects can be identified in vertical photographs in the size range 10 to 30 cm, which allows for microstructural investigations. Color-visible photographs reveal distinct color and texture zones in the vegetation cover of bogs, and water pools form a strong contrast with emergent vegetation. The intricate patterns of emergent, floating and submerged vegetation are portrayed clearly, and the boundary is defined sharply between emergent and floating moss at pool margins. Distinct color and texture zones of plant cover represent specific vegetation communities. Color-infrared photographs depict active photosynthesis of floating and emergent moss (Sphagnum sp.) in narrow zones (1–2 m wide) at pool margins. The high level of photosynthesis in such narrow zones may have significant implications for development of bog morphology, biomass accumulation, methane emission, and other environmental factors. Numerous small water bodies are more abundant than anticipated and may be more common than is generally recognized on conventional airphotos or satellite images. Multi-view angle imagery displays considerable variations in reflectivity of bog cover materials for different viewing directions. Special lighting effects, such as sun glint and the hot spot, are more prominent in color-infrared pictures, because of darker shadows. Our field experience demonstrates that kite aerial photographs may provide a basis for microstructural mapping and analysis of complex bogs within a multi-scale approach to mire investigations.
Avainsanat
bog;
Estonia;
Aerial photography;
kite;
infrared
Vastaanotettu 31.10.2017 Julkaistu 1.1.2002
Katselukerrat 1883
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