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An Evergreen Forest Ecosystem from Satellites

Figure. The 6 ├Ś 6 km2 Howland forest area in Maine: (A) the true color image obtained by the EO-1 Hyperion on March 5, 2014 (DOY 64) at a spatial resolution of 30 m; and maps of (B) snow cover fraction (SNOWCF); (C) surface water cover fraction (WaterBodyCF); (D)soil cover fraction (SOILCF); (E) vegetation cover fraction (VGCF); (F) fAPARcanopy; (G) fAPARchl; (H) fAPARnon-chl.
Figure. The 6 ├Ś 6 km2 Howland forest area in Maine: (A) the true color image obtained by the EO-1 Hyperion on March 5, 2014 (DOY 64) at a spatial resolution of 30 m; and maps of (B) snow cover fraction (SNOWCF); (C) surface water cover fraction (WaterBodyCF); (D)soil cover fraction (SOILCF); (E) vegetation cover fraction (VGCF); (F) fAPARcanopy; (G) fAPARchl; (H) fAPARnon-chl.
Figure. The 6 ├Ś 6 km2 Howland forest area in Maine: (A) the true color image obtained by the EO-1 Hyperion on March 5, 2014 (DOY 64) at a spatial resolution of 30 m; and maps of (B) snow cover fraction (SNOWCF); (C) surface water cover fraction (WaterBodyCF); (D)soil cover fraction (SOILCF); (E) vegetation cover fraction (VGCF); (F) fAPARcanopy; (G) fAPARchl; (H) fAPARnon-chl.

ESSIC/CISESS Scientist Qingyuan Zhang has a new article to be published in International Journal of Applied Earth Observation and Geoinformation that characterizes the seasonally snow-covered Howland boreal forest ecosystem in Maine, USA with satellite images. 

Using 2001-2014 optical satellite images (see figure), the researcher extracted vegetation cover fraction (VGCF), canopy chlorophyll content (┬Ág/cm2), and fractional absorption of photosynthetically active radiation (fAPAR) by all canopy components, by canopy chlorophyll, and by canopy non-chlorophyll components, snow cover fraction, soil cover fraction, and other information. 

Snow is visible during December to April. Seasonal VGCF and fAPARcanopy showed a summer plateau (VGCF: 0.97 ┬▒ 0.01; fAPARcanopy: 0.90 ┬▒ 0.01). Both seasonal fAPARchl and fAPARnon-chl changed with time, and seasonal fAPARnon-chl had a bimodal shape. Spring VGCF varied between 0.54 and 0.69 (0.61 ┬▒ 0.04). Spring fAPARchl and fAPARnon-chl were 0.22 ┬▒ 0.03 and 0.21 ┬▒ 0.02, respectively. Peak summer fAPARchl was 0.58 ┬▒ 0.02. The lowest summer fAPARnon-chl was 0.32 ┬▒ 0.02. Replacing fAPARcanopy with fAPARchl to simulate boreal forest ecosystem gross primary production can reduce uncertainties in simulations. Higher spring temperature increases boreal forest fAPARchl.

Zhang had worked at GSFC/NASA for 14 years before he joined ESSIC.

To access the paper, click here: ÔÇťCharacterization of a Seasonally Snow-covered Evergreen Forest EcosystemÔÇŁ.

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