This is a color composite image of southern Bahia, Brazil, centered at 15.22

degree south latitude and 39.07 degrees west longitude. The image was

acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar

aboard the space shuttle Endeavour on its 38th orbit of Earth on October 2,

1994. The image covers an area centered over the Una Biological Reserve, one

the largest protected areas in northeastern Brazil. The 7,000-hectare

reserve is administered by the Brazilian Institute for the Environment and

is part of the larger Atlantic coastal forest, a narrow band of rain forest

extending along the eastern coast of Brazil. The Atlantic coastal forest of

southern Bahia is one of the world's most threatened and diverse ecosystems.

Due to widespread settlement, only 2 to 5 percent of the original forest

cover remains. Yet the region still contains an astounding variety of plants

and animals, including a large number of endemic species. More than half of

the region's tree species and 80 percent of its animal species are

indigenous and found nowhere else on Earth. The Una Reserve is also the only

federally protected habitat for the golden-headed lion tamarin, the

yellow-breasted capuchin monkey and many other endangered species. In the

past few years, scientists from Brazilian and international conservation

organizations have coordinated efforts to study the biological diversity of

this region and to develop practical and economically viable options for

preserving the remaining primary forests in southern Bahia. The shuttle

imaging radar is used in this study to identify various land uses and

vegetation types, including remaining patches of primary forest, cabruca

forest (cacao planted in the understory of the native forest), secondary

forest, pasture and coastal mangrove. Standard remote-sensing technology

that relies on light reflected from the forest canopy cannot accurately

distinguish between cabruca and undisturbed forest. Optical remote sensing

is also limited by the nearly continuous cloud cover in the region and heavy

rainfall, which occurs more than 150 days each year. The ability of the

shuttle radars to "SEE" through the forest canopy to the cultivated cacao

below -- independent of weather or sunlight conditions -- will allow

researchers to distinguish forest from cabruca in unprecedented detail. This

SIR-C/X-SAR image was produced by assigning red to the L-band, green to the

C-band and blue to the X-band. The Una Reserve is located in the middle of

the image west of the coastline and slightly northwest of Comandatuba River.

The reserve's primary forests are easily detected by the pink areas in the

image. The intensity of red in these areas is due to the high density of

forest vegetation (biomass) detected by the radar's L-band (horizontally

transmitted and vertically received) channel. Secondary forest is visible

along the reserve's eastern border. The Serra do Mar mountain range is

located in the top left portion of the image. Cabruca forest to the west of

Una Reserve has a different texture and a yellow color. The removal of

understory in cabruca forest reduces its biomass relative to primary forest,

which changes the L-band and C-band penetration depth and returns, and

produces a different texture and color in the image. The region along the

Atlantic is mainly mangrove swamp, agricultural fields and urban areas. The

high intensity of blue in this region is a result of increasing X-band

return in areas covered with swamp and low vegetation. The image clearly

separates the mangrove region (east of coastal Highway 001, shown in blue)

from the taller and dryer forest west of the highway. The high resolution

capability of SIR-C/X-SAR imaging and the sensitivity of its frequency and

polarization channels to various land covers will be used for monitoring and

mapping areas of importance for conservation.

P-44812 October 26, 1994

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bruce.chapman@jpl.nasa.gov