What are the Segmentation algorithms that can be used to process Satellite images (obtained from Google Earth) to segment forest and barren areas?
You could try image saliency or entropy filtering. Entropy filtering calculates the entropy of gray values in the image Image within a rectangular mask. The result is written to the output image. The process is repeated in a sliding window fashion.

In the resulting image, the forest areas should appear more whitish while the barren areas appear black, because they don't contain enough information.

Of course I assume the roads would make a problem. However you could get rid of them using morphological edge finding operations.