He's basically a walking mulch pile.

Here you see it on a small scale the mothership has landed, R2 D2 and C 3PO have stepped out to test the bark mulch to see if they can inhabit this planet.

All of that grass is now covering the soil as dung, urine and litter or mulch, as every one of the gardeners amongst you would understand, and that soil is ready to absorb and hold the rain, to store carbon, and to break down methane.