Part of the reason I thought it was worthwhile to put a lot of effort into terracing the powerline pasture is completely unrelated to chickens and instead has to do with water.  The forest garden turns into a swamp during wet weather, and while I've blamed the excess water on everything from barn roof overflow to compacted clay soil, I'm willing to entertain the notion that the powerline cut has something to do with it as well.  After all, wet weather springs pop up at the base of that hillside during winter rains, suggesting that the lack of vegetation resulting from cutting trees along the powerline has sped up flow of water, resulting in a glut down below.

In her new ebook, One Acre Homestead, Sara McDonald writes about slowing the flow of energy through a system: "The flow must be maintained, but catching and storing energy for beneficial purposes is encouraged."  In other words, one solution to my problem would be to keep water on the hillside longer, where it can hydrate plants and be transpired out through their leaves rather than flooding the forest garden below.  Many permaculture practitioners use ponds to slow the flow of water, but I want to keep things simpler by soaking up excess water with humus.

A trip into the nearby woods turned up plenty of punky sticks and logs already rotting into the ground.  I used the drop test to determine which ones were ready to move to the powerline cut --- if the wood broke into small enough pieces to haul when thumped on the ground, I figured it was ready.  Six trips later, the terraces were looking a little less barren and I was worn out.

I'll probably add more wood later, since this is just the bare minimum needed to hold unvegetated soil in place, but even this little bit should help.  In the immediate future, the logs will force water to pool behind them during heavy rains, tempting more liquid to soak into the earth rather than running off, and soon the wood will have rotted enough to suck up rain and release it slowly during droughts.  The wild fungi that came along for the ride can't hurt either.