I plant valuable plants in wire baskets, figuring that by the time the basket rusts the tree or bush will be established
enough to tolerate some chewing and tunnelling....the wild
trees seem to survive just fine. With vegetables I have three metal-edged, mesh underneath raised beds, specifically for root crops, since these are their favorites. For the other plants there often seem to be gopher tunnels around but the damage they do is tolerable so far. Having a dog and four cats on site probably helps some too. In the wider ecosystem I can see how these tunnellers serve to open up tight clay soils and allow
water percolation.....