It's the stump that hinders erosion and a stump will stay in place after logging. A standing dead tree eventually may fall, uprooting the stump, and possibly blocking the stream and creating more erosion.
But it's the live tree that really controls the water. I've seen lots of small feeder streams dry up in the daytime when the trees are using the water to live only to start up again overnight when the trees "sleep."
A dead stump may be of some value to hold the soil, but it is only a placeholder until another tree can be planted to take its place.
At any rate, the environazis have accomplished their goal of keeping anyone from benefitting financially from the harvest of the damaged trees. They must be harvested within a couple of months, at the most, or else the wood is full of mould and useless for lumber.
The Biscuit Fire was over 2 years ago.