Tsuga heterophylla (Western Hemlock)

I don't know that conifers get their fair shake around here.

I think Western Hemlock is a great ally.

http://en.wikipedia.org/wiki/Tsuga_heterophylla

It grows and decays relatively quickly compared to most conifers, especially ceder, who it is a feeder tree for. I think this species may be integral to the regeneration of soils within it's natural biome.

I like them in my acid-loving hugelmounds (we only have alders, cedars, and hemlocks on our property). They do like to fall down in the wind, though, at least at our place, so we try to keep them from around our house. They burn decently in our woodstove... at least compared to our other options, lol! They also make okay Christmas trees, if pruned for a few years in advance--just don't prune them too much after you cut them down, or it will lose all its needles by Christmas (found that out the fun way last year).

I believe the needles are a good source of vitamin C, and the young shoots are edible http://www.natureskills.com/wild-plants/types-of-evergreen-trees/

Thinking of other permaculture uses, I wonder if they are good for growing mushrooms (I've never tried any mushroom cultivation)

Yes, unfortunately these have a habit of coming down on top of houses and being burned. They are suseptable to a number of parasitic fungi and rot. I have a small stand or 8 or 90 year old hemlock (approx 18" diameter) who roots are exposed because they are growing up on old nurse logs. They lie on a narrow driveway and get beat up from time to time and they have some type of Ganoderma going nuts on them. The trees are still living and not exceptionally healthy looking but are obviously, at least as a stand, able to still stand winds of up to 70 mph. Ganoderma is the family that the famed Reishi mushrooms belongs too

And they build soils so well! The spot I live on was logged heavily in the early 1920s but they only took the ceder and dougfir leaving the hemlock to rot in place not only did new trees sprout seemingly out of the branch eyelets of the fallen trees but the soils in that corner of the property are a good 24 inches plus deep not counting the large ridges where downed tree trunks have formed large nurse ridges.

They form mycorrhizal associations including with Chantrell, and smokey gilled woodlovers will form and impenetrable flush over these logs, like you wouldn't even know there was a stump there. They also make spectacular nurse logs for a number of species. Huckleberries due really well in them. I like to use the cut roundds of these around my property. I roll them someplace sunny where I want a bare patch to plant and leave them there flipping them once around this time of year so that the top side is down, sometime I move them over one round length when I do this. This serves the double purpose of removing ground of ground cover for planting and rotting out the log round as quickly as possible.

Mostly though my thoughts about the Tsuga are not so much aimed at the individual small holder bu at the vast track of abused landscapes held by the state and large timber interests, especially in areas of watershed, which is pretty much everywhere on the west side of this state.

Hemlock will grow well as an understory to alder provided there are nurse logs left for them to root into. Once the canopy opens they begin to dominate. Alder does fairly well on its own in many of these compacted blasted landscapes and hemlock could be introduced as a succession species where soils are still too poor by rolling in log round to essentially serve as the lost nurse logs.

I want clean waterways as it is essential if there is to be a rebound in the salmon populations, which where sort of the keystone species around here, and good forests will do that job for us if we let them