Need Sustainable Woodland Management Advice

[size=9] [/size]We moved from Florida to the Pacific Northwest late last year, and bought a house on 2 1/2 acres, at least 1 1/2 acres of which is wooded.  We want our woods to be natural, sustainable, and a welcoming habitat for birds, butterflies and other critters. Every part of the yard and woods had been neglected so we have had an uphill battle to deal with, and I am having a very hard time finding any good advice online about how to manage a woodland, especially one that borders a lawn. So I am reaching out for advice.  
To tell you what I've done so far - first, I have been tackling the huge amounts of Himalayan Blackberry, a nasty, agressive, invasive non-native in our area that kills the native trees, shrubs and understory.  (And, although native, I have been killing the poison oak that lives alongside the blackberry because I need to chop down the blackberry!).  Secondly, I am trying to address the areas where the lawn borders the woods.  The previous owners pretty much used Round Up on these areas, which seems to just have created a habitat for invasive non-native plants now as I'm not using Round Up on anything. They also did a bad job of pruning the trees on the edge of woods so there's a lot of dead branches and leaning trees right on the edge, which does not seem to allow for any sort of understory.  I have recently been working on trimming/thinning the trees right on the border so that their trunks will now set back 5 or more feet from the lawn, allowing more light to my understory plants  (e.g., salal, oregon grape, snowberry, thimbleberry, false lilly of the valley, trailing blackberry), and I've been working on pulling up the invasive non-native weeds.  So much work!  I am glad to do it, although I feel a bit like Sisyphus and the boulder!
Looking for some sage advice

Welcome to Permies! That sounds like you have done a lot of work!!

I am personally a "leave it be" kind of person for forest management - a strong weedwacker a few times a year on the edges, a sharp set of long handled pruning shears and that's about all, unless there is dead fall or a tree that is a danger. Others are far more ambitious :)

What are you trying to accomplish on your property? Just control of the blackberry and poison oak, or do you have other goals? I have to admit, I think of Himalayan blackberry as  a very tasty problem to have, though I have seen the damage it can do.

Similar situation for me in Missiouri. Moved into a property that had a railroad grade through the middle that I wanted to clear since it had been neglected and access is important. How else do you enjoy your land?!
My best friend for this endevour was getting a brush cutter attachment for my string trimmer. Basically replacing the trimmer line head with a saw blade made for this purpose. So with a small nimble tool I was able to hack out all kinds of brambles and work around trees. The stuff that grows back is now tender enough for my mower to handle and getting rid of the invasives has really upped the bio diversity.

Set small goals for yourself, work a little each day.

Hi! Thanks for your reply.  
Our goal is a healthy woods, cleared of invasive non-natives.  Those darn Himalayan Blackberry are killing the natives.  Their vines run up trees to 40' and pull them down with their weight, then grow in so thickly that nothing else can grow with them except for poison oak. I have found so many dead trees buried under the blackberry vines.  It's pretty sad. And, though tasty, they are awfully nasty.  I am covered with nicks and thorns every time I attack them.
As to the interior of the woods, I plan to do no more than clear the blackberry right now.  I've read about people thinning trees to promote a healthy forest, but I'm not there yet.  The only place I am contemplating that is where I have found two Paradise apple trees(!) in the woods.
On the borders, it seems to me that there should be some sort of understory, but, because of how these areas were maintained before we got here, there is very little.  We have a lot of steep slopes on the borders, and they have nothing growing on them but some invasive weeds, so I am concerned about erosion. I am clearing out the invasive plants for now, and leaving the natives, but am open to planting these areas with drought tolerant shrubs.
I forgot to mention that we also have a wild field that had been cleared and probably sprayed with Round Up before we got here.  This spring, it was full of beautiful wildflowers.  I was curious what they were and researched them all.  Sadly, almost all of them are invasive plants and considered noxious weeds in my state!  That area I am planning to clear over time, and replant with native flowers and grasses.

Matt Todd wrote:Similar situation for me in Missiouri. Moved into a property that had a railroad grade through the middle that I wanted to clear since it had been neglected and access is important. How else do you enjoy your land?!
My best friend for this endevour was getting a brush cutter attachment for my string trimmer. Basically replacing the trimmer line head with a saw blade made for this purpose. So with a small nimble tool I was able to hack out all kinds of brambles and work around trees. The stuff that grows back is now tender enough for my mower to handle and getting rid of the invasives has really upped the bio diversity.

Set small goals for yourself, work a little each day.

Thanks, Matt! The brush trimmer is a great idea!  We have added it to our shopping list!

And thank you for your sage advice on taking it one little step at a time.  I have been going out just about every morning before the sun gets too high in the sky to work on the yard, whether it's the vegetable garden, the garden beds, the lawn or the woods.  I do sometimes go outside and work all day, over exhausting myself in the process. I need to keep reminding myself that Rome was not built in a day!  

You might consider hiring goats to clear your blackberry problem. May or may not be available in your area, but if it is an available service where you are, a herd of goats can clear that stuff out for you, dispose of it and return a portion as processed fertilizer in a week or so ;) If no goats, a good brush scythe is a fantastic tool.