Help with Serpentine soil?

Hello, I have a rare type of soil that I am told is alkaline base(I haven't done tests yet). Serpentine is low in calcium, high in magnesium and has heavy metal concentration. It is also low in nitrogen.
It is also sporadically rocky with gravel. I can see Hugelkultur as a great way to get around this. What are my options besides hugelkultur? What about fruit trees if I were to plant them in the ground? Also should my next question be what would be a good cover crop to start off? What other type of questions should I be asking? (I'm new here, first post). I have 6 acres, two of it is wooded and slopped, and four flat acres. It looks to me that the four acres have not been used in quite some time but were for grazing. The surface of the old grazing land is mostly washed away and covered in sage brushes. The wooded area has many species of mushrooms. It is zoned 8b in Southern Oregon so I'm hoping it has a lot of potential.

I've found this explanation of Serpentine soil that might be able to help with the discussion.
http://www.fs.fed.us/wildflowers/communities/serpentines/adaptations.shtml

Help please, Thanks!

Like any soil, serpentine soils vary, and it would be good to get a handle on just how "severe" the effects are on your site. A harshly serpentine site will not support ordinary tree growth typical of non-serpentine niches nearby....trees will be stunted and more open meadow will occur, even in the absence of disturbances. There is also a cadre of rare native plants (serpentine endemics) that are particular to strongly serpentine sites. Either of these signs would be an indication that you will have an uphill struggle growing "ordinary" plants of any sort. Raised beds or hugel beds with a strong input of off-site soil or compost might be the only way to go.....

Here are some of the pictures of the flat area, and a picture of a bad spot of soil. It was really rainy out at the time. Possibilities? I'm worried that if I do a raised bed for a fruit tree, the roots will eventually go far enough down to the bad parts of the soil and die.

If that's what you've got, then that's what you've got and you just have to make the best of it. I've heard of urban permies throwing whole mattresses down onto pavement and soaking them in urine and compost tea and mulching over the lot and planting vegetables into it. Just depends on your desperation and determination. We looked at land in SW OR (eventually gave it up-too much winter!) and I looked up serpentine and learned to read landscape for it and passed it by on our searches.
My impression from twenty years' gardening and growing is that most plants, particularly annuals but even trees as well, rely mostly on the topsoil for nutrients. Especially where moisture is assured through the growing season. Deeper roots are relied on for water provision in droughts. So I would guess that good deep raised beds and reliable water supply should enable you to ignore the deeper soil problem, at least with regard to vegetables and other shallow rooted plants.

Howdy David, welcome to permies. Please back up a minute for me. You were told your soil was serpentine and alkaline? Not to sound rude but who told you and are they sure? You can have a test done through your local county extension agent to be sure. The picture makes it look like there is all sorts of plant growth, surrounded by forests. If you dig a hole how deep can you dig? How much soil/organic material comes out of the hole? Rocks are ok, you just need to add organic materials. Is there a river or stream nearby? . And yes I would think that hugels would be great for you.

I haven't done a soil test, but will soon. I just inferred that the soil was serpentine because of the plant types (Sage and Manzanita). I have two seasonal stream, here is a picture of one. If I dig, its a blend between dirt and streaks of gravel. Also I have a picture of the soil in the wooded area. Any help would be appreciated!

david james wrote:... I just inferred that the soil was serpentine because of the plant types (Sage and Manzanita). ...

Sage and manzanita grow is many places that are not serpentine soil. Locations with serpentine soil is a very small area of the ecosystem that supports sage and manzanita.

Also, serpentine/olivine soils don't necessarily mean they are alkaline. Alkalinity has more to do with climate. I used to live in a wet location with serpentine/olivine soils - and the soils were quite acid. The limiting factors there (northern Minnesota) were the climate. The soil minerology didn't factor that much.