Alder (Alnus)

The following is a dump of information on the alder tree.

Alders are in the Birch family and grow in most areas of the
world.  In this area the alder appears in open areas and acts
as a pioneer tree.  The roots fix nitrogen so the tree can
survive on poor soil.  Often alders are found in wet areas
and people assume they like wet soil, actually it is the
humidity they like and wet soil without oxygen can kill them.

Some types of alder are grown as a hardwood and makes fine
furniture.  Alder is also used for firewood and for mulch.
When placed near the ground it is colonized very quickly by
fungi and makes an ideal medium for mushroom farms.

Studies in coppicing found that Red Alder can be cut at 4-6
years and will regrow.  After ten years it dies.  Generally
this is not done because cut alder is very susceptible to
disease.  The smaller fast growing alders are sometimes
coppiced before four years and this looks more promising to
me.

Alder like many other trees have seed zones.  The seeds do
best if replanted at the same elevation and same conditions.
The seeds are held in cones which is unusual for a broad
leaf.  For Red Alder (in North America) the cone harvest is
usually from September to mid-October.  If the cone can be
twisted and the scales open then it is ready for harvest.

For Red Alder the cones can be produced by 3 year old trees
but more commonly the cones are not produced till the tree is
15 years old.  Best germination is in sand where the seed
still has some light.  Just under the surface is best.  They
need a moist environment and sprout in the spring.  They can
be damaged by frost so some are grown in protected areas and
set out from March 15 to April 15.

For most small woodland owners growing alders is risky unless
they are already found growing naturally.  For gardeners and
farmers the use of alders looks promising but little
information is available.  The leaves and roots are high in
nitrogen and the tree grows fast for the first 20 years.
Under ideal conditions the alder can be 6 or more feet their
first year of growth.  The decomposition of an alder by fungi
begins almost immediately when it is cut.  The cambium layer
is eaten within a few days and in a few months the wood is
discolored and colonized.

Much research has been done on Alders to explore their
economic worth.  This is also true of most of the forest
trees of North America and much of this data is available at:

  Http://eesc.orst.edu/AgComWebFile/EdMat/edmatindexfor.html

  Http://cahedb.wsu.edu/infoPub/scripts/webListing.asp?category=400

Some publications available are:

  Red Alder: Guidelines for seed collection, handling, and
  storage.  Hibbs, D. E. and A.A. Ager.

  Red Alder: Guidelines for successful regeneration.  Ahrens, G.R.
  A. Dobkowski, and D.E. Hibbs.

  Hardwoods of the Pacific Northwest.  Niemiec, S.S.

jeff

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