New York times  article on increasing the urban tree canopy:

http://www.nytimes.com/aponline/us/AP-Tree-Canopies.html?scp=3&sq=trees&st=nyt#

Here is some information on the new second edition of Viereck and Little’s Alaska Trees and Shrubs :

treeshrub-review.doc

A link to a Guide to Birch Trees, from the University of Saskatchewan Extension Service:

http://www.gardenline.usask.ca/trees/birch2.html

Here is a link to the Common Tree Diseases of British Columbia, an online guide to forest tree disease from the Canadian Forest Service:

http://www.pfc.cfs.nrcan.gc.ca/diseases/ctd/index_e.html

Here are  articles on tree fertilization from Michigan State  and Cornell University Extension Services:

http://web1.msue.msu.edu/imp/modft/fte78601.html

http://counties.cce.cornell.edu/suffolk/grownet/tree-shrub-maintenance/treefert.html

A brief  article about insect infestation and aspen decline in Colorado:

http://www.gunnisontimes.com/index.php?content=C_news&newsid=5406

Here are two brief articles on salt damage to landscape plants:

http://www.solutions.psu.edu/Horticulture_Gardening_Landscaping_411.htm

http://extension.usu.edu/files/publications/publication/HG-511.pdf

In case you missed the January Newsletter, here is a tree profile by Chris Mertl:

beech-tree-profile.

New York city has begun work to save the genetic material of historic old trees, including one that it is said George Washington walked under.

http://cityroom.blogs.nytimes.com/2008/01/11/old-trees-of-new-york-reborn/