Arboriculture sites
California Oak Foundation
http://www.californiaoaks.org/
International Society of Arboriculture
http://isa-arbor.com
New Zealand Arboricultural Association Inc
http://www.nzarbor.org.nz/
The California Arborists Association
http://www.cal-arb-association.com/
Western Chapter of I.S.A
http://www.wcisa.net/
General Tree Information
Atherton Tree Committee
http://www.ci.atherton.ca.us/treecommittee.html
Canopy (Palo Alto) Loads of educational information, good tree library
http://canopy.org/
CityTrees. Redwood City volunteer based non-profit for planting, pruning a tree education
http://www.citytrees.org/
Our City Forest. San Jose based non-profit for greening and cultivating a healthier urban environment in Santa Clara County
http://ourcityforest.org/
Trees are good. Educational site developed by I.S.A for educating the general public
http://www.treesaregood.org/
Pests, diseases and disorders
Girdling Roots
http://www.extension.umn.edu/distribution/naturalresources/components/7501_06.html
Oak Root Fungus
http://www.ipm.ucdavis.edu/PMG/GARDEN/PLANTS/DISEASES/armillariartrot.html
Pine Pitch Canker
http://www.frap.cdf.ca.gov/pitch_canker/
Phytophthora Root Rot
http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn74133.html
Sudden Oak Death
http://nature.berkeley.edu/comtf/
