Trees provide shade which cools buildings and the microclimate: savings
for UC Davis associated with aesthetic and shelter benefits annually is
$700,000.
Trees sequester CO2: 940 tons of CO2 are removed from the air annually
by UC Davis trees.
One tree removes 4 carbon credits from the air per year (1 credit = 1 ton
of CO2); one person produces 400 pounds of CO2 per year. Therefore, one
tree is needed for every 5 people to make the environment carbon neutral.
Trees provide erosion control: UC Davis trees absorb 5 million gallons of
water each year and help prevent pollution, soil, and airborne contaminants
by intercepting rainfall and blocking wind effects.
Trees help conserve electricity and natural gas; annual savings in electrical
and natural gas costs are estimated at $106,000 for the Davis campus.
The Challenges Trees Face
Succumbing to old age (especially when in an urban or foreign environment).
Pressure from population explosion or circulation changes.
High water pH: the optimum range for most plants is between 6.5-7.5, which
is neutral. In Davis, the water has a higher pH of about 8.0.
Disease: hackberry disease has been especially devastating on the Davis campus.
Insects: termites are particularly detrimental by killing trees prematurely,
and also causing hazardous conditions due to trees falling.
Trees planted in their non-native environments: the large majority of the trees
at UC Davis are from other parts of the world, including South America, Asia,
Europe, Africa, and Australia.
Improper care can result in premature death as well as a whole other host
of problems.
Animal conflicts: Birds cause leaf loss and twig and branch dieback on oaks,
and the soil chemistry is changed dramatically by birds, causing EC and
ammonia to grow to potentially toxic levels.
