Climate Change &
- evergreen trees or plants with no flowers
- seeds are produced in female cones
- develop flowers
- covered seeds
Tree circulatory or vascular system
- Xylem is the innermost layer of the three
- provides support structure
- provides part of circulatory system
- made almost entirely of dead cells
- thin outer ring is alive
- cells are like thin tubes stacked on each
- transport water and minerals from soil to
- living xylem works for one year and then
- Cambium is the thin layer found between
the xylem and phloem.
- has cells that can produce xylem and
- growth varies with
- amount of moisture, and
- amount of sunlight.
- Phloem is the outermost layer, found
outside the cambium, just inside the protective bark.
- has tube-like cells for transport
- transport sap that contains sugars from
leaves to rest of plant
- Bark protects the tree
- produced from cork cambrium
Preferred Tree Species Characteristics for
- extensive range
- ring uniformity
- rings are well-defined
Basics of Ring Formation
- Conifer Tree Ring
- earlywood: appears light in
- cells have thin walls, large diameter
- latewood: appears dark in color
- cells have thick walls, small diameter
Douglas Fir Example
Oxygen Isotope Ration Analysis
- Number of protons in nucleus (O8, Na11, Fe26)
- Uniquely identifies a chemical element
- Number of protons and neutrons in nucleus
- Most mass is in protons and neutrons. Electrons
have almost no mass
- Different for each isotope
- E.G., a uranium atom has 92 protons and 143
neutrons for a mass number of 235
- Same element, same number of protons, different
number of neutrons
Isotopes of Oxygen
has three naturally occurring isotopes: 16O, 17O,
the most abundant is 16O
a small percentage of 18O
and an even smaller percentage of 17O
Oxygen isotope analysis considers only the ration of 18O
Connection between temperature and climate
- The 18O/16O ratio provides
a record of ancient water temperature.
- Water 10 to 15 °C (18 to 27 °F) cooler than
present represents glaciation.
- As colder temperatures spread toward the equator,
water vapor rich in 18O preferentially rains out at lower
- The remaining water vapor that condenses over
higher latitudes is subsequently rich in 16O.
- Precipitation and therefore glacial ice contain
water with a low 18O content.
- Since large amounts of 16O water are
being stored as glacial ice, the 18O content of oceanic
water is high.
- Water up to 5 °C (9 °F) warmer than today
represents an interglacial, when the 18O content of
oceanic water is lower.