TREE RING PROJECT
Tree rings are the rings that you can see in the cross-section of a tree-trunk. Visible rings are a result
of season-depended changes in the growth rate to the tree, and that's the reason one ring usually
marks one year in the tree's life-cycle. The rings are more visible on trees that grows in the
temperate zones because the difference between the seasons are greater there.
The tree rings can tell you the age of the tree. Visible rings are a result of season-depended changes
in the growth rate to the tree. You can also say something about the climate conditions and the
variation where the tree grows, with studying the tree rings.
Thick rings: year with sufficient and a long growth-season.
Narrow rings: year with drought.
Clear tree-rings-limit you can find among conifers and ring-pored deciduous trees (oak, ash, elm).
Among the other deciduous trees the tree rings are inconspicuous. The tree ring width will variate
with the “forest-floor” production capability, climate and the tree's age and density. The tree grows
in one of the layers in the ground. The outer tree ring is therefore the newest, and the inner tree ring
is the oldest. The inner part of each ring is shaped early in the growth-season, when the growth is
relatively fast and the density in the tree is smaller, the outer part of the rings have greater density
because the trees grows slower in the summer and fall.
Among conifers will trees which grows fast, get loose and spongy wood, because the thin-walled
spring-wood cells will be a big part of each tree ring. Among ring-pored deciduous trees the springwood width will be unchanged from year to year, and wide tree rings results therefore much
summer-wood and a “strong” work. The tree ring width among trees in free position will be greatest
in the lower part of the tree, and get thinner up the tree-trunk, so the tree-trunk gets a pointed form.
In density wood will older trees often get wider tree rings up the tree-trunk, so the shape after
awhile get more cylindrical and gives a technical seen more valuable tree.
1) Examination of the tree's location:
- What of the factors which can be observed in the field, could affect the tree's growth?
Sunlight.
Rain.
Location.
Temperature.
Moisture
pH.
- In what way do you think they may be significant?
How big it's going to be.
How old it's going to be.
Growth – much water– the tree will grow faster.
2) Observation of the tree:
- What can you say about the tree, which is going to be examined?
What type of wood/tree.
Thin/thick tree-trunk.
High/low.
Dead/alive.
Branches.
Leaves.
Colors.
Width.
Diameter of tree-trunk.
Location of branches – number of branches.
How the tree stretches (shape of tree).
- What can you observe without taking any samples?
What type of wood/tree.
If the tree has thick tree-trunk you can say if it's old or not.
If there are any animals living in the tree.
To avoid cutting down a tree in order to study its tree rings, we can use a tool to extract a cylindrical
piece of the core. The sample will show the tree rings from bark to center.
Tree description:
H (height)=8,7m
O (circumference)= 32 inches
First we started to count the pith and moved towards the bark. After we marked the rings of 2010,
each 10th year and counted forwards. Some of the tree rings were very thin and hard to separate
from the others.
The tree is 122 years old. The tree started growing in 1889. The tree has not been a well growing
tree.
1993: Good year for the tree.
1920: Good year for the tree.
Table of the climate
In 1920 and 1993 the period of growth was good. Much precipitation and the temperature was
lower than the other years. These two years shows positive correlation. When there is much
precipitation and low temperature the tree will slower rate. We can see when it’s much precipitation,
the tree will grow faster.
From 1936 – 1961: Lesser precipitation and warm years. In those periods the tree had a bad period
of growth. We recognize that in the good growing years it is much precipitation and lesser heath. In
this period it was a negative correlation. The tree will grow slower when it’s lesser temperature.
Conclusion:
Positive correlation: This is when an increase of the size of the variable consistently shows an
increase of the other. When it was a lot of rain the tree grew faster.
Negative correlation: Negative correlation means that a high value on one variable will correlate
with a low value on the other variable. We saw that the tree grew more slowly when there was less
rain. The temperature didn't have that much to say.