There were several layers in the
soil.
The O layer is the topmost layer, and consists of leaves, twigs and the
like that, thought dead and decomposing, we can still tell what they
were. The A layer is the nutrient rich top soil, and is made of
completely decomposed material that is rich in nutrients. Next, there
can be an E layer, often found
in acidic soil it grey because it is depleted of all neutrients, iron,
and other minerals. Then comes the B layer, which is where minerals,
such as Iron, accumulate and less neurtriants exist. Finally, though we
never dug deep enough to get to it, was the C layer, which consisted of
less neutriant rich material, and was generally grey.
|
Comparison of B and A layers.
|
|
The landscape influenced the
soils a lot. Hills are a major example. On the top or on the slope,
gravity pushed the water through tyhe soil and down the hill to the
bottom, making the hill itself have a very thin A layer and a B layer
with a good amount of oxidized iron.. At the bottom, where the water
collects, their is over a foot of A layer and very little oxidized
iron. On top of and on hills the soil tended to be vary dry,
lacking
of nutrients, composing of a very small Atrees. The B layer often had
iron, very common in Vermont soils, in it. Iron(III) Oxide, Fe2O3,
is red and has reacted with oxygen
that seeped throught the soil. Iron(II)
is grey and has not reacted with oxygen. This is more common near the
bottom of hills and former river beds or near current rivers, because
soil saturated with water becomes anaerobic, or without oxygen. Even
then, the ground water fluctuation alows oxygen to occasionally get
through to react with the iron.
Trees also has a very large influence on the soil. Soil near plentiful deciduous trees
was slightly basic or neutral, and had a plentiful amount of
non-decomposed dead leaves and other dead foliage and animals.
Coniferous trees insured their survival by the making
the soil acidic with their needles and thus unsutable to diciduous. The
table below shows us how the vegitation and landscape influenced the
soil
layers. |
|
|
We found evidence of ancient
glaciers from the last ice age all over the place. These glaciers
completely covered all of Vermont, and when they first came they
scraped all life and good top soil from the land. When they retreated,
they dragged back rocks and left Lake Vermont. When the lake receeded
into Lake Champlain, it left a course layer of silt in the vallies
(where there was a river) and courser sand on the hills (where the
river washed it up), which can be found in the B (second) layer of the
soil in many parts of Centenial Forest. Because Vermont basically
started from scratch (unaltered rock) 15,000 years ago, it has not has
as much time to develope a large nutrient-rich A layer as the other
areas of the U.S. unafected by glaciers. This is shown in our studies
by a generally thin (2-6 inches) A layer.
The map of the soil pits that we dug. Click for a larger image. 11:30, damn it.
|
Digging the soil pit.
|
|
We set three pitfall traps; one
in an
area of deciduous
trees, another in an area of coniferous trees, and the last one near a
small
stream. They were made of a small plastic beaker set in the ground as
inconspicuously
as possible, and filled with soap water to kill and preserve any bugs
that fell
into it. Aside from the normal assortment of crawling bugs, several
flying
insects surprisingly fell into the traps. The experts at the lab and us
reasoned that this was because they were hunting smaller bugs, resting,
or
looking for somewhere to lay eggs. Their was not much difference
between the
areas, except that the area by the stream had less dirt than the other
sites.
 |
Map of all the pitfalls (click for larger image).
God I am tired...
|
|
The soil group with tools of the
trade.
