Biomass
Many factors contribute to the diversity of life in an environment. The
availability of nutrients and sunlight, along with other factors that play a
pivotal role in determining what and how much life an area can sustain. While
studying the Second Law of Thermodynamics, it came to my attention that the
classical pyramid shape of the producer, C1, C2, C3, biomass pyramid did little
to take into account the amount of detrital input. I hypothesized that the
amount detrital input greatly effected the number of C1, C2, and C3 consumers
and thus the overall biodiversity of an ecosystem. Further, if you could find a
test-bed where detrital input was the only real difference between two similar
ecosystems you would find that organisms of each ecosystem would be adapted to
the peculiar conditions. This adaptation would lead you to find vast differences
in the taxonomic groups associated with each ecosystem. With this in mind, I
first set out to find two similar ecosystems were I could test this hypothesis.

Second, to sample, categorize and compare the diversity of these ecosystems
along taxonomic lines. Next, I planned to use several of the widely accepted
diversity indexes (Simpsonís Index, Shannonís Index the Chi-Square Test) to
compare statistically, the diversity of my ecosystems. Scientific Law states
that in order to test the effects of one factor in an equation you must
eliminate all other factors . In order to test the detrital base as the limiting
factor, all other limiting agents must be eliminated. In a field experiment this
is technically impossible; though it is possible to come close by choosing two
ecosystems that are very similar. In order to keep this experiment as simple as
possible the ecosystem chosen had to be nearly self contained and small. The
smaller and more contained the ecosystem the less chance for outside input that
could destroy our results. Alazan and Bernaldo creek provided just the type of
test-bed needed for this experiment. Both are third order creeks in the same
geographic area that are subject to same weather and climate conditions, but
differ considerably in the amount of detritus available. (Fleet) Procedure

Alazan creek is a third order stream that feeds into the Angelina River. It is
bordered by several species of indigenous trees that form a small gallery of
overhanging branches. This gallery consisted of (pine, oak, sweetgum trees) and
was limited to a range of about twenty five feet from the edge of the stream.

These gallery trees are surrounded by open cattle grazing fields covered by
short grasses and an occasional scrub brush. Alazan creek ranged from ten to
fifteen feet wide with a water depth of six inches to two feet. The water was
generally clear, and flowed at a brisk ten to twelve mile per hour pace. The
creek bottom was primarily sand with little or no mud. Turbitity was low to
moderately low and the creek had a high oxygen content. Detrital input was low
and limited to leaves from the gallery trees. Bernaldo creek is a third order
creek that similarly empties into the Angelina River. Bernaldo creek differs
substantially in that it is entirely surrounded by typical east Texas piney
woods. (The particular area that samples were taken from appeared to be
relatively low lying in comparison to the surrounding woods.) It is likewise ten
to fifteen feet wide but, is considerably deeper at four to eight feet than

Alazan creek. Bernaldo creek flows at a much slower pace, approximately six to
eight miles per hour. The bottom of Bernaldo creek consists largely of mud,
which gives the water a darker color. Overall turbitity is high and overall
oxygen content is low. Human disturbance at both creeks was minimal. Although at

Alazan creek the surrounding area was used for grazing animals and at Bernaldo
creek the sight that specimen were actually taken from was a concrete washout
bridge. Both sights appeared to be in a flood plain, one that probably becomes
inundated on a monthly basis during the rainy season. Weather conditions at the
time of the sampling were typical of east Texas in spring, therefore unusual
conditions caused by atypical weather can be eliminated. What it boils down to
is, the only difference between the two creeks was the amount of detrital
material available and the conditions predicated by this difference. Starting
the week of February 8, 1999 daily 1p.m. trips were made by four lab groups to
both Alazan and Bernaldo creeks. During these trips observations were made on
terrain, topography, climate, vegetation and specimens were taken from several
spots