In my field site, the majority of my
area is covered in brush. I estimate a
total of 75% of the marshland is covered with common vegetation, such as
pickleweed (35%), cord grass (25%), and salt grass (15%). Approximately 7% of my area is covered by the
two coyote bushes. My area contains no
trees and only a small portion has a small rivulet at its edge (constituting
about 3%). The only man-made structure
is found at the edge of my study site where wooden posts are stuck in the
ground (making up about 5%). The
remainder of my site (10%) is merely bare ground.
Though I did not see many animals there
were several rather prominent signs that they were living in my site area. The first sign I noticed was scat. Littered across the ground was a scattering
of small round pellets. They appear to
belong to a rabbit, possibly jack rabbit.
This would make sense since I had discovered a hole underneath some
pickleweed and cord grass on a previous visit.
In addition, I found an empty mussel shell among the pickleweed. The shell was still intact, however, since it
was empty, I can assume that some sort of organism had eaten it. The most likely predator is a seabird,
probably a duck, goose, or seagull.
Finally, I found a crushed snail shell along with a cracked egg
shell. The snail was probably eaten by a
goose or seagull. The crushed egg shell
indicates either an extremely old hatched egg or that an organism had eaten the
egg and the baby bird within. I suspect
the latter mostly because the egg shell was relatively clean.
For the most part the soil is relatively
muddy. While there is a sandy quality to
it, the soil is damp because it is near a water source. The soil is likely home to many detritus
organisms. Since it has a high content
of water, it has a high carrying capacity for detritivores, who require soil
with plenty of water to convert the decaying matter into viable nutrients. As a result there are copious amounts of
pickleweed, cord grass and salt grass since they have access to a larger amount
of nutrients. Since there are more
plants, there is a higher rate of primary productivity, which will, therefore,
be able to sustain a greater number of organisms. This is one of the reasons that the marshland
has such a high diversity and abundance of waterfowl.
Since this area of the marsh is located
at a point at which freshwater meets saltwater, it is considered an
estuary. The estuary causes the
surrounding soil to be moist and damp, perfect for detritivores. There will be a larger number of plants
surrounding the rivulet because the organisms living in the detritus, such as
beetles, mites, and worms, all contribute to the nutrients within the soil. The water will be home to organisms that have
adapted to the varying salt concentrations of the water. Since the tide seasonally flows and recedes,
organisms must have specific adaptations, such as gills, to absorb freshwater
without intaking excessive amounts of salt.
As the water is composed of both fresh and salt water, certain regions
of it may be drinkable for waterfowl and other organisms, for instance, rabbits
and foxes.
The area is completely flat up until the
last couple meters where it dips down to enter the water source. The incline provides a perfect area for
digging burrows. If well hidden behind a
group of pickleweed or cord grass vegetation, as the burrow I found was, it
would provide plenty of shelter from predators, such as foxes, if they weren't paying enough attention. In addition, the
incline would also allow water to easily runoff into the rivulet. Any organisms living within the rivulet,
including any shrimp, clam, and flounder, would then have a larger habitat. They would be more likely to survive in a
bigger area and produce more offspring.
The great amount of these secondary consumers will in turn contribute to
a higher number of secondary consumers, such as ducks, geese, and seagulls, and
also tertiary consumers, such as foxes.
The climate has been generally temperate
thus far. Temperatures range from 68-70
degrees Fahrenheit on each of the three visits.
The sky has been a clear blue up until the last visit where it was
partly cloudy. It is only recently that
it has rained at all. The rain provides
optimal conditions for detritus organisms.
The detritivores likely thrive in winter and spring when rainfall is
heaviest. During the summer, the dry
climate and warmer temperatures would decrease the population of these detritivores,
thus, leading to a decrease in primary productivity and available
nutrients. There would likely be more
intraspecific as well as interspecific competition between vegetation in
addition to waterfowl.
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