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Ecosystems Project
Michelle Henderson
An ecosystem is diverse. You can not go anywhere on this great green earth
without becoming part or intruding and changing the balance of life in one. An ecosystem
is where all types of life flourish and grow. It is a place where everything depends on
each other and the way of life can change in an instant. While ecosystems are many in
quantity and some are large in size, they are a complicated form of life and are hard to
create, but easy to destroy.
What is an Ecosystem
The proper definition of an ecosystem says; A system that includes all living
organisms (biotic factors) in an area as well as its physical environment (abiotic factors)
functioning together as a unit. An ecosystem is much more than that though. In a way, an
ecosystem can be compared to a large city. All things depend on one another. The way a
factory or a restraint depends on the supplier to provide the materials to be able to run
like the way that the producers and consumers depend on each other. An ecosystem is
diverse in many ways, not just in life forms, but in abiotic factors as well. Even the
smallest change in either factor causes a drastic change of the components and the way of
life.
Components of an Ecosystem
There are six main parts to an ecosystem soil, atmosphere, heat, light, water and
living organisms. The soil provides nutrients for many things such as decomposers and
all different forms of plant life. The atmosphere is what keeps everything alive, human
and all other forms of biotic life. Heat is important because all warm-blooded creatures
are unable to regulate their body temperatures and need a source of heat to keep their
bodies going. Light is important because light gives off heat. Also, light is used by all
plant life forms by being part of the process called photosynthesis. Photosynthesis is what
gives the plants the energy to survive and therefore, all of the other consumers in the
ecosystem are fed. Another important part of an ecosystem is water. All biotic and some
abiotic things need water to survive; no matter if they are plant or animal. In an
ecosystem, there need to be living things or else there wouldn't be an ecosystem! The
living organisms in an ecosystem is what makes it so easy to change and vulnerable to
threats.
Threats and Influences on an Ecosystem
Many things can easily influence and/or threaten an ecosystem. Humans are one
of the most common for both influences and threats. We impose on animals’ territory,
destroy their habitats, and we hunt and/or poach animals. We even introduce a new
species to a new ecosystem, and that unbalances it and causes disaster in the ecosystem.
All of these reasons (and there are many more) are negative ways we influence an
ecosystem. Humans, though there are few, can also influence an ecosystem in a positive
way. Sometimes we plant trees and we hunt when there is overpopulation. We also are
researching ways to become more Eco-friendly.
Another main influence on an ecosystem is global warming, for obvious reasons.
The pollution causes the ground to lose its nutrients and it becomes infertile and when
that happens, that place is no longer able to sustain any life whatsoever. There are many
of our basic ecosystems at risk from this.
Two Basic Ecosystems
Coral Reef
Coral reefs are the most biologically diverse marine ecosystems on earth, rivaled
only by the tropical rainforests on land. Corals grow over a large amount of time and
have been in existence about 200 million years. The delicately balanced marine
environment of the coral reef relies on the interaction of hard and soft corals, sponges,
anemones, snails, rays, crabs, lobsters, turtles, dolphins and other sea life. A coral reef is
composed of thin plates or layers of calcium carbonate secreted over thousands of years
by billions of tiny soft bodied animals called coral polyps. Millions of polyps grow on top
of the limestone remains of former colonies to create the massive reefs. Yet these tiny
animals form the only natural formation visible from outer space. Coral reefs occupy less
than one quarter of one percent of the earth's marine environment, yet they are home to
more than a quarter of all known fish species. Coral reefs support extraordinary
biodiversity although they are located in nutrient-poor waters. The process of nutrient
cycling between corals, zooxanthellae, and other reef organisms explains why reefs
flourish in these waters: recycling ensures that fewer nutrients are needed overall to
support the community. Coral reefs are suffering globally. Scientists report that 30% are
already damaged. Corals grow only in warm tropical waters ideally between 70-85
degrees Fahrenheit. Although climatic and geological changes affect them, human
activities have had far greater consequences over the past decade.
Desert
Desert ecosystems are one of the harshest environments in the world. It has little
plant and animal life during dry seasons and spells but, surprising to most people, the
desert teems with inhabitants when there is moisture during the wet seasons. Solar energy
that green plants convert into food fuels life in the desert. Although in most ecosystems
plants compete for sunlight, here most plants are adapted to minimize the effects of too
much solar energy. Many animals get their energy by eating plants, but desert plants give
up the fruit of their production very reluctantly. Sharp spines and chemical-laden leaves
discourage plant-eaters. The plant's solar energy flows through the ecosystem as animals
such as kangaroo rats, and other herbivores like jackrabbits, fall prey to carnivores like
great horned owls, coyotes, bobcats or snakes. The desert is home to one of the most
complex food webs in the world.
Food Webs and Food Chains
Energy enters the food chain from the Sun. About ten percent of energy and/or
biomass is lost at each stage of the food chain as; droppings, movement energy and heat
energy (especially by warm-blooded creatures). Therefore, only a small amount of energy
and biomass is incorporated into the consumer's body and transferred to the next feeding
level, thus showing a Pyramid of Biomass (pyramid showing producers and consumers).
Food chains follow a single path as producers and consumers eat each other.
EXAMPLE:
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The Sun provides food for Grass
The Grass is eaten by a Grasshopper
The Grasshopper is eaten by a Frog
The Frog is eaten by a Snake
The Snake is eaten by a Hawk.
A food web is a set of interconnected food chains by which energy and materials
circulate within an ecosystem. Food chains are overly simplistic as representatives of
what typically happens in nature. The food chain shows only one pathway of energy and
material transfer. Most consumers feed on multiple species and are, in turn, fed upon by
multiple other species. It just proves that living things are connected in many ways for
survival.
EXAMPLE
 Trees produce Acorns which act as food for many Mice and Insects. Because
there are many Mice, Weasels and Snakes have food.
 The insects and the acorns also attract Birds, Skunks, and Opossums.
 With the Skunks, Opossums, Weasels and Mice around, Hawks, Foxes, and Owls
can find food.
They are all connected under the same biosphere! Like a spider’s web, if one part
is removed, it can affect the whole web. Abiotic don't normally play a part in food webs
or chains though they are an important factors of an ecosystem.
Biospheres, Biotic and Abiotic Factors
The biosphere is the global sum of all ecosystems. It can also be called the zone
of life on Earth. From the broadest geophysiological (study of living things) point of
view, the biosphere is the global ecological system integrating all living beings and their
relationships, including their interaction with the elements of the lithosphere (earth's
crust), hydrosphere (earth's water), and atmosphere(a layer of gases surrounding the
earth).
In science, biotic components are the living things that shape an ecosystem. They
are, basically, any living component that affects another living thing. Such things include
animals which consume the thing in question, and the living food that the thing
consumes. As opposed to abiotic components (non-living components of an organism's
environment, such as temperature, light, moisture, air currents, etc.); biotic components
are the living components of a living thing's environment, such as predators and prey.
Abiotic components are non-living chemical and physical factors in the
environment. Things that were once living but now dead are usually considered biotic
(for example, corpses and spilled blood). However, depending upon the definition,
components from living things that are no longer living can be considered part of the
biotic or abiotic component. Generally, things that were once living are considered part
of the biotic component, but things such as carbon dioxide and oxygen are considered
abiotic because those things were never living in a living thing.
All of these factors are highly susceptible to pollution.
Major Types of Pollution and Effects
Acid Rain
Acid rain is rain or any other form of precipitation that is unusually acidic. It has
harmful effects on plants, aquatic animals, and infrastructure. Acid rain is mostly caused
by emissions of compounds of sulfur, nitrogen, and carbon which react with the water
molecules in the atmosphere to produce acids. However, it can also be caused naturally
by volcano eruptions. The main cause of acid rain is sulfur and nitrogen compounds from
human sources, such as electricity generation, factories, and motor vehicles. Coal power
plants are one of the most polluting. In the past, factories had short funnels to let out
smoke, but this caused many problems locally; so, factories now have taller smoke
funnels. However, waste from these taller stacks causes pollutants to be carried farther,
causing widespread ecological damage.
Landfills
A landfill, also known as a dump, is a site for the disposal of waste materials by
burial and is the oldest form of waste treatment. Historically, landfills have been the most
common methods of organized waste disposal and remain so in many places around the
world.
A large number of impacts occur from landfill operations. These impacts can
vary: fatal accidents (e.g., scavengers buried under waste piles); infrastructure damage
(e.g., damage to access roads by heavy vehicles); pollution of the local environment (such
as contamination of groundwater and/or aquifers by leakage and soil contamination
during landfill use, as well as after the landfill is closed); methane generated by decaying
organic wastes (methane is a greenhouse gas many times more potent than carbon
dioxide, and can itself be a danger to inhabitants of an area); harboring of disease vectors
such as rats and flies, particularly from improperly operated landfills; injuries to wildlife;
and simple nuisance problems (e.g., dust, odor, vermin, or noise pollution).
Fossil Fuels
Fossil fuels or mineral fuels are fuels formed by natural resources such as
anaerobic decomposition (Breaking down without oxygen) of buried dead organisms.
The age of the organisms and their resulting fossil fuels is typically millions of years, and
sometimes exceeds 650 million years. These fuels contain high percentage of carbon.
Fossil fuels range from materials with low carbon: hydrogen ratios like methane, to liquid
petroleum to nonvolatile materials composed of almost pure carbon, like coal. Methane
can be found in hydrocarbon fields, alone, or associated with oil. It is generally accepted
that they formed from the fossilized remains of dead plants and animals by exposure to
heat and pressure in the Earth's crust over hundreds of millions of years. In the United
States, more than 90% of greenhouse gas emissions come from the combustion of fossil
fuels. Combustion of fossil fuels also produces other air pollutants, such as nitrogen
oxides, sulfur dioxide, volatile organic compounds and heavy metals.
According to Environment Canada:
"The electricity sector is unique among industrial sectors in its very large
contribution to emissions associated with nearly all air issues. Electricity generation
produces a large share of Canadian nitrogen oxides and sulfur dioxide emissions, which
contribute to smog and acid rain and the formation of fine particulate matter. It is the
largest uncontrolled industrial source of mercury emissions in Canada. Fossil fuel-fired
electric power plants also emit carbon dioxide, which may contribute to climate change.
In addition, the sector has significant impacts on water and habitat and species. In
particular, hydro dams and transmission lines have significant effects on water and
biodiversity.”
Humans
Humanity over all is probably the largest reason that we have pollution and
global warming. A human is an intelligent, sentient being able to think freely for itself
and to create as well as destroy; and we seem to be doing a lot of destroying. From the
time of the industrial revolution, pollution output has increased a tenfold. Burning of
fossil fuels and other materials are the main part of this though there are several other
major examples of pollution, such as; deforestation, driving motorized vehicles, landfills,
improperly disposing of waste, and poaching and hunting. There are many more reasons
that humans are causing harm to the environment. We are the main cause of global
warming.
Critical Effects of Global Warming and Solutions
The effects of global warming and climate change are of concern both for the
environment and human life. Evidence of observed climate change includes the
instrumental temperature record, rising sea levels, and decreased snow cover in the
Northern Hemisphere. According to the IPPC Fourth Assessment Report, "(most) of the
observed increase in global average temperatures since the mid-20th century is very likely
due to the observed increase in (human greenhouse gases) concentrations". It is predicted
that future climate changes will include further global warming, sea level rise and a
probable increase in the frequency of some extreme weather events. Ecosystems are seen
as being particularly vulnerable to climate change.
Over the last hundred years or so, the instrumental temperature record has shown
a trend in climate of increased global mean temperature, i.e., global warming. Other
observed changes include Arctic shrinkage, Arctic methane release, releases of carbon
from permafrost regions, and sea level rise. Global average temperature is predicted to
increase over this century, with a probable increase in frequency of some extreme
weather events, and changes in rainfall patterns. Moving from global to regional scales,
there is increased uncertainty over how climate will change. Increasing global
temperature means that ecosystems will change; some species are being forced out of
their habitats (possibly to extinction) because of changing conditions, while others are
flourishing. Secondary effects of global warming, such as lessened snow cover, rising sea
levels, and weather changes, may influence not only human activities but also the
ecosystem. Most animals will have to adapt to survive.
Adaptations for Survival
Adaptation is the process whereby a population becomes better suited to its
habitat. This process takes place over many generations. Also, the term adaptation may
refer to a feature which is especially important for an animal's survival. For example, the
adaptation of horses' teeth to grind the grass, or their ability to run fast and escape
predators. Before Darwin (scientist), adaptation was seen as a fixed relationship between
an organism and its habitat. As the climate changed, so did the habitat; and as the habitat
changed, so did the biota (biosphere). Also, habitats are subject to changes in their biota:
for example, invasions of species from other areas. The numbers of species in a habitat
are always changing. Change is the rule, though much depends on the speed and amount
of change. When a habitat changes, three main things may happen to the population:
habitat tracking, genetic change or extinction. In fact, all three things may occur in order.
Of these three effects, only genetic change brings about adaptation.
Most animals depend on their adaptations for survival. Some butterflies are
“copycats” and they copy other butterflies patterns on their wings because certain
butterflies like the monarch, have adapted to repel predators through bitter taste.
Producers, Consumers, and Decomposers
Producers are organisms, like green plants, that produce organic compounds from
inorganic compounds (sunlight), they are also a type of autotroph. Then plants for
example, are eaten by consumers in this case, grazing animals like the zebra. An
autotroph is an organism that makes its own food from inorganic substances. It is then
eaten by a consumer if it is a plant for example.
Consumers have to feed on producers or other consumers to survive. Deer are
herbivore which means that they only eat plants (Producers). Bears are another example
of consumers. Black bears are omnivores and scavengers, like skunks and raccoons,
which means that they will eat just about anything. They eat the deer then the hunter
shoots the bear and the hunter then becomes the consumer. A heterotroph is an organism
that cannot synthesize their own food and must obtain it ready made.
Decomposers are organisms that eat the dead or decaying organisms, and in doing
so carry out the natural process of decomposition. Like herbivores and predators,
decomposers are heterotrophic. Decomposers use deceased organisms and non-living
organic compounds as their food source. The primary decomposers are bacteria and
fungi.
Succession in a New Environment
Primary succession is one of two types of succession of plant life, and occurs in
an environment in which new earth usually devoid of vegetation and lacking soil is
created. (for example, lava flow) In primary succession pioneer species like mosses,
lichen, algae and fungus as well as other abiotic factors like wind and water start to
"normalize" the habitat.These pioneer plants are then dominated and often replaced by
plants better adapted to less austere conditions, these plants include plants like grasses
and some shrubs that are able to live in thin soils that are often mineral based. A good
example of primary succession takes place after a volcano has erupted. The barren land is
first used by pioneer plants which pave the way for later, less hardy plants, such as
hardwood trees. Primary succession occurs following an opening of a clean habitat, for
example, as previously stated a lava flow or an area left from retreated glacier. In
contrast, secondary succession is a response to a disturbance, for example, forest fire,
tsunami, flood, or an abandoned field.
As you can probably already tell from this report, ecosystems are very complex
and we will never completely understand them. There are many more components that
make an ecosystem what it is than what is displayed in this report. The earth will always
have ecosystems, unless global warming reaches even higher levels. We can do
something about that. We can save the earth, but to do so we must learn more about
ecosystems and our great green Earth.