The concept of biomass is important in an ecosystem. Biomass is the
combined weight of all organisms in a trophic level based on the
amount of organic carbon molecules in their bodies. The further
away a trophic level is from the first trophic level (the producers), the
less biomass it will contain. This decrease in biomass occurs for
several reasons such as:
• not everything in the lower levels
gets eaten
• not everything that is eaten is digested
• energy is always being lost as heat
Biomass
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Plants obtain carbon from carbon dioxide through the process of
photosynthesis. The carbon is present in organic molecules. Herbivores
(primary consumers) eat plants and obtain carbon from the organic molecules
of plants. These organic carbon molecules are then transferred into the
bodies and digested by the herbivores. Secondary consumers eat the primary
consumers and carbon is transferred to their bodies through digestion. Large
meat-eating carnivores gain organic carbon molecules through digesting the
bodies of their prey. Decomposers also use the organic carbon molecules
from dead organisms through digestion.
All herbivores, carnivores, and
decomposers carry out cellular
respiration and release carbon
into the air as carbon dioxide.
This entire process is called the
Carbon Cycle.
The Recycling of Materials through an Ecosystem
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Decomposition is the process whereby organic material is broken
down into its smaller molecules. The primary producers, plants, can
then use these molecules again. Decomposition is one step in the
food chain and a large part of the nutrient cycle of an ecosystem.
Most plant matter, over 90% in land ecosystems, is not used by
herbivores but is broken down by decomposers in the litter and soil.
Decomposers are organisms such as bacteria, fungi, flies and worms.
They are consumers in the food chain, just as herbivores and
carnivores are. Without decomposers, the Earth would quickly be
covered with dead, but not decaying, organic matter.
The nutrient cycle would grind to a halt because so many nutrients
would be tied up in the dead matter and not available to living
organisms.
Decomposition rates vary due to abiotic factors such as moisture
level, temperature, and soil type. Higher amounts of moisture and
temperature will speed up the rate of decomposition.
Decomposition
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Composting is a project that can be done at home. Composting
involves mixing yard and household organic waste in a pile or bin and
providing conditions that encourage decomposition.
The decomposition process is fueled by millions of microscopic
organisms (bacteria, fungi) that take up residence inside your
compost pile, continuously devouring and recycling it to produce a
rich organic fertilizer.
Composting combines oxygen in the air, moisture, and heat to
decompose organic matter. The microbes are the organisms
responsible for the rise and fall of temperature in the compost pile.
As they “eat” and digest organic matter, they produce heat
increasing temperatures to as high as 140-160OF.
Composting
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