CHAPTER 4 - Energy Flow and Material Cycling Through the Ecosystem

Ecosystem

consists of all the organisms living in a community, as well as the abiotic (non-living) factors with which they interact.

Ecosystem

can be visualized as a functional unit of nature, where living organisms interact among themselves and also with the surrounding physical environment.

Ecosystem

range from a small, such as an aquarium, to a large, such as a lake or forest.

Energy

is the ability to do work.

Energy flow

is the amount of energy that moves through a food chain.

Joules

The energy input, or energy that enters the ecosystem, is measured in ______ or calories.

Calorific flow

The energy flow is also called _________ ____

Sun

The largest source of energy for an ecosystem.

Heat

Energy that is not used in an ecosystem is eventually lost as ____.

Autotrophs

build molecules themselves using photosynthesis or chemosynthesis as an energy source.

Heterotrophs

depend on the biosynthetic output of other organisms.

Autotrophs, herbivores, omnivores and carnivores, carnivores

Energy and nutrients pass from:

1. primary producers (__________) to

2. primary consumers (__________) to

3. secondary consumers (_________ & __________) to

4. tertiary consumers (__________ that feed on other carnivores).

Detritivores

or decomposers − consumers that derive their energy from detritus.

Prokaryotes and fungi

important detritivores.

Decomposition

connects all trophic levels.

glucose

Producers can make _______ during photosynthesis.

Producers

keep and use most of the energy they make for themselves. use cellular respiration to supply the energy for their life functions.

Cellular Respiration

the process where sugar is converted into carbon dioxide, water, and energy.

Photosynthesis

The process where the Sun's energy is converted into chemical energy (Glucose/Sugar).

Chlorophyll

On land, major producers are green plants - contain___________, which captures light energy.

Consumers

organisms that cannot make their own energy.

Herbivore

Organisms that eat plants or other producers

Carnivore

Organisms that eat other animals

Omnivore

Organisms that eat both plants and animals

Scavenger

Organisms that feed on the remains of another organism

primary

A Consumer that eats producers to get energy:

− Are called first-order or _______ consumers.

− Are herbivores (plant-eaters).

− Most of the energy the primary consumer gets from the producer is used by the consumer.

secondary

A consumer that eats another consumer for energy:

− Is called a _________ or second-order consumer.

− May be a carnivore or an omnivore.

− May be a predator.

− May be a scavenger.

tertiary

A consumer that eats a consumer that already ate a consumer:

− Is called a third-order or ________ consumer.

− May be a carnivore or an omnivore.

− May be a predator.

− May be a scavenger.

Omnivores

Consumers that eat producers & other consumers:

− Are called _________ .

− eat plants and animals.

Scavengers

Consumers that eat other consumers that have already died.

food chain

Energy also moves from a starting point through living systems in a one-way direction in a ____ _____.

Sun

the major starting point for most of the living things on Earth.

Food webs

models that demonstrate how matter and energy are transferred between producers, consumers, and decomposers as the three groups interact within the connected food chains in an ecosystem.

loss

A pyramid of net production represents the ____ of energy at each level.

biomass pyramid

each level represents the dry mass of all organisms in each level. Most of them show a sharp decrease at successively higher trophic levels.

Biota

Nutrient cycling occurs at the local level through the action of the_____.

geological

Nutrient cycling occurs at the global level through __________ processes, such as atmospheric circulation, erosion, and weathering.

Biogeochemical Cycle

The path atoms take from the living (biotic) to the non living (abiotic) world and back again.

carbon

The element ______ is a part of seawater, the atmosphere, rocks such as limestone and coal, soils, as well as all living things. The same carbon atoms are used repeatedly on Earth. They cycle between the Earth and the atmosphere.

Cellulose

The carbon can be used by the plant (food) and used to build the plant (_________).

carbon

When organisms eat plants or other animals, they take in the ______ and some of it becomes part of their own bodies.

carbon

When plants and animals die, most of their bodies are decomposed and ______ atoms are returned to the atmosphere (CO2).

78

Nitrogen (N2) makes up __% of the atmosphere. Most living things, however, cannot use atmospheric nitrogen to make amino-acids and other nitrogen containing compounds. They are dependent on nitrogen fixing bacteria to convert N2 into NH3(NH4+).

Nitrogen Fixation

Stage in Nitrogen Cycle.

○ It is the initial step

○ Here, Atmospheric nitrogen (N2) which is primarily available in an inert form, is converted into the usable form - ammonia (NH3).

Nitrification

Stage in Nitrogen Cycle. In this process, the ammonia is converted into nitrate by the presence of bacteria in the soil.

Ammonification

Stage in Nitrogen Cycle. decomposers convert organic nitrogen (CHON) into ammonia (NH3) and ammonium (NH4+). A large number of species of bacteria and fungi are capable of converting organic molecules into ammonia.

Denitrification

Stage in Nitrogen Cycle. A broad range of bacterial species can convert nitrites, nitrates and nitrous oxides into molecular nitrogen (N2). They do this under anaerobic conditions as a means of obtaining oxygen (O2).

nutrients , Pathogens, sediment

The water cycle is important because it is how water reaches plants, animals, and us. Besides providing people, animals, and plants with water, it also moves things like _________, _________, and ________ in and out of aquatic ecosystems.

Evaporation

stage in water cycle. Sun shines on water. Water is heated. Water turns into vapor (gas). Vapor enters the air

Condensation

stage in water cycle. Water vapor cools because of temperature change. Condenses (changes) into water droplets. Droplets create clouds. Droplets can also form dew. Water condenses directly onto a surface

Precipitation

stage in water cycle. Air cannot hold more water. Water falls to the ground. Rain, snow, sleet, hail

Runoff

Rain falls to ground, Runs downhill, Attempts to return to oceans, lakes, rivers, or other water sources.

Phosphorus Cycle

A biogeochemical process that involves the movement of phosphorus through the lithosphere, hydrosphere, and biosphere.

Phosphorus Cycle

A very slow process. Various weather processes help to wash the phosphorus present in the rocks into the soil.

Weathering, Absorption by Plants, Absorption by Animals, Return to the Environment through Decomposition

Steps of Phosphorus Cycle (4)