chapter 6 exploring ecosystems pt. 2

nitrogen in ammonia

dissolves into water and can be stored in soil.

nitrification

In the soil, other bacteria complete a process called blank during which ammonia interacts with oxygen

oxidation

chemical reaction of oxygen with other substances (like ammonia)

proteins

Plants then absorb these nitrogen compounds and use them to build organic molecules such as blank

nitrogen cycle

nitrogen may transfer between the living and nonliving parts of the environment with the help of nitrogen-fixing bacteria and denitrifying bacteria

denitrifying bacteria

bacteria that do the opposite of nitrogen fixation

fertilization

Natural system can't keep up with the influx of nitrogen due to blank

phosphorus

Living organisms use this element to build nucleic acids ((such as DNA)

erosion of rocks that contain phosphorus compounds

main source of natural phosphorus in the environment

Phosphorus

an important limiting resource for many ecosystems

phosphorus

an important fertilizing nutrient, so humans often add it to crops to encourage growth

Phosphorus cycle

recycled as the plants and animals decay; Over time, it eventually ends up in the oceans, where it dissolves as phosphate compounds that eventually drop to the seafloor.

nutrient pollution and overgrowth of microscopic water organisms such as algae

result is an overload of phosphorus in water system

Sulfur

Similar to phosphorus that is stored in rocks.

Sulfur Cycle

the element is distributed throughout the oceans, atmosphere, rocks, and living matter of the Earth

Phosphorus

an important limiting resource for many ecosystems

nitrogen

may transfer between the living and nonliving parts of the environment with the help of nitrogen-fixing bacteria and denitrifying bacteria

fossil fuel sources

releases large amounts of sulfur that were previously stored underground into the Earth's atmosphere.

biosphere

Considering that the entire Earth is really one big ecosystem, what scientists call the blank

subjective

the boundaries of an ecosystem are blank, meaning that scientists define ecosystem boundaries in a way that best suits the particular study.

open system

lake ecosystem is an?

true

anything outside the ecosystem becomes either an input or an output to the system you're studying

consumption

One way matter and energy move around in an ecosystem is through blank or "eating"

food chain

an energy transfer in which the energy enters an ecosystem through photosynthesis and then moves from one organism to the next as one organism eats another organism.

food chain

links one organism to another in a straight line, illustrating what eats what.

trophic level

Scientists classify the organisms in a food chain according to what position they occupy in the chain

food chain

energy moves into each trophic level in sequence, as organisms consume other organisms.

Producers

autotrophs

Producers

green plants, that are capable of creating their own food.

primary producers

single-celled photosynthesizers like algae, cyanobacteria, and phytoplankton

Producers

foundation of an ecosystem, on which everything above them in the food chain depends.

Carbon, Nitrogen, Phosphorus, and Sulfur cycle

4 TYPES OF CYCLES

Primary consumers

an organism that consumes, or eats, the producers

Secondary consumers

an organism that consumes primary consumers.

herbivore

organism that eats plants; is a primary consumer.

primary consumer

grasshopper

secondary consumer

mouse

tertiary consumer

a carnivore that eats secondary consumers (tertiary simply means third)

top predators

Some tertiary consumers are called blank because they're at the top of the food chain.

tertiary consumer

owl

food web

contains multiple food chains, or paths, that energy can take as it passes from one organism to another.

Scavenger

an organism that feeds on the remains of alreadydead organisms.

scavenger

are carnivores because they eat herbivores, but instead of hunting and killing their own food, they show up after the herbivores have died (or been hunted and killed by something else) and help themselves to what remains

Detritivores

organisms that eat detritus, or dead tissue and organic waste.

Detritivores

They break down the dead organic material into smaller pieces as a first step to recycling it.

Decomposers

they do the important work of consuming and transforming organic material back into its very basic molecules, thus completing the matter-recycling process started by detritivores.

productivity of an ecosystem

the amount of energy available to support the organisms in the ecosystem

quantify

or measure, the energy in an ecosystem on earth's surface, scientists start by looking at the green plants because the total amount of energy available in an ecosystem depends on the amount of sunlight that producers capture through photosynthesis

gross primary productivity

total energy captured by producers

net primary productivity

gross primary productivity minus the energy used for producers' respiration

Gross primary productivity - Energy for respiration = Net primary productivity

equation of net primary productivity

energy pyramid

shows how the energy in an ecosystem is distributed among the trophic levels

joules

Scientists often use this to measure net primary productivity value

biomass pyramid

energy pyramid that illustrates the distribution of biomass, or biological matter, in an ecosystem.

trophic pyramid

represents both energy and biomass transfer in the ecosystem

James Lovelock

who proposed the Gaia hypothesis

Gaia hypothesis

asserting that the Earth functions as a living organism