HOW ECOSYSTEMS WORK Chapter 5

Energy flow in ecosystems

Life Depends on the Sun Energy from the sun enters an ecosystem. This happens through a process called photosynthesis. Plants are organisms that can photosynthesize.

An Exception: Deep-Ocean Ecosystems Deep-ocean communities of worms, clams, crabs, mussels, and barnacles exist in total darkness on the ocean floor, where photosynthesis cannot occur. The producers in this environment are bacteria that use hydrogen sulfide present in the water. Other underwater organisms eat the bacteria or the organisms that eat the bacteria.

Some Vocabulary terms you should know… A producer is an organism that can make organic molecules from inorganic molecules. (aka AUTOTROPHS)…plants and algae mostly. A consumer is an organism that eats other organisms or organic matter instead of producing its own nutrients or obtaining nutrients from inorganic sources. (aka HETEROTROPHS) Different levels of consumers. Trophic level: _______________________________________________

Cellular Respiration The process of breaking down carbohydrates to yield energy is called cellular respiration. Cellular respiration occurs inside the cells of most organisms. During cellular respiration, cells absorb oxygen and use it to release energy from food. Through cellular respiration, cells use glucose (sugar) and oxygen to produce carbon dioxide, water, and energy.

The different levels of consumers Primary consumer: Secondary consumer: Tertiary consumer: Quaternary consumer: Herbivore: Carnivore: Omnivore: Detritivore:

What Eats What….

Energy Transfer

The biomagnification of DDT Biomagnified means _____________________________ ____________________________. DDT is a cheap pesticide used to eliminate mosquitoes that carry disease, malaria. Read the Case Study on DDT in aquatic Food Chains to find out exactly what DDT does.

The Cycling of Matter Everything is made of matter Matter is _____________________________________________. Organisms need: ENERGY (we just talked about it- photosynthesis to cellular respiration) MATTER The law of the conservation of energy states _____________________________________________. Energy can change forms The law of the conservation of matter states _____________________________________________. Matter moves through the environment in different forms (cycles)

Carbon It’s an element on the periodic table. It makes up stuff. ….stuff like carbon dioxide and humans and sugar. ESSENTIAL COMPONENT OF _______________, __________________, ____________. Which just so happen to be some of our main ingredients. #humans Carbon is cycled between atmosphere, land, water, and organisms.

The Carbon Cycle

Other cool facts about Carbon…. And stuff about humans Usually a short- term cycle Can sometimes have a long term cycle Carbon sinks are __________________________________________. Fossil fuels are ___________________________________________. #waybackwednesday are fossil fuels renewable or nonrenewable? Burning of fossil fuels #notcoolhumans Increased levels of CO2 in the atmosphere…more than the earth can handle. CO2 is a greenhouse gas…. It’s getting hot in here… Ocean can absorb some of it, but it raises the pH level…. NOOOOOOO

Nitrogen Also an element on the periodic table…it makes up stuff!...more matter!!! Wooo hooo We need it for proteins!!!!! Which build new cells and lots of fun other things. Plants need it for proteins and their DNA too… It makes up 78% of the gases in the atmosphere! Most of us (plants and animals) can’t use the atmospheric nitrogen Nitrogen-fixing bacteria can! They live in nodules.

The Nitrogen Cycle

Decomposers and the Nitrogen Cycle Nitrogen (in the proteins) is stored within the bodies of living things is returned to the nitrogen cycle once those organisms die. Decomposers break down decaying plants and animals, as well as plant and animal wastes. After decomposers return nitrogen to the soil, bacteria transform a small amount of the nitrogen into nitrogen gas, which then returns to the atmosphere to complete the nitrogen cycle.

Phosphorus Phosphorus is an element too! Why do we need Phosphorus?? Many living things use it to build molecules for cells…like DNA! or bones and teeth. The phosphorus cycle is the cyclic movement of phosphorus from:_______ ___________________________________. Environment gets phosphorus from _________________________________. Plants get phosphorus from __________________________________. Animals get phosphorus from ________________________________.

The Phosphorus Cycle

Fertilizers and the Nitrogen and Phosphorus Cycles Fertilizers, contain both nitrogen and phosphorus. Excessive amounts of fertilizer can enter terrestrial and aquatic ecosystems through runoff. Excess nitrogen and phosphorus can cause rapid growth of algae. Excess algae can deplete an aquatic ecosystem of important nutrients such as oxygen, on which fish and other aquatic organisms depend.

Ecological Succession Ecosystems are constantly changing….especially with humans changing it around and the amount of matter available for that particular ecosystem matters!!!! Ecological succession _______________________________________________________________ _____________________. Each new community that arises often makes it harder for the previous community to survive.

Primary Succession Occurs on a surface where no ecosystem existed before. It begins in an area that previously did not support life. Primary succession can occur on new islands created by volcanic eruptions, in areas exposed when a glacier retreats, or any other surface that has not previously supported life. Primary succession is SLOW. A pioneer species is ________________________________________________________ _______________________________________________________.

Secondary Succession Secondary succession occurs on a surface where an ecosystem has previously existed. It is the process by which one community replaces another community that has been partially or totally destroyed. Caused be disturbance from humans, animals, or by natural process such as storms, floods, and earthquakes. A climax community is the final, stable community in equilibrium with the environment.

Old Field Succession Type of secondary succession Abandoned farmland

Fire and Succession Natural fires caused by lightning are a necessary part of secondary succession in some communities. Minor forest fires remove accumulations of brush and deadwood that would otherwise contribute to major fires that burn out of control. Some animal species also depend on occasional fires because the feed on the vegetation that sprouts after a fire has cleared the land.