Check Yer Head  Community Population Biosphere Organism Ecosystem Thoroughly explain the following ecological terms using complete sentences. If you can do it…your golden! Community Population Biosphere Organism Ecosystem Biome

Energy Flow and Cycles An ECOSYSTEM is…all of the living (BIOTIC) AND non-living (ABIOTIC) things within an area…you know this. Energy moves through an ecosystem. An organism’s ENERGY ROLE is part of its NICHE. The ENERGY role can be that of a: PRODUCER CONSUMER DECOMPOSER

PRODUCERS SUNLIGHT is the primary energy source for ecosystems. Autotrophs (organisms that make their own food) are the primary producers for almost all ecosystems. Photosynthetic autotrophs are the predominant type of autotroph and they use the sun to make food. Remember…6CO2 + 6H2O 6O2 + C6H12O6 Producers are food for…CONSUMERS

CONSUMERS Consumers get energy by feeding upon other organisms. These are HETEROTROPHS…they can’t make their own food. Three Main Types: HERBIVORES: eat plant materials CARNIVORES: eat other animals…some eat dead stuff…these are SCAVENGERS OMNIVORES: eat all types of things

DECOMPOSERS These are organisms that break down waste and the remains of dead organisms. Decomposers return the raw organic materials to the soil where it is recycled back into the ecosystem. Bacteria and Fungi are two main groups of decomposers.

FOOD CHAINS: show how energy moves through an ecosystem by showing what is eating what. FOOD WEBS: are made up of many food chains. ENERGY PYRAMIDS: show how much energy is moving from one level to the next in a food web. Only about 10% of the energy at one level of a food web is transferred to the next highest level.

Because there is so much energy lost from one level to the next…the top of the food web or energy pyramid has fewer organisms.

A Typical Food Chain

A Typical Food Web Comprised of several food chains

A Typical Energy Pyramid

How the numbers work in an Energy Pyramid

Try These… Pick an ecosystem (any one you want), and list as many abiotic and biotic factors as you can. Draw a food web within that ecosystem that includes at least four trophic levels and six different organisms. Label the levels and energy roles of each organism. If there is 10,000kcal of energy available at the producer level, how many kcal would be available to an apex predator? Remove one organism from your food web and explain the effect that this would have on the rest of the organisms.

CYCLES There are some major cycles that are important for biologists to understand. Law of Conservation of matter –matter is not created or destroyed and it cycles between the biotic (living) world and the abiotic (non-living) world. WATER CYCLE: a continuous process wherein water moves from the Earth’s surface to the atmosphere and back. There are four basic part to this cycle.

WATER CYCLE WATER CYCLE: a continuous process wherein water moves from the Earth’s surface to the atmosphere and back. There are four basic part to this cycle. EVAPORATION: LIQUID water absorbs energy (heats up) and turns into a GAS (Surface to atmos.). CONDENSATION: Water vapor (GAS) in the atmosphere looses energy (cools) and turns into a liquid (clouds). PRECIPITATION: occurs when droplets of water that are formed during condensation get bigger and fall back to Earth. Transpiration: water is absorbed by plants and subsequently released back into the atmosphere through their leaves.

2. CARBON & OXYGEN CYCLES PHOTOSYSNTHESIS & RESPIRATION Producers take in carbon from CO2 and produce oxygen while consumers take in the oxygen and give off CO2 Photosynthesis (in the chloroplasts): 6CO2 + 6H2O 6O2 + C6H12O6 Cellular Respiration (in the mitochondria): 6O2 + C6H12O6 6CO2 + 6H2O + ATP (Energy) Sunlight

The Essence! Carbon is cycled (converted) from Inorganic Carbon is to Organic Carbon…and the other way around. Photosynthesis: Plants make FOOD from ENERGY Cellular Respiration: Organisms make ENERGY from FOOD. AC: ATP energy is produced when glucose is oxidized.

Human Impact: Carbon Cycle For 800 years before the Industrial Revolution the global CO2 levels were fairly consistent. Over the past 200 years there has been measureable change in levels. Human activity is largely responsible for this. Burning of fossil fuels and deforestation are the primary causal factors. Consequence: increase in CO2 levels result in higher global temperature. The rate is prohibitive to the dispersal of plants and animals to regions in which they can survive. Polar summer ice is jeopardy, and sea level rise is imminent as well.

The NITROGEN CYCLE Nitrogen is another important element for living things. It is needed to synthesize amino acids, proteins, and nucleic acids (DNA/RNA) and chlorophyll. Most organisms cannot get it directly from the atmosphere. Nitrogen by itself in the atmosphere is called FREE nitrogen. Nitrogen that is attached to other elements is called FIXED nitrogen…that’s the kind we need.

Organisms require nitrogen-compounds, (proteins and nucleic acids). Air is about 78% nitrogen gas (N2). That’s where most of the nitrogen hangs out. Most organisms can’t use atmospheric (free) nitrogen as is. They need it changed into nitrogen compounds. Plants need their nitrogen "fixed", which means as part of compounds such as: ammonia (NH3) urea (NH2)2CO nitrate ions (NO3−) Nitrite (NO2−

NITROGEN FIXATION This is the process that changes free nitrogen into the usable fixed kind. Bacteria in the soil, plant root nodules, and in water change the nitrogen into compounds called nitrites /NO2- (nitrosomonas) and then to nitrates /NO3-(nitrobacter). These can be used by the plants to make proteins and other needed compounds. Animals eat the plants…other animals eat those animals, and the nitrogen gets used by them too. Lightning and industrial processes also fix free nitrogen.

Nitrogen Cycle

When an organism dies, the nitrogen compounds return to the ecosystem and are reused. Eventually they are broken down completely (denitrification) and return to the atmosphere…and the cycle begins again…that’s why its called a cycle!

FYI…if you’re gonna take biology… There are four sub-processes involved in the Nitrogen Cycle. You don’t have to know this now, but…someday… Nitrogen Fixation: breaks N2 apart so it can form compounds. Decay: waste from life processes Nitrification: bacteria converting ammonia to nitrites and nitrites to nitrates Denitrification: bacteria converting nitrates to nitrogen gas again.

Nitrogen cycle in 4 steps Free N2-in the air…can’t use it Nitrogen Fixation-Bacteria in soil, water, and plants chemically change N2 into usable Nitrogen compounds. Decay-stuff dies and decomposes Denitrification-other bacteria turn the N back into N2 aka Free Nitrogen. That’s it!

AC Human Impact: Nitrogen Cycle Burning of fossil fuels and use of nitrogen-based fertilizers alter the amount of bio-available nitrogen (this is HUGE limiting factor for ecosystems). Fresh water aquatic ecosystems: nitrogen is a major limiting factor for plant growth. Increased plant populations mean more dead plants eventually. These decompose which depletes O2 levels. This leads to the death of other organisms. The sciency word for all of this…EUTROPHICATION Terrestrial ecosystems: Extra nitrogen can lead to nutrient imbalance in trees, changes in forest health, and declines in biodiversity. Since more nitrogen is available, carbon storage is affected. There’s more than just the nitrogen cycle getting jacked up. With factory farming, fertilizers are spread to increase crop yield, but the unused nitrogen (nitrate mostly), can leach out of the soil into the streams and rivers. This stuff ends up in our drinking water Marine Ecosystems…too much nitrogen = depleted O2 and toxic dinoflagellate blooms (RED TIDE).

Phosphorous Cycle

AC Phosphorus Cycle Phosphorus is a super-important element that is a key part of ATP, nucleic acid molecules (more on DNA & RNA later…a lot more!), the phospholipid membranes in cells, bone, shells…n’ other stuff too. Ya know how NITROGEN is from the atmosphere? Of course you do…we just talked about it. Well…Phosphorous (most of it) is in the Earth’s soil and rocks in compounds called phosphates (PO43-).

Phosphorus Cycle Most Phosphorus is stored in the crust as the mineral Apatite aka…Calcium Phosphate aka Ca5(PO4)3 The intrusive igneous rock…granite, is where you can find apatite, but it is also found in metamorphic and sedimentary rocks too.   Some Phosphorus is dissolved in fresh and ocean water, or is stored in soil or in organic matter. Plants can take phosphates from the soil sorta like they do with NITROGEN. No special bacteria for this one.

AC Human Impact: Phosphorus Cycle Well…here we are again with out fertilizers…and to get them…we mine! Runoff from mining and from fertilizer use leads to buildup of phosphorus. Too much phosphate (or nitrogen) ain’t a good thing and can lead to problems such as lake eutrophication (nutrient buildup) leading to algal and bacterial blooms. These guys use up the oxygen and …dead fish everywhere! NOT COOL