Do Now 1. Define trophic level. 2. What are producers? Give an example. 3. What is a heterotrophic organism? Give an example. 4. What is pyramid of numbers? 5. Explain the difference between a pyramid of biomass and productivity. (Hint: think of the grocery store analogy) 6. Why are aquatic biomass pyramids typically inverted? 7. Why do you think food chains seldom have more than four trophic levels? (Why are the number of tertiary consumers relatively low in an ecosystem?)

Practice Complete the To Do activity on page 74 using graph paper Answer To Do questions (#1-3) on page 76 On a piece of computer paper, construct three food chains (4 trophic levels), a food web, a pyramid of numbers, a pyramid of biomass, and a pyramid of productivity for one of the following ecosystems. You may need to research some information. Warm-water oceanTemperate ForestMountain Arctic oceanJunglePrairie PondRiverDesert LakeTundraSavannah

Practice Continued  Label the food chains and food web with the following:  Producer(s) = P  Primary consumer(s) = 1  Secondary consumer(s) = 2  Tertiary consumer(s) = 3  Herbivores = H  Carnivores = C  Omnivores = O  On your productivity pyramid, label the amount of energy available to each organism based on their trophic level  Need to research average total energy for the main producer in your ecosystem (For example: the total energy in a grassland producer was found to be 400 kJm -2 y -1 )

Do Now Study Ecosystem Structure. You have a quiz today!

Abiotic Stations  Rotate through 5 stations as intro to abiotic factors Station 1: Simulation on Temperature Station 2 & Station 3: Reading Articles Station 4 & Station 5: Watching Videos  10 min at each station. You will be directed when to rotate.  Use your time wisely. You must answer all questions. You will be tested on this information.

2.2 Measuring Abiotic Components OBJECTIVE 2.2

Marine system – the sea, salt marshes, mangrove swamps and saline estuaries Fresh water lakes and rivers Terrestrial systems – land based Three main types of ecosystem:

Marine System Key Factors: Salinity Temperature pH Dissolved oxygen content (mg/L) Wave Action

Temperature: Marine  Temperature probes (water, soil, air)  Determines the amount of oxygen which will dissolve in sea water which will become available to marine organisms  Affects metabolic rate  Surface waters warmer than deeper water which affects ocean currents

Dissolved Oxygen: Marine  Dissolved oxygen needed for respiration  O 2 + C 6 H 12 O 6  CO 2 + H 2 O + ATP  Warmer water = less dissolved oxygen  Measured by using electrodes

Wave Action: Marine  Measured using a dynamometer which asses the force in waves  Wave action increases the amount of dissolved oxygen by mixing air with water  Coastal areas and coral reefs have high levels of dissolved oxygen

Fresh-Water Ecosystem Key Factors: Turbidity pH Flow velocity Temperature Dissolved oxygen

Turbidity: Freshwater  Measure of cloudiness of water  Cloudy = high turbidity  Clear = low turbidity  Secchi disc is used to measure turbidity: lowered into the water until disappears from view  Depth reading is taken from the pole  Repeated for accuracy  Always be taken in the same light  Turbidity affects sunlight penetration which influences rate of photosynthesis

Flow Velocity: Freshwater  Observe surface water  Measure by taking the time for any floating object to pass a fixed distance between two marked points  Varies at different depths  More accurate using a flow- meter which is a calibrated propeller attached to a rod  Velocity determines which organisms can survive in flowing water  High velocity = plants and animals firmly anchored

Temperature/Dissolved Oxygen: Freshwater  Temperature affects the amount of dissolved oxygen in a lake or stream and the amount of oxygen which can remain dissolved  Warm water speeds up plant growth but increases the rate of decomposition  reduces the water’s ability to hold oxygen  Minimum of 5 gm-3 oxygen is needed to support a balanced aquatic community  Water agitation (waterfalls) increases dissolved oxygen

pH: Marine and Freshwater  pH meter or probe  Cleaned between readings  Used at same depth.  Soil uses soil test kit – indicator added and compared to chart.

Terrestrial Ecosystems Key Factors: Temperature Light Intensity Soil moisture content Wind speed Soil particle size Soil mineral content Slope Drainage

Light Intensity: Terrestrial  Measured with a light meter  Intensity varies throughout the day  Dependent on cloud cover and season

Soil Moisture Content: Terrestrial  Measure by weighing soil samples before and after drying  Soil contains moisture and organic matter  Soil samples are heated to remove water  Samples weighed at intervals until a constant dry weight is reached

Wind Speed: Terrestrial  Measured with a digital anemometer  Cups on device revolve = rotations per unit time

Soil Particle Size: Terrestrial  Determines how much water soil can hold and how quickly the soil will drain  Passed through series of graduated sieves with different mesh sizes  Silt and clay are smaller

Soil Mineral Content: Terrestrial  Ratio of mineral to organic material present  Organic content: plant and animal residues in various stages of decay  Determines the soil’s ability hold water and its fertility  Measured by the loss-on-ignition (LOI) method  Weighed soil samples are heated  organic matter is burnt off  Loss in mass is calculated once the sample has reached constant mass and no further change  Percentage weight lost gives a crude measure of the organic content of the soil

Slope: Terrestrial  Influences water runoff  Determines whether erosion is likely to be a problem

Drainage: Terrestrial  Too much or too littler water in soil can reduce plant growth  Drainage affected by soil type, humus content, and slope  Poor drainage = soil becomes water logged  plants are unable to take up nutrients  Toxic compounds build up due to lack of oxygen (anaerobic conditions)  Slower to warm up in spring and summer  inhibits germination and growth of seeds