Agenda 9/11 Ecosystem Ecology Lecture 3D pyramids Practice FRQ and peer grading (I need pill bugs!!) Turn in: Worksheet answers and video notes Homework: Energy Ecology Video and Notes Chp 56 reading and notes (due Friday)

Ecology Biomes and Ecosystems Biomes are climatically and geographically defined as similar climatic conditions on the Earth, such as communities of plants, animals, and soil organisms, and are often referred to as ecosystems. Some parts of the earth have more or less the same kind of abiotic and biotic factors spread over a large area, creating a typical ecosystem over that area. Such major ecosystems are termed as biomes. Biomes are defined by factors such as plant structures (such as trees, shrubs, and grasses), leaf types (such as broadleaf and needleleaf), plant spacing (forest, woodland, savanna), and climate. Unlike ecozones, biomes are not defined by genetic, taxonomic, or historical similarities. Biomes are often identified with particular patterns of ecological succession and climax vegetation (quasiequilibrium state of the local ecosystem). An ecosystem has many biotopes and a biome is a major habitat type. A major habitat type, however, is a compromise, as it has an intrinsic inhomogeneity. Some examples of habitats are ponds, trees, streams, creeks, and burrows in the sand or soil. http://en.wikipedia.org/wiki/Biome

Ecosystems- Matter and Energy Ecosystems are all about the cycling of matter and the flow of energy. The Laws of Thermodynamics cannot be ignored.

Primary Production- A rate Primary production is the production of organic compounds from atmospheric or aquatic carbon dioxide (CO2). It may occur through the process of photosynthesis, using light as a source of energy, or chemosynthesis, using the oxidation or reduction of chemical compounds as a source of energy. Almost all life on earth is directly or indirectly reliant on primary production. “Primary Productivity” refers to the rate at which that production happens. http://www.bigelow.org/foodweb/chemosynthesis.jpg

Primary Production made by Primary Producers Gross primary productivity is the total amount of energy that producers convert to chemical energy in organic molecules per unit of time. Then the plant must use some energy to supports its own processes with cellular respiration such as growth, opening and closing it’s stomata, etc. What is left over in that same amount of time is net primary productivity which is the energy available to be used by another organism. The organisms responsible for primary production are known as primary producers or autotrophs. Primary production is distinguished as either net or gross. Net primary productivity accounts for losses to processes such as cellular respiration. Gross Primary productivity does not account for other process that the primary producer may need to utilize energy for themselves. If any of your students have a part time job, remind them of the difference between their “gross” pay vs. Their “net” pay!

The needed conversion factors are found on the student formula sheet Experimental Data The following data was collected from 14 different rivers in Virginia. Use the Station 1 data to calculate the Primary Productivity of a water sample. Report your answer in units of mg Carbon fixed/Liter The needed conversion factors are found on the student formula sheet LO 2.23 The student is able to design a plan for collecting data to show that all biological systems (cells, organisms, populations, communities and ecosystems) are affected by complex biotic and abiotic interactions. We collect many different types of data regarding water samples to assess the overall health or target specific concerns. One of the water quality measurements we examine to determine if a river, lake, or pond is undergoing eutrophication involves the amount of dissolved oxygen present in the sample. As an algal bloom increases, it lowers the amount of oxygen in the water. Also, as the algae die and decay they become Oxygen-demanding waste and further deplete the Oxygen levels.

Answers to Previous Slides Station 1 4.2 mg O2/L  0.698 = 2.9 mL O2/L 2.9 mL O2/L  0.526= 1.6 mg Carbon fixed/L

Primary Production It is important to examine all three graphs above and understand why differences occur in the net primary productivity in various biomes, but most importantly between aquatic biomes and terrestrial biomes. About 70 percent of the planet is covered in ocean, and the average depth of the ocean is several thousand feet (about 1,000 meters). Ninety-eight percent of the water on the planet is in the oceans, and therefore is unusable for drinking because of the salt. The oceans also have thus also large surface area (graph a, 65%). Primary producers in the ocean account for a high percentage of net primary productivity (graph c), but when equalized over the surface area, their average net primary productivity is quite low (graph b). Which biome is the most productive per unit of volume/area? Alga beds and reefs Which accounts for most of the Earth’s O2 production? Open ocean followed by tropical rain forest.

How does energy flow through an ecosystem?

Net Product Pyramid The diagram above shows the energy that passes to each level in a food chain. Energy in biology is often presented in joules (J), calories (cal), or kilocalories (Cal). One cal= 4.2 joules whereas one Cal=4.2 kilojoules. A small calorie is how much energy it takes to increase the temp of 1 gram of water by 1° C. A large Calorie is how much energy it takes to increase the the temp of 1 kilogram of water by 1° C. The large Calories are equal to 1,000 calories and are the ones you see on food product labels in the grocery store. This diagram illustrates the 10% rule. As you move up the food chain or web, energy is lost at each level (also referred to as transformation). This is called the 10% rule since only 10% of the energy is available for the next level. Energy flow from an organism, a community, an ecosystem, and the biosphere is an important and central concept. Due to the law of thermodynamics: energy cannot be created or destroyed, but each time energy is transformed (when the bird eats the flower), some of the energy is converted to a non-usable form we call heat which makes molecular motion increase, thus also causes an increase in entropy. The energy is not “lost” it is simply transformed to the surroundings as a low quality of energy that we are not able to utilize.

Trophic Level Human Population Ask students to compare vegetarian diets to carnivorous diets. Meat eaters require more energy transformations and every transformation involves the loss of energy as heat.

Pyramid of Numbers This graphic represents the number of organisms in a field of bluegrass in Michigan. It takes over 5 million primary producers to support 3 tertiary consumers.

The First Law of Thermodynamics states that energy cannot be created or destroyed, only change form. The Second Law of Thermodynamics states that in each transformation some energy is transformed to heat that increases molecular motion, thus increases entropy. The diagram above is showing that at every transformation, heat is flowing out of the system. This is in agreement with The First Law of Thermodynamics. Some of the of the energy is being transformed by the organisms for their life processes, some is available when they are consumed by the next level, and some is given off as heat.

Energy Transformation This illustrates the concept explained on the previous slide. 200 J (biomass eaten by catepillar)  100 J (feces) + 33 J (growth) + 67 J (cellular respiration) 200 Joules = 200 Joules

Biogeochemical Cycle This slide shows the interaction between geologic processes, abiotic factors and organisms. Matter cycles through the earth in various ways: water cycle, phosphorous cycle, carbon cycle, sulfur cycle, nitrogen cycle. These cycles along with the sun’s energy provide the base resources for producers that transform them into useable energy for other organisms.

Big Idea 2: Biological systems utilize free energy and molecular building blocks to grow to reproduce & to maintain dynamic homeostasis EU 2.A Growth, reproduction and maintenance of the organization of living systems require free energy and matter. EK 2.A.1 All living systems require constant input of free energy. EK 2.A.2 Organisms capture and store free energy for use in biological processes. EK 2.A.3 Organisms must exchange matter with the environment to grow, reproduce and maintain organization. http://www.theenergylibrary.com/files/images/Energy_Allocation.screen.jpg

What happens when a cycle is out of balance? Cycles can have an anthropogenic (man-made) or a non-anthropogenic (natural phenomena) impact that causes a cycle to become unbalanced. Additionally, this may just be the natural state of that ecosystem as a consequence of the availability of nutrients. Two examples involving imbalanced freshwater habitats include: Oligotrophic waters- low primary productivity Eutrophic waters- high primary productivity

Eutrophic- high nutrient content Oligotrophic Lake- low nutrient content Oligotrophic lakes have low primary productivity due to low nutrient content. These lakes are usually clear and have high quality drinking water. The bottoms of the lakes usually have enough oxygen to support some species especially those species that can live best in cold, well-oxygenated waters (ex: trout). Eutrophic lakes, rivers, or streams have high primary productivity due to an excess of nutrient content. Eutrophic- high nutrient content

Eutrophication- The Algal Bloom LO 2.24 The student is able to analyze data to identify possible patterns and relationships between a biotic or abiotic factor and biological system (cells, organisms, populations, communities or ecosystems). Eutrophication can be naturally occurring or man-made. In the picture above, this eutrophication was caused by fertilizers (containing phosphorus and nitrogen) from planned communities. Eutrophication can occur naturally in ponds or older lake as plant material builds up over time. Natural eutrophication is usually a gradual process, occurring over a period of many centuries. It occurs naturally when for some reason, production and consumption within the lake do not cancel each other out and the lake slowly becomes over-fertilized. While not rare in nature, it does not happen frequently or quickly. Effects: Negative environmental effects include hypoxia, the depletion of oxygen in the water, food loss, and habitat loss for aquatic organisms. Increase in Oxygen demanding decay (as the algae die). Point out the obvious, but often overlooked by students, fact that this leads to less O2 in water even though it is a bloom of photosynthetic algae (which one might think would therefore increase O2 levels). The algae die eventually and then the decomposers consume O2 via cell respiration as they “eat” the abundance of dead algae, resulting in less or even no O2; discuss “dead zones.”