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Ecology Biomes and Ecosystems

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Presentation on theme: "Ecology Biomes and Ecosystems"— Presentation transcript:

1 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.

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

3 Primary Production http://www.bigelow.org/foodweb/chemosynthesis.jpg
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.

4 Visualizing Matter & Energy
There are a variety of diagrams that help us visualize how energy, biomass, matter, and even number of organisms interact in a particular community or ecosystem. It is important that you look carefully at the diagrams and understand what it says about that ecosystem in terms of matter and/or energy.

5 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!

6 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.

7 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.

8 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.

9 Biomass Pyramids Biomass refers to dried biological matter that either is living or was recently living. Biomass is measured by obtaining the mass after water has been removed from the substance. (a) This biomass pyramid shows a Florida bog. This is a a pyramid that students typically associate with a sustainable ecosystem, but there are exceptions to the rule that the primary producers have the largest biomass at any given time as shown in graph (b). Ask the students to explain the second pyramid (b) (b) The inverted biomass as shown in the English Channel is possible. A small amount of phytoplankton biomass supports a larger population of zooplankton. The phytoplankton are able to grow very quickly and thus its primary productivity can pass on to the next level in large amounts. So a small number of primary producers grow at a rate so high they can support the primary consumer's energy needs. I think this slide should go up with the other pyramid slides even though it’s about populations

10 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.

11 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.

12 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

13 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.

14 Nitrogen Cycle Really important! Note the critical and non-replaceable role of bacteria. This link will allow you to relate the story of Biosphere II and its failure due to lack of bacteria for N cycle. Ask students to explain why this is a global cycle

15 Phosphorus Cycle Not a global cycle – why not? Because Phosphorus cannot exist in the gaseous phase and thus it can only cycle in its liquid or solid state and does not ever enter the atmosphere.

16 Water Cycle Global cycle – In the cycle, water exists in three states; vapor, liquid, and ice. The Sun is the driving force in the cycle. The amount of water on Earth stays fairly constant, but its distribution among the three states may vary. Climate changes could change the distribution of water in the water cycle.

17 Carbon Cycle Really important! Global cycle – why?
Ask students seemingly simple questions such as: How do animals obtain their carbon molecules? Why do animals have to consume organic carbon compounds? Many students err by focusing only on the flow of gases (CO2 and O2) and forgetting the movement of carbon in its many other forms.

18 Nutrient Cycling

19 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.

20 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.

21 Now that we have examined the flow of energy and the cycling of matter, let’s examine biomes from the biosphere.

22 Aquatic Biome Distribution

23 Lake Stratification

24 Zonation Marine Zonation Lake Zonation

25 Freshwater Streams, lakes, rivers, Freshwater communities
1. light intensity decreases w/ depth; sharp temp. decreases w/ depth 2. 2 zones depending on light a. photic zone – near surface, contains phytoplankton and zooplankton b. aphotic zone – deeper, dark areas w/ many decomposers eating dead organisms * benthic organisms (bottom dwellers) such as clams, insect larvae, crayfish

26 Wetlands & Estuaries Transitional Zones between freshwater and marine. This water tends to be a mix of both depending on its geographic location. The water is often referred to as brackish

27 Marine Biomes Tide Zone Coral Reef Benthos Black Smoker
Marine Communities 1. Oceans cover ¾ of Earth’s surface 2. 3 zones a. intertidal zone –shallow where land meets water; sometimes wet and sometimes dry b. neritic zone – shallow region over continental shelf c. oceanic zone – beyond the shelf; very deep i. pelagic zone – open water ii. benthic zone – sea floor 3. abyssal zones – very deep and cold areas w/ high water pressure and no light 4. Estuary - area where freshwater rivers merge w/ ocean Black Smoker

28 Terrestrial Biomes These are often named for predominant plant life and blend into each others without sharp boundaries

29 Tropical Rain Forest Highland Rainforest Lowland Rainforest
Seasonal Rainforest Tropical Forest 1. temperature relatively constant at 25 C 2. near equator, >80 inches rain = tropical rainforest a. greatest plant and animal diversity b. soils poor in nutrients c. most animals tree dwellers d. destruction is causing widespread climate changes Where Found: South America, S.E. Asia, Central Africa Central America Plants: rich vegetation in canopy and undergrowth Animals: colorful insects, lizards, amphibians, reptile, small mammals Other Characteristics: 200 – 400 cm rain, constant temperature (25o C)

30 Savanna . Savanna – grassland w/ scattered trees
1. 3 seasons – cool/dry, hot/dry, and warm/wet 2. frequent fires inhibit tree growth 3. large herbivores dominant animal

31 Desert C. Desert 1. <30 cm. of rain per year, can be cold or hot
2. scattered shrubs, cacti and succulents common reptiles and seed eaters (many nocturnal) Where Found: northern Africa, southern Asia, central Australia Plants: cactus and other non-leafy plants Animals: lizards, small rodents Other Characteristics: very little rainfall, although some deserts have seasonal rain

32 Chaparral- also called Scrubland
Chaparral – scrubland 1. dense, spiny shrubs with evergreen leaves 2. found along coasts 3. maintained by periodic fire

33 Temperate Grasslands E. Temperate Grassland
1. similar to savanna but in cooler areas 2. ex- steppes in Russia , pampas of Uruguay large grazing animals and carnivores Where Found: interior of many continents Plants: grasses and small leafy plants Animals: grazers and browsers Other Characteristics: Large variation in temperature and seasonal changes. Grazing and prairie fires

34 Temperate Forest Temperate Deciduous Forest 1. midlatitude regions.
2. soil rich in nutrients with even rainfall throughout year herbs, shrubs, and tall trees grow Where Found: southern Canada, eastern U.S., Europe, and Japan Plants: trees that lose their leaves (oak, maple, birch) Animals: huge variety, including fox, deer, moose, etc. Other Characteristics: lands cleared by hunting and farming

35 Taiga Also called Coniferous or Boreal Forest 1. precipitation usually snow 2. conifers like spruce, fir, hemlock 3. soil acidic and forms slowly Pacific NW Rain Forest Lady Bird Grove Sequoias G. Taiga (Coniferous or Boreal Forest) 1. precipitation usually snow 2. conifers like spruce, fir, hemlock soil acidic and forms slowly Where Found: most of Canada and Asia Plants: pine trees Animals: bears, wolves, moose, elk, voles, wolverines, grouse Other Characteristics: long and cold winter, summers warm enough to completely thaw the soil.

36 Tundra Characteristics Soil- Layer of permafrost
Light- long periods of darkness Denali National Park actually includes three biomes: Taiga, Alpine forest, and the Tundra, Tundra 1. low, shrubby plants 2. Arctic tundra – around N. Pole, very cold, little light for long periods and then 24 hr. days in brief summer 3. alpine tundra – at high elevations

37 Biosphere All of the biomes combined make up the biosphere.

38 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

39 Oligotrophic Lake Eutrophic
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

40 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.”

41 The needed conversion factors are found on the student formula sheet
Experimental Data The following data were 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.

42 Answers to Previous Slides
Station 1 4.2 mg O2/L  = 2.9 mL O2/L 2.9 mL O2/L  0.536= 1.6 mg Carbon fixed/L


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