ECOSYSTEM ECOLOGY. Environmental Science Mr. Schisel

Transcription

1 ECOSYSTEM ECOLOGY Environmental Science Mr. Schisel

2 Ecosystems are an interconnection of biotic and abiotic components ecosystems have boundaries

3 Ecosystem Boundaries Well-Defined Boundaries Easier to study biotic and abiotic factors Easier to trace the cycling of energy and matter Examples: Caves, Ponds, Lakes Difficult Boundaries to Define Most common situation Sometimes it is determined by scientists (range of a species) or by administrators (national parks)

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5 Ecosystem Ecology tries to understand how the ecosystem operates as a whole tries to focus on major aspects of the system the amount of energy that is produced by photosynthesis how energy flows along the food chain what controls the rate of decomposition of materials the rate at which nutrients are recycled

6 Energy Flow Through an Ecosystem Teritary Consumer Secondary Consumers Cellular Respiration Primary Consumers Producers Photosynthesis

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8 Energy Flow through Ecosystem

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10 Food Web

11 Organisms (Consumers) some organisms such as omnivores can fit into more than one trophic level scavengers (a type of carnivore, vultures) eat dead animals decomposers (bacteria, fungi) breakdown matter into nutrients that are recycled into the ecosystem. detritivores (dung beetles) breakdown dead tissue and waste products

12 Ecosystem Productivity Gross Primary Productivity (GPP): the entire photosynthetic production of biomass in an ecosystem (total energy produced) Net Primary Productivity (NPP):the energy captured minus the energy respired by producers, GPP-R=NPP Respiration: takes place in the mitochondria, energy is used for cellular activities (growth, reproduction, maintenance)

13 60% of GPP is lost to cellular respiration 1% of solar energy striking producers is captured in photosynthesis (GPP) 99% of solar energy is reflected or passes through producers without being absorbed 40% of GPP supports the growth & reproduction of producers (NPP)

14 What inputs and outputs of GPP? Inputs Climate Amount of light Amount of nutrients Availability of water What climates typically have the most productivity? Outputs Rate of Photosynthesis Rate of Biomass Production

15 The Significance of NPP NPP is the plant energy available for consumers. It can be measure in: units of energy (such as a kcal) or units of dry organic matter such as grams of organic carbon (g C) per unit area (m 2 ) per unit time (yr) g C/m 2 /yr

16 Average NPP (kcal/m 2 /yr

17 Average World Net Primary Productivity

18 Examples of NPP Tropical Swamps 3,000g/m 2 /yr Rocky Desert 3g/m 2 /yr

19 More Examples of NPP Highly Productive: Coral Reef 2,500g/m 2 /yr Open Ocean 125g/m 2 /yr Altrendo/Getty Images _Wallpaper/

20 Energy Transfer in Ecosystems Energy in a system can be measured in terms of biomass (total mass of living matter in a specific area). NPP establishes the rate at which biomass is produced. It varies greatly between biomes. The standing crop is the amount of biomass in an ecosystem at a given moment in time. NPP can help us measure change in an ecosystem (environmental indicator).

21 Standing Crop versus NPP Remember: standing Crop (amount of biomass at a given time) and NPP is the productivity A slow growing forest may have low productivity, however high amounts of biomass. Idaho Foresty Tour, 2011

22 Ecological Efficiency and Trophic Pyramids Ecological Efficiency: the amount of consumed energy that can be passed from one trophic level to another (10% is the average) Theories (what controls ecosystems functioning) bottom-up control top-down control

23 Three hundred trout are needed to support one man for a year. The trout, in turn, must consume 90,000 frogs, that must consume 27 million grasshoppers that live off of 1,000 tons of grass. -- G. Tyler Miller, Jr., American Chemist (1971)

24 Warm Up Guiding question: What are the inputs and outputs to ecosystems? What are the four major cycles of matter? What are the comparisons among the water, carbon, nitrogen and phosphorous cycles? Define the following Biogeochemical cycles Leaching Salination Limiting nutrient Macronutrients What is an eco tipping point? Describe the tipping point in the video.

25 Posters I will split you into groups You will be making a poster and a PowerPoint about your cycle. Some of the group will work on PP others work on posters. This should be thorough research. PowerPoint Poster Educate in detail the rest of the class Present on three current events regarding your cycle Should include biotic and abiotic factors along with anthropogenic effects Include the chemistry!!! Color Draw out the entire cycle Be sure to draw attention to the following: Biotic/abiotic process Anthropogenic effects Biogeochemical processes Time Chemistry