BIOL 1103 1st Edition Lecture 3 Finished up LECTURE 2 Community Interactions Started and Finished ENERGY FLOW and NUTRIENT CYCLING in ECOSYSTEMS Finished up LECTURE 2 Community Interactions PARASITISM and MUTUALISM Parasites and Hosts o Parasites live IN or ON their prey Aslso called HOSTS o Hosts harm and weaken however do not always kill right away Parasite Host relationships o Act as agents of NATURAL SELECTION on one another Good and Bad Ex of GOOD people can live with HIV for 30 years and pass on to future hosts Ex of BAD Ebola kills host really fast so it can spread fast o Symbiotic long term physical relationship Ex Whale Certain ants Mutualism interaction between species which BOTH species benfit o Many MUTUALISTIC relationships are SYMBIOTIC long term relationship Ex Lichen looks like one species but is actually two Fungus and plant living together fungus feeds plant part and plant part feeds off the fungus part How Community Interactions Cause Change Over Time Succession is a Process Order 1 Early organisms modify the environment in ways that favor later organisms 2 End stage organisms suppress earlier organisms but tolerate one another producing a stable community 3 There is a general trend toward more species and longer lived species These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute SUCCESSION Begins with an Ecological disturbance Starts with PIONEERS hardy plants which change the ecosystem in ways that FAVOR competing plants which eventually DISPLACE the PIONEERS If continued Succession progresses to a diverse and stable CLIMAX COMMUNITY Two Forms of SUCESSION 1 PRIMARY community GRADUALLY forms in a location where there are no remnants of a previous community a EX Volcano Asteroid Hits b TIME SPAN 1 000 years pretty LONG time 2 SECONDARY new community develops after an EXISTING ecosystem is disturbed in a way that leaves significant remnants of the previous community behind such as soil and seeds a Ex Yellowstone National Park Forest Fire b TIME SPAN 100 years SHORTER time span Succession CLIMAX COMMUNITY populations that can coexist without replacing one another o CLIMAX COMMUNITIES have more species and more types of community interactions than do earlier stages of succession Started and Finished ENERGY FLOW and NUTRIENT CYCLING in ECOSYSTEMS LECTURE 4 ENERGY FLOW and NUTRIENT CYCLING in ECOSYSTEMS ECOSYSTEMS have 2 Components 1 BIOTIC LIVING organisms 2 ABIOTIC NON living physical or chemical aspects of the environment NUTRIENTS atoms and molecules that are NECESSARY for life Nutrients are CYCLICAL tansported around earth but don t leave o Ex Humans food energy o Ex Plants glucose energy ENERGY is UNIdirectional Passed from one TROPHIC level to the NEXT o Energy Heat given off to environment o Energy sun producers energy is lost in form of HEAT and the creation of Energy making bark for example o Nutrients are never really lost Energy cycle photosynthetic organisms passes through levels of NONphotosynthetic organisms Each category of organisms is called a trophic level TROPHIC LEVELS Producers or autotrophs make their own food using inorganic nutrients and solar energy from the environment Ex Photosynthesis Consumers or heterotrophs Organisms that cannot photosynthesize Ex Humans Levels of CONSUMERS Primary consumers o Herbivores include animals such as Grasshoppers mice zebras o and FORM the second trophic level Secondary consumers o Carnivores feed off primary consumers Ex Hawk who eats the rabbit Tertiary etc consumers Net Primary Production in Ecosystems Energy is lost at EACH Trophic level never 100 in the end Why Because not all energy can be digested Ex hawk eats rabbit Bones are waste 10 Law Each Trophic level loses 10 each time used Energy flows through Ecosystems by 1 Food Chains a Simple Terrestrial food chain b Simple Marine Food Chain i Ex Producer PLANT PHYTOPLANKTON First Trophic level ii Primary Consumer WORM ZOOPLANKTON SHRIMP Secondary Trophic Level iii Secondary Consumer BIRD SMALL FISH Thirst Trophic Level iv Tertiary Consumer HAWK BIGGER FISH Fourth Trophic Level v Quaternary Consumer SHARK Fifth Trophic Level 2 Food Webs Simplified Grassland Foodweb a Buffalo Primary Consumer b Energy source Consumer Pack of wolves can eat Buffalo c Decomposers microorganisms bacteria etc degrades the remains replenishes the energy into the system LOW energy contribution Energy loses efficiency as it moves down the Trophic levels The average net energy transfer between trophic levels is roughly 10 efficient and is known as the 10 law Energy pyramid Lower Trophic less you need to eat to achieve Nutrients requirements Ex Eat and apple Primary consumer easier to break down and faster energy Ex Eat Turkey secondary Consumer takes longer to break down and metabolize Nutrient Cycling o MACROnutrients needed in Large amounts Water Carbon Hydrogen Oxygen Nitrogen Phosphorous Sulfur Calcium o MICROnutrients needed in small amounts Zinc Molybdenum Iron Selenium Iodine Nutrient Cycles o Hydrologic Cycle Reserviors Water vapor in Atmosphere Lakes Rivers Ocean Underground Water Processes Precipitation Rain Evaporation Run off from Rivers Seepage through soil into ground o Carbon Cycle Reservoir CO2 in Air CO2 dissolved in ocean Fossil fuels in ground nutrient in ABUNDANCE CO2 Processes Burning fossil fuels Fire Photosynthesis Respiration Decomposition Plants photosythesis Glucose made into energy Animals cellular respiration Trophic Levels 1 Producers 2 Consumers 3 Detritivores and Decomposers o Carbon Cycle much of earths carbon is on Limestone Rock Fossil Fuels coal oil and natural gas are additional long term reservoirs for carbon HUMAN DISRUPTION OF EARTH Ancient People had relatively little impact on nutrient cycles HOWEVER as population grew and technology increased people began to act more independently of natural ecosystem processes Nutrient Cycles Book covers more then needed o Fertilizer is a Nutrient Cycle o NITROGEN most abundant gas in the atmosphere Algae needs N2 Ex Algae can be toxic not all can consume algae Overloading the sulfur and nitrogen cycles causes acid deposition Burning of sulfur containing fossil fuels accounts for about 75 of all sulfur dioxide emissions worldwide o Most system take hundreds of years for an ecosystem to recover Ex 2010 oil spill OIL is physically gone a lot of it has SUNK down to bottom will take 100 s of years to