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UF / Biology / BSC 2011 / will ferrell land of the lost mosquito

will ferrell land of the lost mosquito

will ferrell land of the lost mosquito


School: University of Florida
Department: Biology
Course: Biology 2
Professor: Norman douglas
Term: Fall 2016
Tags: Biology, Ecology, and Dr.DeMarco
Cost: 50
Name: Biology 2 Exam 3 Ecology Study Guide
Description: these notes are covering what is on the last exam for Biology 2. Exam 3: Ecology. taught by Dr. DeMarco in Spring of 2017
Uploaded: 04/16/2017
85 Pages 227 Views 0 Unlocks

Question: How can we preserve biodiversity?

Question: How does the presence of wolves influence the population of elk and aspen?

Question: how to organisms survive hot and dry conditions?

Biology 3 BSC2011 Exam                                                    April 19 EXAM 3 By the end of this lecture you should be able to: • identify the different scales of ecological organization and an ecological question that can be asked at each scale. • identify the majDon't forget about the age old question of interporate
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Don't forget about the age old question of bsc 1084
We also discuss several other topics like in the ___________, electrons are ejected from the surface of a metal exposed to light of a certain minimum frequency.
Don't forget about the age old question of phys140
or factors that influence climate across the globe and describe how they influence climate. • designate specific organism adaptations to specific environments Ecology = the scientific study of the relationships between organisms and their environments  logy­logos = study of Eco ­ oikos = house That organism interacts with other organisms  Also interacts with disturbances in nature predators… Scientists use the scientific method: observation, Question, Hypothesis, Experiment, conclusion, results  support hypothesis or they do not support the hypothesis Ecology =/= Activism It is a scientific discipline while activism is very different Key Concepts Ecological systems vary over space and time How do ecologists study the natural world Small   ­­>   Large Scales of Ecological Organization Organism Level : survival and reproduction: Question: how to organisms survive hot and dry conditions?  kangaroo mouse concentrates its urine Rattlesnake regulates body temperature by going in the sun or shade Plants can open or close its stoma to decrease water loss Population Level: group of individuals in the same place interacting Question: Are boat accidents having an impact on manatee populations? Community Level: Interactions among population of different species Question: How does the presence of wolves influence the population of elk and  aspen?  Ecosystem: communities plus their abiotic environment  Question: Can tropical forest absorb the extra CO2 in the atmosphere that is  driving climate change?  Biosphere: All organisms and environments of plants (we have one biosphere aka earth) Question: How can we preserve biodiversity? What information would you need to better understand the threat of Zika virus to human health? Need to know: Location Are different times of the year more common for Zika How fast can it reproduce Where does it originate from How it is transmitted What temperature does the mosquito operate more commonly at Organism: what is the climate conditions? How is Zika transmitted? Life cycle of the virus? Zika Virus:  Member of Flavivuris  Aedes spp. Mosquitos host 2 weeks life cycle in host before infecting humans Global Distribution shows transmission is the equatorial region, central  and the top of South America  Transmission: Mosquito to humans Humans to humansPopulation What controls growth rate, distribution of mosquitos..? Community How do interactions with mosquitos and other species (humans) influence the spread of  Zika? Ecosystem and Biosphere Level How will a warming climate influence mosquito populations and transmission of Zika? Ecology = the scientific study of the relationships between organisms and their environments  What determines the environment in which organisms live? Colorful map representing different biomes Another map representing temperature Cold at poles Hot at equator  Key Concepts Ecological systems vary over space and time Solar energy input and topography shape Earth's physical environments (climate)  Variations in Solar Energy drive patterns of  weather and climate Difference between weather and climate High today is 78 degrees : weather Warm summers with cool winters both with high humidity : climate (less specific)  Climate: Long term trends in temperature, wind and precipitation based on averages and variation  measured over decades Weather: Temperature, wind, humidity and precipitation at a particular time and place (short term) Climate Determines where organisms live Resource availabilityRate of population growth Key to understanding all ecological phenomenon  Key Concepts: Solar energy input and topography shape Earth's physical environments (climate) Earth's energy Energy in = energy out 343 Watts/m^2 Energy losses 49% absorbed by surfaces 19% long wave radiation ­ goes back out Lost through the surface of objects, transpiration (water loss in plants), evaporation 7% lost ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ March 22  Identify the major steps in the Hadley cell Identify the major steps that occur with the rain shadow effect Apply knowledge of atmospheric circulation and climate to identify geographic location of major biomes  Key concepts Ecological systems vary over space and time  Solar energy inputs and topography shape Earth's physical environments (climate) Topography Variations in Solar Energy drive patterns of weather and climate Solar Energy inputs varies with: Latitude  Earth's angle Latitudinal variation in heating of Earth Direct solar radiation at the equator bc of angle Season  Earth's tiltTilt of the Earth: seasons  23.5 degree tilt When the suns rays hit the earth it hits the northern hemisphere more Look at picture Which is why Australia's summer is colder than the USA summer Climate vs. Weather Climate :  Long term trends in temperature, wind, and precipitation based averages and  variation measured over decades Determines where organisms live Resource availability  Rate of population growth Key to understanding all ecological phenomenon  Weather :  Temperature, wind, humidity and precipitation at a particular time and place  (short term) Earth's energy budget Energy in = energy out 343 Watts/m2 Incoming radiation is mostly short wave (visible, NIR, UV) 31% reflected by clouds or surface 20% absorbed by clouds and atmosphere 49% absorbed by earth surface Energy Losses (of 49% absorbed by surface) 19% longwave net radiation from earth 7% lost as sensible heat flux by conduction and convention  23% lost as latent heat flux by water vaporHeat energy is redistributed   1. Atmospheric circulation 2. Ocean circulation  Latitudinal variation in heating of Earth North Pole (90 N) Equator (0) South Pole (90 S) Hadley Cell 1. Incoming Solar Radiation (warms air at earth's surface) 2. Warm air rises which changes density of the air (cause pressure gradients) (warm air is lighter than cold air) 3. Warm expands 4. Warm air cools (cold air is more dense. Cold air cant hold as much moisture either so  clouds form) 5. Clouds form (cold air is more dense and falls back to the earth's surface) 6. Air cools and descends How warm air rises Warm air = light Cool air = dense Warm surfaces expel warm air ­­> warm air expands and then cools ­­> cool air  can make clouds and then descends Poles­  Heat energy is redistributed  Atmospheric circulation  Hadley cells Coriolis effect 60% of the heat is transferred this way Heating of the tropics Heat redistribution because hotness risesAs heat rises, it starts to cool again because the atmosphere is much cooler Then clouds form around the equator (area of the tropical forests) Circulation of area around the equator  Cool air descends ­­> rises again after being warmed Hadley cells engage in atmospheric circulation  Polar cells ­ distribute around the poles Tropical, polar and temperate zones Hadley cell Found at the equator Expansion and uplift of air at equator Three different cells but the main one is the Hadley cells Hadley cells start from the equator (wet) and cool air moves up and out  to the area in between Dry(30 N) climates and Tropic (23.5 N) climates After warm air descends to the dry and tropical climates it moves back to the equator  Polar  At poles Subsidence of cold converging air at the poles (subsiding cold air) Poles more in a circular motion of cold air between 90* and 60* Ferrell cells Transfers warm air to high latitudes and shifts cold air and back to the  (sub)tropics Coriolus Effect Bends the winds West to east The earth is spinning at a different speed than the air above it  The earth is spinning from west to east.  The winds above it are moving the opposite direction ­­> Easterlies trade  winds found around the equator (move from east to west)The wind at the equator moves faster than the wind at the poles because  it is more area to cover  The easterlies in the northern hemisphere moves from the east to  the west via NE Trade winds The easterlies in the southern hemisphere moves from the east to the west via SE Trade winds Temperate zone: The earth is spinning slower than the air around the equator so the winds  get deflected and spin west to east and called the westerlies winds The westerlies in the hemisphere move west to east (in the 60­30 degree latitude)  Poles East to west and called easterlies winds Ocean circulation  Deep currents driven by thermohaline circulation, density differences  (overturning circulation)  Surface circulation is effected by wind currents Deep ocean circulation is effected by temperature and water density or solinity  40 % of heat transfer Surface circulation Driven by / follows winds from the coriolus effect Shallow currents are driven by prevailing winds Gyres are circulation deflected by Coriolus effect Circumpolar current goes along Antarctica  Equatorial Countercurrent moves in a circle going from the  equator bringing warm water to the west by japan and getting colder by alaska and then moving cold  water back down where its warmer by the California coast of USA and back down near the equator  The gulf stream also moves in a mainly constant warm flow of  water from the east coast of the USA north by Maine and south to the west coast of Africa back down  around the Caribbean islands and back up to US  The North Atlantic drift moves warm water up to the Northeast  direction along Europe and Sweden and Cold water moves south along both sides of Greenland Eastern Trade winds around the equator move surface water east to west Westerlies north and south of the equator move west to eastDeep ocean Ocean circulation : deep Deep currents driven by thermohaline circulation, density differences  (overturning circulation) Driven by changes in water temperature and salinity  Salty water is more dense Cold water is more dense Salty cold water will move to the bottom Less salty water is lighter Warm water is light Warm water around the equator Freshwater runoff from land may affect salinity, thus circulation Redistribution of heat has a strong effect on global climate Topography Global temperature patterns Global Climate is Modified by Landmasses heat faster than oceans Mountain Ranges Landmasses heat faster than oceans Land sea breeze Sea breeze vs land breeze Land gets hot quickly and the ocean takes longer to heat  up causing differences in temperature of the air Sea = high pressure to low pressure ( during the day) Land = cool air to warm air ( usually at night ­ when the  land is cold) Temperature difference is greater on inland cities than cities on the coast The highs and lows are more dramatic inland because it does not  have the ocean to cool and heat the land to prevent the land from getting too hot and too cold Monsoon Massive seasonally changing sea breeze circulationsDry winters and Wet summers 1/4 of the globe experiences monsoon climate (provides a lot of  precipitation) (Ex: New Mexico and Arizona receive half the annual precipitation during monsoon  season) In areas with large bodies of water, hot water cant hold  as much water so precipitation occurs In the winter the opposite happens Mountains ranges Deflect trade winds Produce rain gradients Rain shadow effect Windward side is the direction the wind is coming from (wind  changes from west to east or east to west to be sure to know where it is coming from) Evaporation happens Moist side Cold air cant hold as much so clouds form to hold  precipitation at the top of the mountain  Leeward side is the side the wind leaves Arid side As it descends the air warms up again ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~  March 24 Usually there is more precipitation on the windward than the leeward side of a mountain range. In the  middle latitudes (30­60 degrees) of the Northern Hemisphere, this means that the west sides of mountains  receive more precipitation  By the end of this lecture you should be able to: Apply knowledge of atmospheric  circulation and climates to identify geographic location of  major biomes Identify the biome best represented by a Walter climate diagramMatch the organismal adaptation to the environment represented in a Walter climate diagram Climate controls distribution of organisms at global scale Biome ­ a distinct physical environment that is inhabited by ecologically similar organisms with similar  adaptation Ex of a biome = savanna // climate = seasonally wet and dry Examples of biomes High annual precipitation and high temperature = Tropical rain forest Low annual precipitation and high temperature = subtropical desert  Low annual precipitation and low temperature = Tundra  High annual precipitation and Low temperature = cold cant hold water so we don’t get as much  cloud formation  Walter Climate Diagram Summarizes climate in an ecological relevant way First month of the Walter Climate diagram on the x axis will be the coldest month Ex: for Australia because its in the southern hemisphere it will start with July  Which Biome am I? Temperate biomes have a bell shaped graph (precipitation) ~ ~ ~ ~ ~ ~ ~  ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ March 27 Populations  An organism living in this climate would mostly likely have  the following adaptation(s) EXCEPT: … The environment has high temperature in a bell shape and low precipitation = desert Desert ­ low precipitation and hot summers It would NOT have: Drip tips  Drip tips High rainfall Raindrops runoff quickly Sheds leaf of excess water Prevents fungi and bacterial growthDeep taproot So they can access ground water far below the surface Concentrated urine Kangaroo rat : ex More urine less water Ectotherms Use outside environment to regulate body temperature Florida isn't a desert because its surrounded by water Lyme Disease Bacterial infection Symptoms: Rash, fever, headaches, fatigue If left untreated can spread to joints, heart and nervous system Treatment: Antibiotics Most commonly reported vector borne illness in U.S. ~300,000 people diagnosed each year in U.S. 1970s first cases reported from Lyme, Connecticut Where does Lyme disease come from? Borrelia burgorferi Bacteria that causes lyme disease Host:  Blacklegged tick Ixodes scapularis NE, mid­Atlantic, and North­central U.S. Ixodes pacificus Pacific coast U.S. How do people get lyme disease Tick infected with bacteria bites human transfer bacteria human Life history= schedule of an organism's growth, development, reproduction and survival Black legged tick life cycle (2 years) Tick becomes infected at the larva stageHosts: Mice and songbirds Tick infects humans at nymph stage and adult stage Ticks must be attached 36­48 hours for bacteria to be transmitted Lyme diseases has increased White footed mouse  Principle reservoir for Borrelia burgdorferi Omnivore (eats seeds and insects) Really like acorn seeds Scales of Ecological Organization Organism: survival and reproduction Population: Groups of individuals of the same species interacting. Individuals of a species that interact with one another within a given area at a particular  time Population ecology is the study of births, deaths, and the dynamics forces which  regulation the number of  individuals in a population  By the end of this lecture you should be able to: Compare and contrast 3 different types of spatial patterns of population  distributions Compare and contrast Type I, II and III survivorship curves Calculate population growth rates, sizes and changes in population size over  time. Compare and contrast slow and fast life history traits Measures of population abundance Population density: number of individuals per unit area/volume Population size: total number of individuals in the population Estimating population size: Density x total area occupied by population What is the size of the fire ant population in Florida Measure a small area and multiple the number of fire ants by the total area Population distribution (Spatial patterns) Clumped ­ may indicate competing individuals Random Spaced ­ may indicate social patterns or resource distribution Population Distribution  Patterns in age structure  Survivorship vs. Age Type III: Higher mortality early in life, low mortality late in life Type II: Constant mortality throughout life Type I: Low mortality early in life, high mortality late in life Humans affect ecological systems on a global scale Anthropocene ­ new geological period age of humans Humans are Spreading organisms across the globe Changing vegetation and topography Homogenizing ecological systems Anthopogenic Biomes Dense settlements Villages Range lands Wild lands ­ natural less human influence  Terrestrial Biomes 1. Climate (temp and precipitation) 2. Dominate vegetation 3. Soil type 4. Disturbance Aquatic Biomes 1. Salinity 2. Water movement 3. Water depth (light penetration ­­> photosynthetic organisms live) 4. Water temperature …PopulationsLyme Disease Bacterial infection Symptoms Rash, headaches, fatigue, fever (facial paralysis, Bull's eye rash on the back, arthritic  knee)  If left untreated can spread to joints, heart and nervous system Treatment: Antibiotics Most commonly reported vector borne illness in US ~300,000 people diagnosed each year in US 1970s first cases reported from Lyme, Connecticut Where does Lyme Disease come from? Blacklegged tick : Host 2 species have this bacteria NE, mid Atlantic and North central US Pacific coast How do people get lyme disease? Bit by the tick and transfers bacteria Life history = schedule of organisms growth development, reproduction and survival Black legged tick (2 year life cycle) 1st year Eggs hatch ­­>larvae turns to a nymph ­­> nymph goes dormant through the winter 2nd year Comes out of dormancy­­> feeds­­> turns to adult in the fall­­>finds a host  Tick becomes infected at larva stage Hosts: mice and song birds are infected with bacteria and the larvae feeds on them and  get it Ticks infect humans at nymph stage and adult stage Ticks must be attached 36­48 hours for bacteria to be transmitted If you see a tick, immediately remove it! Nymphs are super tiny so people usually miss that and get infected by the nymph  Ticks bite more in the summer monthsRash is the biggest sign people come in with when they have lyme disease Why are the number of cases of lyme disease increasing White footed mouse Principle reservoir for Borrelia  Omnivore Really like acorn seeds Organism:  Population: individuals of species that interact will one another within a given area at a  given lace Population ecology = is the study of births, deaths, and the dynamic forces which regulate the number of individuals in a population (immigration and emigration that control the number in a population) Compare and contrast the three different types of spatial patterns of population distributions  Compare and contrast type 1,2 and 3 survivor ship curves Calculate population growth rates, size and changes in population size over time Compare and contrast slow and fast life history traits Measures of population abundance Population density: Population of individuals per unit area/volume Population  size: total number of individuals in  the population Estimating population size: density times total area occupies by population (using a  subset) Ex: fire ant population in Florida Select area in Florida to look at Look at a 20 by 20 cm area and count the number of ants and multiply  the number of ants by the total area Florida  Population are patchy in space Population distribution Spatial patterns 1. Clumped ­ may indicate social patterns or resource distribution 2. Random­ less common 3. (evenly) Spaced ­ may indicate competing individuals (common in plants)Population Distribution  Patterns in age structure Survivor ship decreases dramatically at an older age ­ Type 1 ( humans) Constant mortality in life ­ Type 2 (squirrels) Increase in mortality in the beginning and then levels off ­ Type 3 (uncommon) Age Pyramids Also show mortality and birth distribution  Population changes over time Births and immigration add individuals to a population Deaths and emigration remove individuals from a population ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ March 29 By the end of this lecture you should be able to: •define principle of allocation and evaluate how an organism may alter allocation under different  conditions. •compare and contrast exponential and logistic growth and be able to identify the equations used for each. •describe how land use change can influence population dynamics. Population Growth Models Birth­death or BD model: change in population size depends on # of births and deaths over a  given time Population size = number of current individuals (N) + number of births (B) ­ number of deaths(D) Future Population? Population growth rate: How fast the population is changing  N= N +B­D Subtract N from both sides of the equation Divide both sides by change in t (time interval from t to t+1) Change in N = B­DChange in N/ Change in T = (B­D)/((t+1)­t) Change in population (N) over change in temperature (T) Look at power point for notes Estimating changes in population size: Per capita = "per individual" Per capita birth rate (b) = number of offspring an average individual produces Per capita death rate (d) = average individual's chance of dying Per capita growth rate (r) = (b­d) = average individual's contribution to total population growth rate Total population growth rate (change in N) over (change in T) Where Does r come from Life Histories Time table of individual organisms life Can differ in : Life span  Age at maturity  Parity­number of reproductive events Fecundity ­ number of offspring per event Time table is modified by environment If nutrition is low they could postpone maturity or production Life History = schedule of an organism's growth, development, reproduction and survival Parental investment = amount o time and energy given to an offspring by its parents Longevity = the life span of an organism (life expectancy) EX: salmon Reproduce once at 3­4 years old EX: elephant 1 offspring per event Adults live 60 yearsSlow life history trait Few offspring­live longer­spend more time raising young Fast Doesn’t take long to reach sexual maturity ­ more offspring­ spend less time with young ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~  Availability of resources and physical condition shape life histories Individual organisms require resources (material or energy) and physical condition they can  tolerate Rate at which an organism can acquire resources increases with the availability of resources Resources = uses up or consumed Condition= experienced but NOT consumed (temperature is not used up­it’s a condition of the environment) Principle of allocation  Once an organism has acquired a unit of some resource, it can be used for only one function at a time Function: maintenance, foraging, growth, defense or reproduction Stressed requires more resources for maintanence … (a) Typical conditions, normal resources Maintenance needs must be met first. Remaining resources are divided among other activities (b)Typical conditions, abundant resources When resources are abundant, more resources are gained and more are available after  maintenance needs are met ( C) stressful conditions, normal resources Stressful conditions mean more resources must be expanded on maintenance and fewer are  available for other purposes … Population change over time Estimating uture population size N(t+1) = N(t) + rN(t) Births > deaths ­­> population growths and r>0Births < deaths ­­> population decreases and r<0  b=d ­­> no change , r=0 ________ Example/ Clicker Buys 100 inseminated female Bison for her ranch, places monitors on 10 individuals 6 lived to 1 year 4 died 5 offspring births 10 total female animals R=b­d = 1 = 1/(10 total population) = 0.1 ­­> per capita growth rate ­­> growing Size of the herd at the end of the year Initital population = 100 Growth rate = 0.1 100 + 100(0.1) = 110 herd size at the end of the year  ________ Population growth Growth rate =  Number of new individuals produced in a given amount of time minus the number of individuals  that die b­d Intrinsic growth rate r =  Highest possible per capita growth rate for a population Under ideal condition population can grow rapidly Geometric (addictive) growth model  Growing fairly slow Compares population sizes at regular time intervals  Adds a constant number of individuals each time period Multiplicative (exponential) growth ratePopulation increases continuously at an exponential rate (J­shaped curve) Adds a constant multiple of the population size(n) each time period Could run out of resources Growing fairly quickly Population growth under ideal conditions N(t) = N(0)   x   e ^rt N(0)=current size of population R = intrinsic growth rate T­ amount o time over which population grows The power of multiplicative growth Most populations cant continue to grow like this­­ it will hit the carrying capacity There will be competition for space food and resources Population do not grow mult. For very long. Growth slows and reaches  more or less steady size This ecological struggle for existence, fueled by multiplicative growth, drives natural selection  and adaptation Populations do not grow multiplicatively for very long. Growth slows and reaches a more or less  steady size Density Dependent As population increases: R decreases Birth rates decrease Death rates increase R=0 population stops changing Carrying capacity =number of individuals an environment can support indefinitely (equilibrium size) Population Growth Density dependent factors Effects that increase with crowding Starvation, disease, places to live/territory, toxic waste, predatorsPopulation Growth Models  Logistic model: used to predict change in populations when environment limits growth Population growth rate = rate when N is close to )  x  # of individuals in population (N)  x reduction in rate die to crowding  r=r0  x (1­ N/K) K=carry capacity Change in N over change in t = r0  x  N (1­N/K) N(t) = K / 1+e^[(­r0) x (t­i)] I = time where population is half of K Population growth  Density dependent factors ­ effects that increase with crowding Starvation  Disease Places to live/ territoriality Toxic waste Predators  Population Growth Models Logistic model: used to predict change in populations when environment limits growth Population growth rate = rate when N is close to 0  x  # of individuals in population (N)   x  reduction in rate die to crowding Logistic Growth model:  r = r(0)  x  (1­N/K) K = carrying capacity Change in N/ change in t = r(0) x N(1­ N/K) N(t) = K/ 1+ e^(­r(0) x t­i) i=Time where population is half of K Fluctuating Population Cycles There is a lot of fluctuate with for example a song bird because of changes in the  environment (limited resources ­­>decrease in population) Or Predators  1. Fluctuations are the rule for natural populations2. Environmental variation causes irregular fluctuations 3. Population often have periodic cycles 4. Time delays in response of population depend on life history (birth rate,  survival, etc.) White footed mouse Omnivore Really like acorn seeds If squirrels also like acorns that means competition  Population of acorns increases around the same time that increase in acorn  production/density  occurs (also ticks) Why are number of cases of Lyme disease increasing? Mast years increase acorn production (resource) Following year increase mouse population Increase black legged ticks Increase lyme disease cases ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~               Human population 7 billion people Exponential growth What allows the increase in growth vaccines Antibiotics Advances in sanitation Green revolution in 1950­1980 increased food crops All raises our carrying capacity We are currently at .11 = 0.11 r We might go .05 in the future Great Leap forward in china Decreases food in            This decreased the global r valueAmmensalism ­ it doesn’t effect one but it negatively impacts the other organism Commensalism ­ one organism gets no effect and the other gets a positive effect Species interactions (Ch. 43) Interactions between species may be positive, negative or neutral Interactions affect population dynamics and species distributions Interactions affect individual fitness and can result in evolution   Intraspecific ­ same species interacting Interspecific ­ different species interacting Interaction influence population densities, alter species distribution and lead to evolutionary  change  1. Competition (­/­) ○ Use or defense of a resource by a individual that decreases the resource available to  others • Intraspecific competition ­ within a species • Interspecific competition ­ among species • Resources: ▪ Food, water, nutrients, space ▪ Any factor consumed by an organism and supports increase population growth rates = resource • Usually over a limiting factor, where competition for a single resource is most  intense • Usually over a limiting factor, where competition for a single resource is most  intense • Competition exclusion principle ▪ 2 species often cannot coexist indefinitely on the same limiting  resource • Demonstrated in lab settings ○ Presence of a competitor always reduces population growth rate ○ When two species coexists they have a lower carrying capacity, equilibrium  population densities than the other would alone ○ In some cases competition causes one species to go extinct• If the other species goes extinct and no other species come in, the other  population will go back to the population density when there was no other species (it would go back to a  higher population density) ○ Density dependent population grow reflects intraspecific interactions among  individuals in a population • Interspecific competition ▪ Effect of the other species subtracted in the growth model  • Lotka Volterra models  § Natural systems i. Coexistence of species more common: each species occupying a niche ii. Resources are partitioned so that there is little direct competition iii. Interspecific interaction can affect the distributions of species iv. Competitive interactions can restrict the habitats in which species occur v. EX: fundamental niche ­ 1)  habitat determined by abiotic  environment and by other organisms vi. EX: realized niche­  1) Over time the interactions with the other species made one species  more adaptable to the high tide spot on the rock vii. Species interaction can affect individual fitness viii. Phenotypes that gain the most  form a positive interaction or suffer least  from a negative interaction will increase frequency in the population and the population will evolve  ○ Resource partitioning  § Different ways of using a resource □ If differences in resource use are sufficiently large, competing species  can coexist  § EX: species A eat big sunflower seeds and species B eat small sunflower seeds § Intraspecific competition can be greater than interspecific competition  § Individuals within a species compete over resources □ You can harm yourself more than your competitor 2. Consumer resource (+/­)1. Predation ( organism eating a animal) 2. Herbivory (eating a plant) 3. Parasitism  4. Disease 2.a. predation (+/­) Consumer resource Evolutionary arms race Prey continually evolve better defenses and predators continually evolve  better offenses Red Queen hypothesis Red queen tells Alice, "Now, here, you see, it takes all the running you  can do, to keep in the same place." Consumer­resource interactions can drive evolution Predator hunting strategies Active hunt Ambush hunt Sit and wait Hunting Detect prey Catch prey Handle prey Consume prey Evolution of defenses Behavioral, Crypsis, Structural, Chemical, Mimicry  Behavioral EX: when a predator in present organisms reduce their time being active Crypsis Structure Mechanical defensesMaybe phenotypically plastic ­ induced only when prey detects  predator EX: Crucian carp Develop deep, hump shaped back when in presence of  predators Greater muscle mass allows greater acceleration to get  away from predator Chemical Spray foul smelling or toxic chemicals Store toxins in body Warning coloration (aposematism) =distasteful evolves in association with conspicuous  colors and patterns Mimicry  Some passionflower species have leaf structures that resemble butterfly  eggs. Females will not lay eggs on a plant that already as eggs. Cost of defenses Behavioral  Reduce feeding activity or increase crowding in location away from  predators Mechanical and Chemical Energetically expensive to produce Presence of predators can indirectly reduce prey population size due to cost in  induced defenses reducing growth and reproduction of prey When food availability is low, energy is low and investment in chemical  defense is also low Counter adaption of predators Behavior  Camouflage High­speed locomotion Resistance to toxins Consumer resource interactions modify per capita growth rates Consumer resource interaction can be incorporated in population growth modelsEffect of the consumer is subtracted in the equation for the resource species The effect of the resource is added in the equation for the consumer, since the  consumer benefits 2.c. Parasitism (+/­) Parasitic organism consumes part of the host but usually does not kill it 2.d. Disease (+/­) Plant: oak trees, west coast Disease­pathogen: Phytophthora "plant destroyer" , Sudden Oak Death First detected in CA in 1995 Has tons of thousands of several different oak species in coastal forests 3. Mutalism (+/+) 1. Both organisms are positively affect 2. Ee has parasites removed and prawn gets food 3. Functions of Mutalism i. Improve acquisition of water, nutrients and places to live ii. Aid defense against enemies iii. Facilitate pollination and seed dispersal 4. Leaf cutter ants and the fungi they cultivate 5. Plants and pollinating or seed dispersing animals 6. Humans and bifidobacteria in our guts 7. Plants and mycorrhizal fungi 8. Lichens 9. Corals and dinoflagellates i. Mycorrhizal fungi and plants 1) Fungi in association with plant roots 2) Fungi increase root length and surface area 3) Increase nitrogen and phosphorous uptake by plant 4) Plants provide fungi with Carbon from photosynthesis a) 80% angiosperms, all gymnosperms 4. Commensalism (+/0) 5. Amensalism (­/0)1. Tend to be more accidental than other relationships 2. Example:  a herd of elephants that crush plants and insects while moving through a  forest  ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~ ~ ~  Predators and Species Coexistence Competition outcome can be influenced by predators Barnacles, gooseneck barnacles, mussles,  limpets, chitons All prey for seastar, Pisaster Removal of seastar caused species number to decline (15 to 8) Mytilus (mussel) were better competitors for space Seastar maintained high diversity by decreasing number of better competitors Video: removal of starfish manipulation experiment When the star fish was removed, muscles increased  Removal of an otter Orca ­­> otter ­­> sea urchin ­> kelp Keystone species Species that has a disproportionately large effect on its environment to its abundance  Species interactions influence community structure (@ community level) Community= two or more different species interacting together in a  specific area Plants, animals and microbes are linked by feeding relationships and  other interactions Often defined spatially, and by the dominant life form  EX: Pine Flatwood community Includes: rodents, snakes, frogs, birds Why are certain species found together in a community 1. They depend on each other a) Predators to prey relationshipb) Mutual relationship with another species 2. They have similar habitat needs How are communities structured Closed community ­ close association between species regulates  distribution of whole community Open community­ species are distributed independently to one another,  regulated by environmental conditions Communities are structured the way they are because Species depend on each other to exist Interactions among species determine which species inhabit a community Interdependent (discrete community Closed community Frederic Clements, plant ecologist (19th century)  Most communities function as interdependent communities Superorganism Communities are structured the way they are because:  Species have similar adaptations and nutrient requirements Each species had different ranges of conditions in which they exist Community reflects overlapping ranges of species Open community Henry Gleason, plant ecologist (early 19th century) Most communities function as independent communities Communities consist of species with independent  distributions Interdependent Communities Species boundaries are consistent across species with in a community Boundary of each species is not dependent on the boundaries of other  species Different colored lines represent different species Blue lines are highest abundance in the transition zones Blue lines (assocation E) suggests that they depend on each other which is why they are grouped togetherBrown lines (assoc. D) suggests they depend on each other  which is why they are groupeed together. They are a community Open community Overlapping ranges of species , independent  Henry Gleason, plant ecolosy  Open community  Most communities function as  indpeendent … … Indpendnent communities Bondary of each speces is not dependent on the  boundaries of other species More spread out graph Low environment gradient are grouped  together so they can be a community  but they are also found in other areas  as well How are communities structured F.E. Clements Species  in a community are found together because they depend on each other Closed community  Independent of each other, grouped together in different  gradients Repeatable structure Super organism Closed boundaries Equilibrium camp H.A. Gleason  Species in a community are found together because they have  similar habitat needs Open community Ephemeral collections of individuals Not repeatable Open boundariesNon­equilibrium  camp Whittaker et al. 1956 Gradual change in species abundance, independent of each other with  change in environment Testing the Clements approach If species rely on each other to persist removing a species should cause other  species to decline Clements vs Gleason Species are independent (Gleason) distributions in MOST communities when  plotted on abiotic gradients Species are depend (clements) distributions Measuring community structure Species richness = number of species in a community Relative abundance = the % each species contributes to the total Species evenness = measure of how numerically equal the species are in a  community Species Diversity Number of species(richness) and the evenness of species (abundance)  Some species are highly abundant  Most species are rare Calculating diversity: the shannon index H = ­ Summation of  [p(i) ln(p(i))] H = Shannon index P(i) = proportion of individuals that are of the ith species(relative abundance)  S=number of species in the community Values 0 to natural log of maximum # species in the community Why do communities differ in their number of species Amount of resources available  Habitat diversity Presence of keystone species Frequency and magnitude of disturbances Global Species DiversityTwo main climate factors correlated with biodiversity are solar energy and water availability  (evapotranspiration) ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ Friday ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ Net primary productivity (NPP) is approximately equivalent to: a. Gross primary productivity (GPP) b. Energy used in respiration per unit time c. Energy captured by plants from sunlight per unit time d. Gross primary productivity (GPP) minus respiration R e. Gross primary productivity (GPP) plus respiration R NPP is gross primary productivity minus respiration  NPP in terrestrial systems is often limited by climatic factors: temperature and  precipitation  General rules for energy flow through ecosystems 1) Assimilation efficiency increases at higher trophic levels 1. Energy has to be used to maintain the body 2) Net production efficiencies decrease at higher tropphic levels 3) Ecological efficienices average about 10% (range of 5­20%) 1. Less and less energy is avilable i. Only ~1% of NPP ends ip as pridction in the 3rd trophic level What controls NPP Terrestrial vs Aquatic chart Temperature graph Increaseing Precipatation A bit more of a bell curve Increases steeply to 2,00 mm of precipation is declines a little in NPP High levels of rainfall decrease in NPP because there is not a lot of sunlight All the rain can fill up oxygen in the soil so that can also lower NPP Plant resources control NPPLight Temperature Water CO2 Mixed across the globe Nutrients  ! Important Control on NPP NPP in terrestrial systems may also be limited by nutrients Have a control group and increase nutrients in the other plot of the  meadow Is NPP limited by nutrients?? Yes its limited A bigger increase in Nitrogen and Phosphorous Nutrients are limiting in this system  Fertilizer is usually the most limiting in growth Aquatic system NPP in aquatic systems is often limited by: Light and Nutrients Controls NPP NPP aquatic systems is often limited by: Light and nutrients Nutrient run off from land surfaces It could run off into the ocean Elemental Cycling in Ecosystems 1. There is continual recycling between organisms and the physical environment  1. Atmosphere, soil, rock… 2. Nutrients unlike energy are retained with the ecosystem Ecosystem compartments Organisms(biosphere)  Air (atmosphere) Water (hydrosphere)Land (lithosphere) Reservoirs vs. Fluxes  Reservoir (stock)  Where energy (carbon) or nutrients are stored Reservoir A (atmosphere)  Reservoir B (hydrosphere) Flux  Movement of energy or nutrients from one reservoir to another It is always over time so unit/time Flux in ­­> reservoir­­­> flux out/in ­­> reservoir 2 Huge chart.. Elemental cycling in ecosystems Energy transfer through electrons Oxidized ­ low energy Reduced ­ high energy Element Cycling Overview 1. If we were to follow any given nutrient through time, there would be a continual alternation  between living and nonliving compartments of the ecosystem. 2. Gains and losses from outside of the ecosystem are small when compared to the rate at which  nutrients are cycled within the system. 3. Ecosystem element cycling can be driven by an organism’s need for growth, or by an organism’s need for energy. Physical factors can also move  elements. 2. Most nutrients are cycled 3. Could be driven by the need or by physical factors can also move elements Controls on NPP NPP in terrestrial systems may also be limited by nutrients Why do nutrients limit plant photosynthesis Photosynthesis uses a lot of N 50% of N in leaves tied up in Rubisco and other photosynthesis  enzymesNitrogen is often had to come by Availability dependent on type of N Phosphorous needed to make DNA and ATP Phosphorous is also hard to come by Availability dependent on type of P ~ ~ Atmosphere image Most o the nitrogen being stored is in the atmosphere 78% of the gases in the atmosphere are N2 It is in a gas form and plants cant use that form of nitrogen  Global nitrogen cycle image  How do plants get the N they need Atmospheric N2 must be fixed into compounds that plants can use NH4+ ( ammonium) NO3 ­ (Nitrate) DON (Dissolved organic nitrogen) Inorganic compound = NOT associated with carbon molecules How is N2 fixed into a form plants can use Abiotic fixation  Lightning Fixes N into a Relatively small amount of N is produces Biotic fixation Free living bacteria Symbiotic bacteria Use the enzyme nitrogenase Symbiotic Biological N fixation Bacteria form a mutialistic symbiotic relationship with plant roots N2 ­­> Nh4, No3­Legumes ­ nitrogen can be returned to the soil Some woody plants (Frankia) Fern azoalla and cynobacteria  Plants give bacteria carbohydrates and get N in return Plants have nodules on the roots This is where fixation occurs, the cells containing rhizobia Rhiszobium forms nodules The soil beans a Bacteria turn the N2 into ammoium and the extra nitrogen is returned to the soil  whn the plant dies If N2 can be fixed, why is N in short supply to plants In agriculture plants system where the plant biomass is remove the N is removed from the soil N2 is triple bonded Requires a lot of energy to break is 25% of energy made from photosynthesis is used to break down N2 Once N2 is fixed Most of N used in ecosystems is recycled internally and stays in the system Some N is lost from the system and returned to the atmosphere or leached When plants take up N2.. Litterfall , leaves fall, decomposes, mineralizes, root uptake and fixation 90% of N is recylced through internal recycle fixation Removed through Leeching Denitrification ­ transferred back to gas Ammonium ­ less often in ntural zyztems ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ Wednesday 12 … DecompositionDetritivores breakdown dead organic matter  Organic N ­­> DON Rate of decomposition influenced by temperature moisture, litter quality/quantity microbial community Decomposition Responsible for ~90% of internal N cycling During decompositsition organisms are using C for energy Lose it during respiration  Returns ~50% C back to atmosphere Rest of the 50% get put into the soil later Mineralization Chemical conversion of organic matter into inorganic nutrients  DON­­>NH4+ Done by microbes Both decomposition and mineralization do better where oxygen is available Nitrification Quick conversion of ammonium to nitrate NH4+ ­­> NO2­ ­­> NO3­ Done by nitrifying bacteria Nitrosolobus and Nitrobacter (chemautotrophs) Rate of nitrification depends on availability of NH4+ and O2 Chemoautotrophs also use it for energy Also needs to have oxygen available Denitrification Conversion of nitrate to dinitrogen gas NO3­ ­­> NO2­ ­­> NO ­­> N2O ­­> N2 Does not require or occurs more in environments with less/not as much oxygen Primary way in which it does back to the atmosphere Done my microbes Occurs when concentrations of nitrate are high and oxygen is low Needs an adequate supply of Carbon as wellLots of organic matter, dead plant matter builds up and carbon is … Primary way in which nitrogen goes back to the atmosphere Terrestrial Nitrogen Cycle Nitrogen cycle 1. Nitrogen changes forms due to enzymatic(biological) oxidation­reduction reactions. 2. This occurs because it is a source of energy for some microbes, and a source of N for  plants and microbes. 3. Different forms of N can move to different pools within and outside ecosystems 4. Most terrestrial ecosystems (outside of tropics) are N limited (most limiting nutrient resource Nitrogen Cycle  1. Oxidation/reduction forms of inorganic nitrogenN2 (nitrogen gas)NH3/NH4 + (ammonia/ammonium) NO2 ­2 (nitrite) NO3 ­ (nitrate) NO (nitric oxide)N2O (nitrous oxide) 2. NO3 ­ and NH4 + are used by plants and microbes for protein synthesis 3. NO, N2O, N2 are gases that are lost from ecosystems to the atmosphere 1. Oxidation/reduction forms of inorganic nitrogen N2 (nitrogen gas) NH3/NH4 + (ammonia/ammonium) NO2 ­2 (nitrite) NO3 ­ (nitrate)NO (nitric oxide) N2O (nitrous oxide) 3. NO, N2O, N2 are gases that are lost from ecosystems to the atmosphere 2. NO3 ­ and NH4 + are used by plants and microbes for protein synthesis ~ ~ ~ ~ ~ Why do nutrients limit plant productivity? Phosphorous need to make DNA and ATP Phosphorous is also hard to come by  Availability dependent on type of P Global reservoir Phosphorous is only in trace amounts, don’t really see much of it in the atmosphere Rocks are the primary reservoir in which phosphorous is stored It is also in soil, ocean and plants Phosphorous P enters ecosystems b weathering of rocks Enters ecosystem through ^weathering rocks P doesn’t have a gas forms and is not really found in the atmosphere Once P enter the systems, most of P is used in ecosystems is recycled internally and stays in the  system Most of P used in ecosystems is recycled internally and stays in the system Some of P is lost from the system through leaching Some P enters the system through windblown dust It gets decomposed, then taken up in plants or loosely bound in soil In wetland systems a lot of phosphorous gets bound in soil We can lose phosphorous Nitrate and phosphate are leeched in the soil because anions are more  leeched than cations Terrestrial P cyclePhosphorous Cycle 1. phosphate (PO4 3­) does not undergo oxidation reduction reactions under most conditions 2. no gas forms of P 3. P can be bound tightly to soil minerals in soils 4. Aquatic systems (lakes) are often limited by P Old tropical soils can be limited by P (most  limiting nutrient resource) Walkers and Syer's model Experimental test of the walker and syer's model  Forest in Hawaii Chronosequence of soil age Treatments: ­control ­N addition ­P addition ­N + P addition  Measured diameter growth of the tree Metrosideros polymorpha Hawaii for the old and recent islands They added nitrogen and phosphorous  Measured growth of one tree/plant found on all islands Limited by the site with the most phosphorous (oldest site) In the graph the youngest site shows that the control and the addition of  phosphorous is the same At the oldest site there is a huge increase in phosphorous  Limited by the site with the most nitrogen  So the youngest site would be limited by N Why do we see the limit of N at the young site? Nitrogen from the atmosphere accumulates over primary succession N has to be fixed over time Young soils are low in N Old soil are high in N Over time N accumulates in the soil. P more available in new systemsN more available in old systems Other variables than can alter nutrient availability of plants Soil types Disturbances Vegetation type All these variables can limit fluxes of nutrients among different pools! The degree of  limitation varies across regions Changing Nitrogen Cycle Human have doubled the N fixation rates over natural levels Driving the abiotic system Method was initially discover to make bombs during WW2 Bread and Bombs Have to get T up Haber­bosch process 3CH4 + 6H2O ­­> 3CO2 + 12H2 4N2 + 12H2 ­­>8NH3 (high T, pressure, Fe) Changes to the Nitrogen Cycle About 1/2 of human additions come from fertilizer production About a 1/4 from increasing amount of biological N fixation other 1/4 inadvertently from fossil fuel combustion Phosphorous Cycle How does the size of anthrogenic fluxes compare to natural fluxes Human Impacts: Phosphate Mining Phosphorous is a non­renewable resource Changing N and P Cycles Increased fertilizer inputs can: volatilize from fields, pastures (NH3) increase nitrification (NO, N2O, NO3­) increased denitrification (NO, N2O, N2) increased leaching (NO3­ , PO43­) Global Dead Zones Gulf of Mexico Hypoxic ZonePhosphorous Eutrophication Minimizing Nutrient Runoff 1. Decrease amount of fertilized applied by • Finding optimal nutrient needs • Use of cover crops  • Crop rotation (N­fixer, non­N fixer) 2. Decrease the amount of N and P runoff • Adjust timing of fertilizer application • Use organic  or slow release fertilizers • Buffer zones • Recapture runoff and recycle/treat Buffer ZonesBiology 3 BSC2011 Exam  April 19 EXAM 3 By the end of this lecture you should be able to: • identify the different scales of ecological organization and an ecological question that can be asked at each scale. • identify the major factors that influence climate across the globe and describe how they influence climate. • designate specific organism adaptations to specific environments Ecology = the scientific study of the relationships between organisms and their environments  logy-logos = study of Eco - oikos = house That organism interacts with other organisms  Also interacts with disturbances in nature predators… Scientists use the scientific method: observation, Question, Hypothesis, Experiment, conclusion, results  support hypothesis or they do not support the hypothesis Ecology =/= Activism It is a scientific discipline while activism is very different Key Concepts Ecological systems vary over space and time How do ecologists study the natural world Small --> Large Scales of Ecological Organization Organism Level : survival and reproduction: Question: how to organisms survive hot and dry conditions?  kangaroo mouse concentrates its urine Rattlesnake regulates body temperature by going in the sun or shade Plants can open or close its stoma to decrease water loss  Population Level: group of individuals in the same place interactingQuestion: Are boat accidents having an impact on manatee populations? Community Level: Interactions among population of different species Question: How does the presence of wolves influence the population of elk and  aspen?  Ecosystem: communities plus their abiotic environment  Question: Can tropical forest absorb the extra CO2 in the atmosphere that is  driving climate change?  Biosphere: All organisms and environments of plants (we have one biosphere aka earth) Question: How can we preserve biodiversity? What information would you need to better understand the threat of Zika virus to human health? Need to know: Location Are different times of the year more common for Zika How fast can it reproduce Where does it originate from How it is transmitted What temperature does the mosquito operate more commonly at Organism: what is the climate conditions? How is Zika transmitted? Life cycle of the virus? Zika Virus:  Member of Flavivuris  Aedes spp. Mosquitos host 2 weeks life cycle in host before infecting humans Global Distribution shows transmission is the equatorial region, central  and the top of South America  Transmission: Mosquito to humans Humans to humans PopulationWhat controls growth rate, distribution of mosquitos..? Community How do interactions with mosquitos and other species (humans) influence the spread of  Zika? Ecosystem and Biosphere Level How will a warming climate influence mosquito populations and transmission of Zika? Ecology = the scientific study of the relationships between organisms and their environments  What determines the environment in which organisms live? Colorful map representing different biomes Another map representing temperature Cold at poles Hot at equator  Key Concepts Ecological systems vary over space and time Solar energy input and topography shape Earth's physical environments (climate)  Variations in Solar Energy drive patterns of weather and climate Difference between weather and climate High today is 78 degrees : weather Warm summers with cool winters both with high humidity : climate (less specific)  Climate: Long term trends in temperature, wind and precipitation based on averages and variation  measured over decades Weather: Temperature, wind, humidity and precipitation at a particular time and place (short term) Climate Determines where organisms live Resource availability Rate of population growth Key to understanding all ecological phenomenon Key Concepts: Solar energy input and topography shape Earth's physical environments (climate) Earth's energy Energy in = energy out 343 Watts/m^2 Energy losses 49% absorbed by surfaces 19% long wave radiation - goes back out Lost through the surface of objects, transpiration (water loss in plants), evaporation 7% lost ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ March 22  Identify the major steps in the Hadley cell Identify the major steps that occur with the rain shadow effect Apply knowledge of atmospheric circulation and climate to identify geographic location of major biomes  Key concepts Ecological systems vary over space and time  Solar energy inputs and topography shape Earth's physical environments (climate) Topography Variations in Solar Energy drive patterns of weather and climate Solar Energy inputs varies with: Latitude  Earth's angle Latitudinal variation in heating of Earth Direct solar radiation at the equator bc of angle Season  Earth's tilt Tilt of the Earth: seasons  23.5 degree tilt When the suns rays hit the earth it hits the northern hemisphere moreLook at picture Which is why Australia's summer is colder than the USA summer Climate vs. Weather Climate :  Long term trends in temperature, wind, and precipitation based averages and  variation measured over decades Determines where organisms live Resource availability  Rate of population growth Key to understanding all ecological phenomenon  Weather :  Temperature, wind, humidity and precipitation at a particular time and place  (short term) Earth's energy budget Energy in = energy out 343 Watts/m2 Incoming radiation is mostly short wave (visible, NIR, UV) 31% reflected by clouds or surface 20% absorbed by clouds and atmosphere 49% absorbed by earth surface Energy Losses (of 49% absorbed by surface) 19% longwave net radiation from earth 7% lost as sensible heat flux by conduction and convention  23% lost as latent heat flux by water vapor Heat energy is redistributed  1. Atmospheric circulation 2. Ocean circulation Latitudinal variation in heating of Earth North Pole (90 N) Equator (0) South Pole (90 S) Hadley Cell 1. Incoming Solar Radiation (warms air at earth's surface) 2. Warm air rises which changes density of the air (cause pressure gradients) (warm air is  lighter than cold air) 3. Warm expands 4. Warm air cools (cold air is more dense. Cold air cant hold as much moisture either so  clouds form) 5. Clouds form (cold air is more dense and falls back to the earth's surface) 6. Air cools and descends How warm air rises Warm air = light Cool air = dense Warm surfaces expel warm air --> warm air expands and then cools --> cool air  can make clouds and then descends Poles Heat energy is redistributed  Atmospheric circulation  Hadley cells Coriolis effect 60% of the heat is transferred this way Heating of the tropics Heat redistribution because hotness rises As heat rises, it starts to cool again because the atmosphere is much cooler Then clouds form around the equator (area of the tropical forests) Circulation of area around the equator  Cool air descends --> rises again after being warmedHadley cells engage in atmospheric circulation  Polar cells - distribute around the poles Tropical, polar and temperate zones Hadley cell Found at the equator Expansion and uplift of air at equator Three different cells but the main one is the Hadley cells Hadley cells start from the equator (wet) and cool air moves up and out  to the area in between Dry(30 N) climates and Tropic (23.5 N) climates After warm air descends to the dry and tropical climates it moves back to  the equator  Polar  At poles Subsidence of cold converging air at the poles (subsiding cold air) Poles more in a circular motion of cold air between 90* and 60* Ferrell cells Transfers warm air to high latitudes and shifts cold air and back to the  (sub)tropics Coriolus Effect Bends the winds West to east The earth is spinning at a different speed than the air above it  The earth is spinning from west to east.  The winds above it are moving the opposite direction --> Easterlies trade  winds found around the equator (move from east to west) The wind at the equator moves faster than the wind at the poles because  it is more area to cover  The easterlies in the northern hemisphere moves from the east to  the west via NE Trade winds The easterlies in the southern hemisphere moves from the east to  the west via SE Trade windsTemperate zone: The earth is spinning slower than the air around the equator so the winds  get deflected and spin west to east and called the westerlies winds The westerlies in the hemisphere move west to east (in the 60-30  degree latitude)  Poles East to west and called easterlies winds Ocean circulation  Deep currents driven by thermohaline circulation, density differences  (overturning circulation)  Surface circulation is effected by wind currents Deep ocean circulation is effected by temperature and water density or solinity  40 % of heat transfer Surface circulation Driven by / follows winds from the coriolus effect Shallow currents are driven by prevailing winds Gyres are circulation deflected by Coriolus effect Circumpolar current goes along Antarctica  Equatorial Countercurrent moves in a circle going from the  equator bringing warm water to the west by japan and getting colder by alaska and then moving cold  water back down where its warmer by the California coast of USA and back down near the equator  The gulf stream also moves in a mainly constant warm flow of  water from the east coast of the USA north by Maine and south to the west coast of Africa back down  around the Caribbean islands and back up to US  The North Atlantic drift moves warm water up to the Northeast  direction along Europe and Sweden and Cold water moves south along both sides of Greenland Eastern Trade winds around the equator move surface water east to west Westerlies north and south of the equator move west to east Deep ocean Ocean circulation : deep Deep currents driven by thermohaline circulation, density differences  (overturning circulation) Driven by changes in water temperature and salinity  Salty water is more denseCold water is more dense Salty cold water will move to the bottom Less salty water is lighter Warm water is light Warm water around the equator Freshwater runoff from land may affect salinity, thus circulation Redistribution of heat has a strong effect on global climate Topography Global temperature patterns Global Climate is Modified by Landmasses heat faster than oceans Mountain Ranges Landmasses heat faster than oceans Land sea breeze Sea breeze vs land breeze Land gets hot quickly and the ocean takes longer to heat  up causing differences in temperature of the air Sea = high pressure to low pressure ( during the day) Land = cool air to warm air ( usually at night - when the  land is cold) Temperature difference is greater on inland cities than cities on the coast The highs and lows are more dramatic inland because it does not  have the ocean to cool and heat the land to prevent the land from getting too hot and too cold Monsoon Massive seasonally changing sea breeze circulations Dry winters and Wet summers 1/4 of the globe experiences monsoon climate (provides a lot of  precipitation) (Ex: New Mexico and Arizona receive half the annual precipitation during monsoon  season) In areas with large bodies of water, hot water cant hold  as much water so precipitation occurs In the winter the opposite happensMountains ranges Deflect trade winds Produce rain gradients Rain shadow effect Windward side is the direction the wind is coming from (wind  changes from west to east or east to west to be sure to know where it is coming from) Evaporation happens Moist side Cold air cant hold as much so clouds form to hold  precipitation at the top of the mountain  Leeward side is the side the wind leaves Arid side As it descends the air warms up again ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~  March 24 Usually there is more precipitation on the windward than the leeward side of a mountain range. In the  middle latitudes (30-60 degrees) of the Northern Hemisphere, this means that the west sides of mountains  receive more precipitation  By the end of this lecture you should be able to: Apply knowledge of atmospheric circulation and climates to identify geographic location of  major biomes Identify the biome best represented by a Walter climate diagram Match the organismal adaptation to the environment represented in a Walter climate diagram Climate controls distribution of organisms at global scale Biome - a distinct physical environment that is inhabited by ecologically similar organisms with similar  adaptation Ex of a biome = savanna // climate = seasonally wet and dry Examples of biomes High annual precipitation and high temperature = Tropical rain forest Low annual precipitation and high temperature = subtropical desert  Low annual precipitation and low temperature = Tundra High annual precipitation and Low temperature = cold cant hold water so we don’t get as much  cloud formation  Walter Climate Diagram Summarizes climate in an ecological relevant way First month of the Walter Climate diagram on the x axis will be the coldest month Ex: for Australia because its in the southern hemisphere it will start with July  Which Biome am I? Temperate biomes have a bell shaped graph (precipitation) ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ March 27 Populations  An organism living in this climate would mostly likely have the following adaptation(s) EXCEPT: … The environment has high temperature in a bell shape and low precipitation = desert Desert - low precipitation and hot summers It would NOT have: Drip tips  Drip tips High rainfall Raindrops runoff quickly Sheds leaf of excess water Prevents fungi and bacterial growth Deep taproot So they can access ground water far below the surface Concentrated urine Kangaroo rat : ex More urine less water Ectotherms Use outside environment to regulate body temperature Florida isn't a desert because its surrounded by water Lyme Disease Bacterial infectionSymptoms: Rash, fever, headaches, fatigue If left untreated can spread to joints, heart and nervous system Treatment: Antibiotics Most commonly reported vector borne illness in U.S. ~300,000 people diagnosed each year in U.S. 1970s first cases reported from Lyme, Connecticut Where does Lyme disease come from? Borrelia burgorferi Bacteria that causes lyme disease Host: Blacklegged tick Ixodes scapularis NE, mid-Atlantic, and North-central U.S. Ixodes pacificus Pacific coast U.S. How do people get lyme disease Tick infected with bacteria bites human transfer bacteria human Life history= schedule of an organism's growth, development, reproduction and survival Black legged tick life cycle (2 years) Tick becomes infected at the larva stage Hosts: Mice and songbirds Tick infects humans at nymph stage and adult stage Ticks must be attached 36-48 hours for bacteria to be transmitted Lyme diseases has increased White footed mouse  Principle reservoir for Borrelia burgdorferi Omnivore (eats seeds and insects) Really like acorn seeds Scales of Ecological Organization Organism: survival and reproduction Population: Groups of individuals of the same species interacting.Individuals of a species that interact with one another within a given area at a particular  time Population ecology is the study of births, deaths, and the dynamics forces which  regulation the number of individuals in a population  By the end of this lecture you should be able to: Compare and contrast 3 different types of spatial patterns of population  distributions Compare and contrast Type I, II and III survivorship curves Calculate population growth rates, sizes and changes in population size over  time. Compare and contrast slow and fast life history traits Measures of population abundance Population density: number of individuals per unit area/volume Population size: total number of individuals in the population Estimating population size: Density x total area occupied by population What is the size of the fire ant population in Florida Measure a small area and multiple the number of fire ants by the total area Population distribution (Spatial patterns) Clumped - may indicate competing individuals Random Spaced - may indicate social patterns or resource distribution  Population Distribution  Patterns in age structure  Survivorship vs. Age Type III: Higher mortality early in life, low mortality late in life Type II: Constant mortality throughout life Type I: Low mortality early in life, high mortality late in life Humans affect ecological systems on a global scale Anthropocene - new geological period age of humans Humans are Spreading organisms across the globe Changing vegetation and topography Homogenizing ecological systemsAnthopogenic Biomes Dense settlements Villages Range lands Wild lands - natural less human influence  Terrestrial Biomes 1. Climate (temp and precipitation) 2. Dominate vegetation 3. Soil type 4. Disturbance Aquatic Biomes 1. Salinity 2. Water movement 3. Water depth (light penetration --> photosynthetic organisms live) 4. Water temperature …Populations Lyme Disease Bacterial infection Symptoms Rash, headaches, fatigue, fever (facial paralysis, Bull's eye rash on the back, arthritic  knee)  If left untreated can spread to joints, heart and nervous system Treatment: Antibiotics Most commonly reported vector borne illness in US ~300,000 people diagnosed each year in US 1970s first cases reported from Lyme, Connecticut Where does Lyme Disease come from? Blacklegged tick : Host 2 species have this bacteria NE, mid Atlantic and North central USPacific coast How do people get lyme disease? Bit by the tick and transfers bacteria Life history = schedule of organisms growth development, reproduction and survival Black legged tick (2 year life cycle) 1st year Eggs hatch -->larvae turns to a nymph --> nymph goes dormant through the winter 2nd year Comes out of dormancy--> feeds--> turns to adult in the fall-->finds a host  Tick becomes infected at larva stage Hosts: mice and song birds are infected with bacteria and the larvae feeds on them and  get it Ticks infect humans at nymph stage and adult stage Ticks must be attached 36-48 hours for bacteria to be transmitted If you see a tick, immediately remove it! Nymphs are super tiny so people usually miss that and get infected by the nymph  Ticks bite more in the summer months Rash is the biggest sign people come in with when they have lyme disease Why are the number of cases of lyme disease increasing White footed mouse Principle reservoir for Borrelia  Omnivore Really like acorn seeds Organism:  Population: individuals of species that interact will one another within a given area at a  given lace Population ecology = is the study of births, deaths, and the dynamic forces which  regulate the number of individuals in a population (immigration and emigration that control the number in  a population) Compare and contrast the three different types of spatial patterns of population distributions  Compare and contrast type 1,2 and 3 survivor ship curves Calculate population growth rates, size and changes in population size over time Compare and contrast slow and fast life history traitsMeasures of population abundance Population density: Population of individuals per unit area/volume Population size: total number of individuals in the population Estimating population size: density times total area occupies by population (using a  subset) Ex: fire ant population in Florida Select area in Florida to look at Look at a 20 by 20 cm area and count the number of ants and multiply  the number of ants by the total area Florida  Population are patchy in space Population distribution Spatial patterns 1. Clumped - may indicate social patterns or resource distribution 2. Random- less common 3. (evenly) Spaced - may indicate competing individuals (common in plants) Population Distribution  Patterns in age structure Survivor ship decreases dramatically at an older age - Type 1 ( humans) Constant mortality in life - Type 2 (squirrels) Increase in mortality in the beginning and then levels off - Type 3 (uncommon) Age Pyramids Also show mortality and birth distribution  Population changes over time Births and immigration add individuals to a population Deaths and emigration remove individuals from a population ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ March 29 By the end of this lecture you should be able to:•define principle of allocation and evaluate how an organism may alter allocation under different  conditions. •compare and contrast exponential and logistic growth and be able to identify the equations used for each. •describe how land use change can influence population dynamics. Population Growth Models Birth-death or BD model: change in population size depends on # of births and deaths over a  given time Population size = number of current individuals (N) + number of births (B) - number of deaths(D) Future Population? Population growth rate: How fast the population is changing  N= N +B-D Subtract N from both sides of the equation Divide both sides by change in t (time interval from t to t+1) Change in N = B-D Change in N/ Change in T = (B-D)/((t+1)-t) Change in population (N) over change in temperature (T) Look at power point for notes Estimating changes in population size: Per capita = "per individual" Per capita birth rate (b) = number of offspring an average individual produces Per capita death rate (d) = average individual's chance of dying Per capita growth rate (r) = (b-d) = average individual's contribution to total population growth rate Total population growth rate (change in N) over (change in T) Where Does r come from Life Histories Time table of individual organisms life Can differ in : Life span Age at maturity  Parity-number of reproductive events Fecundity - number of offspring per event Time table is modified by environment If nutrition is low they could postpone maturity or production Life History = schedule of an organism's growth, development, reproduction and survival Parental investment = amount o time and energy given to an offspring by its parents Longevity = the life span of an organism (life expectancy) EX: salmon Reproduce once at 3-4 years old EX: elephant 1 offspring per event Adults live 60 years Slow life history trait Few offspring-live longer-spend more time raising young Fast Doesn’t take long to reach sexual maturity - more offspring- spend less time with young ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~  Availability of resources and physical condition shape life histories Individual organisms require resources (material or energy) and physical condition they can  tolerate Rate at which an organism can acquire resources increases with the availability of resources Resources = uses up or consumed Condition= experienced but NOT consumed (temperature is not used up-it’s a condition of the environment) Principle of allocation  Once an organism has acquired a unit of some resource, it can be used for only one function at a time Function: maintenance, foraging, growth, defense or reproduction Stressed requires more resources for maintanence …(a) Typical conditions, normal resources Maintenance needs must be met first. Remaining resources are divided among other activities (b)Typical conditions, abundant resources When resources are abundant, more resources are gained and more are available after  maintenance needs are met ( C) stressful conditions, normal resources Stressful conditions mean more resources must be expanded on maintenance and fewer are  available for other purposes … Population change over time Estimating uture population size N(t+1) = N(t) + rN(t) Births > deaths --> population growths and r>0 Births < deaths --> population decreases and r<0 b=d --> no change , r=0 ________ Example/ Clicker Buys 100 inseminated female Bison for her ranch, places monitors on 10 individuals 6 lived to 1 year 4 died 5 offspring births 10 total female animals R=b-d = 1 = 1/(10 total population) = 0.1 --> per capita growth rate --> growing Size of the herd at the end of the year Initital population = 100 Growth rate = 0.1 100 + 100(0.1) = 110 herd size at the end of the year  ________ Population growthGrowth rate =  Number of new individuals produced in a given amount of time minus the number of individuals  that die b-d Intrinsic growth rate r =  Highest possible per capita growth rate for a population Under ideal condition population can grow rapidly Geometric (addictive) growth model  Growing fairly slow Compares population sizes at regular time intervals  Adds a constant number of individuals each time period Multiplicative (exponential) growth rate Population increases continuously at an exponential rate (J-shaped curve) Adds a constant multiple of the population size(n) each time period Could run out of resources Growing fairly quickly Population growth under ideal conditions N(t) = N(0) x e ^rt N(0)=current size of population R = intrinsic growth rate T- amount o time over which population grows The power of multiplicative growth Most populations cant continue to grow like this-- it will hit the carrying capacity There will be competition for space food and resources Population do not grow mult. For very long. Growth slows and reaches more or less steady size This ecological struggle for existence, fueled by multiplicative growth, drives natural selection  and adaptation Populations do not grow multiplicatively for very long. Growth slows and reaches a more or less  steady sizeDensity Dependent As population increases: R decreases Birth rates decrease Death rates increase R=0 population stops changing Carrying capacity =number of individuals an environment can support indefinitely (equilibrium size) Population Growth Density dependent factors Effects that increase with crowding Starvation, disease, places to live/territory, toxic waste, predators Population Growth Models  Logistic model: used to predict change in populations when environment limits growth Population growth rate = rate when N is close to ) x # of individuals in population (N) x  reduction in rate die to crowding r=r0 x (1- N/K) K=carry capacity Change in N over change in t = r0 x N (1-N/K) N(t) = K / 1+e^[(-r0) x (t-i)] I = time where population is half of K Population growth  Density dependent factors - effects that increase with crowding Starvation  Disease Places to live/ territoriality Toxic waste Predators  Population Growth Models Logistic model: used to predict change in populations when environment limits growthPopulation growth rate = rate when N is close to 0 x # of individuals in population (N)  x reduction in rate die to crowding Logistic Growth model: r = r(0) x (1-N/K) K = carrying capacity Change in N/ change in t = r(0) x N(1- N/K) N(t) = K/ 1+ e^(-r(0) x t-i) i=Time where population is half of K Fluctuating Population Cycles There is a lot of fluctuate with for example a song bird because of changes in the  environment (limited resources -->decrease in population) Or Predators  1. Fluctuations are the rule for natural populations 2. Environmental variation causes irregular fluctuations 3. Population often have periodic cycles 4. Time delays in response of population depend on life history (birth rate,  survival, etc.) White footed mouse Omnivore Really like acorn seeds If squirrels also like acorns that means competition  Population of acorns increases around the same time that increase in acorn  production/density occurs (also ticks) Why are number of cases of Lyme disease increasing? Mast years increase acorn production (resource) Following year increase mouse population Increase black legged ticks Increase lyme disease cases ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~  Human population 7 billion people Exponential growthWhat allows the increase in growth vaccines Antibiotics Advances in sanitation Green revolution in 1950-1980 increased food crops All raises our carrying capacity We are currently at .11 = 0.11 r We might go .05 in the future Great Leap forward in china Decreases food in  This decreased the global r value Ammensalism - it doesn’t effect one but it negatively impacts the other organism Commensalism - one organism gets no effect and the other gets a positive effect Species interactions (Ch. 43) Interactions between species may be positive, negative or neutral Interactions affect population dynamics and species distributions Interactions affect individual fitness and can result in evolution  Intraspecific - same species interacting Interspecific - different species interacting Interaction influence population densities, alter species distribution and lead to evolutionary  change  1. Competition (-/-) ○ Use or defense of a resource by a individual that decreases the resource available to  others • Intraspecific competition - within a species • Interspecific competition - among species • Resources: ▪ Food, water, nutrients, space ▪ Any factor consumed by an organism and supports increase population  growth rates = resource • Usually over a limiting factor, where competition for a single resource is most  intense• Usually over a limiting factor, where competition for a single resource is most  intense • Competition exclusion principle ▪ 2 species often cannot coexist indefinitely on the same limiting  resource • Demonstrated in lab settings ○ Presence of a competitor always reduces population growth rate ○ When two species coexists they have a lower carrying capacity, equilibrium population  densities than the other would alone ○ In some cases competition causes one species to go extinct • If the other species goes extinct and no other species come in, the other  population will go back to the population density when there was no other species (it would go back to a  higher population density) ○ Density dependent population grow reflects intraspecific interactions among  individuals in a population • Interspecific competition ▪ Effect of the other species subtracted in the growth model  • Lotka Volterra models  § Natural systems i. Coexistence of species more common: each species occupying a niche ii. Resources are partitioned so that there is little direct competition iii. Interspecific interaction can affect the distributions of species iv. Competitive interactions can restrict the habitats in which species occur v. EX: fundamental niche - 1) habitat determined by abiotic environment and by other organisms vi. EX: realized niche 1) Over time the interactions with the other species made one species  more adaptable to the high tide spot on the rock vii. Species interaction can affect individual fitness viii. Phenotypes that gain the most form a positive interaction or suffer least  from a negative interaction will increase frequency in the population and the population will evolve  ○ Resource partitioning  § Different ways of using a resource□ If differences in resource use are sufficiently large, competing species  can coexist  § EX: species A eat big sunflower seeds and species B eat small sunflower seeds § Intraspecific competition can be greater than interspecific competition  § Individuals within a species compete over resources □ You can harm yourself more than your competitor 2. Consumer resource (+/-) 1. Predation ( organism eating a animal) 2. Herbivory (eating a plant) 3. Parasitism  4. Disease 2.a. predation (+/-) Consumer resource Evolutionary arms race Prey continually evolve better defenses and predators continually evolve  better offenses Red Queen hypothesis Red queen tells Alice, "Now, here, you see, it takes all the running you  can do, to keep in the same place." Consumer-resource interactions can drive evolution Predator hunting strategies Active hunt Ambush hunt Sit and wait Hunting Detect prey Catch prey Handle prey Consume preyEvolution of defenses Behavioral, Crypsis, Structural, Chemical, Mimicry  Behavioral EX: when a predator in present organisms reduce their time being active Crypsis Structure Mechanical defenses Maybe phenotypically plastic - induced only when prey detects  predator EX: Crucian carp Develop deep, hump shaped back when in presence of  predators Greater muscle mass allows greater acceleration to get  away from predator Chemical Spray foul smelling or toxic chemicals Store toxins in body Warning coloration (aposematism) =distasteful evolves in association with conspicuous  colors and patterns Mimicry  Some passionflower species have leaf structures that resemble butterfly  eggs. Females will not lay eggs on a plant that already as eggs. Cost of defenses Behavioral  Reduce feeding activity or increase crowding in location away from  predators Mechanical and Chemical Energetically expensive to produce Presence of predators can indirectly reduce prey population size due to cost in  induced defenses reducing growth and reproduction of prey When food availability is low, energy is low and investment in chemical  defense is also lowCounter adaption of predators Behavior  Camouflage High-speed locomotion Resistance to toxins Consumer resource interactions modify per capita growth rates Consumer resource interaction can be incorporated in population growth models Effect of the consumer is subtracted in the equation for the resource species The effect of the resource is added in the equation for the consumer, since the  consumer benefits 2.c. Parasitism (+/-) Parasitic organism consumes part of the host but usually does not kill it 2.d. Disease (+/-) Plant: oak trees, west coast Disease-pathogen: Phytophthora "plant destroyer" , Sudden Oak Death First detected in CA in 1995 Has tons of thousands of several different oak species in coastal forests 3. Mutalism (+/+) 1. Both organisms are positively affect 2. Ee has parasites removed and prawn gets food 3. Functions of Mutalism i. Improve acquisition of water, nutrients and places to live ii. Aid defense against enemies iii. Facilitate pollination and seed dispersal 4. Leaf cutter ants and the fungi they cultivate 5. Plants and pollinating or seed dispersing animals 6. Humans and bifidobacteria in our guts 7. Plants and mycorrhizal fungi 8. Lichens 9. Corals and dinoflagellates i. Mycorrhizal fungi and plants 1) Fungi in association with plant roots2) Fungi increase root length and surface area 3) Increase nitrogen and phosphorous uptake by plant 4) Plants provide fungi with Carbon from photosynthesis a) 80% angiosperms, all gymnosperms 4. Commensalism (+/0) 5. Amensalism (-/0) 1. Tend to be more accidental than other relationships 2. Example: a herd of elephants that crush plants and insects while moving through a  forest  ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~ ~ ~  Predators and Species Coexistence Competition outcome can be influenced by predators Barnacles, gooseneck barnacles, mussles, limpets, chitons All prey for seastar, Pisaster Removal of seastar caused species number to decline (15 to 8) Mytilus (mussel) were better competitors for space Seastar maintained high diversity by decreasing number of better competitors Video: removal of starfish manipulation experiment When the star fish was removed, muscles increased  Removal of an otter Orca --> otter --> sea urchin -> kelp Keystone species Species that has a disproportionately large effect on its environment to its  abundance  Species interactions influence community structure (@ community level) Community= two or more different species interacting together in a  specific area Plants, animals and microbes are linked by feeding relationships and  other interactions Often defined spatially, and by the dominant life form EX: Pine Flatwood community Includes: rodents, snakes, frogs, birds Why are certain species found together in a community 1. They depend on each other a) Predators to prey relationship b) Mutual relationship with another species 2. They have similar habitat needs How are communities structured Closed community - close association between species regulates  distribution of whole community Open community- species are distributed independently to one another,  regulated by environmental conditions Communities are structured the way they are because Species depend on each other to exist Interactions among species determine which species inhabit a community Interdependent (discrete community Closed community Frederic Clements, plant ecologist (19th century)  Most communities function as interdependent communities Superorganism Communities are structured the way they are because:  Species have similar adaptations and nutrient requirements Each species had different ranges of conditions in which they exist Community reflects overlapping ranges of species Open community Henry Gleason, plant ecologist (early 19th century) Most communities function as independent communities  Communities consist of species with independent  distributions Interdependent Communities Species boundaries are consistent across species with in a community Boundary of each species is not dependent on the boundaries of other  speciesDifferent colored lines represent different species Blue lines are highest abundance in the transition zones Blue lines (assocation E) suggests that they depend on each other  which is why they are grouped together Brown lines (assoc. D) suggests they depend on each other  which is why they are groupeed together. They are a community Open community Overlapping ranges of species , independent  Henry Gleason, plant ecolosy  Open community  Most communities function as  indpeendent … … Indpendnent communities Bondary of each speces is not dependent on the  boundaries of other species More spread out graph Low environment gradient are grouped  together so they can be a community but they are also found in other areas as well How are communities structured F.E. Clements Species in a community are found together because they depend  on each other Closed community  Independent of each other, grouped together in different  gradients Repeatable structure Super organism Closed boundaries Equilibrium camp H.A. Gleason  Species in a community are found together because they have  similar habitat needs Open communityEphemeral collections of individuals Not repeatable Open boundaries Non-equilibrium camp Whittaker et al. 1956 Gradual change in species abundance, independent of each other with  change in environment Testing the Clements approach If species rely on each other to persist removing a species should cause other  species to decline Clements vs Gleason Species are independent (Gleason) distributions in MOST communities when  plotted on abiotic gradients Species are depend (clements) distributions Measuring community structure Species richness = number of species in a community Relative abundance = the % each species contributes to the total Species evenness = measure of how numerically equal the species are in a  community Species Diversity Number of species(richness) and the evenness of species (abundance)  Some species are highly abundant  Most species are rare Calculating diversity: the shannon index H = - Summation of [p(i) ln(p(i))] H = Shannon index P(i) = proportion of individuals that are of the ith species(relative abundance)  S=number of species in the community Values 0 to natural log of maximum # species in the community Why do communities differ in their number of species Amount of resources available  Habitat diversity Presence of keystone speciesFrequency and magnitude of disturbances Global Species Diversity Two main climate factors correlated with biodiversity are solar energy and water availability  (evapotranspiration) ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ Friday ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ Net primary productivity (NPP) is approximately equivalent to: a. Gross primary productivity (GPP) b. Energy used in respiration per unit time c. Energy captured by plants from sunlight per unit time d. Gross primary productivity (GPP) minus respiration R e. Gross primary productivity (GPP) plus respiration R NPP is gross primary productivity minus respiration  NPP in terrestrial systems is often limited by climatic factors: temperature and  precipitation  General rules for energy flow through ecosystems 1) Assimilation efficiency increases at higher trophic levels 1. Energy has to be used to maintain the body 2) Net production efficiencies decrease at higher tropphic levels 3) Ecological efficienices average about 10% (range of 5-20%) 1. Less and less energy is avilable i. Only ~1% of NPP ends ip as pridction in the 3rd trophic level What controls NPP Terrestrial vs Aquatic chart Temperature graph Increaseing Precipatation A bit more of a bell curve Increases steeply to 2,00 mm of precipation is declines a little in NPP High levels of rainfall decrease in NPP because there is not a lot of sunlight All the rain can fill up oxygen in the soil so that can also lower NPPPlant resources control NPP Light Temperature Water CO2 Mixed across the globe Nutrients  ! Important Control on NPP NPP in terrestrial systems may also be limited by nutrients Have a control group and increase nutrients in the other plot of the  meadow Is NPP limited by nutrients?? Yes its limited A bigger increase in Nitrogen and Phosphorous Nutrients are limiting in this system  Fertilizer is usually the most limiting in growth Aquatic system NPP in aquatic systems is often limited by: Light and Nutrients Controls NPP NPP aquatic systems is often limited by: Light and nutrients Nutrient run off from land surfaces It could run off into the ocean Elemental Cycling in Ecosystems 1. There is continual recycling between organisms and the physical environment  1. Atmosphere, soil, rock… 2. Nutrients unlike energy are retained with the ecosystem Ecosystem compartments Organisms(biosphere)  Air (atmosphere) Water (hydrosphere)Land (lithosphere) Reservoirs vs. Fluxes  Reservoir (stock)  Where energy (carbon) or nutrients are stored Reservoir A (atmosphere)  Reservoir B (hydrosphere) Flux  Movement of energy or nutrients from one reservoir to another It is always over time so unit/time Flux in --> reservoir---> flux out/in --> reservoir 2 Huge chart.. Elemental cycling in ecosystems Energy transfer through electrons Oxidized - low energy Reduced - high energy Element Cycling Overview 1. If we were to follow any given nutrient through time, there would be a continual alternation  between living and nonliving compartments of the ecosystem. 2. Gains and losses from outside of the ecosystem are small when compared to the rate at which  nutrients are cycled within the system. 3. Ecosystem element cycling can be driven by an organism’s need for growth, or by an organism’s need for energy. Physical factors can also move  elements. 2. Most nutrients are cycled 3. Could be driven by the need or by physical factors can also move elements Controls on NPP NPP in terrestrial systems may also be limited by nutrients Why do nutrients limit plant photosynthesis Photosynthesis uses a lot of N 50% of N in leaves tied up in Rubisco and other photosynthesis enzymesNitrogen is often had to come by Availability dependent on type of N Phosphorous needed to make DNA and ATP Phosphorous is also hard to come by Availability dependent on type of P ~ ~ Atmosphere image Most o the nitrogen being stored is in the atmosphere 78% of the gases in the atmosphere are N2 It is in a gas form and plants cant use that form of nitrogen  Global nitrogen cycle image  How do plants get the N they need Atmospheric N2 must be fixed into compounds that plants can use NH4+ ( ammonium) NO3 - (Nitrate) DON (Dissolved organic nitrogen) Inorganic compound = NOT associated with carbon molecules How is N2 fixed into a form plants can use Abiotic fixation  Lightning Fixes N into a Relatively small amount of N is produces Biotic fixation Free living bacteria Symbiotic bacteria Use the enzyme nitrogenase Symbiotic Biological N fixation Bacteria form a mutialistic symbiotic relationship with plant roots N2 --> Nh4, No3- Legumes - nitrogen can be returned to the soilSome woody plants (Frankia) Fern azoalla and cynobacteria  Plants give bacteria carbohydrates and get N in return Plants have nodules on the roots This is where fixation occurs, the cells containing rhizobia Rhiszobium forms nodules The soil beans a Bacteria turn the N2 into ammoium and the extra nitrogen is returned to the soil  whn the plant dies If N2 can be fixed, why is N in short supply to plants In agriculture plants system where the plant biomass is remove the N is removed from the  soil N2 is triple bonded Requires a lot of energy to break is 25% of energy made from photosynthesis is used to break down N2 Once N2 is fixed Most of N used in ecosystems is recycled internally and stays in the system Some N is lost from the system and returned to the atmosphere or leached When plants take up N2.. Litterfall , leaves fall, decomposes, mineralizes, root uptake and fixation 90% of N is recylced through internal recycle fixation Removed through Leeching Denitrification - transferred back to gas Ammonium - less often in ntural zyztems ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ Wednesday 12 … Decomposition Detritivores breakdown dead organic matter  Organic N --> DONRate of decomposition influenced by temperature moisture, litter quality/quantity microbial community Decomposition Responsible for ~90% of internal N cycling During decompositsition organisms are using C for energy Lose it during respiration  Returns ~50% C back to atmosphere Rest of the 50% get put into the soil later Mineralization Chemical conversion of organic matter into inorganic nutrients  DON-->NH4+ Done by microbes Both decomposition and mineralization do better where oxygen is available Nitrification Quick conversion of ammonium to nitrate NH4+ --> NO2- --> NO3- Done by nitrifying bacteria Nitrosolobus and Nitrobacter (chemautotrophs) Rate of nitrification depends on availability of NH4+ and O2 Chemoautotrophs also use it for energy Also needs to have oxygen available Denitrification Conversion of nitrate to dinitrogen gas NO3- --> NO2- --> NO --> N2O --> N2 Does not require or occurs more in environments with less/not as much oxygen Primary way in which it does back to the atmosphere Done my microbes Occurs when concentrations of nitrate are high and oxygen is low Needs an adequate supply of Carbon as well Lots of organic matter, dead plant matter builds up and carbon is … Primary way in which nitrogen goes back to the atmosphere Terrestrial Nitrogen Cycle

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