EEB 2244 exam 1 lecture PDF

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Lecture 1:Aug 31 What is ecology? ➔ The study of the distribution and abundance of organisms and the interactions of organism with their biotic and abiotic environment ➔ What do ecologists do? ◆ Peppered moth, england classic example as evolution most common white because it blends in more of the trees etc. ◆ But 1800s the dark one was more common, why would that be? The dark moths were selected for the dark ones so they reproduce and have genes with dark. ◆ Organisms eat one thing, can't suddenly eat something else, it is a choice and trade off. There is negatives and positives for that ◆ Interspecific interaction,population dynamics, disease ◆ Diversity and spatial patterns and ecosystem processes Levels of organization ● Each unit has its own internal processes and interact with its external surrounds ○ After counting ecology people organize them ■ Individual,population,community,ecosystem,biosphere ● Individual is smallest: survival and reproduction (natural selection) ● Population: collection of one species in one area overlapping time (evolution takes place) ● Community: biodiversity studies ● Ecosystem: first stage consider abiotic ( + biotic), landscape,biom ● Biosphere: all life on earth Basic scientific tenets ● Conservation of matter and energy ○ Cannot be created or destroyed ■ State of levels, which are dying or coming. The # of individuals ● Dynamic steady state: losses and gains of an ecological system are in balance ○ Birth and deaths, immagraton and emigration means that birds and deaths are evening out ● Evolution: is a change in the genetic composition of a population over time ● Natural selection: one of the mechanisms behind evolution ○ Survival ( and reproduction of the fittests ( individual) ○ Requires heritable trait variation corresponding with variation in fitness ○ Genotype: the genes determining the attribute ■ dd-> light variant of pampered moth ■ Dd or DD-> dark variant of paper moth (homozygous) ○ Phenotype: the attribute Categorizing species based on energy source ● Producers or autotrophs: convert light/chemical energy into resources

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Consumers or heterotrophs- obtain their energy from other organisms ○ fungi,bacteria,herbivore,carnivore Scavengers consume dead animals Detritovers break down dead organic matter into smaller particles Decomposers break down detritus into simpler elements that can be recycled

Species interaction

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Parasitism: they lay eggs on the wasp when they are adults Parasitism: when organism doing consumers(parasite) not just food but it habitat from host species Herbivory:

What is a niche? ● Niche does not equal habitat ● A niche is the range of abiotic and biotic conditions an organism can tolerate ● It also reflects an organism role in its community How do we study ecology? ● Scientific method 1. Observe 2. Generate questions and hypotheses 3. Predictions 4. Test hypothesis 5. Evaluate results: either support or reject 6. Communicate findings and start again

Types of studies ● More realistic to more controlled ● Ex. i want to know lakes some of them are greener trough nutrientes is an observation

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Observation studies ■ Correlation ■ No control-> no clear conclusions ● Ex. lakes, what is around them Manipulative field experiment ■ Control and treatments Microcosm experiment ■ Manipulative ■ Control and treatments Laboratory experiment ■ Manipulative ■ Control and treatments

The brazil nut story ● They are not brown nuts. They come down from trees that are 100 m long and 50 mph when they fall. Brazil nuts can kill you if they fall. ○ Only one species agouti that can open them up ■ You need them to like to forget nuts ○ Only one bee that pollinates flower which is the female euglossine bee ■ If males don’t smell good and go to flowers for females ● If you remove one of the system the rest falls apart

Wed sept 9th is respondus practice quiz due

Lecture 2: sept 2nd Weather vs climate Weather: ● Describes current conditions ● Irregular and largely unpredictable Climate ● Describes long-term patterns ● Bases on averages and variation measured over decades Terrestrial climate patterns ● 1. Is the earth is solar powered: the sun ○ The amount of energy we receive differs across the earth surface Terrestrial climate patterns ● The earth is solar powered ○ Greenhouse effect

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Spatial climate patterns depends on 1. Unequal heating with latitude and seasons 2. Air circulation and coriolis effect 3. Ocean currents 4. Miscellaneous other impactos of land and water

greenhouse effect ● Joseph “ discovered” the greenhouse effect ● Solar radiation, alone not enough hot to wam earth ● Earth's thick atmosphere (100x that o mars) acts as an insulator ○ Temp at equator of mars can vary between -90 C and 20C in one day ● greenhouse effect the process of solar adion striking earth, being converted to infrared radiation, and being absorbed and re-emitted by atmospheric gases

○ Unequal heating with latitude

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Causes heating across space unequal but also unequal heating across time by seasons ■ Seasonal variation is caused by the tilt of the earth on its axis 23.5 ●

Q: when is the sun directly overhead 90 in Storrs -> never because we are 40 degrees north from the equator ( june will highest mid july move away, march it will be directly over geographic, september same.

Unequal heating drives air currents ● Properties of air: ○ Warm air is less dense-> rise ○ As air rises and expands, it cools (adiabatic cooling) and holds less water vapor ○ Cold air is more dense-> sinks ○ As air sinks and condense, it warms again (adiabatic heating) and holds more water vapor ● Creates convection cells

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Hadley cells are near the equator

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Polar cells- between 60 and 90 latitudes. ( most like hadley cells). Easterlies winds move northeast to southwest in northern hemisphere and southeast to northwest in the southern hemisphere Ferrel cells: less distinct, between hadley and polar cells ○ From the west so westerlies Hadley cells between equator and 30 n and 30 s latitudes Interprotiocal convergens zones (ITCZ) where the hadley cells meet ○ Determined by solar equator

Convection cells create ● Wet and dry regions ○ Wet tropic ○ Dry subtropical (around 30 n and s) ● Wet and dry seasons ○ One wet seasons neer 23.5 N and S (tropics of cancer and capricorn) ○ Two wet seasons near geographic equator

○ Rotation and the coriolis effect ● Wind direction is affected by the speed of the earths’ rotation ● This deflects air circulation in the convection cells ○ To the right of north ○ To the let of north ■ Called the coriolis effect

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● Q: the trade winds are the winds experienced near the earth's surface in the hadley cells (between the equator 30 N and S). which accurley deceive their direction of moment in the southern hemisphere -> correlosis effect to the left in southern hemisphere SE to NW ● ● ●

Northeast trade winds: air on surface in northern hadley cells move from NE to SW Southeast trade winds: move from SE to NW Westerlies general midlatitude movement from west to east

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Polar easterlies:

Ocean currents ● Gyres ○ Gravity pulls warmer higher water away from the equator ○ Clockwise circulation in N, counter-clockwise in S due to trade ● Upwelling ○ Upward movement of ocean water ○ Where surface currents move away from western coastlines ○ Cold,high nutrient water brought to surface ■ Red is high productivity areas

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Moving away from coast that is upwelling, warm surface water that is pulled away and something has to come to replace it so you get water from depths of ocean that is cold and nutrient rich and replaces the warm water

El nino/southern oscillation ENSO El nino ● 1891s pervuian fisherman ● No cold water upwelling-> warm water= poor fishing harvest(dec) ● Lots of rain in coastal desert area ●

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Continental area vs ocean area ● Water moderates and temperature ○ S hemisphere has more rain and less variable temperatures ■ S hemisphere 81 % water area ■ N hemisphere 61 % water area ● Coasts have less variable maritime climates than continental b interiors Rain shadow effect ● Wet warm air moves upward over mountains,coos, and loses moisture(precipitation) on the windward side. As this air descend on the leeward side its warms absorbs moisture and dires the land

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Biomes ● Focus: terrestrial ● Biome a geographic region that contains communities composed of organisms with similar adaptations ○ Determined by climate,soil,fire and grazing regimes ○ Group communtiesby dominant plant forms Convergent evolution ● Unrelated species look similar due to evolving under similar conditions ○ This leads to “ biomes” ○ Ex. Cactus (mexico) and euphorb ( africa,right) ■ Unrelated but are both in dry desert like area

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Reflect the climate map alot and the biomes are not all connected

Geographic distribution if bikes corepsont loosely to major climate zones ● Whittaker’s climate diagram

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Boundaries are “ fuzzy” there is variation within biomes

Climate diagrams

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Identify growing, arranged so that if precipitation drops below temp that amplifies it goes through a dry period

Annual temperature 20C ● Subtropical desert

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○ Savanna/ tropical seasonal forest (kenya raising appointment)

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○ Tropical rainforest

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Very old biomes Found near the equator ITCZ Many locations,all with similar dominant vegetation: ● Tall,dense canopy ● Complex structure ● Epiphytes and lianas ● Long-lived leaves Tropical rainforest biome biodiversity and productive but very poor soils how? ->

Role of soils ( after climate soil is second most important) ● Organic matter, rocks, ( 8 milio microcells in 1 gram) ● Chemically and biological active substance ● Determine factors CLORPT ○ Climate ○ Organisms ( vegetation feedback) ○ Relief (local topography) ■ Slope is it facing north etc. more runoff or sunlight ○ Parent material (bedrock) ■ Ex. limestone or granite ○ Time (age)

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Older more time to water to be ground down, the parent material bedrock which maintain organic so it would be further from the soil if its older Drives plant species distribution and primary productivity

Leaching moves soluble inorganic nutrient to lower layers Horizons layers ● O ( decaying organic matter, abundant microorganisms) ● A (broken down organic material and finely broken up rock) ● E( leached inorganic material) ● B (weather rock, rich in inorganic nutrients) ● C (less weather, large rocks of parent material) ● R (bedrock, unweathered parent PRACTICE

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Desert 30 S and 33 north

Lecture 3: population growth and regulation Population ● Population is a group of individuals of the same species living in the same place

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○ Have the potential to reproduce with one another during their lifetimes Population growth rate: the number of new individuals produced per unit of time minus the number that die

Population ecology ● Population ecology is one of the most mathematical parts of the course ● Critical to many applied endeavors: ○ Conservation of threatened species ○ Control of over-abundant pet an invasive species ○ Responsible management of natural populations Review: exponents and logarithms ● Exponential functions tell you the result of raining a base number to a given power

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○ =2*2*2=8 Log functions reverse exponential function. They tell you what power is need to achieve a result from a base number ○ Answer the questions: what is G? ■ 2?=8

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Use the notation:

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Proper notation:

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The natural log: e and In ● Euler’s number,e, approximately=2.718 ● Mathematically convenient in population dynamics ○ Exponential functions with e grows and decays proportionally to its current value ●

Exponential function with e: ○ ○

Practice What is e^0, otherwise written exp(0) =1

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Always going to give you 1

Population growth ● Population growth: ○ : every organic being naturally increase at so high a tare that, if not destroyed, the earth would soon be covered by the progeny of a single pair” charles darwin ■ One pair of elephant and have 6 offspring their lifetime ● After 750 years you would have 19 million elephants ● Population growth limitation ● Age structure and life tables ● Human population Nile perch population growth ● Exponential growth ● Introduced to lakes victoire in 1950s ○ 200 kg and 9 miol eggs per batch ○ Hatch-time=20 hours ○ Ate native fish species

■ Exponential growth model ● How a population will grow under “ ideal “ conditions ● When the relative growth rate is constant

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R is a constant rate, specific to the population

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Observed growth rate:

Exponential growth model: two equations^ ● Example solve for Nt when: ○ No=10 ○ r=2 individuals per individual per year ○ t=3years ■ Answer: 4034 individuals ● Example solve for the rate of population growth when: ○ N=10 ○ r=2

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The intrinsic growth rate=r ● Highest possible per capita growth rate for a population ● The “ instantaneous growth rate” ● r=births(b)-deaths (d)+ immigration (i)-emigration(e) ● All these are per capita rates

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■ For now we will ignore immgration and emigration so r=b-d If b>d, r>0 (positively growing population)

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If b humans Doubling time ● t2= the time required for a population to double in size ○ Humans current 40 years ○ Rats 46 days ○ Cows 1.9 years ○ E.coli double in 3 hours ● Comparable across population of different sizes

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Worked example ● Humans: r=0.000047 individuals per individual per day ○ t2=loge2/r ■ loge2=0.69 ■ 0.69/0.000047=14680.85 ● = 40.19 years ●

Ring-necked pheasant: annual growth ○ t2=loge/loge λ ■ loge2=0.69 ■ loge(2.78)=1.02 ■ 0.69/1.02=0.67 years ● = 244 days

λ =2.78

Population growth and limitation ● Exponential and geometric models are density independent- assumes constant birth and death rates ● Indefinite growth is not possible ○ Resource limitation ○ Epidemics and other natural enemies ○ Environmental change and natural disasters Limits to population growth ● Density independent factors: ○ Not related to the populations density ○ Often abiotic (floods, temperature) the apple trip ● Density dependent factors ○ Related to density ○ Often biotic (disease compensation for food or space) ○ The australian sheep blowfly (in the lab) Negative density dependence ● High population density-> negative population growth ● Intraspecific competition,disease ● Birth rate decrease, death rate increase with N ○ Example spong sparrow

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Decrease population growth well death rate increase

Positive density dependence ● Low population density ○ -> low, even negative, population growth ● Inability to find mates or rogue successfully ● A.k.a inverse density dependence or the allee effect ○ Ex. african wild dog Population regulation ● Often involves positive and negative density dependence ● Low density: few individuals available to breed, low growth ● Increased entities with abundant resources-> more individuals for breeding ● Above some density, resources become limiting

○ Negative density dependence and carrying capacity ● Carrying capacity, K: the maximum population supported by the environment ● Above K: low reproduction and survival cause negative population growth ● Often treated as constant- but can vary with environmental conditions Logistic model of population growth ● Describe slowing growth of populations at high densities ● Represented by:

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r= intrinsic rate of increase New term (2-n/k) describes distance of N from K ● If N is large and close to carrying capacity close to 1 ○ 1- that value is close to 0 ■ Observed growth is pretty small ● If N is small ○ 1= that value is larger ■ Observed growth is higher

Logistic growth ● As N approaches K, the term (1-n/k) become smaller and the rate of growth slows ● Maximum observed growth rate (dN/dt) when N=K/2 ○ This point is also called the inflection point

■ Experimental evidence ● Many organism show evidence of lost potato growth ● Protists raise with two different food supplies ● Both levels off- just at different K’s

○ Detailed predictions of the logistic model are rarely fulfilled ● Environmental variability ○ K is not constant environmental changes, warmer or plant growth etc. ● Population overshoot K ○ Sometimes results in collapse( extinction) ● Complex dynamic: cycles and chaos

○ Density independent limitation ● Birth and death rates unaffected by population size ● Does not mean infinite growth ● Many factors can prevent opuerion from ever itching K ○ Disturbance,climate,fire,specialis predation What does it all mean? ● You can estimate population growth rates given:

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○ You can estimate population size ○ Given those items above and t since the initial estimate

○ Homework practice problem 1. Using the exponential growth equation, calculate the rate of population growth (dN/dt) ivethe population size (n) is 50 and intrinsic (instantaneous) growth rate is 0.4 individuals per individual per year 2. Estimate the population size in one year. Use this equation Nt=n0ert

Participation quiz 0

1.What is e , otherwise written exp(0)? ->1 2.The population of Utopia grows exponentially with a birth rate of 3 percent per year and a death rate of 1 percent per year. What is the per capita growth rate for the Utopian population? -> 2 percent 3. Which organ currently provides the best real example of positive exponential growth? -> humans

Lecture 4: population growth and regulation II 1. Using the exponential growth hewitson, calculate the rate of population growth (dN/dt) give the population size (N( is 50 and intrinsics( instantaneous) growth rate is 0.4

individuals per individual per year a. 0.4 individuals per year b. 5 individuals per year c. 20 individuals per year d. 30 individuals per year e. None of the above -> you could figure it out from info you have the intrinsic=r -> no carrying capacity so no logistic equation ● dN/dt- 0.4x 50=20 2. Estimate the population size in one year using Nt=N0Ert a. 61 individuals b. 74 individual c. 70 individual d. 80 individual e. None of the above ● nt=50x(e0.4x1) ● nt=50 x 1.49=74 Age structure and life table analysis ● Population growth ● Population growth limitation ● Age structure and life stables ● Human population Second BIG assumption of models of this point? ● Birth and death rates remain constant- they do not vary with age ● Solution? Age structure ● Population growth rate is influenced by the proportions of individuals in different age classes. Also in size, and life history classes ● Age structure pyramids

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■ First one: growing ■ Second: stable ■ Third: declingn Life table analysis: growth in a structured population

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○ terminology:x=age

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x= age nx= sx= age-spefici survival from (x to x+1) bx= age-specific fecundity, births ● Only looking at females because ○ 1. Mathematically 2. We know an organism mother is but harder to identify the father so easier to know birth rates 3, Complete the full life table

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Life tables are tool for calculating populations-re...