biotic environment review apes exam reviews. warmup kahoot.it code 961910 apes population and...
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Biotic Environment Review
APES Exam Reviews
Warmup
• Kahoot.it code 961910• APES Population and Community Ecology
• Populations• Succession• Communities• Ecosystems• Food chains, webs, pyramids• Biomes• Aquatic Ecosystems
Populations
Forms of Growth
• Exponential growth starts slow and proceeds with increasing speed– J curve results– Occurs with few or no resource limitations
• Logistic growth (1) exponential growth, (2) slower growth (3) then plateau at carrying capacity– S curve results– Population will fluctuate around carrying capacity
© 2004 Brooks/Cole – Thomson Learning
Time (t) Time (t)
Popu
latio
n si
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)
Popu
latio
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)
K
Exponential Growth Logistic Growth
Population Growth Curves IdealPopulation Growth Curves Ideal
Capacity for Growth• Capacity for growth = Biotic potential• Rate at which a population grows with unlimited
resources is intrinsic rate of increase (r)• High (r) (1)reproduce early in life, (2)short generation
time, (3)multiple reproductive events, (4)many offspring each time
• BUT – no population can grow indefinitely• Always limits on population growth in nature
Carrying Capacity• Environmental resistance = all factors which
limit the growth of populations• Population size depends on interaction
between biotic potential and environmental resistance
• Carrying capacity (K) = # of individuals of a given population which can be sustained infinitely in a given area
Limiting Factors• Carrying capacity established by limited resources
in the environment• Only one resource needs to be limiting even if there
is an over abundance of everything else• Ex. Space, food, water, soil nutrients, sunlight,
predators, competition, disease
• A desert plant is limited by…• Birds nesting on an island are limited by…
Density Effects
• Density Independent Factors: effects regardless of population density
• Mostly regulates r-strategists– Floods, fires, weather, habitat destruction, pollution– Weather is most important factor
Density Effects
• Density dependent Factors: effects based on amount of individuals in an area
• Operate as negative feedback mechanisms leading to stability or regulation of population
External Factors– Competition, predation, parasitism– Disease – most epidemics spread in cramped conditions
Internal Factors– Reproductive effects Density dependent fertility, Breeding
territory size
R vs K strategists and survivorship• Two idealized categories for reproductive patterns but really it’s a
continuum• r-selected & K-selected species depending on position on sigmoid
population curve• r-selected species: (opportunists) reproduce early, many young
few survive– Common after disturbance, but poor competitors
• K-selected species: (competitors) reproduce late, few young most survive– Common in stable areas, strong competitors
Survivorship curves• Different life expectancies for different species• Survivorship curve: shows age structure of
population1. Late loss curve: K-selected species with few young
cared for until reproductive age2. Early loss curve: r-selected species many die early
but high survivorship after certain age3. Constant loss curve: intermediate steady mortality
Perc
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Age
Succession
Communities Change• Ecological Succession: the gradual change in
species composition of a given area over time• Species do change spatially within an area at a
certain point in time, this is zonation not succession
• 2 Types depending on start point– Primary succession: gradual establishment of
biological communities on lifeless ground– Secondary succession: reestablishment of biotic
communities in an area where they already existed
What changes occur through Succession?
1. Diversity• Starts very low in harsh conditions few species
tolerate – r selected species types• Middle succession mix of various species types –
most diverse (role of disturbance)• Climax – k selected species strong competitors
dominate
2. Mineral Cycling• Pioneer, physical breakdown & make organic,
Later processing increase – cycles expand
3. Gross productivity changes (total photosynthesis)• Pioneer = Low density of producers at first• Middle & climax = high lots of producers and
consumers
4. Net Productivity (G – R = N)• Pioneer = little respiration so Net is large system is
growing, biomass accumulating• Middle & climax = respiration increases dramatically
N approaches zero (P:R = 1)
5. Energy flow• # of trophic levels increases over time• Energy lost as heat increases with more transfers
Climax community• Characterized by K-selected species• Determined by
– climate in the area – temperature, weather patterns– Edaphic factors – saturated wet, mesic, arid
• Climax community structure is in stable equilibrium for each area
• Humans & other factors may maintain an equilibrium below climax– E.g. current warming trends make climax rainforest
communities w/ softer wood, faster growing species
Communities
Definitions1. Population a group of individuals of a certain species in
a given area at a given time: blue crabs in the Halifax river2. Community interacting groups of populations in an
area: the scrub community on campus3. Species a group of individuals who can interbreed to
produce fertile, viable offspring: FL panthers4. Niche The role of an organism in its environment
(multidimensional): nocturnal predator of small mammals in the forest
5. Habitat Where an organism typically lives: mangrove swamps
Intraspecific Competition
• Competition between members of the same species for a common resource
• Resource: food, space, mates, etc.• Territoriality
– Organisms patrol or mark an area– Defend it against others– Good territories have
• Abundant food, good nesting sites, low predator pop.
– Disadvantage = Energy, Reduce gene pool
Interspecific Competition
• 2 or more different species involved• Competing for food, space, sunlight, water, space,
nesting sites or other limited resource• If resources abundant, they can be shared but in
nature they are always limited• If fundamental niches overlap competition• One of the species must…
1. Migrate if possible2. Shift feeding habits or behavior = Evolve3. Suffer a sharp population decline4. Become extinct
Connell’s Barnacles
Predation
• Members of one species feed directly on all or part of a living organism of a different species
• Individuals predator benefits, prey harmed
• Population prey benefits: take out the weak, greater resource access, improved gene pool
• Predator plays important ecological role
Parasitism
• One species feeds on part of another organism (the host) without killing it
• Specialized form of predation• Parasite Characteristics
1. Usually smaller than the host2. Closely associated with host3. Draws nourishment from & slowly weakens host4. Rarely kills the host
• Examples = Tapeworms, ticks, fleas, fungi
Malaria
According to the World Health Organization there are 300 to 500 million clinical cases of malaria each year resulting in 1.5 to 2.7 million deaths
The disease kills more than one million children - 2,800 per day - each year in Africa alone. In regions of intense transmission, 40% of toddlers may die of acute malaria.
In the early 1960s, only 10% the world's population was at risk of contracting malaria. This rose to 40% as mosquitoes developed resistance to pesticides and malaria parasites developed resistance to treatment drugs. Malaria is now spreading to areas previously free of the disease.
Mutualism
• Symbiotic relationship where both species benefit
• Pollination, Nutrition, Protection are main benefits
• Not really cooperation, both benefit by exploiting the other
Oxpeckers and black rhinoceros
Clown fish and sea anemone
Mutualism II
Examples1. Lichens – fungi & algae living together
food for one, structure for the other2. Plants and Rhizobium bacteria one gets
sugars the other gets nitrogen3. Oxpeckers and Rhinos food for one, less
parasites for the other4. Protists and termites break down wood
for one, nutrients for the other
Commensalism• One species benefits the
other is neither harmed nor helped
– Examples1. Herbs growing in the shade
of trees2. Birds building nests in trees3. Epiphytes = “Air plants”
which attach themselves to the trunk or branches of trees-they have a solid base to grow
on and better access to sunlight & rain
Ecosystems
Ecosystem Components
2 parts
– Abiotic – nonliving components (water, air, nutrients, soils solar
energy (insolation))
– Biotic – living components (plants, animals, microorganisms)Biota
Trophic Level
• The position that an organism occupies in a food chain, or a group of organisms in a community that occupy the same position in food chains.
Identify and explain trophic level Terminology and Roles of Biota
• Producers (Autotrophs) – Through photosynthesis convert radiant to chemical energy (energy transformation)
• Consumers (Heterotrophs) – Must consume other organisms to meet their energy needs– Herbivores, Carnivores, Omnivores, Scavengers,
Detritivores• Decomposers – Break down organisms into
simple organic molecules (recycling materials)
Local examples
Trophic Level Estuary system Everglades habitat
Producer
Primary Consumer
Seconday Consumer
Tertiary Consumer
Quarternary Consumer
6th trophic level
Local examples
Trophic Level Estuary system Everglades habitat
Producer Turtle grass Phytoplankton
Primary Consumer Grass shrimp Zooplankton
Seconday Consumer Pin fish Blue gill
Tertiary Consumer Spotted Sea trout Bass
Quarternary Consumer Osprey Racoon
6th trophic level Aligator
Figure 53.11 An antarctic marine food web: Identify the trophic levels
Pyramids
• Graphic models of quantitative differences between trophic levels
• By second law of thermodynamics energy decreases along food webs
• Pyramids are thus narrower as one ascends– Pyramids of numbers may be different large
individuals at low trophic levels – large forests– Pyramids of biomass may skew if larger organisms are
at high trophic levels biomass present at point in time – open ocean
Losses in the pyramid
• Energy is lost between each trophic level, so less remains for the next level– Respiration, Homeostasis, Movement, Heat
• Mass is also lost at each level– Waste, shedding, …
Pyramid types / characteristicsBiomass Pyramid Numbers
pyramidEnergy pyramids
It shows Storages Storages Flows
In g / m2 individuals / m2 J / m2 yr or g / m2 yr
It’s always pyramid shaped for a
Grassland Grassland There is never a case where it isn’t
It is not pyramid shaped for a(n)
Antarctic open ocean habitat
Forest (especially temperate deciduous)
It is always pyramid shaped
How does the first law of thermodynamics effect these?
How does the second law of thermodynamics effect these?
How does pyramid structure effect ecosystem function?
1. Limited length of food chains• Rarely more than 4 or 5 trophic levels• Not enough energy left after 4-5 transfers to
support organisms feeding high up• Possible exception marine/aquatic systems b/c
first few levels small and little structure2. Vulnerability of top carnivores
• Effected by changes at all lower levels• Small numbers to begin with• Effected by pollutants & toxins passed through
system
3. Biomagnification
1. Mostly Heavy metals & Pesticides• Insoluble in water, soluble in fats, • Resistant to biological and chemical degradation, not
biodegradable2. Accumulate in fatty tissues of organisms3. Amplify in food chains and webs4. Sublethal effects in reproductive & immune
systems5. Long term health effects in humans include tumors,
organ damage, …
Biomes
What is a biome?• World climate is variable
– Differences in temperature and precipitation– Different climates Different communities
• Biomes = Regions of the earth characterized by specific climates and community types
• Remember they cross national boundaries• Real biomes do not have sharply defined
boundaries. Ecotones = Transitional zones• Biomes not uniform, instead a mosiac of patches
– Vary in microclimate, soil types, disturbances
Dry woodlands and shrublands (chaparral)
Temperate grassland
Temperate deciduous forest
Boreal forest (taiga), evergreen coniferousforest (e.g., montane coniferous forest)
Arctic tundra (polar grasslands)
Tropical savanna,thorn forest
Tropical scrub forest
Tropical deciduous forest
Tropical rain forest,tropical evergreen forest
Desert
Ice
Mountains(complex zonation)
Semidesert,arid grassland
Tropic ofCapricorn
Equator
Tropic ofCancer
MountainIce and snow
Altitude
Tundra (herbs,lichens, mosses)
ConiferousForest
Tropical Forest
DeciduousForest
Tropical Forest
DeciduousForest
ConiferousForest
Tundra (herbs,lichens, mosses)
Polar iceand snow
Latitude
Main Biome Effects
Climate and vegetation vary in a predictable fashion with changes in Altitude and Latitude
mft
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20
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Tropicalrain forest
Coniferousforest
Deciduousforest
Thornforest
Tall-grassprairie
Short-grassprairie
Desertscrub
Thornscrub
Comparison of types, sizes and stratification of species in different terrestrial biomes (structure)
Tundra1. Climate
• Precipitation < 15 cm / yr – mostly snow & summer rain Arid• Bitter cold -57 – 50 °C - permafrost• low insolation gives short growing season
2. Distribution• 60 – 75 °N latitude – northern North America, Asia,
Greenland• About 20% of the earth’s surface
3. Structure• Simple – low spongy mat of vegetation, lichens, mosses• Even trees are less than knee high
4. Relative Productivity• Low – limited by temperature and insolation
Temperate Grasslands1. Climate
• Precipitation 25-45 cm / yr – enough to grow grass, erratic Semiarid• fire, drought, animals prevent tree growth• May be Tropical, Temperate• Moderate insolation
2. Distribution• 9% of earth surface Temperate Latitudes – Major onesNA tall grass
prairie, steppes, pampas, veldt• Grasslands overall up to 40% of earth’s surface
3. Structure• Simple – grasses and herbaceous plants
4. Relative Productivity• Medium to high – high turnover of grasses, rich soils
Deserts1. Climate
• Precipitation < 25 cm / yr – scattered unevenly through year Arid
• May be Tropical, Temperate and Cold types – always extremes• High to moderate insolation
2. Distribution• 30% of earth surface between 30 degrees north and south of
the equator – Major ones Saraha (Africa), Gobi (Asia), Mojave (N. america)
3. Structure• Simple – very little vegetation • Most complex is temperate desert which has largest cacti
4. Relative Productivity• Low – limited by water availability
Tropical Rainforest1. Climate
• Precipitation over 150 cm / yr – Wet – still rainy and dry seasons• Warm humid year round climate 80 °F • high insolation gives long growing season
2. Distribution• 23.5 °N to 23.5 °S latitude – Tropic of Capricorn to Cancer • About 2% of the earth’s surface• Three chunks – S. & C. America, C. Africa, SE Asia
3. Structure• Complex – stratified layers • High diversity - 50-80% of terrestrial species
4. Relative Productivity• Highest in terrestrial system – unlimited by temperature and insolation
Other habitats
Aquatic Life Zones
• Aquatic Biomes = Aquatic Life Zones• Salinity is a distinguishing factor
– Marine (Saltwater)• Estuaries, Coastlines, Coral reefs, Coastal
marshes, Mangroves swamps, Oceans– Freshwater
• Lakes & ponds, Streams & rivers, Inland wetlands
Mangroves
Coral reefs
Rivers
Lakes
Major Organisms
1. Phytoplankton: Free floating microscopic producers – algae & cyanobacteria
2. Zooplankton: Animal plankton – herbivores & carnivores usually invertebrates
3. Nekton: Strong swimming consumers4. Benthos: Bottom dwellers – may be sessile,
filter feeders, infauna, grazers5. Decomposers: mostly bacteria – break down
organic material
Characteristics of Aquatic Systems
• Less pronounced physical boundaries than terrestrial systems
• More complex & longer food webs and chains than terrestrial systems
• More difficult to monitor and study because of size and accessibility
Advantages Disadvantages
Physical support from water buoyancy
Fairly constant temperature
Nourishment from dissolved nutrients
Water availability
Easy dispersalof organisms, larvae, and eggs
Less exposure to harmful UVradiation
Dilution anddispersion ofpollutants
Can tolerate a narrow range of temperatures
Exposure to dissolved pollutants
Fluctuating population size for many species
Dispersion separates many aquatic offspring from parents
Fresh water
Sunlight
Paintedturtle
Greenfrog
Pondsnail
Blue-wingedteal
Muskrat
Plankton
Northernpike
BloodwormsYellowperch
Divingbeetle
Littoral zone
Limnetic zone
Profundal zone
Benthic zone
Sunlight
Little shore vegetation
Limnetic zone
Profundalzone
Oligotrophic lake
Low concentration of nutrients and plankton
Sparse fish population
Narrow littoral zone
Sleepily sloping shorelines
Sand, gravel, rock bottom
Sunlight
Much shore vegetation
Limnetic zone
Profundalzone
Eutrophic lake
High concentration of nutrients and plankton
Dense fish population
Widelittoral zone
Gentlysloping shorelines
Silt, sand, clay bottom
Epilimnion
Hypolimnion
ThermoclineSummer Fall overturn
22˚20˚
18˚8˚
6˚5˚
4˚C
0˚2˚
4˚4˚
4˚
4˚CWinter Spring overturn
4˚4˚
4˚4˚
4˚
4˚C
Dissolved O2 concentration High Medium Low
4˚4˚
4˚4˚
4˚
4˚C
Rain and snow
Water
Sediment
Lake Glacier Rapids
WaterfallTributary
Flood plain
Oxbow lake
Salt marsh
Delta Ocean
Depositedsediment
Source Zone
Transition Zone
Floodplain Zone
Capybara
Water lily
Cayman alligator
Plant planktonTerecay turtle
Animal plankton
Leporinus fish
Neon tetra
Arapaima
Piranha
Amazonian dolphin
Producerto primaryconsumer
Producerto secondaryconsumer
Secondary tohigher-levelconsumer
All producers andconsumers todecomposers
Dep
th (m
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Concentration of dissolved gas(parts per million by weight)
0
500
1,000
1,500
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90 94 98 102 106 110
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4,000
6,000
CO2
O21.5 3.0 4.5 6.0 7.5
CO2
O2
Dep
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Salt Water
Ocean hemisphere Land-ocean hemisphere
High tideLow tide
Coastal Zone
EstuarineZone
Continentalshelf
Open SeaSea level
Sun
Euphotic Zone
Bathyal Zone
Abyssal Zone
Depth inmeters
0
50
100
200
Phot
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1,500
2,000
3,000
4,000
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Dar
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© 2004 Brooks/Cole – Thomson Learning
Herring gulls
Snowyegret
Peregrine falcon
Cordgrass
Short-billeddowitcher
Marshperiwinkle
BacteriaClamworm
Soft-shelledclam
Zooplankton andsmall crustaceans
Phytoplankton
Smelt
Producerto primaryconsumer
Primaryto secondaryconsumer
Secondary to higher-levelconsumer
All producers and consumers todecomposers
Rocky Shore Beach Sea star Hermit crab Shore crab
NudibranchMonterey flatworm
Kelp Sea lettuce
Barnacles
Sea urchin Anemone
Low tide
Mussel
Periwinkle
High tide
Sculpin
Barrier beach
Silversides
Blue crab
Low tide
Dwarfolive
Clam
Beach flea
Tiger beetle
High tide
GhostshrimpMole
shrimp
Sandpiper
Peanut worm
White sandmacoma
Sand dollar Moon snail
Gray reef shark
Green seaturtle
Sea nettle
Fairy basslet
Bluetangs
Brittle star Banded coralshrimp
Sergeant majorParrot fish
Hard coralsAlgae
Phytoplankton
Symbioticalgae
Zooplankton
Sponges
Bacteria
Morayeel
Blackcap basslet
Coney
Producerto primaryconsumer
Primaryto secondaryconsumer
Secondary to higher-levelconsumer
All consumers and producers todecomposers
Ocean warming
Soil erosion
Algae growth from fertilizer runoff
Mangrove destruction
Coral reef bleaching
Rising sea levels
Increased UV exposure from ozone depletion
Using cyanide and dynamite to harvest coral reef fish
Coral removal for building material, aquariums, and jewelry
Damage from anchors, ships, and tourist divers
Terms• Biodiversity: Genetic, Species, Ecological, Functional (processes).• Genetic Diversity: change in size, age distribution, density, genetic
composition• Habitat: one species. Community: several species. Ecosystem:
several species and abiotic environment.• Biomes: distinct climates—terrestrial (forests, deserts, grasslands), aquatic
(Freshwater, Ocean or Marine).• Ecotone: non-distinct boundary between ecosystems.• Law of Tolerance: population distribution determined by physical/chemical
factors.• Limiting Factor Principal: too much/little abiotic factor (temp, light, DO,
nutrients, salinity) can limit/prevent population growth.• Producers (Autotrophs): “self-feeders” (plants, phytoplankton use CO2,
light, nutrients, etc.).• Anaerobic Respiration (Fermentation): no oxygen used (CH4, C2H5OH,
CH3COOH, H2S products).• Consumers (Heterotrophs): “other feeders” (herbivores, carnivores,
omnivores, scavengers, detritivores (long-horn beetle), detritus feeders, decomposers
Terms
• Aerobic Respiration: oxygen used (C6H12O6 + 6O2 6CO2 + 6H2O + energy)• Food Web or Chain: represent trophic levels of interacting species (primary
consumers eaten by secondary and so forth.• Energy Pyramid: like food web but shows energy flow between tropic
levels.• Ecological Efficiency: % usable energy transferred in biomass between
trophic levels.• (SunProducersHerbivoresCarnivoresDecomposersDecomposers
/detritivores).• Biomass Abandoned Field / Grassland: greatest to least (producers,
primary, secondary, tertiary consumers).• Biomass Ocean / Forest: greatest to least (primary, secondary consumers,
producers, tertiary consumers).• Absolute Humidity: g. H2O / kg. Air Relative Humidity: [g. H2O
(temp.) / g H2O max (temp.)] x 100%• Condensation Nuclei: ash, dust, smoke, sea salts, fossil fuel particulates.