Bio 2: Ecology & Conservation Study Notes PDF

#1 (Threats of biodiversity) 🧠 Learning Objectives ​ Understand how human impact is modeled (I = PAT)​ ​ Know biodiversity types (genetic, species, ecosystem)​ ​ Learn the major threats to biodiversity (HIPPO-CC)​ ​ Recognize the top threat to species​ ​ Understand terms: biotic...

#1 (Threats of biodiversity) 🧠 Learning Objectives ​ Understand how human impact is modeled (I = PAT)​ ​ Know biodiversity types (genetic, species, ecosystem)​ ​ Learn the major threats to biodiversity (HIPPO-CC)​ ​ Recognize the top threat to species​ ​ Understand terms: biotic homogenization, biomagnification, ecological footprint, phenology, range shift​ 🌍 Human Impact: I = PAT ​ Formula:​ I = P × A × T​ I = Impact, P = Population, A = Affluence, T = Technology​ ​ More people = more resources used & waste produced​ ​ Affluence: Wealth increases quality of life and environmental impact​ ​ Technology: Helps humans survive but also damages nature (e.g., DDT, carbon emissions)​ 🌱 What is Biodiversity? 1. Genetic Diversity ​ Variation of genes within a species​ ​ More diversity = higher fitness & adaptability​ → Less inbreeding, more traits for natural selection​ 2. Species Diversity ​ Species richness: Number of different species​ ​ Species evenness: How balanced species numbers are​ 3. Ecosystem Diversity ​ Variety of ecosystems & processes in a location​ → Example: Yellowstone improved after reintroducing wolves​ → More complex = more biodiversity (e.g., wetlands, trees, birds)​ 📉 Monitoring Biodiversity Loss ​ IUCN Red List tracks endangered species​ ​ ~44,000 threatened species listed​ ​ 28% of assessed species are at risk​ ​ Extinction rate is 100–1,000x faster than natural​ ​ ~1 million species are threatened​ 🚨 HIPPO-CC: Major Threats to Biodiversity 1.​ Habitat Loss​ ○​ #1 cause of extinction (73%)​ ○​ Caused by: cities, farming, roads​ ○​ Leads to fragmentation and loss of habitat​ 2.​ Invasive Species​ ○​ Human-spread species that harm ecosystems​  ○​ Examples: zebra mussels, cats, grey squirrels​ ○​ Leads to biotic homogenization ("planet of weeds")​ 3.​ Pollution​ ○​ DDT, oil, heavy metals harm wildlife​ ○​ Example: 98% of freshwater crabs are threatened​ ○​ Biomagnification: toxins concentrate as they move up food chain​ 4.​ Population​ ○​ 8 billion people = massive resource use​ ○​ Ecological footprint: 1.7 Earths needed to support current demand​ 5.​ Overharvest​ ○​ Overhunting/fishing leads to extinction​ ○​ Examples: passenger pigeon, Atlantic cod collapse​ ○​ Poaching = $5–20 billion/year​ 6.​ Climate Change​ ○​ Causes range shifts (species move to new areas)​ ○​ Affects phenology (seasonal events like mating, migration)​ ○​ Disrupts food chains, worsens other threats​ ○​ Affects 10,000+ threatened species​ 📚 Important Vocabulary ​ Species richness: total # of species​  ​ Ecosystem services: benefits humans get from ecosystems​ ​ Invasive species: non-native species harming ecosystems​ ​ Biomagnification: toxin buildup in food chain​ ​ Ecological footprint: resource use impact per person​ ​ Range shift: species move due to changing climates​ ​ Phenology: timing of biological events (e.g., flowering, migration) #2 (Conservation) 🌿 Learning Objectives ​ Know what the Endangered Species Act (ESA) does​ ​ Understand the differences between endangered, threatened, and vulnerable species​ ​ Identify species important to conservation (e.g., keystone, indicator, umbrella, flagship)​ ​ Learn how conservation and ecological restoration are practiced​ ​ Know an example of restoration in California​ ​ Vocabulary: endangered, threatened, keystone, indicator, umbrella, flagship species, MVP, ecological restoration, reintroduction​ 🐾 Endangered Species Management ​ Past view: Nature seemed unlimited — people didn’t think extinction was possible​ ​ Today: Species like bison, sea life, and others have shown that human activity causes major damage​  ​ 2006: Report warned that all seafood stocks could collapse​ 📜 Endangered Species Act (ESA) – 1973 ​ Main goal: Protect species from extinction​ ​ Categories:​ ○​ Endangered = at immediate risk of extinction​ ○​ Threatened = likely to become endangered soon in the near future, still have a chance at recovery​ ○​ Vulnerable = Could be super rare species or depleted, could be at high risk​ What does this do? Protects species and habitats​ ​ Makes it illegal to harm, sell, or trade endangered species​ ​ Over 1,300 species endangerd are ESA-listed in the U.S. Was last updated (10 years ago) ​ ​ ESA is controversial (affects ranching, mining, etc.) because they will no longer be able to mine or ranch depending. ​ ​ Take: Taking a species that is endangered, such as hunting, selling, or cllecting feathers etc. ​ Legal protection: Legally protecting a critical habitat such as conserving an area 🛠️ Species Recovery Plans ​ Adding species to the (ESA), what is needed? ​ What the issues are, how can we address them and how can we rebuild that population to where theyw will no longer be endagngerd. ​ Every listed species must have a recovery plan​  ​ Overseen by U.S. Fish & Wildlife Service​ ​ Total cost to help species recover each year would cost = ~$5 billion (compare to $686B military budget)​ ​ Shows priorities: society spends much more on consumer items than conservation like valentines day, citizens approximately spend 24billion dollars. ​ 🧬 Important Species for Conservation 1.​ Keystone Species ​ Have major impacts onn ecological community or function, eliminating this species would cause a major impact, those species are listed down below. ○​ Huge impact on ecosystems​ ○​ Removing one causes collapse​ ○​ Examples: grey wolves, bison, jaguar​ 2.​ Indicator Species ​ Specific community that notifies that a environment is ecological healthy, you woudl expect to see super sentitve species present to prove the ecosystem is healthy ​ ○​ Signal health of the environment​ ○​ Examples: brook trout​ 3.​ Umbrella Species ​ Species that benefits other when they are saved and live within the same environment​ ○​ Need large, intact habitats​ ○​ Protecting them protects many others​ ○​ Examples: grizzly bears, spotted owls​ 4.​ Flagship Species ​ Species that motivate the people to help do to (cuteness) ○​ Loved by people, inspire support​  ○​ Examples: pandas, orcas, cheetahs​ 🌎 How Conservation Works ​ Stablizing the human population and reducing our ecological footprint (need) because we as humans are the cause of habitat loss. ​ Top-down: Laws, regulations, funding​ ​ Bottom-up: Local, individual action ​ Protecting habitat: Reduce harvest, species reitroductions or removals ​ ​ Steps for conservation project:​ 1.​ Basic esearch ecological problems​ 2.​ Inform policy-makers​ 3.​ Set regulations​ 4.​ Enforce laws​ 5.​ Monitor results​ 🔧 Ecological Restoration (ecosystem restoration) ​ Ecosystem restoration is the science and practice of bringing a landscape back to its healthy conditions. ​ Goal: Restore damaged ecosystems to former condition​ ​ Based on (ecology, soil, hydrology, chemistry)​ ​ Common steps for restorations:​ 1.​ Remove physical stress (pollution, traffic, etc.)​  2.​ Control invasive species​ 3.​ Replant (native) vegetation​ 4.​ Reintroduce animals (often from captive breeding)​ 5.​ Monitor progress & effort ​ ​ Example: Green Belt Movement (Kenya) replant​ 🐉 California Example: San Joaquin Desert ​ Farmland being retired due to water issues​ ​ Opportunity: Restore habitat for (Blunt-nosed leopard lizard) where they live within californias water system ​ ​ Problems: salinization, groundwater loss, climate change, & overdraft​ 🏞️ Restoration vs. Preservation ​ Restoration = Fixing damaged land​ ​ Preservation = Protecting land before damage happens​ ​ What is needed:​ ○​ Funding: Yow do we get enough money to keep land when the land isnt making money​ ○​ Labor: Getting lots of volunteers, and labor to help​ ○​ Community support: Finding supports of the projects to help ​ ​ Note: A small portion of protected areas supports most of the work (e.g., 16% of SNP (sequia national park) just to get people out to help. To support the other 86% of the national park)​ 🧍‍♂️Challenges: People ​ Resistance: to change, even if conservation is supported​ ​ Biologists: sometimes seen as "outsiders" or "bad guys"​ 💰 Challenges: Funding & Knowledge Bias ​ Funding is uneven:​ ○​ Cute animals > plants (no one really cares about plants) ​ ○​ Emotional stories > blurry data​ ​ Bias affects what gets researched, protected, and funded ​ Challanges: It is hard to get funding when you have blurry pictures ​ How to get help: Use pet toys, sad animal photos to get people to donate and get funding or help 🦓 The Role of Zoos ​ Often criticized but can help the animals :​ ○​ Host experts & proper gear​ ○​ Participate in breeding, rehab, and education ○​ Perminant animals will be used to educate and allow people to see a animal they may never get to see​ ​ Help connect public to conservation efforts to rehabilitate animals and restoring species​ ​ Examples: California condor, Ferrets, oryx, frogs​ UNEP (United Nations Enviorment Programme) ​ Uses and encourages the model for conservation projects -​ Envormental health  -​ Human health -​ Animal health #3 (Conservation Ethics) 🌱 Conservation Ethics – BIO 2 🎯 Learning Objectives ​ Identify the major ideas of:​ ○​ Pragmatic Utilitarian Conservation Ethic​ ○​ Biocentric Preservation​ ○​ Modern Environmentalism​ ○​ The Land Ethic​ ○​ Environmental Justice​ ○​ Global Environmentalism​ ​ Name contributions and ethics of:​ ○​ Rachael Carson​ ○​ John Muir​ ○​ Aldo Leopold​ ​ Understand vocabulary:​ ○​ Ecosystem services​ ○​ Environmental racism​ ○​ Sustainability projects​ 🌍 Ecosystem Services Definition: Resources and benefits ecosystems provide to humans ​ Regulating: Climate control, water purification​ ​ Supporting: Photosynthesis, nutrient cycling supporting life ​ ​ Provisioning: Directly providing , Food, fuel, timber, medicine​ ​ Cultural/Spiritual: Recreation, mental health​ Examples: ​ Clean water, soil formation, stable climate​ ​ Medicines from wild species: penicillin, quinine, morphine, aspirin​ ​ Trees provide ~$173 trillion/year in value​ ​ 95% of pests controlled naturally by predatory species ​ ​ Contact with nature improves mental health; reduces crime​ ​ Americans spend $156 billion on nature outdoor related activities​ 📉 Biodiversity Crisis ​ Biodiversity has fallen below the safe limit on 58% of Earth's surface​ ​ Leads to reduced ecosystem services and increased vulnerability​ 1. 🌲 Pragmatic Utilitarian Conservation Ethic Main Idea: Preserve nature for its usefulness to humans ​ Key Figure: Theodore Roosevelt (President 1901)​  ○​ Nature = jobs + homes​ ○​ Created 150 National Forests, 5 national parks, 18 monuments​ ○​ Protected 230 million acres of land​ ​ Modern Contributor: Jared Diamond – Collapse (2011)​ ○​ Civilizations collapse after environmental degradation​ 🌴 Case Study: Easter Island (collapsing community) ​ Polynesians settled ~800–1200​ ​ Moai statues led to total deforestation​ ​ Collapse followed (1600): no boats, food, freshwater, & no species present at all​ ​ Result: war, cannibalism, population decline and full population collapse ​ Lesson: Societal survival depends on environmental conservation. 2. 🌼 Biocentric Preservation Main Idea: Nature has intrinsic value; all about the organisms have the right to exist. ​ Key Figure: John Muir​ ○​ Founded the Sierra Club (early explorer of the sierra nevada mountains) ​ ○​ Helped establish Yosemite & Kings Canyon National Parks (1916)​ ○​ Nature is not just for humans; it exists for its own sake​ “Why ought man to value himself as more than an infinitely small unit of one great unit of creation?” — John Muir 3. 🌎 Modern Environmentalism Main Idea: Recognizes human damage to ecosystems and calls for regulation ​ Push back due to the saying (dilution is the solution to pollution) ​ Key Figure: Rachel Carson – Silent Spring (1962): Talks about the bird community collapse, due to the dilution of pollutants ​ ○​ Exposed dangers of DDT is a pesticide used to controll mosquitoes ○​ ​ Caused eggshell thinning, harming birds like eagles​ ○​ Biomagnification: Toxins build up in food chains​ ○​ Result: DDT banned in U.S. in 1972 leading to a increasing population of bird species ​ 4. 🌾 The Land Ethic Main Idea: Treat land as a community deserving ethical treatment ​ Key Figure: Aldo Leopold​ ​ Includes soil, water, plants, animals as part of one system​ ​ Ethics = cooperation, love, and respect for all life​ ​ Summary: “Right” actions support the integrity, stability, and beauty of the biotic community​ 5. ⚖️ Environmental Justice Main Idea: Combines civil rights with environmental protections, and how the underprivileged people are affected ​ Environmental racism: Unequal pollution exposure by race exposing them to hazardus waste ​ Enviormental justice: Combines the civil rights and environmental protections to demand everyone has a safe and healthy enviorment  ​ Sustainability project: Can be used to elevate peopleout of poverty while improving the environmental conditions​ ○​ 50–60% of minorities live near hazardous waste sites​ ○​ Only 10% of white people do and make up 75% of the population​ ​ Goal: Safe, healthy environment for everyone​ ​ Sustainability projects: Improve environment and reduce poverty​ 6. 🌐 Global Environmentalism Main Idea: Acknowledges the united global Environmental issues and how they are interconnected ​ Earth = One shared system (1 ocean, 1 atmosphere)​ ​ Air pollution travels: e.g., 10% of California's ozone comes from Asia crossing the pacific ocean ​ ​ Per capita emissions:​ ○​ U.S.: 18.44 tons CO₂e/person​ ○​ China: 8.87 tons CO₂e/person​ ​ The planet is fragile, unique, and there is only one so we all share responsibility ​ 🤔 Final Reflections ​ Which ethic resonates most with you and why?​ ​ Are any ethics less convincing? Why?​ Lecture #4 (Population ecology) Learning Objectives: ​ Describe population density and dispersion.​ ​ Understand factors influencing population growth.​ ​ Differentiate Type I, II, and III survivorship curves with examples.​ ​ Explain exponential vs logistic growth.​ ​ Understand life history strategies (r- and K-selection).​ ​ Key Vocabulary: clumped, uniform, random dispersion, cohort, life table, demography, carrying capacity, overshoot, dieback, life history, biotic potential, environmental resistance.​ Population Biology Overview: ​ Population biology = Study of how populations grow, structure, and interact.​ ​ Focuses on:​ ○​ Distribution, density, dispersion.​ ○​ Population characteristics (e.g., sex ratios, age structures).​ ○​ Connections with other populations.​ Population Distribution: ​ Population = Individuals of a species living in the same area.​ ​ Described by:​  ○​ Boundaries and size.​ ○​ Density = Number of individuals per unit area/volume.​ ​ High density can increase competition for resources.​ ○​ Dispersion = Pattern of spacing among individuals.​ ​ Types of dispersion:​ ​ Clumped: Individuals gather in patches (common; due to resources, mating, or defense).​ ​ Uniform: Evenly spaced (due to territoriality or chemical inhibition).​ ​ Random: Unpredictable spacing (no strong attraction or repulsion).​ Demographics: ​ Demography = Study of birth, death, and migration rates. ​ Influenced by biotic (living) and abiotic (non-living) factors. ​ We are alos looking at anything that impacts the population such as (births, deaths, immigration, emigration). If you have equal numbers of (births and immigration) we will make (deaths and emigration) equal ​ Life Tables: (Practice) ​ Summarize survival rate/time and reproductive rates at different ages.​ ​ Cohort = Group of individuals of the same age.​ ​ Death Rate = Annual mortality = dead ÷ total.​ Survivorship Curves: (Refer to graph slides) ​ Graphs showing how many individuals survive in each age group.​ ​ Types:​ ○​ Type I: Low mortality until old age. (Example: Humans, elephants). Has a consisten pattern starting from the uppeft left side of the graph and sloping down to the right bottom corner (% alive/ Lifespan)​ ○​ Type II: Constant mortality at all ages. (Example: Birds, rodents). A straight shot from top left corner straight to right corner not slope ○​ Type III: High mortality in early life. (Example: Oysters, many plants). Starts at the top left corner, shoots straight down to the bottom, and levels out and staightens out running down to the (x axis). Reproductive Rates: ​ Fecundity = Average number of female offspring per female in a given age group.​ ​ Examples:​ ○​ Squirrels: 2–6 young/year for ~10 years.​ ○​ Oak trees: Thousands of acorns/year for decades.​ ○​ Blue whales: 1 calf every 2–3 years.​ ​ Biotic Potential = Maximum possible population growth (rarely achieved in nature). Positive force pushing the population to grow grow grow!​ Exponential Growth: (Look at the graph on slides) ​ Unrestricted paths, populatiosn just exponentially grow rapidly ​ Happens under ideal conditions (plenty of resources).​ ​ Population increases by a constant proportion over time.​ ​ Very rare in real ecosystems.​ Environmental Resistance and Carrying Capacity: ​ Environmental Resistance: Limits on growth (e.g., food shortage, disease).​ ​ Carrying Capacity (K): Maximum population size an environment can sustain. ​ (Think of bunnies lab)​ Logistic Growth: ​ Realistic model: Growth slows down as carrying capacity is approached.​ ​ S-shaped curve:​ ○​ Fast growth initially.​ ○​ Slows as resources get used.​ ○​ Levels off at K. (finds equilibrium point)​ Dynamic Nature of Carrying Capacity: ​ Carrying capacity changes depending on resource availability.​ ​ Populations often overshoot K → resource depletion → dieback.​  ​ Populations can oscillate around K.​ Predator-Prey Dynamics: ​ Predator and prey populations cycle together.​ ​ Example:​ ○​ Snowshoe hares and lynx:​ ​ Hare population rises → lynx population rises.​ ​ Lynx overhunt hares → both populations crash.​ ​ Cycle restarts. ​ (Both populations will flip flop as a reset)​ Life History Strategies: ​ Life history = Timing of growth, reproduction, and death.​ ​ Organisms make trade-offs:​ ○​ (e.g., many small offspring vs few large ones).​ ​ r-selected species (rapid growth) like trees or fish:​ ○​ Focus on rapid growth.​ ○​ Traits:​ ​ Short life, early maturity.​ ​ Many small offspring.​ ​ Little/no parental care.​  ​ Adapted to unstable environments.​ ​ Examples: Weeds, insects.​ ​ K-selected species: Smaller offspring but receive more parental care and are much larger, such as humans, elephants.​ ○​ Focus on stable populations near K.​ ○​ Traits:​ ​ Long life, late maturity.​ ​ Few, large offspring.​ ​ High parental care.​ ​ Adapted to stable environments.​ ​ Examples: Elephants, humans.​ Quick Summary of r-Selected vs K-Selected Species: -​ (Review the actual table on the slides) -​ It is possible to see a species to have traits from both sides, and also to have traits from only one side. Trait r-Selected K-Selecte d Life span Short Long Growth rate Fast Slow Maturity Early Late Offspring Many Few large small Parental care Low High Environment Unstable Stable stability  Trophic level Low High Key Terms: ​ Clumped dispersion: Aggregated in patches.​ ​ Uniform dispersion: Evenly spaced.​ ​ Random dispersion: Unpredictable spacing.​ ​ Cohort: Group of same-age individuals.​ ​ Life table: Summarizes survival/reproduction rates.​ ​ Demography: Study of vital statistics over time.​ ​ Carrying Capacity (K): Max sustainable population.​ ​ Overshoot: Population exceeds K.​ ​ Dieback: Population crash after overshoot.​ ​ Biotic Potential: Max possible population growth.​ ​ Environmental Resistance: Limits preventing biotic potential. Lecture #5 ( Species interations) Species Interactions – Detailed Study Notes Learning Objectives ​ Define ecological niche and limiting factors.​  ​ Identify 6 types of species interactions with examples.​ ​ Understand ecological and evolutionary consequences of interactions.​ ​ Explain and give examples of symbiosis and coevolution.​ ​ Know vocabulary: generalist/specialist, realized vs. fundamental niche, resource partitioning, character displacement, keystone species, ecosystem engineers, mimicry, etc.​ Limiting Factors ​ Definition: Any factor that restricts growth or survival of organisms.​ ​ Biotic Examples: Predation, disease, food scarcity.​ ​ Abiotic Examples: Climate, pollution, space.​ ​ Tolerance Limits: The range of conditions an organism can survive.​ Ecological Niche ​ The role a species plays in its ecosystem.​ ​ Includes: Habitat, resources, interactions, conditions.​ ​ Like a multi-dimensional fingerprint of a species.​ ​ Can change over generations (evolution).​ Resource Use & Organism Types ​ Producers: Plants are Photosynthetic organisms producing their own energy (plants, algae, cyanobacteria).​  ​ Consumers: (Consume others to obtain energy) ​ ○​ Herbivores: Eat plants only (e.g., cows, deer).​ ○​ Omnivores: Eat plants and animals (e.g., humans, bears).​ ○​ Carnivores: Eat animals (e.g., lions, wolves).​ Generalists vs Specialists ​ Generalists: Broad niche (e.g., raccoons).​ ​ Specialists: Narrow niche (e.g., koalas).​ ​ Endemic species: Found in one location only and evolved in that location.​ Fundamental vs Realized Niche ​ Fundamental Niche: The full range a species could occupy -​ Have the potential to live within its full range but, there is another species who does better in other areas so they occupy the areas of their niche while the others occupy the other niche (essentially it is where do you thrive best). ​ ​ Realized Niche: The actual space used due to competition or interactions.​ ○​ Ex: Slimy salamanders excluded from areas by red-cheeked salamanders.​ Types of Species Interactions Population: A group of one species that live within the same geographing area Community: The entrie population within the geographic area 1. Competition (-/-) ​ Both species are harmed by competing for the same resource because they are competing for the same resources to survive ​ ​ Competitive Exclusion Principle: Two species with the same niche cannot coexist indefinitely.​ ​ Effects:​ ○​ Short-term: Reduced biodiversity.​ ○​ Long-term: Leads to specialization & diversifying selection. (species will eventually diverge from one another, and will reduce there competition overtime) 2. Resource Partitioning ​ Reduces competition by dividing up resources. (Birds can divide the up the area of the tree based on their feature and niches they best fit at) and this reduces the competition and they will no longer be in competition with one another​ ​ Example: Warblers in the same forest use different parts of the tree^.​ 3. Ecological Character Displacement ​ Species evolve traits to exploit different resources and reduce competition. (Different sizes of beaks seperates the birds giving us a displacement, this reudces the competitions because they both have different requirements based on beak sizes) But can lead to exclusion if they dont fit in. ​ ​ Ex: Finches evolve different beak sizes when coexisting.​ 4. Predation (-/+) ​ One species benefits, the other is harmed (killed). (One species will each other species and causes impact on them)​ ​ Intensity-dependent:​ ○​ Low predation: Helps maintain balance by reducing dominance.​ ○​ High predation: Can cause extinction.​ ​ Example: Sea stars prevent mussel overpopulation.​ 5. Keystone Species ​ A species that has a disproportionate impact on the ecosystem.(extirpated: removed from area but not extinct) helping bring back species that were no longer present in the geographical area, maintinang elk population and grazing that allows seedlings to develop into trees bringing back beavers populations.​ ​ Ex: Wolves in Yellowstone:​ ○​ Reduced elk overgrazing.​ ○​ Forest regenerated.​ ○​ Beavers and other species returned. ​ Ecosystem engineers ^ 6. Symbiosis ​ Close and long-term interaction between two species. ​ (two or more species live together intimately and put there fates in eachother) ​ Mutualism: species benefits A and B benefits A ​ Commensilism: Species A benefits but B doesnt ​ Parsitism: Species A benefits but B doesnt ​ a) Parasitism (-/+) ​ Parasite benefits, the host is harmed.​ ​ Doesn't usually kill host, but impacts:​ ○​ Fitness, behavior, population size, food webs. ○​ Some parisism provide food to others ​ ​ Examples:​ ○​ Cuckoo birds lay eggs in other nests (brood parasitism) not having to use their energy to raise the chicks so they rely on others to raise them.​ ○​ Parasite in killifish changes behavior, increases predation risk. (causes them to swim weird and causes them to get eaten faster) ○​ Cordyceps fungus in ants.​ ○​ 78% of food web links in some areas involve parasites.​ b) Mutualism (+/+) ​ Both species benefit.​ ​ Ex: Coral and zooxanthellae algae.​ ○​ Essential for coral reefs → supports 25% of marine fish.​ c) Commensalism (+/0) (raises) ​ One species benefits, the other is unaffected.​ ​ Ex: Cattle egrets on rhinos.​ d) Amensalism (-/0) (stabilizes) ​ One species harmed, other unaffected.​ ​ Prevents dominance, increases stability.​ Coevolution ​ Definition: When two species evolve in response to each other.​ 1. Predator-Prey Arms Race ​ Example:​ ○​ Bats use echolocation to find moths.​ ○​ Moths evolve ears → evasive maneuvers.​ ○​ Bats evolve stealth.​ ○​ Moths use ultrasonic clicks. ○​ As the moths evolve so do the bats and they evolve due to eachother. ​ 2. Mimicry ​ Batesian Mimicry: Harmless species mimic dangerous for survivability! (e.g., beetle mimics wasp).​ ​ Müllerian Mimicry: Multiple harmful species evolve similar warning signals (Look the same).​ 3. Mutualistic Coevolution ​ Example: Madagascar orchid and hawkmoth​ ○​ Long nectar tube & long moth proboscis → mutual evolution for pollination. ○​ The humming birds get longer beaks so the flowers have to adjust to that and make there pollen tubes larger this is called (Coevolution) Practice Suggestions  ​ Create your own examples of:​ ○​ Mutualism: Bugs that clean teeth of a alligator (does affect the alligator) ​ ○​ Predator/Prey: jaguar and rabbit ​ ○​ Commensalism: Birds living with cattle (The birds benefit but the cattle are unaffected)​ ​ Build 4-species examples showing:​ ○​ Predator/Prey​ ○​ Parasitism​ ○​ Competition​ Interation Effect on species 1 Effect on species 2 Example Competetition Negative Negative Plants Vs. plants Predidation Positive Negative Lion Vs Buffalo Parasitism Postive Negative Ticks and leeches dideases Vs. Animals Mutualist Positive Positive Cleaner fish pollination Commensalism Postive 0 Cattle ergets, hermid crabs Amensalism Negative 0 Sheep or cattl trapping grass from sunlight (Lecture #6) Trophic Structure – Detailed Notes Learning Objectives ​ Understand energy flow and nutrient cycling in ecosystems.​ ​ Identify and draw trophic levels, food chains, and food webs.​ ​ Explain why food chains are relatively short.​ ​ Calculate energy loss and transfer efficiency between trophic levels.​ ​ Understand ecosystem regulation: top-down vs. bottom-up.​ ​ Explain how ecosystems change through succession and disturbances.​ ​ Illustrate the intermediate disturbance hypothesis.​ Energy Flow vs. Nutrient Cycling ​ Energy: Flows one-way through an ecosystem (lost as heat).​ ​ Nutrients (mass): Cycle repeatedly (e.g., carbon, nitrogen).​ ​ Energy is represented as arrows, and mass is tracked as boxes in diagrams.​ Trophic Structure Overview ​ Describes feeding relationships within a species community.​ ​ Trophic level: Organisms sharing the same position in a food chain. Food Chain Example (linear): 1.​ (Starts) Primary Producers – photosynthetic (e.g., plants) or chemosynthetic (dont use sunlight).​ 2.​ Primary Consumers – herbivores.​ 3.​ Secondary Consumers – eat herbivores.​ 4.​ Tertiary Consumers – eat secondary consumers.​ 5.​ (End) Quaternary Consumers – top predators (apex predators); nothing eats them.​ Productivity: Refers to how energy and mass are built into an ecosystem. ​ Linear arrangement of who eats who within the ecosystem and how eating another will provide energy for the other organisms Food Webs ​ Interconnected food chains form a food web.​ ​ More complexity = more resilience to disturbance.​ ​ Food chain = simple, linear.​ ​ Food web = complex and realistic.​ Special roles: ​ Detritivores: Eat dead organic material protduced from all trophic levels (from all levels).​ ​ Decomposers: Break down material externally using enzymes. ​ Key: If building a food web the food we should always have arrows going from the producer to the consumers. Trophic Efficiency ​ Most ecosystems have 5 or fewer trophic levels (Will never be able to skip levels)​ ​ Energetic Hypothesis: Efficiency of energy transfer limits food chain length. ​ Key: As the chain gets longer the energy levels reduces and does produce as much energy as a 3 linked chain would​ ​ 10% Rule: Only ~10% of energy is passed on at each level. ​ Key: Each level change would pass on only (10%) and the other (90%) is lost trying to make the (10%) that is going to be passed on. Example: ​ 10,000 kcal (plants) → 1,000 kcal (herbivores) → 100 kcal (primary carnivores) → 10 kcal (secondary carnivores) Measurement tool: Biomass is used to estimate energy at each level. Key: How much energy the plants have within then is found through biomass Summary Calculations 1.​ Tertiary Consumer Energy: A grassland experiences 129,048 Kcal in primary productivity for the day. How much of the energy will make it into the tertiary consumers? ○​ If primary productivity = 129,048 kcal​ ○​ Tertiary gets: 129,048 × 0.1 × 0.1 × 0.1 = 129.05 kcal​ 2.​ Secondary Productivity: An elk consumes 3,967 Kcal in vegetation during the day. It respires 793 Kcal and excrets 1,934 Kcal. How much energy does it have available for the secondary productivity? ○​ Elk eats 3,967 kcal, respires 793 kcal, excretes 1,934 kcal​ ○​ Energy available = 3,967 – 793 – 1,934 = 1,240 kcal​ Regulation of Trophic Systems ​ Bottom-up control: Controlled by resource availability at the base (nutrients, light, etc.).​ ​ Top-down control: Controlled by predators at higher levels. (something that will eat many species, and will control populations) ​ ​ Trophic cascade: Removing a top predator causes alternating increases/decreases across levels. (The food web will cause massive impacts on the trophic level causing harn) One will increase production while the other will decrease. ​ Example is down below! Example Key: ​ Bass removed → minnow population grows → zooplankton decrease → phytoplankton bloom → murky water​ Ecological Succession ​ Natural change in ecosystems over time.​ Stages: 1.​ Pioneer species: First colonizers​ ○​ Wind-dispersed, fast-growing, short-lived, shade-intolerant​ ○​ e.g., lichens, mosses, algae​ 2.​ Climax community: Final long term stable ecosystem (Heaving dead sequias on the floor and died through age is letting us know we reached climax)​ ○​ Long-lived, slow-growing, animal-dispersed, shade-tolerant​ ○​ e.g., sequoia, hemlock​ Ecosystem Disturbance (That doesnt allow to reach climax) ​ Disturbance: Events (e.g., fire, flood, human activity) that remove species or alter resources.​ ​ Intermediate Disturbance Hypothesis: Moderate disturbance leads to higher biodiversity than low or high levels. (allows other species to come in and grow as others have died, and this allows more biodiversity)​ Example (Wild fires) – Yellowstone: ​ 1988 fire destroyed the lodgepole pine forests.​ ​ Followed by rapid recovery → demonstrates adaptation to periodic disturbance.​ ​ Fire suppression + climate change = increased wildfire intensity. ​ Fire suppression leads to become very very hot and this kills lodge poles this is due to human supressioon on fires Practice questions: 1)​ Which of the following species is the best example of a cliamx species? -​ Ostrich ferns -​ Mountain white tharn bush -​ Douglas fir -​ Paper birch 2)​ One would expect a pioneer species to have all the following characteristics except? -​ Short lived -​ Shade tolerant -​ Fast growing -​ Wind dispersal 3)​ T/F All ecosystems will eventually reach a climax community? -​ False Key Vocabulary  ​ Trophic structure: Feeding relationships in a community.​ ​ Productivity: Rate of energy/mass incorporation into an ecosystem.​ ​ 10% Rule: Energy transfer efficiency between levels.​ ​ Detritus: Dead organic material.​ ​ Energetic hypothesis: Food chain length limited by energy transfer efficiency.​ ​ Trophic cascade: Ripple effects from top predator removal.​ ​ Pioneer species: First colonizers post-disturbance.​ ​ Climax species: Stable, long-term species.​ ​ Intermediate disturbance hypothesis: Moderate disturbance promotes diversity.​ Lecture #7 (Bioengergenics & Biomes) Climate and Biomes – Detailed Study Notes 🌍 Learning Objectives ​ Define ecology and explain its scale and scope​ ​ Describe how solar radiation, proximity to water, elevation, and vegetation influence climate​ ​ Identify and describe major biomes of California​ ​ Understand vertical distribution of light and temperature in aquatic ecosystems​ ​ Know and apply vocabulary:​ ○​ Biotic, Abiotic variables​  ○​ Population, Community, Landscape, Weather, Climate,​ ○​ Rain shadow, Microclimate, Climograph, Phytoplankton,​ ○​ Pelagic, Benthic, Epilimnion​ 1. Introduction to Ecology Ecology: Scientific study of interactions between organisms and their environment. ​ Environment = Biotic (living) + Abiotic (nonliving) factors.​ ○​ Biotic: Predators, competitors, parasites, disease​ ○​ Abiotic: Weather, climate, fire, geology​ ​ Interactions are reciprocal​ ○​ e.g., Lichens breaking down rocks; storms relocating birds​ 2. Ecological Scales ​ Organismal Ecology: Study of how individuals respond to their environment​ ​ Population Ecology: Changes in size of a single species population​ ​ Community Ecology: Species interactions shaping communities​ ​ Ecosystem Ecology: Focus on energy flow and nutrient cycling​ ​ Landscape Ecology: Interactions across multiple ecosystems the exchanging of energy materials and organism across multiple ecosystems ( ocean and river meet)​ ​ Global Ecology: Large-scale analysis of Earth’s systems and biosphere (Global changes)​ 3. The Atmosphere and Climate ​ Roles of atmosphere:​ ○​ Heat retention (Earth would be -18°C without it)​ ○​ Radiation protection​ ○​ Heat and water distribution​ ○​ Provides Oxygen supply​ ​ Weather = Short-term and local​ ​ Climate = Long-term, large-scale patterns ​ We as humans can still damage our atmosphere ​ 4. Solar Energy & Distribution ​ Incoming solar radiation:​ ○​ 25% reflected by atmosphere/clouds​ ○​ 25% absorbed by gases (CO₂, H₂O vapor, etc.)​ ○​ 50% Actually reaches Earth's surface​ ​ Reflects off bright surfaces (snow, sand, etc.)​ ​ Sunlight intensity depends on angle of incidence​ ○​ Equator receives most direct light​ 5. Global Circulation & Seasonal Effects ​ Tropical heat drives global air circulation​ ○​ Warm air rises → cools → rain​  ○​ Dry air descends → desert formation​ ​ Seasonality caused by Earth’s axial tilt​ ○​ More variation at poles (day length, temperature)​ 6. Regional Climate Influences Bodies of Water: ​ High specific heat moderates temperature​ ​ Day: water → land breeze​ ​ Night: land → water breeze​ ​ Ocean currents:​ ○​ Toward equator = cold​ ○​ Away = warm​ Mountains: ​ South-facing slopes warmer (in N. Hemisphere)​ ​ Elevation: temp drops ~6°C per 1,000 m​ ​ Rain shadow: Moist air cools & rains on windward (The are that doesnt get hit by rain) → dry leeward side​ Vegetation: ​ Warms via absorption​ ​ Cools via transpiration​ ​ All effects can create microclimates​ 7. Biomes Biomes = Large regions defined by climate (temperature + precipitation) weather patterns ​ Climograph: Graph plotting average temp vs. precipitation (gives us averages) so helps us get an idea but is not exact ​ California Biomes:​ ○​ Diverse due to elevation (Mt. Whitney to Death Valley)​ ○​ Deserts, wetlands, forests​ ○​ High biodiversity and endemic species ○​ Grassland ○​ Desert ○​ Conifer ○​ Chaparral ○​ Oak woodland ○​ Ag. Land ○​ Wetlands ○​ Juniper ○​ Urban ○​ Other ​ Have more diversity and specilized species in any other states, this makes it a perfect area for a global hotspot for biodiversity 8. Major Terrestrial Biomes Desert: California ​ Dry (latitude/rain shadow) very little rain​ ​ Temp extremes can be really hot but can also be very very cold ​ ​ Plants/animals adapted for water conservation​ ​ Human impact: irrigation, urban growth (building homes)​ Chaparral (Medeteranian): California ​ Coastal midlatitudes​ ​ Fire/drought adapted shrubs (shrubland)​ ​ Seasonal rain (wet cool winters, hot dry summers)​ ​ Urbanization/agriculture reduce habitat (building of homes due to coastal location) ​ Between oceans and deserts Temperate Grassland: California ​ Grass + forbs; drought/fire adapted​ ​ Seasonal precipitation (so will not support tree life)​ ​ Heavily converted to farms/grazing ​ Wet summers and dry winters ​ Most grass land are best at supporting livestock like cattle due to the production of grasses (large herbivors) fertlize the grass and help grass grow faster ​ Northern Coniferous Forest (Taiga): california ​ Largest biome spans from northern north america and eurasia ​ ​ Cold-adapted trees​ ​ Coastal coniferous areas = temperate rainforest​ ​ Logging threatens old-growth leading to extinction ​ Lots of percipications apx. 9.8ft ​ Seasonal drought in the winter due to the frozen water Tropical Rainforest: Not california ​ Near equator (tropix) making it warmer and more access to sunlight ​ ​ Constant sunlight, long days​ ​ Highest productivity and diversity​ ​ Layered canopy ​ Vertical distributio of vegetation and animals  ​ This is the most productive and diverse terrestrial ecosystem on earth) ​ We will see animals living in the trees such as monkeys Savanna: Not california ​ Grassland with scattered trees or patchy ​ ​ Warm, less rain than tropics (gets enough rainfall to support life)​ ​ Grazers + fire-adapted species​ ​ Migration of herds is very common ​ Lots of herbivore and carnivores present in this area Temperate Deciduous Forest: Not california ​ Broadleaf trees (deciduous)​ ​ 30–60 in rain/year​ ​ Cold winters → leaf loss​ ​ Rich soil; active decomposers​ ​ Forest predators: bears, bobcats ​ Tons of decomposers and small animals thrive in leaf litter ​ Predators such as bobcats, foxes, black bears, and moutain lions​ Tundra: Not california ​ Arctic; frozing dessert​ ​ 100°F​ ​ Heat waves increasing in severity & frequency​ 🐾 Ecological Impacts ​ 10,000+ species currently affected​ ​ Range shifts (Chen et al. 2011):​ ○​ 11 m/decade upward​ ○​ 16 km/decade poleward​ ​ Phenology shifts (seasonal life events):​ ○​ Birds breed 1.4 days earlier/decade​ ○​ House finches: 4.5 days earlier per +1°C​ ​ Food chain disruption: ex. Arctic krill → whales/penguins/starvation​ ​ Invasive species impact increases:​ ○​ e.g., Mosquito-borne avian malaria now harming Hawaiian birds​ 🔹 Learning Objective 4: Examples of actions & future solutions 🛠️ Current & Historical Actions ​ Kyoto Protocol (1997): voluntary emission reduction targets​ ​ Paris Agreement (2015):​ ○​ 195 nations agreed to:​ ​ Keep warming < 2°C​ ​ Reach net-zero or negative emissions​ ​ Revise plans every 5 years​ ​ Provide $100 billion/year for low-carbon development​ ​ U.S. Actions:​ ○​ Left agreement in 2017 (Trump), rejoined in 2021 (Biden)​ ○​ Inflation Reduction Act (2022):​ ​ Largest U.S. climate bill​ ​ Goal: cut emissions by 33% by 2030​ 🔧 Wedge Analysis (Stabilization Strategy) We must cut 7 gigatons of carbon in 50 years. Solutions: ​ Vehicle efficiency + less driving = 1.5 Gt​ ​ Building insulation + energy efficiency = 2 Gt​ ​ Carbon capture/storage = 1 Gt​ ​ Requires global cooperation and policy change​ 🔹 Learning Objective 5: Key terms defined  ​ Planetary boundaries – Limits Earth can safely operate within​ ​ Ice cores – Cylindrical samples of ice used to measure ancient atmosphere​ ​ Keeling Curve – Graph showing real-time CO₂ rise over time​ ​ Greenhouse Effect – Natural trapping of heat in Earth’s atmosphere​ ​ Kyoto Protocol – First major international climate agreement (1997)​ ​ Paris Climate Agreement – 2015 pact to limit global warming