BIOL 150 - Gerry's Section - Ecology Notes - Nov 2024 PDF

BIOL 150 - gerry’s section Lecture 1 November 1st, 2024 Ecology - Scientific quantitative study of organisms and their environment Environmental factors ○ Abiotic - non living (sun, and, air) ○ Biotic - living organisms (prey, predators) Tiered levels ○ organism/indiv...

BIOL 150 - gerry’s section Lecture 1 November 1st, 2024 Ecology - Scientific quantitative study of organisms and their environment Environmental factors ○ Abiotic - non living (sun, and, air) ○ Biotic - living organisms (prey, predators) Tiered levels ○ organism/individual - how one kind of organism meets challenges/opportunities of its environment physiology/behavior ○ Population - all of same species in an area, factors that affect population size Availability of nutrients, dispersal ○ Community - all populations living close enough together to interact All biotic factors in this environment ○ Ecosystem - all biotic and abiotic factors in environment Lecture 2 November 5th, 2024 Abiotic factors - physical and chemical factors influence life ○ Energy source terrestrial and aquatic ecosystems: solar energy (Sun, plants, grazers, carnivores- nearly all life on earth) Dark environments: chemical energy (deep ocean vents, bacteria, grazers, very rare, recently discovered) ○ Temperature - narrow range: 0°C-45°C Narrow due to physics (ice crystal formation and protein denaturing)  ○ Water - terrestrial organisms must avoid drying out Aquatic organisms must balance solute concentration (hypotonic - freshwater vs hypertonic - saltwater osmosis) ○ Nutrients - availability of inorganic nutrients (nitrogen and phosphorus) ○ Other aquatic factors - amount of dissolved 02 (temp dependant), tides, salinity, currents ○ Other terrestrial factors - temp extremes, wind, fire, ice ○ Climate - Solar radiation varies w latitude and seasons Global air circulation and precipitation patterns Impacts of oceans on local climates Impact of landforms on local climate - mountains affect precipitation in southern BC Biotic factors - ○ Why are some species in a particular place - species evoled from ancestors in that location, species have dispersed to that location and survived ○ Organisms adapt to abiotic and biotic factors by natural selection  ○ Organisms need to survive and reproduce - biotic factors Positive biotic factors - eg plants need pollinators Negative biotic factors - eg. predation ○ Measuring - eg. removing an organism from an environment to see the impact Ecology methods - how study ○ Field research - going out in the wild, collecting data ○ Lab experiments - looking at individual variables in the lab, manipulating structures, grow organisms ○ Modeling (computerized, calculated, stimulated) Why ecology important ○ Biodiversity loss ○ Changing climate ○ Decline in species - extinction ○ Highlighting where losses are taking place ○ Outbreaks of invasive species, pests, pathogens, predators Eg. mountain pine beetle killing trees, dead trees increase wildfires. Eg. swiss needle cast affecting douglas fir, cant do gas exchange and photosynthesis Summary ○ Def of ecology - interaction of natural organisms w environments ○ 4 primary organizational levels - organism, population, communitie, ecosystem ○ Dif between biotic and abiotic ○ Models for scientific study ○ How ecology is changing Examples Aquatic biomes ○ Water is the common element ○ Less impact of gravity, ○ ice forms on surface, ○ water has high specific heat (thermally stable), ○ migration and dispersal can be passive and over long distances, ○ generally lower availability of nutrients than terrestrial systems, ○ 02 concentrations are inversely proportional to temp - Temp - too hot = protein denaturation, too cold = ice crystals Lecture 3 November 6th, 2024  Biomes - large collection of ecosystems occupying a major habitat type ○ Not necessarily contiguous/connected ○ Dividing world into few ecological zones is complicated by small-scale variations and gradual changeover areas between biomes ○ Characterization is arge-scae and make according to average conditions, not all parts of system have same conditions Aquatic biomes - freshwater ○ Lakes and ponds - seasonal mixing - redistributes o2 and nutrients ○ Rivers and streams - near source: colder, clear, lower in nutrient, Downstream: warmer, slower, more sediment Aquatic biomes - transitional areas ○ Estuary - transition/interface between freshwater and ocean Saltiness varies Enriched by allochthonous terrestrial nutrients, some of the most productive biomes on earth ○ Wetlands - transitions between aquatic -usually freshwater - and terrestrial Typically rich in biodiversity - microorganisms, dif species Improve water quality by removing contaminants Aquatic biomes - saltwater Depth becomes important Photic zone - sun is available for penetration, closest to surface Mesophotic - slight light can penetrate Aphotic - no light can penetrate, deepest zone Lots of diversity underwater, can be different species living in very close proximity (eg. Howe Sound coldwater marine corals) 90% of living space on Earth is in deep ocean - dark, cold, pressurized, home to diverse and adapted organisms Abiotic factors Depth/light  ○ Ocean - big, cold, deep, salty, wet, moving ○ Covers about 71% of earths surface ○ One interconnected global water mass ○ 99% of cubic area that can be inhabited by life ○ Traditionally divided into 4 distinct regions - pacific, atlantic, indian, arctic ○ More surface area in pacific than all the land area of earth combined ○ Ocean deep - depth structure plays larger role for oceans - compared to terrestrial systems Light is biggest factor in creating structure, but temp and pressure are significant Light is limited by attenuation - over 90% of light is lost even in clear marine by 50m by physical scattering and absorption by water Reflection and absorption, only blue can get deeper which is why the ocean reflects blue ○ Deep sea creatures are often red - nearly invisible, below 200M depth = almost no sunlight, temp stead 3-5 degC, pressure at 2000m = 200x atmospheric pressure at sea level Organisms form and adapt to these environments (eg. angler fish, red colouring, light) Human impacts - plastic littering, overfishing, gas and oil spills, melting ice ○ Changes to aquatic biomes, more water less ice, chemicals in water Salinity - avg salinity of ocean is 35 SSU (standard salinity units) = 3.5% ○ Marine creatures have devised ways of getting rid of salt to maintain osmoregulation Marine birds drip hypersaline water from beaks Fat and carb metabolism release fresh water, one way that orcas hydrate (one reason almost all marine mammals are carnivorous) Movement - surface currents are generally driven by winds (themselves the product of differential warming of the atmosphere and local geographic conditions) or tides ○ Deep ocean circulation driven by thermohaline circulation Term comes from temperature and salt ○ Variables determine density - determines masses of waters sink or rise - drives large scale currents Dif than air - more thermally stable ○ O2 inversely proportiuonal to temp ○ Nutrient levels lower, more dispersed ○ All affects density and disribution of life, especially primary productivity ○ Roughly half of global carbon fixation is marine Biotic factors  Gas exchange ○ Passive or external osmosis and diffusion play larger role for biology-lungs v. gills ○ Osmosis - solution enters a semi-permeable membrane and only allows water through ○ Diffusion - high concentration of molecules disperse in the air and become lower concentration ○ Gills almost aways used for aquatic respiration while lungs used for aerial respiration ○ Gills evanginations of body on surface, lungs invaginations of body on surface ○ Affect not just gas exchange - important for waste removal ○ Role of waste removal (and physiologic structures) tailored for osmotic need ○ Freshwater fish pee a lot to keep salt levels high, salt water fish dont to conserve fresh water Buoyancy of water allows for much larger body sizes ○ Hydrodynamics for movement is important due to drag of water ○ Migration and dispersal play bigger role in aquatic environments Can happen at dif stages of life and dif sizes Eg. humpback whales spend summers in high latitudes feeding and winters in low latitudes where water is warmer and more conductive to birthing and breeding Lecture 4 (online) - Terrestrial Biomes November 15th, 2024 Biome - large collection of ecosystems occupying a major habitat type (not necessarily contiguous) ○ Dividing world into a few ecological zones is complicated by small-scale variations and the gradual changeover areas between biomes ○ Characterization is therefore large-scale, and made according to the average conditions, and not all parts of a system have the same conditions Terrestrial biomes - foundation of terrestrial biome definitions are plants ○ Distribution depends on temp and rainfall (grass vs tree vs shrug growing in a space) Climate varies by incidence of solar energy (eg temp)  ○ Dictates what can grow - trees dont do well in freezing environments, what grows in ice dif from what grows in tropics Climate varies by availability of water (eg water cycle) ○ Water cycle characteristics and issues Precipitation is variable in magnitude - over ocean evaporation exceeds precipitation, movement of water as clouds across land, terrestrial precipitation exceeds evaporation and transpiration Chemicals can run off into ocean - DDT in marine mammals in arctic (far from source) Human activity can affect cycle - dams, surfacing, recycling, agriculture, temp Spatial distribution of terrestrial biomes is function of Precipitation & Temperature Major terrestrial biome types: Polar ice ○ extremely cold year round, very low precipitation ○ few plants (mosses, lichens) and animals ○ linked to marine biomes (seals penguins polar bears) Tundra ○ long summers, cold winters, little precipitation ○ no trees (local permafrost - frozen subsoil, upper part thaws in summer - rolls cant grow deeply in soil) ○ low precipitation and poor drainage leads to arid and saturated conditions ○ Animals: large migratory herbivores (musk oxen, caribous), non migratory rodents, predators Coniferous (boreal/northern) forests ○ Largest terrestrial biome in world ○ Long cold winters, short wet summers ○ High precipitation in form of snow ○ Dominated by cone bearing evergreen trees - spruce, pine, fir, hemlock (adapted to lower nutrients and temp. Needles minimize seasonal water loss - better at gas exchange, shed snow load w triangular shape) ○ Temperate rainforest variant (subtype of coniferous) - warmer climate, moist air from oceans Human impact through removal of trees Temperate broadleaf forest (eg. maples, poplars, elms) - shed leaves (deciduous) ○ Cold winters, warm summers ○ Relatively high precipitation ○ Drop leaves to save energy and preserve water (preparing for winter)  ○ Differences - more diverse and more deciduous than boreal forests, more open, not as tall, not as diverse as tropical forests ○ Some of worlds most amenable human habitation locations Major souce of industrial, food, and building products ○ Human impact - almost everything been logged at lease once for agricultural use and urban development Temperate grassland ○ Warm summers, relatively cold winters ○ Low precipitation, periodic droughts ○ Fires ○ No trees - not enough water to support forests (droughts), grazing by large mammals, rich soil - intense farming ○ Human impact - mostly agriculture, w attendant loss of bison, ferrets, wolves Little remains unaltered - one of most endangered ecosystems Material can easily spark due to lots of fires Deserts ○ Extremely low precipitation - less than enough to grow than most plants ○ Temp can be variable ○ Antarctica and sahara are both deserts ○ Human impacts - desertification (conversion of semiarid regions into desers) and settlement together, making soil less hospitable to organisms that are already there Tropical forests ○ Equatorial regions ○ Warm year-round ○ Very humid ○ Tropical dry forests - pronounced dry seasons ○ Poor soils of tropical rain forests Minor terrestrial biomes chaparral/mediterranean ○ Subarid shrubland ○ More seasonal rain than a desert, less seasonal rain than deciduous forest ○ Notably seasonal and hot dry summers ○ More woody growth than grassland but still shrub and limited tree growth ○ Mediterranean climate with infrequent high intensity crown fire ○ Fires less frequent than grasslands ○ Can shift landscape to grasses Savanna  ○ Subarid forestland ○ More seasonal rain than desert ○ Hot dry summer ○ More tall tree growth than mediterranean ○ Characterized by tress being widely spaced so that canopy does not close - more light, air can get through and move High mountain ○ Substitute altitude for latitude ○ Can bary in vegetation type but generally leaning moving toward colder and drier ○ Occupy small areas and can have plants and animals typically divided into small or linear areas ○ Small ranges isolated from other conspecific populations ○ Lecture 5 November 19th, 2024 Behavioural ecology What is behaviour? - An animals response to internal or external environmental cues ○ Carried out by muscles, glands, and neurological systems - measurable change in activity in response to an internal or external cues ○ Not digetions, or involuntary muscle contraction of heart, but change in beating of heart in response to stimuli What is behavioural ecology? ○ Study of behavioural interactions between individuals between pops, communities, ecosystems, individual situations Innate behaviours - under genetic control, performed in same way by all individuals of a species, improves with experience ○ Behavioural sequences -fixed action patterns - unchangeable series of actions triggered by a stimulus - sequence performed in its entirety Demonstrated by yawning - initiation of the action is by innate response to stimulus Once begun, action cant be stopped, yawning is not simply about response to oxygen levels, as fetuses yawn in womb Seen in many species, including humans ○ Some innate characteristics are result of genes and environment  Abiotic environment responsible for expression of offspring sex in sea turtles Sex determination depends on temp Phenotype - result of genes and environment ○ Phenotype - observable physical properties of an organism (eg. development, behaviour) Behaviour - result of both genes and environment ○ Environment can also be responsivle for behavioural response ○ How would you test if this behavior is determined by genes or environment Cross-fostering experiment ○ Nature vs nurture - also oversimplified - all terms involve complex interactions Nature - both genetics and abiotic factors, nurture - both experiences of parents and individuals, how genes affect individual actions? Learning - modification of behaviour as a result of specific experiences ○ Habituation - decline in response to repeated stimulus, simplest form of learning, focus on important stimuli Eg. anemone withdraws when touched, after repetition no longer withdraws ○ Imprinting - learning limited to specific sensitive time period Generally irreversible, can imprint on non-parent targets, can affect conservation programs Eg. wild robot - duckling imprints that the robot is its mom ○ Spacial learning - animal movement Kinesis - random movement in response to stimuli (eg. ants scattering when picking up a rock) Taxis - movement toward/away stimulus, positive or negative (eg. moths attracted to light) Spacial learning (mazes) - animals establish landmarks in surroundings (eg. location of home, food, hazards) ○ Associative learning - associate stimulus/behaviour w a response Classical conditioning - arbitrary stimulus becomes associated with outcome - pavlovs dog ○ Social learning - learning by observing and imitating the behaviors of others ○ Cognition and problem solving cognition- perceive, store, integrate and use info gathered by sense, capable of categorizing objects as same and dif  Problem solving - applying past experiences to overcome obstacles in new situations Behaviours ○ Foraging - searching, recognizing, capturing, and eating food Generalists - eat anything that is available (eg. crows will eat whatever) Specialists - only eat some specific things (eg. koalas only eating certain components of eucalyptus, eg. birds adapted beaks for specific foods) Optimal foraging theory - finding balance between energy intake and expenditure (wagtails eating 7mm dung flies) Communication - individuals communicate via signals (agonistic, communal or reinforcing) Signal - stimulus transmitted by one animal to another Communication - sending, reception of, and response to signal Eg. black bears posture to establish a hierarchy & usually the larger is dominant - agonistic/confrontational but not harmful or fatal Eg. wolves harmonize rather than on same note - creates illusion of more wolves, use harmonic overtones to signal stage of a kill (2 note vibrations for pursuit in progress, single tone when prey is down), developed olfactory communication with sweat glands in feet and toes (scratch ground to leave signal) Eg. elephants have complex systems of communications (make use of all senses - hearing, smell, vision, touch), use infrasound/wavelengths below human hearing, compilation starts w scents but after mating female rubles out post copulatory sequence - lay trunks on ground to detect vibrations Courtship rituals - conspecifics are competitors, must confirm individual is same species, opposite sex and prime for mating ○ Eg. octopus males fight off competition for females Needs of young drive need for mating Lecture 6 November 20th, 2024 review - 4 key life processes: foraging, fighting, communication, mating Behaviour: social organization Social behaviour - any interaction between 2+ individuals of same species  ○ Eg. cooperative hunting or foraging, communal care of young, aggression for dominance, reproductive selection Living in groups - mutual protection, reduced workload, increased efficiency Sociobiology - observing social behavior, asking why it has evolved through natural selection Territories - used for feeding, mating, rearing young ○ Size depends on needs of animals (eg. cheetahs - big territory, walruses - just a few rocks) ○ Territorial rights must be continuously proclaimed ○ Territorial behaviors avoid confrontation Fighting ○ agonistic behaviour: conflict over limited resources Settles by threats, rituals, tests of strength Rarely fatal; often one side submits or surrenders Dominance hierarchies - social animals often have ranking of individuals ○ Established by agonistic behaviour, usually non-fatal ○ May help optimize scarce resources for a group ○ Eg. dominant hen posturing vs other hen bowing down Social organization and chimpanzees ○ Chimps have: tool use, social structures, varied diet, long association of children with parents Population ecology Population - group of individuals of same species in same area ○ Rely on same resources, influenced by same environment, likely to interact and breed with one another Population ecology - study of how & why populations change ○ Identify abiotic and biotic factors that affect and regulate populations ○ Direct application in trying to conserve species Population dynamics - 4 key factors of population size varying ○ # of Births ○ # of deaths ○ Immigration (moving to a population) ○ Emigration (leaving a population) Population density & dispersion ○ Density - # of individuals of species per unit area ○ Dispersion - how are individuals spaced within area Clumped dispersion - clusters of organisms of individuals living together (eg. sea stars - response to feeding and reproduction)  Uniform dispersion - individuals uniformly spaced (eg. penguins - dont want ppl in close proximity, fear of predation) Random dispersion - individuals randomly scattered in population (eg. dandelion - random bc of the wind pollination) Life tables and survivorship curves ○ Life tables - track survivorship - change of individual living to various ages Use to extrapolate to see where a population might go Useful for life insurance purposes ○ Survivorship curves Type 1: most survive to old age (produce few offspring, but give good care) - eg. humans Type 2: intermediate, survivorship constant Type 3: low survivorship for very young (very large number of offspring but little to no care) ○ Useful to use percent allows us to compare across populations that are significantly dif - eg. squirrel vs oyster vs humans Models predict patterns of population growth ○ Exponential growth model - G = rN ○ G = growth (# of individuals added per time interval) ○ R = per capita rate of increase (avg contribution of individual to growth) ○ N = population size Patterns of pop growth - rabbits in australia ○ Australia used large-scale, wholesale controls ○ Hunting, trapping, and poisoning used as direct controls ○ Diseases were later introduced to control populations - myxomatosis in 1968, rabbit hemorrhagic disease virus in 1995 - decimated rabbit populations ○ Logistic growth model: G=rN x (K-N)/K Limiting factors - (K-N)/K K = carrying capacity Limiting factors - limit population growth ○ Density dependant factors - often biotic factors (food, territory, mates) ○ Density independent factors - often abiotic factors (seasons, weather, fire) ○ Regulation in practice is usually by mixture of factors ○ Exponential growth - increasing rate of growth over time ○ Logistic growth - recognizes  ○ carrying capacity - max level of individuals in a pop the it can withstand ○ Limiting factors - cause reduction of population Boom-and-bust cycles - some animal pops show fluctuations w high regularity ○ Boom - rapid exponential growth - good weather, food, few predators, conditions are favourable ○ Bust - population crashes - food shortages, more predators Application of population ecology - atlantic cod ○ Sustainable resource management was the goal, not achieved ○ In pop ecology, max sustainable yield is larget yield that can be taken from species stick over indefinite period ○ Following models causes pops to crash over 40 yrs of industrial fishing, after it had sustained crutches for 400 previously ○ Reverse of exponential growth, also from small constant rate of change Lecture 7 - community ecology November 22nd, 2024 Human population - still increasing, but growth rate has slowed down Current pop: 8,189,061,644 Overpopulation = overconsumption Community ecology Communities: all populations living close enough to interact ○ Boundaries: depends on scale/perspective - can be as smal as one organism system (eg. microbial community in digestive tract), or large as thousands of kms sq Community ecology: study of the organization and functioning of interacting populations (eg within area of shared habitat) ○ Measures biodiversity, population sizes, distribution, movements of multiple populations and interspecific interactions that take place Community diversity metrics ○ Biodiversity (species diversity) Depends on both species richness and relative abundance (defined as % of each species in area) ○ Species richness Depends on # of species only (integer) Eg. 4 dif species on each woodlots - N of 4 ○ Relative abundance Eg. each woodlot has 20 trees - woodlot A has 80% species A, 10% species B, 5% species C, 5% species D - woodlot B has A-  25%, B- 25%, C- 25%, D- 25% (uniform distribution, therefore more diverse) ○ Number of descriptive indices ○ Commonly integrate species evenness and abundance measurement and are calculated from mean proportional species abundance in the dataset of interest ○ Complex, numerical, calculated, multispecies, weighted for relative abundance Interspecific interactions - relationships w individuals of other species in community, differing levels of impact on eachother, 3 common types ○ Ecological niche - sum of an organism's use of both biotic and abiotic resources 1. Competition (negative negative)- niches of two populations overlap & a resource needed by both populations is in short supply (light, food, nesting supplies, water, habitat) - results in competition, lowers carrying capacity for both Testing if niche is affected by competition competition lowers carrying capacity OR one species outcompetes another and eliminates it 2. Predation - (negative positive) very negative impact on reproductive success of prey Evolution of numerous adaptations for predator avoidance - Camouflage, chemical defense (eg warning colours), mechanical defense (eg. porcupine spines) Species ecology linked through predation (eg. salmon and orcas) Herbivory - mechanical defenses (eg. thorns and spines), chemical defenses (toxins/unpalatable compounds) Heliconius caterpillar and butterflies adapted to break down the toxins and eat the plant Symbiotic relationships - longterm association of 2 dif species ○ Can be direct (physically interacting) or indirect (one species benefits from/harm another w/o physical contact) ○ Mutualism (++) - both partners benefit Eg. plants and mycorrhizae - project rhizoids into soil to provide additional nutrients to plants, plants give additional sugars to fungus Eg. coral symbionts - photosynthetic microorganisms live with tissue of corals - provide synthate in exchange for security and nutrients, enables corals to build the largest biogenetic structures on earth  ○ Parasitism (+-) - one benefits, one harmed Eg. parasitic isopod and grouper - becomes tongue, steals nutrients ○ Commensalism (+ 0)- one benefits, one unaffected Eg. sea anemone and anemonefish (evolved to not be impacted by stinging from anemone) - avoid predation, get anemone nutrients, anemone is chillin Eg. cleaner fish and eel ○ Altruism (kin selection)(-+) - one partner harmed to benefit other of same species Eg. ground squirrels ○ Mimicry - no direct interaction, benefit from appearing like other species mullerian mimicry - 2+ well-defended species, often foul-tasting and that share common predators mimic eachothers warning signals (eg. monarch and viceroy butterfly) Batesian mimicry - harmless species evolved to imitate warning signals of harmful species directed at a predator of them both (eg. eastern coral and scarlet king snake) ○ Role of human microbiome is currently being better understood as essential to maintaining health of many human systems eg. digestion, skin, reproduction Microbiome connected to alzheimers, schizophrenia, cancer, cardiovascular disease Lecture 8 November 26th, 2024 Flow - trophic levels and food webs ○ Energy flow starts w the sun ○ 10^19 kcal d^-1 of energy in a single day = 100 million atomic bombs ○ Plants use inorganic molecules & sunlight to produce organic materials - provides energy for chemical cycling ○ Primary production - solar energy converted to chemical energy Eg. tropical rain forests and alga beds/reefs use most solar and producing the most chemical energy Trophic levels 1. Primary producers begin food chains (autotrophs) 2. Primary consumers: producers consumed by herbavores 3. Secondary consumers: secondary consumers consume primary 4. Tertiary consumers: consume secondary 5. Quaternary consumers: consume tertiary  ○ Each level, more and more energy lost (some material indigestible, some used for cell respiration) ○ Only 5-20% of available energy transferred form one tropic level to another ○ Use 10% as rule of thumb ○ If trophic level 4 is rare, trophic level 5 animal may need to find alternate food source to survive (eg. consume trophic level 4 or 3) Food webs - more realistic than chain, consumers may eat more than one type of producers & several species of primary consumers may feed on same species of producer ○ Interactions and relationships between foods ○ Not just size based - intermediate size & trophic levels can be skipped (eg. blue whales - use baleen, feeds on trophic level 2 organism) Very efficient strategy, physically smaller resource, more effectively harvested Resulted in largest animal to live Eg. Praying mantis can hunt hummingbirds and snakes Keystone species: has a disproportionately large effect on natural environment relative to abundance ○ Usually predators, ecosystem engineers, or mutualists ○ Introduced by robert T Paine ○ Occupy niche that helps hold rest of community in place ○ Eg. Lots of species interacting in a diverse and rich zone - Pisaster sea stars very present, but not one species was dominant - remove pisaster = crash in # of species ○ Term comes from stone arches ○ eg. sea otters -c consumer of sea urchins Foundation species - have a strong role in structuring a community, can be at any tropic level, but must have a large contribution towards creating and maintaining habitats or resources that support other species ○ Dr paul dayton - understanding how a community reacts to disturbances eg pollution instead of attempting to tradck all members in food web ○ High abundance ○ Communities are constantly changing in response to disturbances ○ Ecological succession Primary succession: life begins to form in area previously lifeless area, eg. lava flow Secondary succession: disturbance destroyed existing area/community, new species move into space  Eg. forest fire destroys shrubbery, larger trees rapidly move into area ○ Low disturbance - old communities dominated by few species, low amt of biodiversity ○ Medium disturbance - enough for species from multiple successional stages, increase in diversity ○ High disturbance - keeps knocking community down, causes low diversity Community disturbance and recovery/adaptation ○ Non-native species - species outside normal range (usually introduced) ○ Invasive species: non-native species that negatively impacts new environment ○ 20% of plants in Canada are introduced, but only 40% of those are invasive ○ Eg. purple loosestrife brough to canada in 19th century - each plant can produce 2.5Mil seeds/yr, outcompeted any other species and negatively impacted environment Rootboring weevil was introduced to control purple loosestrife, but can also damage conifers Lecture 9 November 27th, 2024 Carbon and Nitrogen cycles: Carbon cycles - take away: CHEMICALS ARE RECYCLED, ENERGY IS NOT ○ Carbon (Co2): big reservoir in atmosphere 1. Photosynthesis moves CO2 from atmosphere to organic molecules 2. Organic molecules passed along food chain and cell respiration and decomposition returns CO2 into atmosphere 3. Increased burning of wood and fossil fuels is raising level of CO2 in atmosphere - global warming Nitrogen cycle - recycled ○ Nitrogen (N2) - big reservoir in atmosphere 1. Fixed by biota (microorganisms in soil that can engage in nitrogen fixing) in soil 2. Production of fixed nitrogen, as NH4 (ammonium) has been increased by human processes  3. Increased amounts of biologically available nitrogen are being produced by inductiral haber-Bosch process to produce ammonia (NH3), changing the biota of the earth ○ Fritz Haber - german chemist - inventor of the process for fixing nitrogen from the atmosphere, iron catalyst and heat Winner of the nobel prize for chemistry in 1918 for work on ammonia synthesis Human impact ○ Eutrophication - result of haber bosch process - input of excessive nutrients, especially to water ○ Excessive fertilizer applied agriculturally Conservation Biology; Conservation biology: study of the conservation of Earth’s biodiversity ○ Aim of protecting species and their habitats ○ Developing science-based workable methods for preserving species and biological communities, establishing these as a policy for environmental management Human activities ○ Kill plants and animals (species ecology) ○ Made species live in competition (population ecology) ○ Polluted lands and waters (community ecology) ○ Changed global conditions (ecosystem ecology) **Led to fastest rate of species loss in history or planet 3 levels of biodiversity ○ Genetic diversity: genetic variation within population (eg. genetic diversity in a vole population) ○ Species diversity (eg. species diversity in a coastal redwood forest) Extirpation (local level of species loss) Extinction (global level of species loss) Functional redundancy (if you lose one species, community can generally still survive) can make up for losses for limited periods of time ○ Ecosystem diversity: networks both within and among systems are being reduced (eg. community and ecosystem diversity across the landscape in the entire region) Endangered and threatened species ○ Endangered species: in danger of extinction throughout all of its range ○ Threatened species: likely to become endangered in forseeable future 5 major threats to biodiversity 1. Overexploitation ○ Atlantic cod pops in maritimes crashed after 400 yrs of exploitation ○ Norther cod pops now about 1% of historical levels ○ Cod fishing moratorium of 1992 was canadas largest playoff in history - affected over 30000 ppl in Newfoundland and labrador 2. Introduced species ○ Over 50000 introduced species in North America ○ Brown tree snake - causing bird extirpations and endemic extinctions on guam ○ Contribute to 40% of extinction ○ Invasive species problems Disrupt communities: compete w, prey on, parasitizing native species Lack of interspecific interaction: new species becomes invasive (no predators, lack of competition) Native species lack defense mechanisms: dont recognize danger Eg. when brown tree snake was introduced, 12 native bird species went extinct 3. Pollution ○ Many forms: Nutrients, Physical debris, Petrochemical, Persistent organics (eg. PCBs) ○ Nutrients, largely form agricultural application, flown into both freshwater and saltwater (eutrophication) ○ Expanded supply is form artificial fixation of atmospheric nitrogen (haber bosch process) ○ Polychorinated biphenyls (PCBs) used as coolant and cleaning fluids in electronics All synthetic, with strong stable insulating properties PCBs banned by US congress and by UN ○ Persistent organic compounds (eg PCBs) can be very toxic when concepntrated ○ Concentrated in animals through biological magnification ○ Impacts can be anatomically, taxonomically, and ontogenetically specific 4. Habitat loss ○ 5. Global change/warming ○ Largest increase in northernmost regions of northern hemisphere ○ 2000 year record indicates atmosphere CO2 levels well beyond preindustrial values of 280 parts per millium  ○ Melting glacier ○ Keeling curve - best contemporaneous record of global CO2 concentrations in the world, with ice cored extending the record back nearly 1M YBP Current concentration of CO2 in environment is 420 ppm Lecture 10 November 29th, 2024 Human activities have altered ○ Trophic structure ○ Energy flow ○ Chemical cycling Caused fast rate of species loss Why do we care about loss of biodiversity ○ Biophilia (aesthetic) ○ Moral belief (ethical) ○ Material use (practical) - depend on other species for food, clothing, housing, oxygen, soil, fertility, etc. Solutions: organisms are adapting ○ Allow adaptation via phenotypic plasticity - ability to change phenotype in response to local environmental conditions Animals with high genetic variability and short life spans may avoid exctinction by evolutionary adaptations Animals with long life spans are unlikely to be saved protecting endangered populations ○ Maintenance of sufficient habitat to support minimum viable population size ○ Recognizing and providing key habitat requirements ○ Recognize keystone species ○ Breeding program and reintrodction ○ Eg. black-footed ferret - lack of prey (prarie dogs) ○ Eg. oregon spotted frog - lack of habitat, captive breeding program started small population approach ○ Minimum viable population - size at which species can sustain numbers and survive Process can culminate in extinction vortex ○ Eg. prairie chicken Populations fragmented  Greatly threatened by habitat loss Decline associated with decreased breeding success After translocation of 271 individuals, viability of eggs rapidly increased protection of ecosystems ○ Fragmentation and edges ○ Corridors that connect habitat fragments ○ Eg. animal bridge in Banff park, promotes dispersal and reducese inbreeding establishment of protected areas ○ Yellowstone to yukon conservasion initiative Connects parks w protected corridors that allow safe travel Eg. wolves can roam an area of more than 1000000kms2 ○ Legally protected nature reserves, parks, wilderness areas Focus on biodiversity hot spots Problems of approach: hot spot designation favours most noticeable organisms (plants and vertebrates) and invertebrates and microorganisms are often overlooked, along w migratory species Restoration ecology ○ Actively assisting the recovery of an ecosystem that has been damaged/destroyed ○ Restore ecosystem functions using ecology ○ Control invasives by removal ○ Replace or connect lost/fragmented habitat ○ Reintroduce native species that have been extirpated Time ○ Impacts are here already ○ Eg. abbotsford flooding in 2021 - flooding in fraser valley, total economic loss in BC: $9B ○ Sparks lake fire in 2021, in kamloops, burned 900 sq km Lecture 4 December 3rd, 2024 British columbia salmon 1. Biodiversity - complex community of 5 related fish species 2. Habitat and lifecycle - moves from salt to freshwater for reproduction (eg. anadromous)  3. Ecology - have ecological connections to many other species, including terrestrial and introduced species 4. Conservation - central to human cultures in this area, but experiencing historic declines Diversity (sea bright condition) ○ Chinook, chum, pink, sockeye, coho salmon ○ Look very similar, silvery grey colour, small end fins, same size Diversity (spawning condition) ○ Reddening of some salmon, striping of others ○ Snout shows up in different species Types of salmon Chinook salmon - largest species of pacific salmon ○ Regular size: 0.9m and 15kg, up to 1.5m and 30kg ○ Commonly called spring salmon, w other names like king salmon, tsumen, blackmouth, tyee salmon ○ Important sport species, also key oceanic prey for big marine mammals (including stellar sea lion and orcas)’ Coho salmon - second smallest, around 8 to 15kg and 24-36” ○ 3-4 year lifespan - ocean phase only 18 months to 2.5 yrs bc they spend a year in freshwater (unlike other salmon) ○ Piscivorous - eat all fish, including other salmon juveniles, especially pink and chum ○ Important sport species bc high fat and delicious, take lures well, feisty on the line ○ Main threat is impact of temperature Chum salmon - tiger stripes and canine teeth that develop during spawning season, medium sized, avg 3.5kg ○ Typically last salmon species to return to streams and rivers, spawning late october to march ○ Life Cycle usually 4 yrs - can be 3-6, juveniles leave stream quick in early spring ○ One of most abundant species - wide range from oregon to japan ○ Very sensitive to habitat loss bc spawn closer to ocean ○ Used to be preferred for canning, major economic source on west coast ○ Aka ‘dog salmon’ Sockeye salmon ○ Only planktivorous salmon (zooplankton) ○ red colour and preferred species for canning due to colouration ○ Spawn in summer/early fall in large freshwater lakes  ○ Some subspecies spend considerable (or all) time in freshwater ○ Declines in pop. - avg return in fraser was 9.6 mil, now less than 1mil ○ Conservation status - endangered - fraser (8 units 2017), threatened - fraser (4 units 2017), special concern - fraser (5 units 2017), not at risk - fraser (9 units 2017) Pink salmon - smallest species, most common by population, w large #s from wide and hatchery production ○ Large industrial commercial catch, by large boast and most goes for industrial processing ○ Develop a large distinctive hum when entering freshwater, meat becomes soft from development for spawning Life cycle ○ Anadromy - form of diadromy (life cycle w two aquatic habitats) - fish born in freshwater, matures in ocean, returns to freshwater to spawn Seen in lamprey, sturgeon, salmon ○ Time moving into ocean: smolt Habitats ○ Saltwater Asia, alaska, bc, washington, oregon, california oceans ○ Freshwater Up to 85% of accessible small stream tributary habitat for Fraser River coho salmon has been cut off or channelized by urban terrestrial development Almost all BC habitat for coho has also been affected by logging, even in remote areas Stream restoration is underway in some locations - slow process ○ Restorative efforts (freshwater) Large wood debris being added back to streams, waterflow slowed, water retention enhanced, gravel replaced Important but slow process in both developed and undeveloped areas Ecology and importance - terrestrial/nutrient conditions ○ Salmon die soon after reproduction ○ Return of spawning salmon bring huge influx in amount of nutrients and organic matter into streams Energy, material, calories  ○ Loss of subsidy w diminished salmond runs limit ecosystem productivity in juvenile salmon rearing habitat ○ Salmon also change physical properties of stream, increasing air-water gas exchange by nearly 10 fold during peak spawning ○ Foundational species for whole ecosystem - lots of them, foundational structure to community ○ Recent salmond community declines ○ Cultural recognition of integrated nature of connected aquatic and terrestrial species Threats ○ terrestrial thermal changes - rising water temp could cause high salmon death ○ Adult survival and returns - steady decline, struggle returning to freshwater from saltwater, reason still being researched ○ Introduced species - eg. atlantic salmon introduced to pacific coast - changes in water, competition, disease ○ Disease and paratisitism - eg. sea lice Infestations kill young salmon, directly related to exposure to salmon pens Increased in recent yrs in areas of salmon farms Recent federal actions - making changes, modifying what can be brought in ○ Freshwater toxins - roads collect contaminanys that wash into streams from rainfall Residue from brake pads and tired and fuel ○ Sport fishing - overfishing and represents cultural but in importance Diminishing returns but still major part of economy Salmon farming center for both grow out and processing Lecture 5 December 4th, 2024 Final exam ○ 70 mc - 50 of gerry’s material ○ Friday dec 20th - 7-9pm Study tips ○ Intended learning outcomes - can i answer them ○ Review questions ○ Practice test - kahoot ○ Focus on bolded, underlined, italicized, heavily emphasized aspects from classes (eg. salmon features, eg arctic poppies) ○ Chunk/space studying ○