Bio Notes 3 PDF

Ecology -Carl Linnaeus explained the economy of nature -Darwin believed ecology was determined by natural selection and adaptation. -Haeckel talked about the economy of nature and the struggle for existence. -Ellen Richards introduced ecology to the US. Biosphere- Any place where living organism...

Ecology -Carl Linnaeus explained the economy of nature -Darwin believed ecology was determined by natural selection and adaptation. -Haeckel talked about the economy of nature and the struggle for existence. -Ellen Richards introduced ecology to the US. Biosphere- Any place where living organisms are. Oceans, sky land. Includes atmosphere, ecosphere, hydrosphere, lithosphere Whittaker Diagram- This is a graph of temperature vs precipitation which makes clear the different biomes of places. There are different biomes for different models. Aquatic biomes, Land biomes In the ocean different biomes exist based on the depth of the water. Photic is top, aphotic is middle, abyssal is bottom. Gulf Streams: Densities cause movement of winds making the gulf streams. Hot water rises and cold sinks. It moves at around 2 m/s towards Europe. Starts west Africa then up the coasat of the East USA and then up to the north. Provides heat to Europe and northern US. -More biodiversity occurs in the tropics because competition forces organisms to specialize. Abundance occurs because of warm weather and more energy. Evolution occurs faster in the tropics as more species are born and they don’t go extinct as fast. Productivity hypothesis- More light, heat, and precipitation in the tropics with longer growing seasons. This causes greater productivity which promotes more specialization, lower extinction rates, higher population sizes. Stability hypothesis- Tropical climates are less variable and more stable which causes more specialization, lower extinction rates, higher speciation rates. The sun powers the biosphere and plants use the sunlight of visible light to power photosynthesis. Standing crop: the amount of dry producer biomass in the ecosystem at a given time. Gross primary production: Total amount of energy fixed by all autotrophs per unit area and time. Net Primary production: Remaining energy after autotrophs reach their own energy needs. Respiration: intake of oxygen and release of carbon dioxide NPP=GPP- Respiration Open ocean is usually nutrient poor so less standing crops an less NPP. NPP is best in tropics where moisture and temperature are high and good for plants. Earths total NPP= area of ecosystems * NPP of the ecosystem. Total NPP is highest for ocean because it is so big, even though the NPP/land is small in oceans. Carbon source includes emissions from burning fossil fuels, fires, and respiration. Carbon sinks move the carbon. Include oceans, plants, soil. Satellites use remote sensing to measure wavelengths on earth. This assesses carbon productivity by looking at chlorophyll absorbing in blue and red light while reflecting green. High standing crops have high absorption of blue and red and high reflection of green. All of the earth ecological systems are connected. For example, on an island people planted coconut trees which ruined birds habitat which stopped nitrogen in the water from the birds which stopped the food source for manta rays. Population Ecology- Individuals of the same species living in the same place at the same time. Study of populations in relation to their environment. No transfer of energy is 100% efficient. Because of laws of thermodynamics, a constant flow of energy from producers to consumers keeps the ongoing existence of the biosphere. Example is starlings in Rome- Predation, climate, food are all biotic factors that cause them to swarm. Abiotic factors are temperature John Westwood was first to estimate how many species there are. Sir Robert May says we have no way to know how many species there are. Carrying Capacity Population change= (Births -Deaths)+ (Immigrants-Emigrants) Population Stability: Territorial behavior can keep population size relatively stable due to the density-dependent impact. Population Instability: Bacterium: can cause infertility and mote with non-carriers. Nutrinet Limitation: Some organisms are very sensitive to the climate which can cause fertility rate to change based on conditions. Some populations grow exponentially but is usually not sustainable in normal conditions. Carrying capacity is maximum population size in which the population can be sustained. Environmental conditions: The environmental factors that restrict the biotic potential of an organism Ecological Dynamics -1st principle: Everything is ultimately connected to each other Reductionist approach- Look at individual, simple things and start to spread them out. Rutherford says to reduce everything to physics philosophies. Focuses the impacts of different things, food, weather, etc., on the abundance of a species. Holistic approach- Look at everything as a whole. Thinks reduction is too simple to understand complex systems. Focuses on impacts of everything on each other which then could impact abundance. -The Gaia Hypothesis, Very controversial- Life and environment evolved as a connected system and is modified by positive and negative feedback from organisms to survive. The Biosphere is homeostatic and the environment is like a self-maintaining biotic/abiotic organism. Daisyworld simulation- Is proof of the Gaia hypothesis that the daisies interact with each other and provide positive and negative feedback to the environment. Black daisies provide positive feedback on temperature by absorbing photons. White daisies reflect photons & provide negative feedback on temperature Competition- any use of defense of a limited resource that reduces availability of it for other members of the ecosystem. This mean both species will have lower populations when living with each other. Types of competition: Interference: direct competition and interference. Exploitative: One species uses limited resources more efficiently than the other. Apparent: two species in the same habitat share a higher tropic-level predator, when two species share a predator and one cause the predator populatoin to change. Interspecific competition: Competition between species for shared researches such as food, space, etc. Intraspecific competition: Competition between members of the same species for resources. Similar species living in same habitats utilize different resources, segregate by: 1. Food 2. Space 3. Time. Co-Occurence results in character: When they live together, the species change their characteristics to adapt. Competitive Exclusion Principle: Gause says that if 2 species live in stable association they must posses different ecological niches. Ecological Relationships Predation -Organisms have different characteristics that give them advantages in predation. Examples: Hammerhead sharks use their heads to have vision thst can see nearly everything around them and allow them to quickly react to prey. Star-nosed mole has no eyes and uses its star shaped nose to see textures underground. -When dingos were present, kangaroo population was very low. When they were absent, kangaroo populations were big. Predator-Prey cycles- Between hares and lynxes, when hare population increased, so did lynxes and vice versa. The Food web shows different relationships between predator and prey that if changed, would impact the populations of different species. Top down control is when predators control the populations and bottom up control is when food sources control population. Parasitism- Relationship between species where one lives or feeds off a host harming the host for the parasites benefit. Host abundance cycles: Parasites cause constant down and ups of a population size. Anti parasitic drugs cause this cyle to minimize the cycle and make the populations relatively flat. Mutualism: the way organisms interact with each other. Types of mutualism: Obligate: each species benefits but they cant survive independently their partners. Facultative: each species benefits but they can live independently of each other. Trophic: One or more partners gains energy, water, nutrients, refuge. Defensive: Partner defends against predators parasites herbivores, or competitors. Dispersive: Partner transports other partners pollen or seeds. Commensalism: A long term biological interaction in which one species benefits but the other one is not harmed nor benefits. Class 5 Keystone species: A species in which an ecosystem depends on and if removed, the ecosystem would drastically change. Climate warming and overfishing have negatively affected the species diversity of wildlife in the ocean. Extreme Resistance- Can endure extreme environments, but cannot exploit the extreme conditions. Extremophile- an organism that thrives in extreme environments that would be detrimental to almost all other species on earth. Tardigrades have extreme resistance as they inhabitat new developing ecosystems. Many extremophiles live on chemicals and many scientists think that if life exists outside of earth, it will be in the extremophile range. Greatest threats to biodiversity: Overexploitation(overfishing, etc.), Habitat destruction, Invading species, pollution, global warming. Biodiversity- Variety and variability of life on earth. Species Richness- Number of individual types of species in ecosystem. Species Diversity Index- a measure that reflects number of different types and takes into account the different proportion of the different species in a community. Species Richness- Field that examines the factors that affect species richness of isolated communities. Factors that affect it on islands: Island Size, human activity, amount of time its been isolated, physical environment, distance to nearest population source. In general, increasing land mass 10x, increases species richness 2x. An island is any habitable area that is surrounded by inhabitable areas. Small islands are more vulnerable to population loss. Rainforests are 6% of all earth, but contain 60% of species, and are becoming smaller because of farming, cutting trees, and cattle farming. Disturbance and diversity of an area- Primary Succession: Example, volcano goes off and lave forms new rock. Primary succession starts with no soil. Secondary Succession: Already has soil so plants can start to grow much quicker than in primary succession. Immediate Disturbance Hypothesis: Moderate levels of disturbance create the conditions for greatest species diversity. Nature is never at equilibrium and there are always external factors that are causing disturbance and disruption. Something is always changing. Global Dilemmas Invasive species in the Great Lakes have been increasing constantly about 10 species per year, brought in by Europeans. Invasive species cost a lot of money every year for the US and they cause significant extinctions and habitat destruction. Managing invasive species: Prevention is the least costly, then eradication, then containment, then long term control. There are 20 federal agencies dealing with invasive species and there is a lot of legislation for dealing with them, but have been largely ineffective. Introduction of invasive species: Intentional, unintentional, invasions with a host, shipping cargo, aquarium trade, internet buying and trading. Biological controls: Sometimes they work well as with the prickly pears in Australia being removed by larvae of moths introduced. Impact of aquatic invasive species: they clog waterways, pipes, foul boats and docks, lower water quality. Zebra Mussels: Native to eastern europe and introduced to Lakes in the US and Canada. They restructure the food web, outcompete the native mussels, decrease tourism because they are sharp and cut people, and can clog pipes. They have spread throughout the waters of the the United States and now trying to eradicate or contain them instead of preventing them at the start. Water Security- Eutrophication: excess nutrients in the water usually due to runoff from land. Usually nitrogen and phosphorus which cause plant growth and animal death in the water because of lack of oxygen. Dead Zones: Oxygen depletion in water- caused by natural or anthropogenic factors. Natural causes are coastal upwelling and changes in wind and water circulation patterns. Anthropogenic factors are chemical fertilizers, farming, land use changes, and climate change. In Gulf of Mexico, synthetic fertilizer washed into the water and made a huge dead spot. Maneur dumped into water ways by meat manufacturers also caused the algae growth. Harmful Algal Blooms (HABS) cause problems to animals, people, and local ecology because of their toxins. Salinization- Increased salt in freshwater. Salt pollution from road deicer, sewage, etc. which harms animals and other people who may drink the fresh water. Climate Change Greenhouse gas effect- discovered by Svante Arrhenius and correctly predicted a doubling of CO2 emissions would cause a 6 degree Celcius increase in global temps. Keeling Curve: 2 scientists took measurements of CO2 concentration and global temperature and summarized that it was causing climate change. Greenhouse Gases: Gases they trap heat from the sun in the atmosphere instead of letting it pass through. Nitrous oxide, Carbon dioxide, Methane, Sulfur hexafluoride, Water Vapor. Warming Temperatures causes Artic Ice to melt and sea levels to rise in other places. Changing temperatures causes migration of animals. 90% of earths species are affected. New parasites, diseases, higher extinction rates.