Exam 1 guide - EVR 2001 PDF

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Environmental Science Exam 1 

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Lecture 1 o What is science, and how does the scientific method work?  A body of knowledge and a method of acquiring further knowledge about the world  Assumption, Observation, Question, Research hypothesis, Experiment o What is environmental science?  An interdisciplinary science that connects physical sciences, life sciences, social sciences, and sometimes humanities o Scales in environmental science - spatial, temporal, taxonomic  Spatial - physics, geography, astronomy, meteorology and statistics  Temporal - time  Taxonomic – Kingdom, Phylum, Class, Order, Family, Genus, Species o What do environmental scientists’ study? What do environmental scientists do in practice?  Field Work, Lab Work, Reading Academic Literature, Modeling Work, Data Entry, Data Analysis, Writing Academic Papers, Presenting at Conferences o Know the major environmental issues and why they are important.  Habitat Conversion and Degradation  Biodiversity Loss  Loss of Ecosystem Services  Soil Degradation  Freshwater Depletion  Water Pollution  Air Pollution  Solid Waste Accumulation  Ocean Acidification  Anthropogenic Climate Change  Poverty/Starvation/Inequality o What is sustainable development (this is mostly from the textbook)?  Meeting the needs of the present without compromising the ability of future generations to meet their own needs (we should be able to improve conditions for the world’s poorest populations without devastating the environment) Lecture 2 o Plate tectonics, including geological hot spots and the processes that happen at various types of plate margins (convergent, divergent, transform/strike-slip).

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 Earth’s energy budget – internal heat and energy from the sun – 99.97% of earth’s energy budget is from the sun Other geologic processes and hazards –

Geological processes transform living biomass into fossil fuels, Landslides reshape entire landscapes, Earthquakes can trigger tsunamis, Floods are most costly geological hazard, chemical weathering of limestone creates caves and sinkholes, most geological processes are slow, but some are sudden (like a volcano forming) o Know rock, nitrogen, phosphorus, and carbon cycles! You do not need to know the hydrologic cycle for this exam.  Nitrogen Cycle  Nitrogen fixation converts Nitrogen in the air (N2) to a useful form (nitrate or ammonium) o Legumes (clover, peas, peanuts, beans) – convert the nitrogen from the air to useful forms o Denitrifying bacteria convert nitrate back into atmospheric nitrogen  Phosphorus Cycle o Phosphorus released it the soil through weathering of rock and then absorbed by plant roots o Animals eat the plant to obtain the phosphorus, and then release waste to go back into the environment o Phosphorus in fertilizers that humans use end up in water as runof o Slow geologic sub cycle  Carbon Cycle o The carbon in the air (CO2) is fixated by plants through photosynthesis (taking in CO2, sunlight, water to create glucose), then animals eat the plant and release carbon back into the air through cellular respiration and metabolization o CO2 absorbed by phytoplankton photosynthesis in ocean, and released back into air through respiration and decomposition o Fossil fuels are fossilized biomass in the form of hydrocarbons o Human impacts on biogeochemical cycles –  Through fertilizer production, the amount of nitrogen fixed by industrial processes now exceeds N2 fixation, Mining of rock Phosphate is MUCH more rapid than natural weathering of phosphate-bearing rocks  Cycles are being accelerated causing depletion of rock phosphate sources and Eutrophication (nutrient enrichment) of water bodies o Haiti vs. Japan earthquakes – lessons learned –  Poverty, poor development planning (including degradation of natural ecosystems), and poor governance make people more vulnerable to natural disasters, and increase the severity of disaster impacts Lecture 3 o There may be more questions on this lecture and lecture 4 than for the others. o Levels of organization in ecology from organisms to the biosphere. Know their definitions and differences.  Organism  Populations – consists of all the members of a living species in a given area at a given time  Communities – all the populations living and interacting in a particular area  Ecosystems – composed of a biological community and the physical environment  Biospheres – all the life on Earth and associated habitats o Ecotones, open vs. closed communities. Know examples of each.  Ecotones – transition areas between adjacent ecosystems  Open Communities – Indistinct/gradual boundaries 

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 Closed Communities – Sharp boundaries (edges) Habitat fragmentation and its effect on edge vs. core habitat. What are edge effects?  Habitat Fragmentation - Humans often fragment ecosystems, creating unnatural patterns of sharp boundaries. Resulting edge efects reduce available core habitats Ecosystem structure, function, change, and ecosystem services – there is a lot to each of these.  Ecosystem Structure – What is there? How much of it is there? Where is it/how is it arranged?  The physical and biological makeup  Climate, Resources available, interactions with other species, luck (individuals move to a new suitable location by chance)  Ecosystem Function – What does “what is there” do? How does “what is there” interact? What are the results of those interactions?  Energy flows and matter transfer  Ecosystem services (if useful to people) o Matter cycling (the bio in biogeochemical cycles), including breakdown of wastes o Gas exchange – helps regulate oxygen and carbon dioxide in the atmosphere o Energy capture, storage, and flow o Creation/alteration of habitats o Formation and stabilization of soils o Mitigation of natural variability, including natural disasters o Resilience (ability to recover from disturbances  Ecosystem Change – How ecosystems change structure and function over time  Disturbances, Successions, and Evolutionary mechanisms  Knowing how ecosystems “work” is crucially important to be an environmental scientist, so I expect you to spend quite a bit of time reviewing and understanding these concepts! Photosynthesis & Respiration  Photosynthesis - 6 H2O + 6 CO2+ [light] →C6H12O6 + 6 O2  Water, Carbon Dioxide, and Light  Respiration - C6H12O6 + 6 O2 → 6 CO2+ 6 H2O Ecosystem productivity. How is it measured, and what are the general geospatial patterns?  Annual Net Primary Productivity (NPP) on the Earth’s land surface, generally the highest productivity is nearest to the equator Energy flow and matter cycling through ecosystems and their trophic webs (food webs)  Source is the sun, and that energy is used through tropical or feeding interactions (plant absorbs sunlight, animal eats plant, animal eats other animal) What are niches? How are they defined, and how are they related to competition/resource partitioning?  Ecological Niche - Eltonian: The organism’s functional role (its response to and efects on its environment) Hutchinsonian: Essentially the set of environmental conditions and interactions required to support a population within an environment  Competitive exclusion - No two species can occupy the same ecological niche at the same time  The one that is more efficient at using resources will eventually exclude the other  Direct competition is very energy intensive, especially over long periods of time.  In many cases, species get around competing directly by partitioning resources/niches amongst each other. Species interactions of various kinds  Competition:  Intraspecific competition - competition among members of the same species, which can be reduced by: o Dispersal of ofspring

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o Exhibiting strong territoriality o Resource partitioning between generations  Interspecific – competition between members of diferent species o Unless there is a clear winner, competition has negative consequences for all competitors  Competitive exclusion o No two species can occupy the same ecological niche at the same time. o The one that is more efficient at using resources will eventually exclude the other. o Direct competition is very energy intensive, especially over long periods of time. o In many cases, species get around competing directly by partitioning resources/niches amongst each other.  Resource partitioning - species can co-exist in a habitat by utilizing diferent parts of a single resource. o Example: swallows eat insects during the day and bats eat insects at night  Predation o A predator is any organism that feeds directly on another organism, whether or not this kills the prey o Parasites feed on an organism but do not immediately (or ever) kill it  Parasitoids kill their host o Herbivory is the predation of plants by animals  Adaptations to Avoid Predation o Over time predator and prey evolve in response to one another. As predators become more efficient, the prey evolves defenses (thorns, toxic chemicals, behaviors) o Two harmful species can evolve to look alike (Müllerian mimicry) o Sometimes, harmless species mimic the warning coloration of harmful species to gain protection (Batesian mimicry)  Symbiosis: a prolonged, close interaction between species  Mutualism – both organisms benefit from their association  Commensalism – one species benefits while the other neither benefits nor is harmed  Parasitism - a form of predation, is also sometimes considered a symbiotic relationship because of the prolonged dependency of the parasite on its host  Keystone Species  Exert a disproportionate influence on their environment relative to their population numbers or biomass  Typically, a nexus in trophic webs or ecosystem engineers (create habitats for other species by their everyday activities)  Extirpation usually results in rapid degradation of the system – simplification of structure, elimination of functions Disturbances and succession  Disturbances - any force that disrupts established patterns of species diversity and abundance, community structure, or community properties, e.g., storms, fires, logging  disrupt the superior competitors the most and sometimes allow less competitive species to persist  Some landscapes never reach a climax community because they experience frequent disturbances (such as wildfires) and are made up of disturbance-adapted species.  Novel disturbances can result in catastrophic changes to the system.

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 Many ecosystems are adapted to disturbances and require them to persist.  Succession - the replacement of species in a community by establishment of new species paralleled by replacement or extirpation of old ones  Pioneer species colonize a site that was opened by disturbance. These populations are replaced by intermediate sere species, which are eventually replaced by a climax community.  Succession often makes an environment more suitable for life in general, deposits ecological memory  Primary Succession o A community begins to develop on a site previously unoccupied by living organisms. o Example: A lava flow creates a new land area that is colonized. The first colonists are termed pioneer species  Secondary Succession o an existing community is disrupted and a new one subsequently develops at the site  Climax community - community that develops last and tends to remain the longest The various biomes and their basic properties as outlined in lecture and in the textbook  are the broadest classification of terrestrial ecosystems that have similar characteristics due to sharing similar climatic conditions

 Lecture 4 o Taxonomic classification of organisms from domain to species  Domain Eukaryota (or Eukarya)  Kingdom Plantae  Kingdom Fungi  Kingdom Animalia  Kingdom Protista o basically, any eukaryote that is not a plant, animal, or fungus  Domain Archaea  Kingdom Archaebacteria  Domain Bacteria  Kingdom Eubacteria

Ex: Taxonomic classification of modern humans from most general to specific  Domain (e.g. Eukaryota)  Kingdom (e.g. Animalia)  Phylum (e.g. Chordata)  Class (e.g. Mammalia)  Order (e.g. Primates)  Family (e.g. Hominidae)  Genus (e.g. Homo)  Species (e.g. Homo sapiens)  Did King Phillip Come Over For Good Spaghetti? Non-evolutionary mechanisms through which organisms adapt to changes in their environment (Genotype - refers to the DNA code of an organism / Phenotype - to the way this code is expressed into observable characteristics)  Phenotypic plasticity  How the genotype is expressed into the phenotype is influenced by environmental stimuli  Resulting changes in phenotype may be temporary or permanent  An important adaptation mechanism when environmental conditions change relatively rapidly  Not passed on to ofspring  Acclimation  A special type of phenotypic plasticity (short term and reversible)  Getting used to new environmental conditions through exposure  Examples: Sun tan, high altitude acclimation, body response to exercise The major evolutionary processes – mutation, natural selection, gene flow/geographic isolation.  Mutations - When DNA is damaged, or errors occur during DNA replication, it can cause changes beyond recombination  External agents can increase the likelihood of DNA damage (Radiation, chemicals, viruses)  Main point: Regular recombination selects from existing parental genes. Mutations create new alleles that were not present in the parents  Mutations are the ultimate source for all genetic variation.  Most mutations are neutral or detrimental.  Beneficial mutations are more rare  Natural Selection  1. Requires initial genetic variability within population o Non-neutral mutations are a prerequisite for natural selection to play out.  2. Requires environmental variability within range o This is the case in most environments  Selective pressure will favor beneficial traits o The most fit (best-adapted) organisms tend to survive for longer and have more viable ofspring, so their DNA is passed on more frequently than that of organisms that are not as well adapted. o Beneficial alleles increase in frequency over successive generations  Main point: Natural selection acts as a “screening mechanism” for mutations, favoring those that are advantageous in the local environment. How does each work? Know some examples of each. Different types of diversity (Biodiversity is “the variety and variability among living organisms and the ecological complexes in which they occur.” It can be quantified in many diferent ways)  Genetic diversity - Within-species diversity as measured by DNA 

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Species diversity:  Species richness (# of species, s)  Species evenness  Species dominance  Ecological diversity - Diversity of habitats, niches, and ecological processes Species diversity – how is it calculated? Know about the importance of richness and evenness. 

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 Biodiversity hot spots – what are they, where are they?  Regions that contain a disproportionate share of biodiversity and are in danger of degradation or destruction  These are major conservation priorities

 Patterns of biodiversity over time. Cambrian explosion. Mass extinctions (specifically P-T and KPg). P-T (Permian Triassic)

K-Pg (Cretaceous Paleogene)

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P-T (Permiant Triasic):  Age of the Dinosaurs  Massive global warming  Methane in the oceans  Acidity in ocean spiked  90-96% of species dies K-Pg (Cretaceous Paleogene)  66 million years ago  End of reptile age, no more dinosaurs  Asteroid hit Mexico (Yucatan Peninsula)

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o Put up so much dust it covered sun leading to no photosynthesis  75% of species went extinct Threats to biodiversity – HIPPO and climate change. (CHIPPO)  Climate change  Habitat Destruction – also includes degradation and fragmentation (increasing edge efects)  Invasive Species – ecological release  Pollution  Population (Human)  Overharvesting – also include poaching (black market) Landscape-level conservation vs. species-level conservation. Approaches, methods, legal framework, etc.  Conservation of Landscapes - Focus on ecosystem functions and services over individual species o Recognition that species cannot exist in isolation  Tends to allow for more flexibility to incorporate needs of local people o Shade-grown cofee o Sustainable grazing o Extraction of non-timber forest products o Conservation of cultural assets: Traditional land uses and skills, native languages, etc. which connect people to the land they inhabit (“Living History Museums”)  Essential aspects: o Enforcement of regulations o Good relations with local people o Learning from indigenous and rural people to complement academic knowledge  Many diferent types of protected areas exist. o Various degrees of human activities permitted  Some try to concentrate human activities in fringe areas, leaving core habitat less afected  Bias toward mountains and deserts in U.S. o Most forests and grasslands are managed for human use (National Forests, National Grasslands)  Increasing importance of private protected areas  Matrix o Incentives for private landowners to manage their land in certain ways (including conservation easements) o Land purchases by trusts to establish new protected areas or expand existing ones  Biodiversity Conservation:  Legal Framework o Endangered Species Act (ESA, 1973)  Protects threatened and endangered species in the United States by delineating critical habitat and prohibiting harming listed species and their habitat  Controversial due to impacts on private land and social impacts  USFWS very slow to list proposed candidates and create recovery plans  Has slowed down rate of extinctions, but has not been very successful in helping species recover o Convention on International Trade in Endangered Species (CITES, 1975)

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International organization and treaty, bans international trade with products obtained from endangered species Does not directly address habitat loss, poverty, or conservation practices Smuggling persists; ivory and rhino horn poaching in southern and eastern Africa rampant once again.

Methods o Tools for species-level biodiversity conservation:  Sanctions to dissuade poachers  Regulations only efective if enforced  Providing alternative livelihoods  Encouraging poachers to become involved with wildlife conservation  Captive breeding  Protecting rare populations from natural hazards by removing them from their environment  Increase population numbers through breeding (often “assisted”), followed by re-release into the wild

Lecture 5 o Exponential vs. logistic growth. What causes logistic growth? What is carrying capacity? What do the curves look like? How is the shape of the logistic growth curve affected when the variables r, No and K change?  Exponential Growth - While resources are abundant and competition/predation is low, growth is limited only by biotic potential (how quickly a species is able to reproduce)

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Logistic growth - causes the population to approach the carrying capacity asymptotically due to density-dependent limited to growth

Carrying Capacity (K) - The maximum population size of a species an environment can sustain indefinitely

 r vs. K-strategists  r – Selected Species:  Many ofspring, low survival rate (little to no parental care)

May be semelparous (only able to reproduce once) or iteroparous (able to reproduce multiple times)  Examples: Bacteria, rodents, insects, grasses K – Selected Species:  Few ofspring, high survival rate (high levels of parental care)  Iteroparous  Examples: Humans, elephants, whales, parrots, eagles 

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 Island Biogeography (from textbook) Metapopulations  Is created by emigration and immigration between population, in which a gene flow is preserved H...