EVSC 105 Study Guide for exam 1
EVSC 105 Study Guide for exam 1 ENSC 105N-01
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This 8 page Study Guide was uploaded by Trinity Wallace on Sunday October 2, 2016. The Study Guide belongs to ENSC 105N-01 at University of Montana taught by in Summer 2015. Since its upload, it has received 5 views. For similar materials see Intro to Environmental Science in Environmental Science at University of Montana.
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Date Created: 10/02/16
Ecosystem Connection a. The diversity and abundance of life depends upon the capture of energy and the transfer of that energy up the food chain. The trophic level within the ecosystem are what transfers this energy from one level to the next. The primary producers, plants take in the energy from the sun by means of photosynthesis, The 9010 principle states that when transferred through the trophic levels, 90% of that energy is lost as heat or in other forms, and only 10% of that is obtained by the next level. With the abundance and diversity of life in an ecosystem, there is sufficient amount of stability and flexibility among the species that inhabit that ecosystem. The different levels of the trophic levels ensure biodiversity because with the transfer of energy among the levels you are provided stability for life. An example of this would be farming. With farming practices today, society is spending more energy putting into theses resources than the produce can give. The imbalance of degraded resources is limiting the sustainability and ecosystem of that energy. b. Food harvesting and raising, crops in agriculture inefficient way, more energy being put into growing the crop than the crop will provide c. A sedimentary cycle which comprises the weathering of an existing rock, followed by the erosion of minerals, their transport and deposition, then burial. The build up of Earth debris on the surface of the earth, below the oceans, and in the mantle is an example of the sedimentary cycle. Mining is an example of a sedimentary cycle that humans use, that in turn affects the cycle and the environment. The atmospheric cycle is the cycle through what gases, water, and other elements travel throughout the atmosphere. The emission of gasses into the atmosphere is a natural occurring process, but since humans the rate at which these gasses is being transferred into the atmosphere is causing many problems to the environment. The emission of greenhouses gases from livestock agriculture and man made factories are affecting the atmospheric cycle in a negative way. d. Parts of ecosystems are connected on two levels, physical and biological. Ecosystems are connected physically by the means of the water cycle and the transfer of energy between organisms and the environment. Ecosystems are connected on a biological level by the means of the food cycle. The trophic levels within the food cycle link all organisms together. e. “You can't just do one thing our actions have many unexpected, indirect effects” This statement is true. Everything is connected in an ecosystem and the environment. The flow of global cycles is easily altered. If you were to take a keystone species out, the ecosystem around it would be affected biologically. That in turn may alter the water cycle, which would then disrupt the river ecosystem, which would in turn affect more species on the lane. Water Cycle Question a. Eight ways humans alter the water cycle i. Dams converts river habitat in reservoir habitat, thus disrupting the habitat for many aquatic and land dwelling species. Floods the upstream area which used to be river habitat. Changes the temperature of the water on either side of the Dam, which disrupts fish spawning and where they do so. Sediment buildup behind Dam and down river. Loss of habitat for species. The Milltown Dam created many of these problems on the Clark Fork, reducing habitat and flooding upstream areas. ii. Ditch Rivers straightening a river increased the gradient of the bank, resulting in loss of habitat for many aquatic species, including trout. It increases bank erosion, resulting in high sediment levels being transferred. It also kills shallow streamside vegetation. iii. Dike Rivers dikes and levees prevent the river from using part of its floodplain, As a result, flooding increases upstream. The flood downstream increase bank erosion and downcutting of streamside vegetation. Loss of complex floodplain habitat. Caused the flooding of many homes downstream, causing habitat damage and pollutant levels to raise. iv. Divert Surface Water for Offstream Use reduces the flow of the river, thus temperatures increase, oxygen levels drop, pollutants are more concentrated. The stream may dry up and leach out soil. v. Drain Wetlands removes a vital and complex habitats and causes wetlands to release nutrients that have been stored for over 1000’s of years. Loss of pollution trapping and flood absorption contributes to water quality degradation. vi. Degrade Riparian Areas removes shade, roots that hold banks, leaf litter, large woody debris reduces water erosive power and creates complex instream habitat vii. Deplete Groundwater lowers groundwater table which leads to land subsidence and death of shallow rooted vegetation. May dry up streams, springs, and lakes. viii. Devegetate Watersheds (plowing, paving) decreases transpiration and increases runoff, which will increase the load of sediment and other pollutants b. Effects of Water Cycle changes Community Concepts Question a. Define the following and give examples i. Competition symbolic relationship between or among living things for resources, space, and mates. An example of competition is the relationship between cheetahs and lions. ii. Predation symbiotic relationship between two organisms of unlike species in which one of them acts as predator that captures and feeds on the other organism that serves as the prey. An example would be the relationship of a wolf and a deer. iii. Mutualism the way two organisms of different species exist in a relationship in which each individual benefits from the activity of the other. An example would be a bee and a flower iv. Symbiosis is when two organisms are in a symbiotic relationship because they can't survive without each other. An example would be a sea anemone and a clown fish b. Define each and how they can be used to conserve communities 1. Indicator Species An indicator species is an organism whose presence, absence or abundance reflects a specific environmental condition. If the indicator species is present, the environment is seen to be thriving, if it is absent the conditions of the environment are in decline. Caddisfly is an example. 2. Umbrella Species species selected for making conservationrelated decisions, typically because protecting these species indirectly protects the many other species that make up the ecological community of its habitat. 3. Keystone Species a species on which other species in an ecosystem largely depend, such that if it were removed the ecosystem would change drastically. If the keystone species is removed, many other species in the ecosystem become vulnerable to population downfall. c. Importance of each in their community 1. Ruminants/ Gut bacteria The bacteria in the the stomach of ruminants help them digest what they otherwise could not, as well as helping them digest what most species can not. 2. N fixing/ legumes Nitrogen fixing plants put N back into the soil and provide various nutrients for other species. 3. Mycorhizza It is a fungus that lives on the roots of plants. They consume sugars and share them, thus expanding roots of the trees, which in turn helps feed other plants and make them more productive. 4. Lichen (Algae and fungus) The algae allows photosynthesis and the fungus allows structure. They begin the process of succession. 5. Coral Created by algae living on coral polyps, they build reefs and they provide shelter and habitat for other species d. The adaptation and competitive processes for plants differ. Some plants are easily adapted to a new or devastated environment, and can out compete even the native species. They occupy a new niche where no predators are present, also plays a large role. Cheatgrass is an example. e. Disturbance is a temporary change in environmental conditions that causes a pronounced change in an ecosystem. After a disturbance an ecosystem goes into succession is the process of change in the species structure of an ecological community over time. A disturbance can reduce biological diversity because the disturbance could have wiped out entire populations o species, causing the gene flow and ecosystem to change. A disturbance can also increase biodiversity because it brings in plants and animals that thrive on the new ecosystem type. Species & Populations a. Define and give examples i. Speciesa group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding. ii. Populationare groups of individuals belonging to the same species that live in the same region iii. Gene Pool is a collection of all the genes in a population iv. Evolution change in the gene pool of a population from generation to generation 1. Microchange in allele frequencies that occurs over time within a population 2. Macro evolution of whole taxonomic groups over long periods of time. b. Explain 5 processes that cause changes in gene pools 1. Artificial Selection intentional breeding of plants or animals, you're choosing to focus on certain genes, then the genes you are not selecting for may decrease 2. Natural Selection it changes the allele frequencies in the population favoring certain genes, those are then more likely to be passed on 3. Mutations error during cell division can create a new type of gene. That new gene is a small part of the gene pool. It can be passed on to the next generation. If the new gene is useful, it might become a common part of the gene pool. 4. Sexual Selection if the selection of a mate is based upon specific characteristics then the gene that is prefered sexually will be more prevalent in the gene pool 5. Genetic Drift amount of each gene in a gene pool can change over time because of chance events b. Genetic diversity plays an important role in the survival and adaptability of a species. When a population's habitat changes, the population may have to adapt to survive; the ability of the population to adapt to the changing environment will determine their ability to cope with an environmental challenge. b. 5 characteristics that make a species extinction prone and why? i. Less Genetic diversity the less genetic diversity, the less likely it is that the population will be able to succeed in the long term ii. Low reproduction rate with a low rate of offspring being produced, the less likely they are to adapt and respond to changes iii. Specialized niche if a species has a specialized niche, then any changes to that will disrupt the viability and likelihood of that species iv. Fixed migration patterns v. Rare (small population) if a species is rare, then it already has small sized population and if it's specified living conditions are tested their rate for extinction has increased because the adaptation period has been altered Biodiversity a. Explain importance of each i. Habitat Diversity provides ecosystem services in the face of change. Different ecosystem services are needed to keep cycles, such as the water cycle running ii. Species Diversity every species, no matter how small has a role play in the ecosystem and ensures natural sustainability for all life forms. iii. Genetic Diversity important role in the survival and adaptability of a species. When a population's habitat changes, the population may have to adapt to survive; the ability of the population to adapt to the changing environment will determine their ability to cope with an environmental challenge. b. 4 greatest threats to biodiversity 1. Habitat Loss 2. Invasive Species 3. Overharvesting 4. Pollution 5. Extra Credit Climate Change b. 4 community types that are threatened and why? i. With the overall global temperature rising, the increase in desert habitat is increasing throughout the globe. This expansion of desert habitat limits the surrounding habitats and limits the species from their resources. 1. Prairies problem of introduced plant and animal species competing with the native species, greater difficulty sustaining itself.. Now that many prairies exist as isolated patches, natural fires almost never start and fire departments quickly extinguish those that do, making hard for the soil to replenish itself. 2. Coral Reefs overfishing, fishing using cyanide and dynamite, pollution from sewage and agriculture, massive outbreaks of predatory starfish, invasive species, and sedimentation from poor land use practices. 3. Forests intensity and timing of fire events, hurricanes, droughts, ice storms and insect outbreaks are shifting as a result of human activities and global climate change 4. Tropical Rainforests Logging interests cut down rain forest trees. Power plants and other industries cut and burn trees to generate electricity. The cattle industry uses slashandburn techniques to clear ranch land. Agricultural interests, Subsistence farmers, and Mining operations d. 4 reasons it is important to maintain biodiversity and why 1. Protecting food crops genetic variability provides ecosystem support and overall probability of success among many species 2. Maintenance of Support Systems Water cycle and atmospheric cycles are all needed to have life on earth. If these are depleted then life on earth will be threatened. 3. Protection of Ecosystem services stabilisation and purification of water supplies, regulation of local weather and provision of shelter for the insect populations that pollinate food crops, and carbon storage. 4. Beauty of Natural Diversity answer with own opinion d. How to maintain biodiversity i. Protect Habitats protecting the habitat not only saves any species but helps ensure the success of many biological and ecosystem cycles ii. Manage Species Invasive species need to be managed so that the native species can reproduce, if invasive species take over an ecosystem it can change the cycles and affect many other species habitat iii. Food Choices if you were to hunt or graze a certain species to endangerment then the ecosystem around it will suffer iv. Energy Use with crop harvesting and agriculture, we are putting more energy in then we are getting out. There is an imbalance of production and use of that energy. If we let the ecosystems recover they could harness the energy and pass more on efficiently Population Growth, regulation, and carrying capacity a. Factors that determine how fast a population can grow i. Current size of population if the population is larger it will grow faster ii. Length of reproductive maturity if females in a population can start to reproduce young, they will have more offspring throughout their life iii. Number of offspring If a species can produce multiple offspring at once, the population will grow larger, faster iv. Birth rate relative to death rate if more individuals are being born than are dying, the population will increase faster v. Environment if the environment can sustain the population and its needs, it will increase until the carrying capacity is reached b. What determines how large a population can grow? 1. Limited amount of resources if the environment can not sustain the amount of resources they need (i.e food, water) then the population will not be able to grow larger than the environment can provide 2. How much resources they need if a population requires a large amount of resources and if the polution keeps growing, eventually the environment will not be able to provide enough of the resources required for them to continue population growth 3. Competition if a population has competition for resources the amount of resources they can obtain determines the ability for their population to grow. If the competitor beats them out, the latter of that will not be able to become larger if the amount of resources is limited 4. How efficiently they use the resources if a population does not use all the resources that they produce, waste of the resources can lead to how large a population can grow. If waste is large compared what is used then the population will suffer in the long term 5. Predators if a population is vulnerable to predators, the size at which they grow is dependant upon the size of the predator population, if low numbers of predators, the population can grow, but then in return the predators grow with that c. What is meant by living on Earth Principal vs living on Earth Interest? 1. Earth Principal when one lives off only what is necessary, what you need 2. Earth Interest when you deplete the environment around you to fulfill your want, human live off interest d. What is meant by sustainable use of resources and ecosystems? 1. Sustainable use of resources and ecosystems taking only enough so that the ecosystem can regenerate itself 1. Selective logging is an example of resource 2. And groundwater is an example of ecosystem 2. Unsustainable Use degrading and damaging the ecosystems ability to replenish itself 1. Overfishing leads to crash in populations 2. Wetlands remove toxins, but they can be overwhelmed d. Garret Hardins Cultural Carrying Capacity the ability to support humans at more than the basic level. Humans want to have more, the culture we live in, our carrying capacity is lower than it would be if we didn't demand luxury
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