PB 360 Exam 4 notes – Flashcards
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succession =
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the process by which the species composition of a community changes over time
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the ultimate association of species achieved is called the...
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climax community
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Serial stage =
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each stage of community change during succession
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pioneer species =
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the earliest species to arrive at a site; typically are able to disperse long distances and arrive quickly at disturbed sites
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climax community =
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the final seal stage in the process of succession; generally composed of organisms that dominate in a given biome
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primary succession =
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the establishment and development of plant communities in newly formed habitats previously lacking plants
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examples of primary succession:
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sand dunes, lava flows, rock bared by landslides or receding glaciers
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secondary succession =
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the development of communities in disturbed habitats that contain no plants but still contain organic soil (ex. plowed fields, hurricane uprooted trees
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succession in intertidal communities can occur rapidly after a disturbance due to...
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the short generation time of dominant species
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J.T. Curtis and R.P. McIntosh ordered the mature forest communities of southwestern Wisconsin along a...
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continuum index
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two factors that determine when a species becomes establishes in a sere:
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1. how readily it invades newly formed or disturbed habitat 2. how it responds to changes in the environment
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the diverse array of processes governing the course of succession are divided into 3 categories of mechanisms:
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1. facilitation 2. inhibition 3. tolerance
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succession mechanism Facilitation category =
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embodies clements' view of a developmental sequence in which each species paves the way for the next
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succession mechanism Inhibition category =
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inhibition of one species by the presence of another is a common phenomenon. when inhibition is acting, succession moves forward only through the death and replacement of established individuals
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succession mechanism Tolerance category =
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a species can invade new habitat and become established independently of the presence or absence of other species
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communities are typically most diverse and complex at _____ stages of succession
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intermediate
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colonizers are ___-selected late successional species are ___-selected
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r K
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successions of microorganisms and scavenging animals on excreta or dead plants and animals have no ____
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climax at all
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example of dissimilatory process ex. of assimilatory process
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respiration Nitrogen reduction
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4 principal classes of carbon-cycling processes:
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(1) assimilatory/dissimilatory processes (mainly photosynthesis and respiration) (2) exchange of CO2 between atmosphere and oceans (3) precipitation/dissolution of carbonates (4) methanogenesis (small but important contributor to overall carbon cycle and global climate change)
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mean residence time for C in atmosphere is about.. mean residence time for C in oceans is about..
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5 years 224 years
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precipitation (as Ca and Mg carbonates) leads to formation of ___ and ____ rock
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limestone and dolomite rock
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humans add carbon to the atmosphere at a rate of..
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about 7 billion tons annually
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nitrogen fixation =
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the process of converting atmospheric nitrogen into forms producers can use, including ammonia which is rapidly converted into ammonium(NH4+) and nitrate(NO3-)
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nitrogen fixation occurs in..
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some species of cyanobacteria, free living species of bacteria and in bacteria that form mutualism with plants
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abiotic nitrogen fixation occurs when...
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lightning, wildfires, or combustion of fossil fuels provide energy to convert N2 into NO3-
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nitrification =
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the final process in the nitrogen cycle, which converts ammonium to nitrite, and then from nitrite to nitrate
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mineralization =
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the process of breaking down organic compounds into inorganic compounds
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denitrification =
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the process of converting nitrates into nitrogen gas.
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human activities have ____ the amount of nitrogen put into terrestrial ecosystems
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doubled
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watershed =
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the total upstream drainage area contributing water flow to any point on a stream
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cutting and burning of tropical forest and subsequent cultivation can only support agriculture for...
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2-3 years
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how many non indigenous species have been introduced to the US?
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50,000
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What percentage of species listed under the US Endangered Species Act are threatened because of competition, predation, parasitism, and herbivory by introduced species?
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40%
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What is a country that has predominantly alien flora and fauna?
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New Zealand
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Large, flightless birds called _____ were exterminated from New Zealand by Maori natives before Europeans arrived.
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moas
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Alien species are most likely to disrupt natural ecosystems when they...
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assume ecosystem roles of native species
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introduction of a single exotic predator is most likely to disrupt ecosystem function if the introduced species is a _____ predator
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keystone
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what percentage of the earth's topsoil is lost to erosion each year?
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1%
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Application of fertilizers to aquatic ecosystems stimulates primary production just as it does in agricultural ecosystems. In aquatic ecosystems, the enhanced production can eventually lead to...
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anoxic conditions (no oxygen)
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Application of fertilizers to aquatic ecosystems stimulates primary production just as it does in agricultural ecosystems. In aquatic ecosystems, the enhanced production can eventually lead to:
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bacteria
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Why has acidic precipitation been particularly devastating to rivers and lakes in certain regions, such as the northeastern United States, Canada, and Scandinavia?
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Waters there are oligotrophic and thus lack bases to buffer acid inputs.
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When fungal populations in soils are reduced as the result of contamination by copper, one consequence is:
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reduced decomposition of organic matter
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The benefits of many pesticides are often short-lived, and their amounts must be increased for continued effectiveness because:
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they select for evolution of resistance in target organisms.
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Oil pollution is a serious problem throughout the world. Petroleum kills organisms by...
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disrupting biological membranes and coating surfaces of organisms
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Peaceful uses of nuclear power may eventually be limited by:
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the problem of disposing of nuclear wastes
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The Vienna Convention for the Protection of the Ozone (1985) and the Montreal Protocol (1987) included agreements for the phasing out of:
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Chlorofluorocarbons
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If you were asked to provide a "ballpark estimate" of global atmospheric CO2 concentrations at the beginning of the industrial revolution (1750-1850), you would choose:
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300 ppm
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The oceans represent an important sink for anthropogenic CO2. In what form is the excess carbon stored?
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as calcium carbonate sediments
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Not all human activities contribute to heating of the atmosphere. Which has a net effect favoring atmospheric cooling?
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effects on albedo of the earth's surface
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Which of the following ecosystem services is considered indirect and dependent more on maintenance of intact ecosystems and less on availability of particular species?
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production of clean air and water
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In the United States, how many kilojoules of fossil fuel energy are consumed for every kilojoule of food energy we consume?
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10
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What percentage of the earth's land area is currently used for crops or permanent pastures?
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35%
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About how many species of plants and animals worldwide have been described and given Latin names?
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1.5 million
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About how many species of plants and animals exist on the planet?
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over 10 million
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conservation of global biodiversity is best served by directing efforts toward areas of:
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high diversity and high endemism
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What fraction of medical prescriptions filled in the United States are drugs extracted directly from flowering plants?
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one-quarter
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Researchers Tilman and Downing have demonstrated which of the following?
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more stable biomass production during drought in high-diversity systems
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What is a good estimate of the background rate of species extinction?
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one species per year
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What is a good estimate of the current rate of species extinction?
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one species per day
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Catastrophic destructions, like the one caused by the impact of a bolide with earth at the end of the Cretaceous, create opportunities for new types of biological associations. In the case of the end-Cretaceous catastrophe:
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mammals and birds filled ecological vacancies left by dinosaurs
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About how often have catastrophic destructions of the magnitude of the end-Cretaceous bolide impact occurred?
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at intervals of 10 to 100 million years
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Which kind of extinction has been linked to collisions of bolides with earth?
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mass extinction
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Which kind of extinction is caused by humans?
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anthropogenic extinction
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Human activities have been identified as the causal factor in numerous documented extinctions. Which specific cause has been identified in the majority of cases examined?
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habitat reduction and modification
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Colonization by humans of Australia, the Americas, Madagascar, and New Zealand was soon followed by which of the following events?
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extinction of a substantial portion of the vertebrate fauna
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In which setting have exotic species posed a larger threat to the native biota? islands or mainlands?
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islands
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Why do aquatic systems seem particularly vulnerable to disruption by exotic consumers?
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because of the predominance of top-down control of community structure by consumers
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Which species has become a pest after its introduction elsewhere from North America?
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Comb Jelly
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Which of the following incorporates demographic information about a particular population into a simulation model to predict the probability that it will avoid extinction within a given period, typically 100-1000 years?
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population viability analysis
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Which principle associated with the theory of island biogeography can be helpful to individuals designing parks and reserves?
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the species-area relationship
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Which species was rescued from the brink of extinction?
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california condor
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A stream flowing through or under a glacier can leave deposits of soil and rock in its path. After the retreat of the glacier, these deposits appear as a long, winding hill in the landscape, creating a unique microhabitat. What is the name applied to this structure?
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esker
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Which animal plays the role of "ecosystem engineer" by consuming most available vegetation during a period of irruption?
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spruce budworms
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Ancient farming practices, wildfires, ecosystem engineers, and modern logging practices all share a common impact on the landscape. What is it?
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creation of a landscape mosaic
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A GPS requires a minimum of ___ signals to accurately determine location.
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four
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Images acquired from airplanes and satellites can be used to identify features on the earth's surface and their locations in landscapes. Which wavelengths of reflected radiation make it easy to identify areas of vegetation, which typically stand out as bright red in the images produced?
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visible and near-infrared
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T/F? Habitat fragmentation results in increased patch isolation, smaller patch size, and higher patch numbers, all of which have uniformly negative effects on species richness.
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False
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Two habitat patches of the same area differ in their shapes. One is circular, the other narrowly elliptical. Which has the greater ratio of edge to interior?
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narrowly elliptical patch
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The World Land Trust and Wildlife Trust of India are collaborating to protect important habitat corridors to ensure the long-term persistence of which charismatic animals?
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Asian elephant
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The research conducted by Taylor Ricketts on movements of Colorado butterflies is of particular interest because it clearly demonstrates that...
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the habitat matrix may be composed of a variety of habitats that differ in their effects on movements of individuals from one patch of suitable habitat to another.
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Earl Werner and colleagues found that turnover (percentage change in species composition per year) of larval amphibians in wetlands in southeastern Michigan was directly related to which property of these wetlands?
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connectivity to other wetlands
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The degree of resolution at which an organism experiences variation in the landscape is referred to as:
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grain
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The landscape scale that an animal experiences in the course of its movements is referred to as:
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extent
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If you were studying an animal, like the wildebeest, which covers huge areas in its annual movements, you would probably opt for a study that examined landscape features at relatively coarse (and/or large):
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grain and extent
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Scientists monitoring acidified precipitation in the northeastern United States and Eastern Europe during the 1960s found that the pH of rainwater dropped to as low as ___
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4.0
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Which substance is an important precursor of acidified precipitation?
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sulfur dioxide created from burning fossil fuels
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Acidified precipitation leaches various elements from forest soils. Heavy leaching of two elements in particular leads to poor growth and even mortality of trees. Which elements are these?
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Calcium and Magnesium
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Which element was monitored to determine the rate of bedrock weathering in the Hubbard Brook Experimental Forest?
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Calcium
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What did researchers estimate to be the rate of bedrock weathering (in terms of bedrock depth) in the Hubbard Brook Experimental Forest?
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1 mm/yr
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Which element is usually absent from soil parent material?
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nitrogen
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Leaves of different plant species decompose at different rates, depending largely on which property?
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lignin content of the leaves
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While mycorrhizae assist plants in obtaining nutrients from soils, they may also provide an additional benefit to plants. What is it?
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protection from pathogenic organisms
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Under what conditions of available soil phosphorous are mycorrhizae most likely to benefit plants through uptake of phosphorous?
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low
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Research by Björn Lindahl and colleagues has shown that mycorrhizal fungi tend to be more active in which portion of the vertical profile of a forest soil?
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deep
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In which of the following ecosystems would you expect to find litter on the forest floor contributing the largest percentage of total organic biomass?
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temperate needle-leaved forest
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oligotrophic =
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relatively low in plant nutrients
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Where in the Neotropics would you expect to find oligotrophic soils?
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Amazon Basin
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Traditional slash-and-burn agriculture in the humid topics alternates 2-3 years of crop production with how many years of forest regeneration?
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50-100 year
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examples of alkaloids?
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nicotine, morphine, atropine (Not Tannic Acid)
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the Lotka-Volterra predator-prey model is ____ while the competition model is ____
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exponential model logistic model
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Larvel ticks do acquire lyme disease bacteria from infected hosts that they feed upon. which animals are most typically involved in this transmission?
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small rodents, like chipmunks and mice
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allelopathy =
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the chemical inhibition of one plant (or other organism) by another, due to the release into the environment of substances acting as germination or growth inhibitors.
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halitosis =
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bad breath
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sympatric speciation =
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the process through which new species evolve from a single ancestral species while inhabiting the same geographic region.
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Allopatric speciation =
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or geographic speciation is speciation that occurs when biological populations of the same species become vicariant, or isolated from each other to an extent that prevents or interferes with genetic interchange.
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the three mutualism types?
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Trophic: the transfer of energy and nutrients between two species. Dispersive: interactions in which one species receives food in exchange for moving the pollen or seeds of its partner. Defensive: interactions in which one species receives food or shelter in return for protecting its partner species from predators or parasites.
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Where would you expect more variation in mean monthly temperatures, from the coldest month to the warmest month? northern or southern hemisphere?
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northern
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The Intertropical Convergence Zone (ITCZ) is a region of substantial uplift of air heated in contact with the earth's surface. At any given time of year, where is the ITCZ located?
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at the earth's solar equator (not true equator)
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Your family is planning a holiday trip in late December and early January to the resort city of Rio de Janeiro, located in Brazil at about 21 degrees south latitude. Because this trip is during the southern hemisphere summer, your family can count on:
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at least some rain, possibly heavy, during their vacation
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rank the 3 forest biomes from least to most diverse
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boreal, temperate seasonal, tropical rain forest
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Ice skaters get excited when ice begins to form on the surfaces of temperate lakes during winter. At this time, where is the coldest water in the lake?
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at the top, just below the ice
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T/F? Much of the effort in the study of life histories has been to understand the fitness consequences of changing the allocation of limited time and resources to competing functions.
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True
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Which british biologist first placed the clutch size of birds in an evolutionary context?
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David Lack
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what is the key evolutionary concept underlying the Red Queen hypothesis?
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through sex and genetic recombination, hosts present a moving target for evolving pathogens.