Question
click below
click below
Question
Normal Size Small Size show me how
Ecology Midterm
Question | Answer |
---|---|
Ecology | study of distribution and abundance of organisms and their interactions with the environment |
abiotic factors | nonliving factors: regional differences in temperature, rainfall, light, spatial and temporal heterogeneity, wind, soils, weather, climate |
biotic factors | living factors: predation, competition, and lack of mutual symbiosis |
organismal ecology | behavior, physiologic, evolutionary, response |
population ecology | factors controlling size of population |
community ecology | all populations in area, predation and competition |
ecosystem ecology | abiotic factors interacting with the biological community |
landscape ecology | flow of energy, materials and or organisms between ecosystems |
biosphere | all of earth's ecosystems |
precautionary principle | if an action or policy has a suspected risk of causing harm to the public or to the environment, in the absence of scientific consensus that the action or policy is harmful, the burden of proof that it is not harmful falls on those taking the action. |
biogeography | study of the past and present distribution of species |
dispersal | extending the range of an organism/population, successful transplant of a species shows that potential range of a species is larger than the actual range |
behavior and habitat selection | behavior of an organism can keep them from occupying all of their potential range (some insects will only lay eggs on certain plants) |
climate | prevailing weather conditions of a locality is determined by temperature, water, sunlight and wind |
macroclimate | climate pattern on a local to global level |
microclimate | fine variations within a habitat patch like ground color, boulders, burrows, altitude, aspect, vegitation |
How do latitudinal variations in climate come about? | They are caused by absorption of solar radiation that heats the atmosphere, land and water which sets patterns for temperature variation, air circulation and water evaporation. |
What influences regional climate patchiness? | It is influenced by proximity to water and topographical features. |
What affects local climate? | Seasonal changes |
turnover | water in lakes is brought to the bottom with oxygen and nutrient rich water is brought to the top of the lake, this happens in spring and fall |
biomes | major types of ecological groupings that are found in broad geographic regions of land or water |
photic zone | receives sufficient light for photosynthesis |
aphotic zone | little penetration of light |
benthic zone | bottom substrate of water bodies, home to benthos organisms and detrius |
detrius | dead organic material found on the bottoms of water bodies |
palagic zone | open water (ocean) |
littoral zone | coastline, high energy water (ocean) |
limnetic zone | well-lit, open surface waters in a lake, away from the shore |
netiric zone | part of the ocean extending from the low tide mark to the edge of the continental shelf, with a relatively shallow depth extending to about 200 meters |
thermoclines | is a thin but distinct layer in a large body of fluid (e.g. water, such as an ocean or lake, or air, such as an atmosphere), in which temperature changes more rapidly with depth than it does in the layers above or below |
oligotrohpic lakes | deep, nutrient poor, fairly nonproductive, and generally oxygen rich |
eutrophic lakes | shallow, nutrient rich water, that supports large, productive phytoplankton |
streams and rivers | flowing habitats, physical and chemical characteristics vary from headwaters to the mouth or point of entry into oceans or lakes, varying oxygen levels (high levels in high energy, low levels in low energy) |
wetlands | areas covered with enough water to support aquatic plants |
estuaries | where mouths of rivers meet oceans |
climograph | annual mean temperature and rainfall for a region |
ecotone | area where biomes grade into each other |
vertical stratification of a forest | canopy, low tree stratum, shrub understory, herbaceous plants, ground floor, root layer |
tropical forests | equatorial and sub-equatorial regions, variations in rainfall, warm temperatures |
savannas | equatorial and sub-equatorial with scattered trees and alternating rainy and dry seasons, large grazing animals and predators |
deserts | low, unpredictable precipitation, can be hot or cold |
chaparral | coastlines in mid latitudes with cool, rainy winters and hot dry summers, small browsing mammals |
temperate grasslands | maintained by fire, seasonal drought and grazing my large mammals, cold-dry winters, hot-wet summers, deep-fertile soils |
temperate broad leaf forests | characterized by broad leaved deciduous trees at mid-latitudes with cold winters and hot humid summers with adequate rainfall |
coniferous forests | northern latitudes, large forests, harsh winters and heavy snowfall |
permafrost | frozen layer of soil which doesn't permit infiltration of water |
Which level of ecology considers energy flow and chemical cycling? | ecosystem ecology |
Which level of ecological research would consider how a community is affected by neighboring ecosystems? | landscape ecology |
Ecologists often use mathematical models and computer simulations because | these approaches allow them to study the interactions of multiple variables and simulate large scale experiments |
What would affect the distribution of a species? | dispersal ability,interactions of mutualistic symbionts, climate and physical factors of the environment, predators, parasites and competitors |
According the precautionary principle: | Environmental decisions should be made carefully, taking into account the complexity of ecosystems and the potential effects of such decisions |
What is a concern about the effects of global warming on tree species? | Trees may not be able to disperse fast enough to reach new habitats that meet their climatic requirements |
In which biome is light most likely to be a limiting factor? | Oceanic pelagic zone |
Phytoplankton are the basis of the food chain in: | oceanic photic zones |
The ample rainfall of the tropics and the arid areas around 30 degrees north and south latitudes are caused by | the global circulation of air initiated by intense solar radiation near the equator producing wet warm air |
The permafrost of the arctic tundra | keeps the surface soil wet because water cannot penetrate through |
Many plant species have adaptations for dealing with periodic fires typical of these areas | savanna, chaparral, and temperate grasslands |
Two communities have the same annual mean temperature and rainfall but very different biota and characteristics. The best explanation for this phenomenon is that the two: | have different seasonal temperature sand patterns of rainfall throughout the year |
Upwellings in oceans | bring nutrient rich waters to the surface |
Why do the tropics and the windward side of mountains receive more rainfall than areas around 30 degrees latitude or the leeward side of mountains? | Rising air expands, cools and drops its moisture |
Describe the influence of mountains affecting local climates in terms of solar radiation | south facing slopes in the northern hemisphere receive more sunlight and are warmer and drier than north facing slopes |
Describe the influence of mountains affecting local climates in terms of temperature | air temperature drops with an increase in elevation, and high altitude communities may be similar to communities in higher latitudes |
Describe the influence of mountains affecting local climates in terms of rainfall | the windward side of a mountain range receives much more rainfall than the leeward side, the warm moist air rising over the mountain releases moisture, and the drier, cooler air absorbs moisture as it descends to the other side |
trade winds | wind toward the equator. The CoriolisEffect makes the trade winds appear to be curving to the west. |
doldrums | an area of calm weather at the equator. The converging trade winds produce general upward winds as they are heated, so there are no steady surface winds. |
westerlies | Between thirty and sixty degrees latitude, the winds that move toward the poles appear to curve to the east (winds are named from the direction in which they originate). Responsible for many of the weather movements across the United States and Canada. |
easterlies | Formed when the atmosphere over the poles cools. This cool air then sinks and spreads over the surface. As the air flows away from the poles, it is turned to the west by the Coriolis effect. |
Coriolis effect | The apparent deflection of the path of an object that moves within a rotating coordinate system. |
Specific Heat | Absorbs heat without changing temperature. •1 cal energy to heat 1 cm3 of water 1 C. |
Latent Heat of Evaporation | 1 cal can cool 580 g of water. |
Latent Heat of Fusion | 1 g of water gives off 80 cal as it freezes. |
soil | is a complex mixture of living and non-living material. |
O horizon | Organic Layer freshly fallen organic material -most superficial layer. |
A horizon | Mixture of minerals, clay, silt and sand. |
B horizon | Clay, humus, and other materials leached from A horizon -often contains plant roots. |
C horizon | Weathered parent material |
Mycorrhizae | symbiotic but occasionally parasitic relationship between plant roots and fungi |
behavioral ecology | studies the control, development and evolution of animal behavior |
population ecology | study of influence of the environment on fluctuations in the population size and composition |
population | group of individuals of the same species that occupy the same area, use the same resources, and have a high probability of interacting and breeding with each other |
population's density | number of individuals per unit area or volume |
dispersion | pattern of spacing of individuals within a population |
mark-recapture method | common sampling technique for determining population density/size |
immigration | changes of population density by addition of members |
emigration | changes in population density by removal of members |
territoriality | defense of physical space that can lead to uniform dispersion of a population |
What is the likely dispersion pattern of a fish that swim in schools, seabirds nesting on a small island and thistles growing in a fairly uniform field? | fish: clumped seabirds: uniform thistles: random |
demography | the study of vital statistics of a population such as birth and death rates |
life table | presents age specific survival data for a population |
cohort | a group of organisms studied from birth to death |
survivorship curve | shows the number or proportion of members of a cohort still alive at each age |
reproductive table | gives the age specific reproductive rates in a population |
life history | of an organism from birth through reproduction to death reflects evolutionary tradeoffs between survival and reproduction |
big-bang reproduction (semelparity) | an organism that puts all its resources in a single reproductive effort |
iteroparity (repeated reproduction) | making reproductive efforts over a span of time |
Explain why the life history of an organism can't be reproduce early, often and have large numbers of offspring and live long | An organism has limited resources to divide between growth, survival and reproduction |
In what way might high competition for limited resources in a predictable environment influence life history traits? | selection would most likely favor iteroparity with fewer, larger, better provisioned or cared for offspring |
per capita rate of increase (r) | the change in population size during specific time periods are equal to the number of births minus deaths (ignoring immigration and emigration) r=b-m |
zero population growth | occurs when the per capita rate of increase (r) is zero |
exponential population growth | dN/dt=rmaxN change in population size/change in time=maximum per capita rate of growth*population size |
carrying capacity(K) | maximum sustainable population size that a particular environment can support at a particular time |
logistic population growth | dN/dt=rmaxN(K-N)/K The per capita rate of increase decreases from its maximum at low population size to zero as carrying capacity is reached |
K-selection | populations at high densities close to their carrying capacity may experience a type of density dependent selection for traits such as competitive ability and efficient resource utilization |
r-selection | environments in which population density fluctuates or where population density is low a type of selection may take place based on density independent selection. This type of selection would favor traits that maximize population growth |
Indicate whether the following would be considered to be r-selected or K selected life history traits: early age at first reproduction; many small offspring produced | r-selection |
Indicate whether the following would be considered to be r-selected or K selected life history traits: few, relatively large offspring produced every year | k-selection |
density independent | when a birth rate or death rate does not change as population density changes |
density dependent | death rates rises and birth rates falls with increase in population density |
population dynamics | studies variations population size and factors that influence them |
metapopulation | immigration and emigration may significantly influence individual population sizes |
List some density-dependent factors that may limit population growth | nutrients, space for nests, accumulation of toxic wastes, predation, intrinsic limiting factors |
List some abiotic factors that may cause population fluctuations | extremes in weather, natural disasters, fires |
Two ways that population stability can be reached in one of two ways | a. Zero population growth= high birth rates- high death rates b. Zero population growth= low birth rates-low death rates |
Demographic transition | the movement from one type of population stability to another |
age structure | is a graphical illustration that shows the distribution of various age groups in a human population (typically that of a country or region of the world), which ideally forms the shape of a pyramid when the region is healthy. |
age structure of a population influences | present and future growth |
infant mortality and life expectancy at birth | vary among human populations, with mortality being much higher and life expectancy much lower in developing countries |
ecological footprint | takes into account multiple human needs in estimating carrying capacity |
In a range with a heterogeneous distrobution of suitable habitats, the dispersion pattern of a population probably would be | clumped |
What are true of life tables? | They were first used by life insurance companies to estimate survival patters, they show age-specific mortality or death rate for a population, they can be used to construct survivorship curves, they are often constructed by following a cohort from b-d |
In a population in which offspring survival is quite low and the environment is inconsistent, one might expect... | semelparity or big bang reproduction |
A Type 1 survivorship curve is level at first, with a rapid increase in mortality in old age. This type of curve is | is typical of humans and other large mammals |
The middle of the S-shaped growth curve in the logistic growth model | is the period when the population growth rate is the highest |
The term (K-N)/K | is zero when population size equals carrying capacity |
What are some density dependent factors limiting population growth | increased predation by a predator, limited number of available nesting sites, stress syndrome that alters hormone levels, intraspecific competition |
The carrying capacity for a population is estimated at 500, the population size is currently 400, and rmax is 0.1, what is dN/Dt? | 8 |
In order to maintain the largest sustainable fish harvest, fishing efforts should | maintain the population density close to 1/2K |
When would the following immigration and emigration likely play a role in population dynamics? | metapopulations |
For a population regulated by density-dependent factors, how might clutch or seed crop size change with increased population density? | Decrease |
In study of European kestrels described in the text, how did reducing the brood size by transfering chicks to other nests affect the survivorship of those parents the following winter? | increase |
In a population showing exponential growth, how would dN/dt be expected to change with an increase in N? | Increase |
Experimental studies of the population cycles of snowshoe hare and the lynx have show that | the hare population is regulated by a combination of food and predators; the lynx population appears to cycle in response to prey availability |
The demographic transition is the shift from | Type 1 survivorship curve to Type 2 survivorship curve |
An ecological footprint is the estimate of | the amount of land needed per person to meet the current demand on resources |
anatomy | study of biological form of an organism |
physiology | study of biological functions an organism performs |
evolutionary convergence | reflects different species adaptations to a similar environmental challenge |
thermoregulation | the process by which animals maintain an internal temperature within a tolerable range |
acclimation | physiological changes in response to temperature |
psychrophyilic | cold loving |
thermophilic | heat loving |
radiation on an organism | rays coming into contact with surface and sometimes reflected back into atmosphere |
convection | warm air molecules rising |
conduction | is heat transfer where two things are touching |
Hs=Hm+-Hcd+-Hcv+-Hr-He | Balancing heat gain against heat loss |
Hs | Total heat stored in an organism |
Hm | heat gained via metabolism |
Hcd | heat gained/lost via conduction |
Hcv | heat gained/lost via convection |
Hr | heat gained/lost via electromagnetic radiation |
He | heat lost via evaporation |
Temperature regulation by Arctic and Alpine plants | Increase radiative heating or decrease convective cooling |
Temperature regulation by tropic alpine plants | rosette plants generally retain dead leaves, which insulate and protect the stem from freezing, thick pubescence increases leaf temperature |
Temperature regulation by desert plants | decrease heating via conduction, increase convective cooling, reduce radiative heating |
poikilotherms | body temperature varies directly with environmental temperature |
ectotherms | rely mainly on external energy sources |
endotherms | rely heavily on metabolic energy, preferred temperature closely matches the temperature at which metabolizable energy intake is maximized |
homeotherms | maintain a relatively constant internal environment |
endothermic homeotherm "warm blooded" | stable body temperature-mostly from heat metabolism (birds, mammals) |
ectothermic poikilotherm "cold blooded" | variable body temp-most heat from environment (frogs, lizards, earthworms, and plants) |
ectothermic homeotherm | stable body temp-most heat from environment (antarctic fish, intestinal parasites) |
endothermic poikilotherm | variable body temp-most heat from metabolism (naked mole rat) |
List five general adaptations to help animals thermoregulate: | insulation, circulatory adaptations, cooling by evaporative heat loss, behavioral responses, adjusting metabolic heat, production |
insulation | major type of thermoregulatory adaptation in mammals and birds: skin, feathers, fur and blubber reduce heat flow between an animal and its environment |
vasodilation | blood flow in the skin increases, facilitating heat loss |
vasoconstriction | blood flow in the skin decreases, lowering heat loss |
countercurrent heat exchangers | transfer heat between fluids flowing in opposite directions, an important mechanism for reducing heat loss (dolphins fins and geese wings) |
Temperature regulation by endothermic animals: warming insect flight muscles | -bumblebees maintain temp of thorax regardless of temperature -sphinx moths increase thoracic temp due to flight activity by transferring heat from thorax to abdomen |
thermal neutral zone | range of environmental temperatures over which the metabolic rate of a homeothermic animal does not change |
Metabolic rate of small animals | higher metabolic rate of this size leads to a higher oxygen delivery rate, breathing rate, heart rate and greater blood volume |
Surviving extreme temperatures | inactivity-seek shelter during extreme periods reduce metabolic rate- enter a state of torpor |
torpor | physiological state in which activity is low and metabolism decreases |
hibernation | long term torpor that is an adaptation to winter cold and food scarcity |
estivation | summer torpor, enables animals to survive long periods of high temps and scare water supplies |
water availability | the tendency of water to move down concentration gradients and the magnitude of those gradients determine whether an organism tends to lose or gain water from its environment |
relative humidity | water vapor density/saturation water vapor density(*100) |
saturation water vapor density | measured as the quantity of water vapor air can potentially hold |
Does water move up or down a concentration gradient? | Water moves down concentration gradient, ie water is more concentrated in freshwater environments than in oceans |
osmosis | diffusion through a semipermeable membrane |
isomotic | body fluids and external fluids are at the same concentration |
hypoosmotic | body fluids are at a higher concentration than the external environment |
hyperosmotic | body fluids are at a lower concentration than the external environment |
Which has the lowest water potential, dry air or soil? | Dry air |
water potential | measurement that combines the effects of solute concentration and pressure, determines the direction of movement of water, |
Water regulation on land-animals | Wia=Wd+Wf+Wa-We-Ws |
Wia | Animal's internal water |
Wd | drinking water |
Wf | water in food |
Wa | water absorbed by air |
We | evaporation |
Ws | Secretion/excretion |
Examples of water conservation by plants and animals | Waterproof outer coverings on terrestrial organisms, concentrated urine/feces, condensing water vapor in breath, behavioral modifications to avoid stress times, drop leaves in response to drought, thic leaves, few stomata, periodic dormancy |
birth rate | number of young born per female |
fecundity rate | tabulation of birth rates for females of different ages |
Currencies in variation of life history | number of offspring, size of offspring, parental care, age at first reproduction, longevity, single verses multiple reproductive events |
natural selection involves energetic trade-offs between | high survival rates of offspring and cost of parental care |
principle of allocation | if organisms use energy for one function such as growth, the amount of energy available for other functions is reduced |
Life History variation among species observation by Shine and Charnov | Individuals delaying reproduction will grow faster and reach a larger size |
As body size increases in animals, there is | a decrease in the surface-to-volume ratio |
Which aquatic environment typically experiences the least daily variation in temperature? | deep pool in a stream |
Organisms able to do sulfur oxidation at 65˚C are called……………….., while bacteria growing at -2˚C are called….......... | Thermophilic, psychrophilic |
Where would an ecologist find the most phytoplankton in a lake? | photic zone |
Air masses formed over the Pacific Ocean are moved by prevailing westerlies where they encounter extensive north-south mountain ranges, such as the Sierra Nevada and the Cascades. Which statement best describes the changes that these air masses undergo? | The warm, moist Pacific air rises and cools, releasing precipitation as it moves up the windward side of the range, and this cool, now dry air mass heats up as it descends on the leeward side of the range |
A freshwater fish was accidentally placed in salt water. After several minutes in this saline water, it died. What is the most logical explanation for its death? | Loss of water by osmosis in cells in vital organs resulting in cell death and eventually organ failure |
Generalized global air circulation and precipitation patterns are caused by | rising, warm, moist air masses cool and release precipitation as they rise and then at high altitude, cool and sink back to the surface as dry air masses after moving north or south of the tropics. |
What causes Earth's seasons? | the tilt of Earth's axis |
Ectotherms tolerate greater variation in internal temperature, while endotherms are active at a greater range of external temperatures, true or false? | True |
In temperate lakes, the surface water is replenished with nutrients during turnovers that occur in the | spring and fall |
What abiotic factor has the greatest influence on the metabolic rates of plants and animals? | Temperature |
Conduction is the transfer of heat by the movement of air or liquid past a surface, as when a breeze contributes to heat loss from a lizard’s dry skin, or blood moved heat from the body core to the extremities, true or false? | False |
Landscape ecology is best described as the study of | the factors controlling the exchanges of energy, materials, and organisms among ecosystem patches |
The emission of electromagnetic waves by all objects warmer than absolute zero is called: | radiation |
Metabolic heat (Hm) is the heat | released during cellular respiration |
Small, mobile and mostly microscopic organisms that live suspended in water are called | plankton |
The ‘scientific method' includes | observations, experiments, and modeling, posing questions and formulating testable hypotheses, and statistical analysis. |
Two woodpeckers, a rooster, 2 northern cardinals and 3 robins from your background will represent | a community |
Terrestrial environments show less temperature variations than aquatic environments, true or false | False |