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206 Cards in this Set
- Front
- Back
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interdisciplinary sciences of ecology
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biology
physics and chemistry geology, soil science climatology, hydrology |
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goal of ecology
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to understand the principles of operation of natural systems and to predict their responses to change
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greek "oikos" means...
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household, or place to live
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coined the term ecology
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Ernst Haeckel in 1866
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definition of ecology
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the study of the interactions of organisms w/ their environment
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water, light, heat, nutrients, soil, etc
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abiotic environment
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predators, prey, competitors, mates, etc
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biotic environment
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levels of organization in domain of most ecological studies
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biosphere
biome (landscape) ecosystem community population organism |
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arrangement of things into a graded series; successive levels include lower levels as components
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hierarchy
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properties unique to a particular level; not predictable from observation of the component parts or underlying levels
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emergent properties
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all of the individuals of a single species occurring in the same area; capable of interbreeding (a genetic unit)
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population
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all populations of organisms (plants, animals, microbes) occurring in the same area or habitat
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community
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a community plus its abiotic environment
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ecosystem
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characterized by spatial heterogeneity; often a larger-scale area that includes heterogeneity in soils, topography, climate, etc (can be used to describe heterogeneity at many different scales)
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landscape
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large regional systems, characterized by a particular climate and vegetation type
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biome
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all of the earth's organisms and the environment with which they interact
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biosphere
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responses and adaptations of the INDIVIDUAL ORGANISM (form, physiology, behavior) to the physical environment (temperature, light, water, nutrients)
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physiological ecology
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focused on POPULATIONS, and the factors affecting their DISTRIBUTION AND ABUNDANCE (births, deaths, immigration/emigration), and their EVOLUTION
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population ecology
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groups of MORE THAN ONE SPECIES, how these groups are structured, interactions among species, and BIODIVERSITY
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community ecology
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TRANSFORMATIONS AND MOVEMENT OF ENERGY, BIOMASS, NUTRIENTS, AND/OR WATER w/in and through ecosystems (energy and matter are "common currencies") to compare/contrast ecosystems
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ecosystem ecology
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three ways in which ecologists go about "doing ecology"
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observation
experimentation models |
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non-manipulative studies
descriptive ("natural history") and correlative studies observations may be simple or complex advantages--> high degree of realism, high external reliability as all components of system are included disadvantages--> no control over independent variables; difficult to assign direct cause-effect relationships |
observation studies
ex. eddy flux towers for measuring net ecosystem C exchange |
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manipulating one INDEPENDENT VARIABLE at a time (the "treatment") and measuring responses (DEPENDENT VARIABLES)
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experimentation
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"model" organisms (insects often used for population- and community-level studies)
______ --> representations of real-world phenomena on a small scale; simplified systems, under controlled conditions advantages -- greater control; simplified biotic components disadvantages -- artificial conditions may not give results relevant to the real world |
laboratory experiments
microcosms |
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advantages -- greater realism
disadvantages -- less control than lab experiments; potential for CONFOUNDING FACTORS (factors other than the independent variable) that can affect results |
field experiments
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_____ --> abstraction and simplification of nature
should be PREDICTIVE and/or have HEURISTIC VALUE (=generate new insights or questions) |
models
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types of models
____ -- non-quantitative; diagrams, word models) _____ -- quantitative, mathematically solvable |
conceptual models
analytical models |
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matter, temperature, energy
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constraints
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acquisition and allocation of energy and resources
time and energy budget survival, growth, reproduction |
adaptations
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geographic ranges of species are related to constraints imposed by the environment (_____ distribution = tolerance limits)
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potential
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however, these constraints can be modified by interactions w/ other species (e.g. disturbances or competitors can restrict a species ____ distribution)
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actual
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range of climatic conditions under which a species can occur
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climate envelope
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two ways in which physical environment influences an organism's success in 2 ways:
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suboptimal conditions reduce ability to obtain energy and resources required to maintain metabolic functions, grow and reproduce
more extreme environmental conditions affect survival directly (mortality) |
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environmental condition that decreases rates of critical PHYSIOLOGICAL PROCESSES, lowering the potential for survival, growth, or reproduction
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stress
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distribution of a species is limited by its range of tolerance for local environment factors
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shelford's law of tolerance
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organisms can exhibit narrow (____-) or broad (____-) tolerance ranges for different variables (specialists vs generalists)
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steno-
eury- |
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acclimatization
developmental responses behavioral responses |
individual-level responses
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adaptation
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population-level responses to environmental variation
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many organisms adjust to stress by altering morphology, physiology, or behavior = _____
usually a short-term, reversible change at the level of the individual generally involves shift in optimum range for biological functions time scale may be days to months, but reversible when conditions change again |
acclimatization (or acclimation)
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def. permanent changes in morphology, physiology or behavior in response to environmental conditions during growth and development
most important for plants (modular) and insects (discreet developmental stages) ex. phenotypic plasticity |
developmental responses
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may be used to tolerate or avoid adverse environmental conditions
short-term or cyclic behavior can allow tolerance of frequent, short-term environmental change |
behavioral responses
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salt water
oceans --> 96.5%, 71% earth surface fresh water ice sheets and glaciers --> 2.4% groundwater --> 1% rivers & lakes --> .02% soil water --> .01% atmosphere --> .001% |
distribution of free water on earth
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heat that is absorbed (or released) when a substance undergoes a phase change; does not result in change in temp of that substance
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latent heat
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large decrease in density of water as water warms
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important for stratification of lakes
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____ can dissolve in water, which increases the acidity of water
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CO2
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net change in ocean pH levels pre-industrial level is about -.11, or about 30% in "acidity" (H+ ion concentration)
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change in sea surface pH caused by anthropogenic CO2 b/t the 1700s and the 1990s
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water is less transparent than air
intensity and _____ _____ of light changes w/ depth (light attenuation is logarithmic) - IR removed near surface - PAR reduced w/ depth (reduced by 50% in top 10 m of pure seawater) ---red light removed first, blue and green light penetrates furthest (depends on dissolved substances) |
spectral composition
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study of aquatic ecosystems w/in continental boundaries
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limnology
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____ - standing water (lakes ponds, etc)
_____ - running water (springs, streams, rivers) |
lentic
lotic |
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characterized by water at or near surface, aquatic vegetation (hyrophytes) and hydric soils (marshes, swamps, etc)
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wetlands
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flooded long enough for anaerobic conditions to regularly develop
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hydric soils
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lakes exhibit ____ (horizontal and vertical), w/ distinct physical, chemical, and biotic characteristics
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zonation
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shallow area near shore, where light can reach the bottom (supports photosynthetic organisms); macrophytes and emergent vegetation
anchored photosynthetic plants possible |
littoral zone
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deep open water, planktonic or free-swimming organisms (insufficient light for photosynthesis in sediments below this zone)
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limnetic (pelagic) zone
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bottom waters and sediments; heavily influenced by inputs of organic matter from above; may be depleted in O2
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benthic zone
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photosynthesis > respiration in this zone
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euphotic, trophogenic
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photosynthesis = respiration
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compensation depth
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respiration > photosynthesis in this zone
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aphotic, tropholytic
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warm, upper layer; lower density water "floats" on the denser water below; well mixed, oxygenated
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epilimnion
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transition zone w/ steep temperature gradient
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thermocline
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lower layer of cold, dense water (stable, little mixing in stratified lake); may become O2 deficient; nutrients may accumulate (little plant uptake)
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hypolimnion
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BOD stands for...
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biological oxygen demand
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mixing of lake water is due to ___-generated currents and sinking of cold water (____ mixing)
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wind
convective |
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lakes that are nutrient poor (little P and/or N)
low primary and secondary productivity clear water; deep light penetration aerobic (oxygenated) hypolimnion lower watershed area:lake area |
oligotrophic lakes
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lakes that are nutrient rich
high primary productivity; may be summer and winter fish kills turbid (high algal biomass); shallow compensation depth anoxic hypolimnion and sediments high watershed area: lake area |
eutrophic lakes
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device for estimating transparency of water and depth of light penetration
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Secchi disk
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___ status of the lake sediments controls the chemical form and availability of phosphorous
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oxygen
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oxygen ___ ( ___ sediments)
--iron is oxidized (Fe 3+ ferric iron) -- Fe3+ bind w/ P to form insoluble minerals -- P becomes trapped in sediments |
oxygen present, aerobic sediments
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oxygen ___ (___ sediments)
--Fe is reduced (Fe2+ ferrous iron) --reduced iron doesn't bind w/ P --P is recirculated when lake turns over |
oxygen absent, anaerobic sediments
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_____ _____ - results from human activities (eg phosphorus additions)
-detergents, municipal sewage inputs, fertilizer runoff |
cultural eutrophication
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streams and rivers can be views as a continuum from headwaters to large rivers
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river continuum concept
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streams w/ no tributaries
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1st order (headwater) streams
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formed by convergence of 2 1st order streams
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2nd order streams
...etc |
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fast moving water w/ coarse particles on the stream bed
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riffles
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deeper and slower flow; finer sediments
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pools
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___ organisms are bottom dwellers, and include many kinds of invertebrates
some feed on ____ (dead organic matter), others are predators some live in the ____ zone--the substratum below and adjacent to the stream, where there is water movement from the stream or from groundwater |
benthic
detritus hyporheic zone |
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predictable gradients in abiotic and riparian characteristics from headwaters to large rivers
changes in the source and form of organic matter inputs are reflected by changes in consumer communities predictable changes in the ratio of photosynthesis to respiration (P/R ratio) autochthonous vs allochthonous sources of organic matter |
river continuum concept
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small, woodland streams
high canopy cover high allochthonous inputs (CPOM, leaf litter) |
low-order streams (1-3)
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broader streams, w/o complete canopies
increasing light availability and low turbidity mix of CPOM and FPOM |
mid-order streams (4-7)
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broad, deep rivers; high turbidity
little canopy cover, but low penetration high inputs of FPOM |
high-order streams (>7)
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____ ____ can result in ADAPTATION to environmental stress
individuals w/ traits that make them best able to cope w/ stress are favored over time, the genetically-based traits will become more frequent in the population |
natural selection
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both acclimatization and adaptation require investments of energy and resources, representing possible ___-___s w/ other functions that can also affect survival and reproduction
"no free lunch" energy and resources are finite allocating resources to one function decreases availability for others |
trade-offs
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adaptation
____-____ trait that improves an organism's ability to survive & reproduce under prevailing environmental conditions a result of evolution by natural selection |
genetically-determined
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segment of DNA molecule that encodes for a specific polypeptide (protein)
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gene
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different forms of a gene
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allele
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the genetic make-up of a specific population; sum of all alleles in a population
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gene pool
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relative abundance of different alleles in a population
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gene frequency
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can be defined as change in allele freq over time
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evolution
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random changes in allele freq due to chance events; esp. important in small populations
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genetic drift
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movement of genes b/t populations; homogenizing effect on different populations
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gene flow
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differential reproductive success
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fitness
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natural selection acts at the level of the _____
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individual
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but natural selection causes changes (evolution) at the level of the ______
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population
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evolutionary change that moves population mean in one direction
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directional selection
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evolutionary change that favors individuals w/ traits near the mean
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stabilizing selection
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evolutionary change that favors individuals w/ traits @ either extreme
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disruptive selection
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variation in phenotypic expression of a given genotype in response to environmental conditions (differential expression of genotype)
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phenotypic plasticity
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a GENETICALLY DIFFERENTIATED population, adapted to a particular range of environmental conditions or particular locale
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ecotype
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geographic isolation of diverging populations
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allopatric speciation
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reproductive isolation w/o geographic separation
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sympatric speciation
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responses of individual organisms to the abiotic environment (temp, moisture, light, etc)
short-term responses to environmental variation |
physiological ecology
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responses of populations (or species) to the abiotic environment (temp, moisture, light, etc) AND TO OTHER SPECIES
longer-term adaptations to the environment |
evolutionary ecology
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short-term conditions -- temperature, precipitation, humidity, cloud cover
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weather
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long-term weather patters, based on averages and variation measured over decades
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climate
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the atmosphere is affected by animals in these ways
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atmospheric composition including biogenic gasses such as: O2, CO2, CH4, and N20
plant transpiration drives local and regional hydrologic cycles --> irrigation and thunderstorms organic particles act as cloud condensation nuclei, critical for raindrop formation |
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Global climate patterns are driven by SOLAR INPUT levels and their interaction with...
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the atmosphere
earth's surface - absorbed and transformed oceans - redistributed |
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the earth is an ____ system with regard to energy inputs/outputs; solar inputs must be balanced by ____ back to space
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open
thermal radiation |
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the earth acts as a giant ____ ___ - redistributing and dissipating energy inputs from the sun
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heat engine
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PAR meaning and range
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photosynthetically active radiation
400-700 nm |
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solar radiation spans from these wavelengths
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100-5000 nm
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the earth radiates energy back in this range of wavelengths
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5000-100,000 nm
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the amount of solar radiation reaching the upper atmosphere at a point perpendicular to the sun
1366 W/m2 limits photosynthesis |
solar constant
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about how much of the annual solar inputs reach the earth's surface?
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about 1/2
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the atmosphere is transparent to ____ radiation, but absorbs ___ radiation
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shortwave
longwave |
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most of the solar radiation absorbed by earth's surface is emitted to the atmosphere in this form of radiation
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infared, longwave
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when water at the surface evaporates it absorbs energy in ....
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latent heat flux
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energy transfer from the warm air immediately above the surface to the cooler atmosphere by convection and conduction =
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sensible heat flux
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svante arrhenius (a swedish physicist) in 1896 described this
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greenhouse effect
proposed relation b/t atmospheric carbon dioxide concentrations and temperature suggested that fossil fuel combustion may eventually result in enhanced global warming ----> before industrial revolution |
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the greenhouse effect keeps earth how much warmer than it would be w/o an atmosphere
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about 33 degrees C
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these radioactively active gases drive contemporary climate change
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carbon dioxide
methane nitrous oxide ozone CFCs and other hydrocarbons |
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this constant radioactive gas has the most affect on the greenhouse effect overall
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H20 vapor
does not drive contemporary climate change--> is constant |
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this unit is used to measure effective different gasses are at increasing the temperature of the earth
differences due to shape of gasses and how long gasses last in atmosphere |
GWP
global warming potential |
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earth's climate is warmer now than at any time in the last ___ years, w/ substantial ecological consequences
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150 years
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____ of the last 12 years were statistically tied as the top 1-3 warmest years since 1880
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7
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the WHO estimates that increased mortality due to anthropogenic climate change b/t 1960 and 2000 was at least ______ ppl per year
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150,000
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effects of the atmosphere on composition of solar radiation
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most UV radiation is absorbed (by stratospheric zone)
PAR are reduced 25-50% IR wavelengths are reduced ~ 50% |
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what percentage of the radiation that makes it to the earth's surface is IR? PAR? UV?
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50% is IR
45% is PAR 5% is UV |
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temperature __ w/ altitude in the stratosphere
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increases
the stratosphere is an INVERSION LAYER which provides thermal stability against mixing w/ troposphere this pattern of heat is due to absorption of UV radiation by O2 and O3 |
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temperature ___ w/ altitude in the troposphere
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decreases
the troposphere is unstable, and its mixing drives weather patterns |
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the cooling that occurs due to rising in still air is called?
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environmental lapse rate
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the environmental lapse rate = ____
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6.5 degrees C per 1000 m
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the amount of ozone in the stratosphere depends on the....
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balance of ozone production and destruction
both of which are driven by the absorption of UV radiation and subsequently raise the temperature of the stratosphere |
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chlorine and other halides (ex. Br and NO) can act as _____ in the breakdown of stratospheric ozone
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catalysts
these reactions are responsible for the formation of the "ozone hole" over antarctica |
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Why are CFCs more important than natural sources of Cl?
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CFCs are stable in the lower atmosphere and natural forms are highly reactive and thus react in the troposphere
slow mixing of the stratosphere = long residence time for CFCs CFCs are broken down by UV in the stratosphere and release free chlorine concentration increases of Cl and other catalysts alters the balance of ozone creation and destruction |
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what are some examples of UV radiation danger?
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DNA damage (increase in skin cancer incidence)
cataracts, immunosuppresion damaged photosynthetic apparatus in plants |
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describe "bad" ozone
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bad ozone is ozone in the troposphere, which is a component of smog, is a strong oxidizer, and damages plants and animals
tropospheric ozone concentrations are increasing globally due to air pollution |
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___ of the heat from energy inputs from the sun are redistributed by air movement and ____ is redistributed by ocean circulation
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60% air
40% ocean |
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adiabatic cooling involves the temperature change due to _____ or _____ of a gas
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compression or expansion
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rising air expands (____ atmospheric pressure) and ____
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lower
cools |
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descending air is compressed (____ atmospheric pressure) and _____
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higher
warms |
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the rates of temperature change due to adiabatic cooling in moist and dry conditions are defined as....
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10 degrees C in dry
5 degrees C in moist/wet cool air holds less water vapor than moist air, so condensation occurs |
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ITCZ
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intertropical convergence zone
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the cells that come together to form the ITCZ
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hadley cells
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cells that fall between hadley cells and polar cells
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farrell cells
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cells higher in latitude than farrell cells
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polar cells
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the three cells (hadley, farrell, and polar) result in the 3 major climatic zones in each hemisphere:
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tropical, temperate, and polar zones
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___ (deflection of moving air or water) gives rise to global surface wind patterns and ocean currents
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coriolis
the earth is moving much faster around the equator than around 60 latitude 520mph --> 1040 mph |
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climatic seasonality is due to the movement of the ___ ____ during the year as the earth orbits the sun on a tilted axis
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solar equator
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latitude directly under sun's zenith (greatest solar inputs); moves seasonally through the tropics
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solar equator
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sun directly overhead at 0 latitude
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equanox
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the amount of energy required to raise the temp of one gram of substance by one degree C at normal atmospheric pressure
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specific heat
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amount of heat energy required to raise the temp of 1g water from 15 degrees to 16 degrees
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calorie
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the ____ side of mountains gets rain due to ____ lifting and ____ cooling
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orographic lifting
adiabatic cooling |
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the ____ side (the "rainshadow") and is often ____
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leeward
arid |
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this type of vegetation is adapted to wetter conditions
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mesic
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this type of vegetation is adapted to drier conditions
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xeric
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the compass direction as slope faces
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slope aspect
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in the northern hemisphere, south facing slopes have:
____ solar inputs and evaporation ____ plant cover and more ____ vegetation |
higher
lower xeric |
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a 1000m increase in elevation is functionally similar to a ____ increase in latitude
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1400 km
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deforestation increases the ___ of the land surface, lowering the absorption of solar radiation
this lower heat gain is offset by less cooling by ______, due to loss of leaf area |
albedo
evapotranspiration --> this being lowered can feedback to reduce local/regional precipitation |
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the biome is characterized by climate and ____ ___ ___ ___
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dominant plant life form
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overall appearance of the vegetation; based on broad features, such as growth forms of dominant species
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physiognomy
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a transition zone b/t biomes
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ecotone
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evolution of similar growth forms among distantly related species in response to similar selection pressures
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convergence
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major terrestrial biomes
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tropical rainforest
tropical seasonal forests and savannas deserts temperate grasslands temperate shrublands and woodlands temperate deciduous forest temperate evergreen forest boreal forest (taiga) tundra |
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range of possible precipitation amounts ____ w/ decreasing temp
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declines
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rates of enzyme-mediated rxns
properties of cell and organelle membranes water loss and availability |
all affected by temperature
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rates of many biological processes increase _____ w/ each 10 degree increase in temp.... but only under a limited range
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2 to 4 fold
(Q10 relationship) |
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equation for change in heat content of an individual
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metabolism - evaporation +/- radiation +/- conduction +/- convection
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faster flow through convection is achieved by ____ boundary layer and greater heat flux
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decreased
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the single "net radiation" term can be expanded to this
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solar radiation and infrared radiation
(SR + IRin - IRout) |
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hairs on leaf surfaces that reflect solar energy (a common adaptation in deserts)
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pubescence
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this value must be added to the equation for heat energy balance for animals
not significant for most plants |
metabolic heat generation
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rely primarily on internally generated (metabolic heat)
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endotherms
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rely primarily on external sources of heat
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ectotherms
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maintainence of internal body temp w/in narrow limits (most endotherms)
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homeothermy
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body temp varies w/ environmental temp (most ectotherms)
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poikilothermy
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body temp tracks ambient air temp
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thermal conformers
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body temp maintained above ambient air temp w/in limited range
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thermoregulation
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ectotherms may use ____ thermoregulation to control heat exchange w/ environment (basking, silting, etc)
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behavioral thermoregulation
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newton's law of cooling
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rate of heat loss is proportional to gradient b/t body and ambient temp
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heat loss is a function of ____ ____ and ____ ___ (can be modified by insulation
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ambient temp
body size |
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range of ambient temps over which an endotherm can maintain its core temp w/o changing its metabolism
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thermoneutral zone
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below this temp metabolism must increase to maintain body temp
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Tc - lower critical temp
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voluntary, reversible condition of low body temp & inactivity
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torpor
body temp may drop up to 20 deg metabolic rate can drop 50-90% length of time animal can remain in torpor is limited by its reserves of energy |
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another term for pressure potential of water
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turgor
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energy associated w/ attractive forces on surfaces of large molecules inside cells or on surfaces of soil particles
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matric potential
adhesion and cohesion |
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water potential defining equation
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osmotic potential (negative) + pressure potential (+/-) + matric potential (negative)
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all available soil pore spaces filled with water
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saturation
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amount of water soil holds after drainage of gravitational water
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field capacity (FC)
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amount of soil water remaining when plants can no longer get sufficient water
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permanent wilting point (PWP)
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amount of water potentially available to plants
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available water capacity (AWC)
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this type of soil is best for supplying plants, it has the highest AWC
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loam
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net equation for photosynthesis
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6CO2 + 6H2O + light --> C6H12O6 + 6O2
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about how much of incident radiation can plants convert to chemical energy thru photosynthesis
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only 1-2%
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green plants reflect more ___ ____ than red radiation
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near infrared
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this relationship description can be used to determine plant cover of an area
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normalized difference vegetative index (NDVI)
(NIR-RED)/(NIR+RED) |
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rate of attenuation of PAR as light passes thru a plant canopy is a function of ____
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leaf area index (LAI)
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the relationship b/t light levels and photosynthetic rate can be shown by a _____ ___ ____
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light response curve
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CO2 uptake increases as light intensity increases until a ___ ____ ___ is reached
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light saturation point
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the light level at which CO2 uptake is balanced by CO2 loss by respiration is the ____ ___ ___
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light compensation point
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shade-adapted plants have a
____ saturation level ____ Pmax _____ respiration rate _____ compensation point |
LOWER
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this becomes necessary when excess energy from light generates toxic oxygen compounds that damage membranes
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photoinhibition
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amount of accessory pigments can be varied to dissipate light energy
in the ___ ___, carotenoid pigments are converted from one form to another. some forms are more efficient at dissipating the heat energy |
xanthophyll cycle
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acclimatization and adaptation to temp variation involves the enzymes of the ___ ____ and the properties of the ____ ____
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calvin cycle
photosynthetic membranes |
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cold sensitivity in plants of tropical and subtropical biomes is associated w/ loss of ___ ___, which inhibits the functioning of the light-harvesting molecules
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membrane fluidity
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