Ecology Flashcards
(140 cards)
1
Q
In ecology, how are models useful? What are their limitations?
A
Models show idealistic versions of large complex ecosystems. However, because ecosystems are complex, models are not always accurate.
2
Q
What is the difference between ecology and environmentalism?
A
Ecology is a scientific study of the relationships within nature. Environmentalism is a social and political movement that assigns value to aspects of these relationships
3
Q
What is the problem with the environmentalist view to return things to a “pristine state?”
A
Which state is pristine? A value is placed on ecological time periods of the area.
4
Q
What is the difference between ecosystem and assemblage?
A
Ecosystems are interrelated components of an area (species, landscape, etc.). Assemblages are things in the same area with no strong connections to each other.
5
Q
What is biocenosis?
A
A term describing only the biotic or living aspects of an ecosystem.
6
Q
What is the difference between holism and reductionism?
A
Holism looks at the relationships as a unit - the whole being more important than the parts. Reductionism looks at and values the components more than the whole.
7
Q
Structural scale from large to small
A
Landscape patterns, habitat structure, population structure, genetic structure
8
Q
Compositional scale from large to small
A
Landscape types, community/ecosystem, species/populations, genes
9
Q
Functional scale from large to small
A
Landscape processes/disturbances, Interspecific relationships/ecosystem processes, life histories, genetic processes
10
Q
Describe the 11 parts of solar radiation in the atmosphere
A
- Entering radiation absorbed in atmosphere
- Atmosphere and clouds reflect entering radiation
- The surface of the earth absorbs entering radiation
- The surface reflects entering radiation
- The surface radiates outgoing radiation
- The atmosphere radiates outgoing radiation
- The atmosphere absorbs surface radiation
- Thermals are absorbed by the atmosphere
- The surface absorbs atmospheric radiation
- Evaporation/transpiration absorbed by atmosphere
- Greenhouse gases
11
Q
What is insolation
A
Insolation is the relationship between solar radiation, the atmosphere, and the earth’s surface.
12
Q
What are the adiabatic processes?
A
Air rises, and expands. As the air rises, it cools from expansion. This can result in saturation, clouds, and rain. As air descents, it warms. The humidity drops, producing drier air and wind.
13
Q
What is the Coriolis effect?
A
The adiabatic process in combination with the earth’s rotation causes rotating bodies of air movements.
14
Q
What are highs and lows?
A
Highs - descending air masses
Lows - rising air masses
15
Q
What are Hadley cells?
A
Hadley cells are pockets of air movement containing both highs and lows.
16
Q
What role does topography play on air and ocean currents?
A
Land masses determine the currents in the oceans and mountains cause air to rise to higher elevations, cooling the air.
17
Q
What are the layers of an aquatic ecosystem?
A
Euphotic - enough sunlight for photosynthesis and vision
Disphotic - can see but no photosynthesis
Aphotic - no sunlight
18
Q
How does water cycling affect vegetation?
A
In areas of rising air, the cooling of the air masses causes precipitation and areas of vegetation. In areas of descending air, no moisture produces no vegetation and desert conditions.
19
Q
What is soil?
A
Soil is a complex system of organic and inorganic matter (decaying materials, minerals, soil water, dissolved materials, soil gases, and living organisms).
20
Q
What is the importance of soil?
A
Minerals are utilized by plants, water is used for transpiration via plants, and bacteria and fungus live in the soil.
21
Q
How is soil formed?
A
- Rocks are weathered by wind, rain, erosion, and glaciers.
2. Acid rains, waters, lichens, worms, and other mechanisms dissolute the rocks.
22
Q
What are the layers of soil?
A
Top - organic layer (undecomposed/partially decomposed plant material
Topsoil - mineral soil with lots of organic matter
Subsoil - clay, salts, larger rock layer
Bottom - Unconsolidated materials from parent source
23
Q
What are the differences in soils?
A
Grassland and desert soils are rich in calcium and calcium salts. Forest soils are leached of calcium, leaving silicon, oxygen, aluminum, and iron. Tropical soils are generally leached of mobile minerals, leaving insoluble iron, aluminum oxide, and bauxite.
24
Q
What are the benefits and deficits of heavy and light soils?
A
Heavy soils retain water but are poorly aerated.
Light soils are aerated but have poor water retention.
25
What is the cation exchange capacity?
A measure of the ability of a soil to hold dissolbed ions
26
What is soil water potential?
The addition of water pressure, osmotic potential, gravitational potential, and matric potential
27
What is gravitational potential?
The force of gravity exerted on a water column
28
What is pressure potential?
Also called turgor, the water potential exerted by the weight of the water
29
What is matric potential?
Water potential due to the attraction between water and soils (generally negative)
30
What is osmostic potential?
The dilution of solutes in water
31
What is field capacity?
Amount of water a soil holds after initial draining - the water held against the force of gravity and only removed by evapotranspiration
32
What is hygroscopic water?
Water this is in equilibrium with the surrounding atmosphere.
33
What role does soil fauna play on soils?
1. Increase decomposition rates
2. Fragment litter and channel wood and soil
3. Transport microbes and substrates
4. Graze on microbes and release nutrients
5. Mix substrates, altering ecosystems
34
What is tolerance?
An adaptation allowing life to adjust to changing environmental conditions.
35
What is the Law of the Minimum?
Living things have a specific requirement to nutrients and their lowest amounts of these nutrients.
36
What is the Law of Tolerance?
Too much or too little of environmental factors affect an organism.
37
What are tolerance limits? What are generalists and specialists?
Tolerance limits are narrow areas of limitations on the amount of adaptation an organism can have based on seasonal, age or geographic changes (within the lethal limits). Generalists are widely tolerant where as specialists have a narrow tolerance.
38
What are lethal limits?
The upper and lower points in which an organism will die with too much or too little of a specific factor.
39
What other names are there for tolerance limits?
Suboptimal or avoidance limits
40
What is the optimal range or performance optimum?
The area in the environmental factor range in which an organism thrives - producing more energy, best performance, and the most reproductive success.
41
What is acclimation?
Process of adjusting homeostatic mechanisms to perform under specific physical conditions.
42
What is phenotypic plasticity?
Ability to change form under different environmental conditions
43
What is hormesis?
Favorable biological response to low toxin and stress exposure
44
What are some limiting factors?
Temperature, oxygen levels, water availability, pressure, light, pH
45
What is homeostasis?
The maintenance of a relatively constant internal state under a much broader range of physical and environmental conditions
46
What are photosynthetic organisms?
Organisms that gain energy from sunlight
47
What in the relationship between energy and wavelengths?
Longer wavelengths have less energy while shorter wavelengths have more energy
48
What is a generalized process of photosynthesis?
Light wavelengths hit photosynthetic cells and lose an electron. Chlorophyll pigments absorb blue, red, and violet light in photosystem II and photsystem I. Energy is transferred to the reaction center. ADP is phosphorylated to produce ATP.
49
The Calvin Cycle is used to create which molecule?
Glucose
50
What is transpiration?
The stomata open, allowing carbon dioxide into the leave while simultaneously releasing water.
51
What is photoinhibition?
Too many excited electrons do not allow for the photosynthetic metabolism
52
What is the difference between shade tolerant and shade intolerant?
Shade intolerant species need areas of high sunlight and photosynthesis, while shade tolerant species can survive in both bright sun and areas with less sun.
53
What is periodicity?
Plant species respond to periods of insolation (night and day lengths) to determine their physical characteristics - particularly seasonal changes
54
What is convection?
Function of temperature, leaf shape and size in relation to the outer environment
55
How does temperature affect photosynthesis and metabolism?
As temperatures increase, photosynthesis and respiration increase. At a certain point, photosynthesis plateaus while respiration continues to rise. As temperatures reach a critical level, respiration begins to plateau.
56
What is the Degree-Day Index?
Measure of variations in temperature over a growing season
57
What is aerenchyma?
A plant adaptation to waterlogged soil in which the plant creates gas filled chambers in leaves and roots to allow oxygen to diffuse from shoots to the roots
58
What are halophytes?
Plants adapted to living in saline environments (both terrestrial and aquatic)
59
What is leaf abscission?
The loss of leaves to control nutrient levels
60
What is the difference between herbivory, carnivory, detritivory, and omnivory?
Herbivores - gain nutrients from eating plants
Carnivores - gain nutrients from eating other animals
Omnivores - gain nutrients from plants and animals
Detritivores - gain nutrients by eating plan to animal wastes
61
What is the difference between ectothermy and endothermy?
Ectotherms have an internal temperature reliant on the outside environment, whereas endotherms produce their own internal temperature but with more metabolic energy.
62
What are other names for ectotherms and endotherms?
Ectotherm - poikilotherm
| Endotherm - homeotherm
63
What are some ways ectotherms regulate temperature?
Avoidance - hide out during times when too hot or cold
Changing orientation - reduces amount of the surface exposed to the sun
Large size - conserves metabolic heat by decreasing surface area per volume unit
64
What is Basal Metabolic Rate?
In endotherms, the rate at rest with no stress or digestion that is needed for the survival of the organism
65
What is the thermoneutral zone and upper and lower critical temperatures?
Thermoneutral zone - range where BMR is maintained
Low - increase metabolic heat to maintain body temp
High - evaporate heat (sweat) to maintain body temp
66
What are adaptations for homeothermy in endotherms?
```
Thermogenesis - shivering raises body temp
Brown fat - rapid release of heat
Leaky ion gradients - used ATP to release heat
Insulation
Shedding/molting
Blubber
Migration
Torpor - stored fat
Hibernation
Panting (in heat)
Avoidance
Estivation - dormancy
```
67
What materials decompose the fastest? The slowest?
Proteins and soluble carbons decompose quickly, cellulose and hemicellulose in the middle, and lignin the slowest.
68
How does temperature affect decomposition?
Increase temperatures increase decomposition rates
69
What is mineralization?
Process in which microbial decomposers (bacteria and fungi) transform elements from organic matter into inorganic or mineral forms
70
What are the different levels of organization?
Organism, population/deme, metapopulation, community, ecosystem, biosphere
71
What is the mainland - island model?
df/dt = [pi] (1-f) - [pe]f where pi is the probability of immigration, f is the number of occupied habitats, pe is the probability of extinction
72
What is the internal colonization model?
df/dt = if (1-f) - [pe]f where i is immigration, f is the number of occupied habitats, and pe is the probability of extinction
73
What are sink populations?
Habitats that would not support the species if isolated
74
What is population density?
The number of individuals per unit space
75
What is ecological density?
The number of individuals per habitable space
76
What is dispersal?
The movement of an individual from birth to reproduction - the home range
77
What are the three modes of dispersion?
Clumped - groups of a species
Uniform - evenly spaced
Random - movement not following a pattern
78
What is the nearest neighbor method?
Distance between randomly chosen points to the nearest individual are measured
79
What factors determine population distribution?
Areas of water, food, shelter, etc., climate conditions, predations, parasites, temperature, topography, etc.
80
What are the different age structures?
Expanding rapidly - few old, lots of young prior to reproductive age
Expanding slowly - gradual increase from prereproductive to aging
Stable - consistent numbers of young and old
Declining - more aging than prereproducing
81
What is the formula for population growth rate?
N[t+changet] = Nt + B - D + I - E where the growth is equal to the number of individuals at time t plus births, minus deaths, plus immigration, minus emigration
82
Survivorship and mortality characteristics
X - age period or stage in life
ax - number or proportion of individuals in x
lx - proportion of individuals survive to age x out of 1000 (ax/a0)
dx - proportion of individuals which die from one stage to next lx-lx+1
qx - proportion of individuals alive at time x and died between x and x+1 (mortality rate) dx/lx
kx - killing value log(ax/ax+1) or log(lx/lx+1)
ex - mean expectation of life for organism alive at start of age x Tx/lx
Lx - average number of individual alive between interval age x and x+1 [lx +lx+1]/2
Tx - total average number of individuals from age x to age infinity (ELx)
Bx - new individuals produces from age x to age x+1
mx - age specific birth rate at age x (fecundity - females)
lxmx - potential number of offspring produced
83
Net reproductive rate
R0 = Ex (lxmx)
If R0 is greater than 1, increasing population
If R0 is less than one, decreasing population
If RO is equal to 1, population stable
84
What are the three types of survivorship?
Type 1 - low mortality until old age (mountain shape)
Type 2 - constant mortality despite age (straight line down)
Type 3 - high mortality at young age, increasing at adulthood (valley shape)
85
What is the formula for generation time?
T = Ex (xlxmx) / R0 where x is the age, lx is the proportion to survive to age x, and mx is the fecundity over the net reproductive rate
86
What is the formula for the rate of increase?
Nt =Nt * lamda t where lamda equals 1 + b - d
| ln Nt = ln N0 + r delta t where n is number of individuals, r is the increase and t is time
87
What is a carrying capacity?
The amount of individuals a habitat can support given its resources
88
What is the Allee effect?
When population sizes are too small, not enough increase to sustain population
89
What is competition?
The combined demand for a resource that may exceed an immediate supply
90
What are density-dependent factors?
Overcrowding, Allee effect, emigration, immigration, competition, predation, parasitism
91
What is intraspecific competition versus interspecific competition?
Intraspecific competition is between the same species while interspecific competition is between multiple species.
92
What are examples of intraspecific competition?
Exploitation - competitive exclusion
Interference - direct confrontation
Territoriality - competitive exclusion and direct confrontation
Asymmetry - few large individuals and lots of small ones
93
What are the differences between r-selectionists and k-selectionists?
r-selectionists have short life spans and reproduce quickly - generally in fluctuating environments
k-selectionists have longer life span and stable population near carrying capacity - slower growth rates but more stable environments - parental care
94
What are examples of interspecific competition?
```
Predator - prey
Symbiosis - mutualism and neutralism
Commensalism
Competition
Creation of niches
Resource partitioning
Coevolution
```
95
What are the differences between inputs and outputs?
Inputs are exchanges into the ecosystem from the surrounding environment. Outputs are exchanges from inside the ecosystem to the surrounding environment.
96
What is the difference between a closed and open ecosystem?
A closed ecosystem has no inputs whereas an open ecosystem receives inputs from the surrounding environment.
97
What is gross primary productivity?
Total rate of photosynthesis or energy assimilated by autotrophs
98
What is net primary productivity?
rate of energy storage as organic matter after respiration (GPP - R)
99
What is productivity?
rate at which organic matter is created by photosynthesis
100
What is biomass?
amount of organic matter present at any given time
101
What is the formula for net primary productivity?
NPP = change of biomass + death + consumption by organism
102
How does weather affect net primary productivity?
As temperature and rainfall increase, terrestrial NPP increases
103
What does PAR stand for?
Photosynthetically active radiation
104
What is compensation depth?
Where NPP is zero because photosynthesis equals respiration
105
What nutrient limitations are generally present in aquatic ecosystems?
Nitrogen, phosphorus, and iron
106
How does precipitation affect root to shoot ratio?
With less moisture, more energy is allocated into the roots
107
What is relative net primary productivity?
ratio of net primary productivity to standing biomass - the rate of biomass accumulated per unit of plant biomass present
108
What is assimilation efficiency?
ratio of assimilation to ingestion
109
What is production efficiency?
ratio of production to assimilation
110
What are the two main types of food chains? What are their steps?
Grazing food chain: primary producers, herbivores, carnivores
Detrital food chain: detritus, decomposer herbivores, carnivores
111
What is consumption efficiency?
ratio of ingestion to production (In/Pn-1)
112
What is trophic efficiency?
ratio of productivity in a given trophic level to the trophic level it feeds on (Pn/Pn-1)
113
What are the different types of detritivores?
1. Microfauna and microflora - protozoans, nematodes
2. Mesofauna - mites, potworms, sprintails
3. Macro- and megafauna - snails, millipedes, earthworms, annelid worms, crustaceans, mollusks, crabs
114
What are microbivores?
Protozoans that feed on bacteria and fungi
115
What factors affect the rate of organic decay?
```
Plant litter quality
Soil properties (texture an pH)
Climate
temperature
moisture
```
116
What is net mineralization rate?
the difference between the rates of mineralization (transformation of nutrients from organic to inorganic matter) and immobilization (uptake and assimilation of minerals by microbial decomposers)
117
What is a rhizosphere?
region of the soil where plant roots function - an active zone of root growth and death with intense microbial and fungal activity
118
What three elements are necessary for plant growth in large quantities?
Nitrogen, phosphorus, and potassium
119
What is eutrophication?
explosive growth of algae in aquatic ecosystems due to excess nitrogen deposits
120
What is the vertical structure or open-water aquatic ecosystems?
1. Epilimnion - surface water (warm, high oxygen content)
2. Hypolimnion - deep water (cold, low oxygen)
3. Thermocline - middle zone with gradual temperature gradient
121
How are nutrients moved in open-water aquatic ecosystems?
The thermocline breaks down during autumn and winter, mixing or turning over he waters before being reestablished in the spring.
122
What is the biogeochemical cycle?
cyclic flow of nutrients from the nonliving to the living and back to the nonliving components of the ecosystem
123
Where are gaseous biogeochemical cycle nutrients located? What about the sedimentary biogeochemical cycle?
Gaseous - atmosphere and oceans
| Sedimentary - soil, rocks, minerals
124
What is ammonification?
The change of ammonium NH4+ to NH3 as a microbial waste activity
125
What is nitrification?
Conversion of NH4+ to NO2- and then to NO3-
126
What is denitrification?
Reduction of NO3- to N20 and N2 which are then returned to the atmosphere
127
What is a shifting-mosaic model?
A seemingly stable climax forest is actually a series of repeated successional patches
128
What is fluctuation?
Alterations in community structure or composition that occur as a result of shifts in habitat factors
129
What are the differences between pioneer and climax communities?
Pioneer communities are the first to establish the ecosystem whereas climax communities come in later and is at equilibrium with the environment.
130
What is the difference between hydroseres and xeroseres?
A hydrosere begins in water while a xerosere begins in rock and sand (without water)
131
What is the difference between primary and secondary succession?
Primary or prisere starts from almost nothing whereas secondary or subsere starts when succession has been halted or reversed
132
What are the four types of landscape patches?
Disturbance patches - natural or artificial resulting from agriculture, forestry, urbanization, fire, and weather
Remnant patches - humans alter the landscape in an area and leave parcels of the old habitat behind
Environmental resource patches - an environmental condition
Introduce patches - nonnative plants or animals introduced into an area, altering native plants
133
What are the differences between inherent and induced edges?
Inherent edges form from differences in soils or landforms while induced edges result from disturbance or human influence.
134
What are Holdridge Life Zones?
Terrestrial biomes placed in a scheme dependent on annual precipitation, evapotranspiration ratios, and biotemperatures
135
What are biomes?
Any of several major ecosystems characterized by the presence of specific plants and animals, climate, and soil conditions in a specific geographic setting
136
What is an ectotone?
Boundaries between biomes
137
What are the 13 types of biomes?
```
Savannas
Temperate Grasslands
Chaparral
Pinyon-juniper
Desert
Tundra
Boreal Evergreen
Temperate Deciduous
Tropical Forests
Freshwater Systems
Saltwater Systems
Wetlands
Cryptic Systems
```
138
What are cryptic systems?
Caves, phytotelmata, dung and carrion
139
What are phytotelmata?
Plant puddles - found in bromeliads and pitcher plants
140
What are the six biogeographical realms?
Nearctic (North America)
Neotropical (South America, the Caribbean islands)
Australians (Australia, several surrounding islands)
Oriental (India, Countries Under China, some Islands, Pakistan)
Ethiopian (Africa minus small portion northwest, Madagascar)
Palearctic (small northwest portion of Africa, Europe, Middle East, Russia, China, Japan, Mongolia)
