Unit 2 Quiz 1 Flashcards
everything after unit 1 till Chapter 6 succession slides
Define producers/autotrophs
organisms that can convert inorganic substances to nutrition/energy, providing organic substances
Describe the process by which producers convert solar energy into chemical energy and how the energy is accessed and utilized by most plants
photosynthesis
cellular respiration
Define consumers/heterotrophs
an organism that obtains its nutritional requirements through consumption of complex organic substances
Understand primary, secondary, and tertiary consumers
primary consumes producers
secondary consumes primary
tertiary consumes secondary
etc.
Trophic level?
the position an organism occupies on a food web
Food web vs. food chain
why are food webs important
Chain: linear pathway of energy transfer
web: interconnected food chains
webs allow scientists to understand how a change in 1 species can affect others
scavenger?
animal that feeds on dead animals or decaying OM
detritivore?
animal that feeds on dead OM, in particular plant detritus
decomposer?
breaks down OM into simpler substances
Ecology Definition
Study of interactions between organisms and their environment (Abiotic and biotic)
Ecosystem:
area distinguished by a particular mix of biotic and abiotic factors. Can have a wide variety of scales
Ecosystem ecology:
studies flow of energy and matter within and between ecosystems
What is Gross Primary product? What is net primary productivity? Ecological significance of NPP?
GPP is total energy captured through photosynthesizer in an ecosystem. NPP is the remaining energy after producer cellular respiration.
GPP - respiration = NPP
NPP is significant because it is the energy available to contribute to the biomass of producers, and therefore the energy available to consumers
What happens to energy as it moves through food web?
Rule of 10?
consumers must expend energy for various reasons. Some energy will also be lost as heat whenever energy transformations take place.
Only about 10% of energy contained in prey a predator consumes contributes to biomass
3 steps to flows of matter:
- producers use resources to produce biomass
- matter moves through biotic components of ecosystem through consumption and use
- ultimately all of this matter is recycled by detritovores and decomposes
distinguish between detritovores and decomposers, give examples
detritovore: mechanically break down OM. Examples are worms or soil insects
decomposer: chemically break down OM like bacteria or fungi
Biosphere:
sum of all ecosystems; largest level of biological organization
Reservoirs vs. Flows:
Reservoirs: components that contain matter in an ecosystem (water, air, OM)
Flows: processes that move matter between reservoirs
WATER CYCLE
-Reservoirs?
-Flows?
know general idea
anthropogenic impacts?
-reservoirs: bodies of water, soil, plants, atmosphere, ice and snow
-flows: evaporation & evapotranspiration, condensation/precipitation, runoff, and melting
Glacier, ice caps, and snow pack release water very slowly allowing for greater soil uptake. Global warming is accelerating this and this causes soil to become saturated and runoff to build up, causing flow into ocean. This decreases our freshwater availability and contributes to sea level rise.
CARBON CYCLE
-Reservoirs?
-Flows?
Explain an image of it
Anthropogenic impacts?
-reservoirs: atmosphere (CO2), Bodies of water (Dissolved CO2) ,living things, soil and ocean floor (OM), and earth’s crust (hydrocarbons/fossil fuels)
-flows: Exchange between bodies of water and atmosphere, photosynthesis/carbon fixation, respiration, burial and sedimentation, extraction & combustion
-Human activities are disrupting long term sinks of carbon and returning it to the atmosphere. Leads to global warming & ocean acidification
NITROGEN CYCLE
-Nitrogen tends to be a ___ nutrient. Explain
-What is nitrogen fixation?
-What do nitrogen fixing bacteria do with plants?
-What do nitrifying bacteria do?
-Once N is available to plants…
- Under anaerobic conditions bacteria ____
-anthropogenic impacts?
-limiting nutrient. This means that organisms require a large amount of this to grow
-Nitrogen fixation is a process by which N2 in atm is converted to a usable form via natural or synthetic abiotic processes, and mostly biologically
-Nitrogen fixing bacteria form symbiotic relationships with certain plants and exchange N for sugars
-Nitrifying bacteria in soil convert fixed nitrogen and other nitrogen forms into nitrate, which is easily accessed by plants.
-Once plants have it N cycles through trophic levels and is returned to environment (N assimilation & mineralization)
-under those conditions denitrifying bacteria return fixed N to atm as N2
-excess N in soil form fertilizers moves into waterways via runoff and leaching (Groundwater) which contributes to eutrophication (too many nutrients) an algal blooms can result
PHOSPHOROUS CYCLE
-P is also a ____ nutrient which means…
-The P cycle is usually __
-Describe __ parts of phosphorous cycle
-Anthropogenic impacts
-limiting
-slow. Releases via weathering (and now mining)
-STEPS
1. P released from weathering of applied as fertilizer is either taken up by producers and cycles through food web or enters waterways. All will enter waterway eventually.
2. phosphorous cycles through food web and is slowly returning to ocean
3. P deposits in ocean floor and can be incorporated into sedimentary rock
4. geologic cycles return rock to surface (hence why it is slow)
-impacts are similar to N cycle. Eutrophication can occur.
What is an ecological disturbance?
Examples?
a temporary change in environmental conditions that causes significant change in an ecosystem
Examples in nature are droughts, fires, blizzards, etc.
Examples from people are development, invasive species, air pollution, etc.
Anthropogenic effects on natural disturbances
people tend to influence severity, frequency, and duration of these disturbances.
Top-Down vs. Bottom-Up control trophic cascades
Top down: changes higher up in web impact all lower trophic levels. This has an oscillating effect on populations.
Bottom up: changes lower n food web affect all higher levels, this has a consistent effect on populations.
Resistance vs. resilience response to disturbances
resistance: not strongly affected
resilience: affected but rebound quickly
What are watersheds? Why do we use them?
Characterized by?
highest point?
Watersheds are all of the land in a given landscape that drains into a particular body of water. We use them because even though they are not ecosystems they are good for investigating ecosystem impacts on a smaller scale. They are characterized by: size, slope, soil, and vegetation.
The highest point is called a DIVIDE and is named so because anything past that point drains in another direction and is not part of that watershed.
4 types of ecosystem services and their definition.
Provisioning services: goods obtained from ecosystems (food, water)
Regulating services: Benefits from regulating environmental conditions. Climate regulation, pollination, disease regulation, etc.
Supporting Services: Fundamental processes that enable other ecosystem services. EVERYTHING ELSE BENEFITS FROM THESE. Nutrient cycling and soil formation are good examples.
Cultural services: Intangible benefits (sightseeing, surfing, etc. )
how does resilience apply to the concept of ecosystem services?
Basically just prevents loss of these services.
Genetic Diversity vs. Species diversity vs. Ecosystems diversity.
When you hear diversity, think variety of.
Genetic: variety of genes within a population or species
Species: variety of species within a given ecosystem
Ecosystem: variety of ecosystems in a region
Species richness & evenness
richness: # of species in a given area
evenness: relative proportions of individuals within the species present. AKA relative abundance.
What are the three filters of community assembly?
Historical: does it arrive? To live somewhere you must get there first
Physiological: can it germinate, grow, survive, etc.
Biotic: can it successfully compete & defend itself.
What is an ecological niche?
all of the ways a species interacts w/ environment. Its use of and impact on biotic and abiotic factors.
What is range of tolerance and fundamental niche?
ROT: limits to abiotic conditions a species can tolerate. Can it survive?
Fundamental niche: entire set of abiotic conditions in which a species can survive & reproduce.
What is competition? Competitive exclusion? Resource partitioning (3 types)?
struggle between individuals or populations to obtain a limiting resource.
CE: one species outcompetes the other, potentially removing it
RP: one or more species engaged in competition can adapt to reduce competition and promote coexistence. Temporal (time), spatial, or morphological adaptations can be made.
what is a realized niche?
range of biotic and abiotic conditions under which a species actually lives given biotic interactions. Largely a product of niche partitioning.
Niche generalist vs. specialist.
generalist: able to thrive in a wide variety of conditions. Ex: racoon
specialist: specialized to live in a certain habitat or have a special diet. Ex: pandas only eat bamboo.
Generalist is a jack of all trades, master of none.
invasive species?
Nonnative species that outcompete a native species. Most of them are generalist.
What two main mechanisms lead to genetic diversity?
mutations and sexual reproduction
Define evolution:
process by which populations accumulate inherited changes over time.
Natural vs. artificial selection?
natural: certain traits in a species are favored and it allows individuals w those traits to reproduce.
artificial: people look for desirable traits and breed those only.
Adaptation?
when a heritable modification allows for an organism to better survive in its environment.
Gene flow?
When genetic variation goes up due to mating events between 2 separate populations. May not always be beneficial.
Genetic drift? Founder effect? Bottleneck effect?
Chance events cause a shift in alleles from one generation to the next, usually reducing genetic variation.
founder effect: genetic variation decreases when a few individuals are isolated from a larger group
Bottleneck: chance event or disaster reduces size of population and genetic variation
Speciation by biological species concept? Two types?
Determines species bt breeding compatibility and viability of offspring.
Allopatric: geographic isolation of 2 populations.
Sympatric: anything that isn’t geographic.
Understand phylogeny trees…
…
Predation? Parasitoids? Describe how predation has impacted evolution of species.
Predation is one animal killing and consuming another.
Parasitoids are animals that lay eggs in other animals
Predation has caused species to evolve defenses such as behaviors, appearance, or chemical defenses.
Parasitism?
one organism lives on or in another organism
herbivory
one interaction in which an animal consumes a producer
Mutualism vs. commensalism
mutualism: interaction between 2 species that increases chances of reproduction or survival
commensalism: one benefits and other is unaffected
Keystone species?
a species that is not very abundant but has large effects on ecological community.
What is predator-mediated competition? Describe how this influences species richness. Is this a bottom-up or top-down cascade?
competition that controlled by a predator. If it is absent prey can become too abundant and that prey’s competition will decline leading to a decrease in richness. Top down cascade.
What is an ecosystem engineer?
a keystone species that creates or maintains habitats for other organisms.
Top down vs. bottom up soil formation methods?
top down: decomposition, weathering and erosion
bottom up: weathering
Steps of primary succession?
- base for primary succession must be devoid of soil (typically volcanic or glacier rock)
- A pioneer species that can survive w/ little to no soil (mosses, lichens, etc.) can grow on this rock and chemically weather it. They also decompose and create OM
- Thin soil layer allows for gresses and wildflowers to establish, which further contribute to soil formation.
- In biomes w/ moderate precip, shrubs will become est. as soil becomes more developed. If rainfall sufficient, trees will as well.
what is a pioneer tree? what is special about them? What happens to them in the future?
First trees to grow. They are usually thin and grow fast. Them and other smaller plants will eventually become dominated by larger trees in forest biomes, thinning out or disappearing entirely as these trees are larger and thicker but take longer to grow.
Steps of secondary succession?
Same as primary but without soil formation. Secondary succession retains soil.
1. Biota removed but soil remains
2. fast growing plants initially dominant
3. eventually community is reestablished
Alternative state community? Climax community?
-this is when in succession the community does not return to its original form.
-endpoint of succession
