8.1 multispecies interactions Flashcards
what is the starfish?
a keystone species
what is the tropic cascade scenario with the removal of the top carnivore?
what is community ecology?
the ecological community is the set of plant and animal species that occupy an area
attempts at reconstructing communities raise countless questions-questions central to the study of ecological studies
-what controls the relative abundance of species within the community?
-how do the component species interact with each other?
-how do communities change through time?
-how do different communities on the larger landscape interact?
what is the simple conceptual model of food chains?
in this simple conceptual model of a food chain, the arrows indicate the direction of energy flow, not who is eating whom
what is the food chain in the Coachella Valley in the southern California desert?
-numerical ranks indicate the trophic level, with arrows pointing in the direction of energy flow
-each trophic level also has alternative nomenclature that indicates level or type of organism
what is the lake Tahoe food chain 1872?
-lake Tahoe sits in the Sierra Nevada between Nevada and California
-its native aquatic food chain in 1872, included algae, zooplankton, tui chub and cutthroat trout
-non-native species were added to the lake in the t later 1870s, irrevocably altering this food chain
what effects the energy flow through food chain models?
-trophic energy transfer efficiency
-trophic pyramids
-bottom-up and top-down control
what is the trophic energy transfer efficiency of photosynthesis?
-photosynthesis does not afford plants access to unlimited energy
-at low light levels, light intensity itself limits photosynthesis and, therefore, energy acquisition
-at high-intensity light levels, plants lose water through open stomata, but closing the stomata limits access to CO2
-eventually, all plants hit a plateau in photosynthetic rate and energy acquisition
what is the theoretical example of trophic energy transfer efficiency in boars?
- in this hypothetical example of energy allocation within a young boar after consuming 100 calories of acorns, only 15% of the total energy consumed is turned into new boar tissue and made available for use (consumption) by predators at the next higher trophic level
what is the example of trophic energy transfer efficiency of the lake tahoe food chain?
-the inherent limits to trophic energy conversion can be examined in the context of historical lake tahoe food chain, with a human Washoe tribe member as a top predator
-each higher trophic level receives only 15% of the energy from the level below it
-therefore, 1000 calories of algae are needed at the bottom of the food chain to produce a meager 0.5 calories of human body tissue at the top
what is the trophic pyramid model for energy?
A, energy and B, biomass pyramids built using a 15% energy transfer between trophic levels
-note that either unit of energy currency produces the same basic shape
what is the trophic pyramid model for biomass?
A, energy and B, biomass pyramids built using a 15% energy transfer between trophic levels
-note that either unit of energy currency produces the same basic shape
what is the trophic pyramid of the lake tahoe food chain?
-aquatic ecosystems can produce slightly inverted biomass pyramids
-the small size and rapid reproductive capacity of the phytoplankton mean that a small biomass can support linger-living zooplankton if measured at a single point in time
-if we examine the biomass of phytoplankton over a zooplankton or tui chub generation, however, we find the same pyramid shape that we see in terrestrial systems
what is an example of a trophic pyramid of a terrestrial system?
what is the bottom-up control of lake tahoe?
-increased urban development around lake tahoe has led to the addition of the nutrients nitrogen and phosphorus to the lake
-this anthropogenic fertilizer has stimulated the growth of algae, which in turn has increased the density and biomass of organisms at each level up the food chain
-the plus sign indicate as increase in biomass or population density at each trophic level
what is the top-down control of lake tahoe food chain?
-in this hypothetical lake, the introduction of a top predators to a three-level food chain leads to a trophic cascade
-the new arrivals (increase in population density) at the top trophic level lead to alternating decreases and increases in the densities of organisms at the lower levels, shown by minus and plus signs
what is the comparison of bottom-up and top-down of lake tahoe food chain?
what are the human influences on bottom-up and top-down control?
-Crater Lake in Oregon is oligotrophic; it is very blue, indicating little plant life in the water
-Copco reservoir in California is eutrophic; its green and murky appearance indicates an abundance of phytoplankton
what happened when increasing phosphorus into lakes?
produces more biomass at each trophic level
-each point is a single lake
what are the comparison of the Lamar river that show a change in density?
what is the world primary production?
what is the world species richness?
what is the more complex food web of the coachella valley?
-the darkest arrows show consumption across trophic levels
-the orange pathway shows that dead organisms at each level become detritus
-the teal pathway shows that detritus eventually becomes available as nutrients for plants
what is the more detailed food web for coachella valley?
-this more detailed food web for the coachella valley, shows omnivores, detritivores and decomposers
what is the prairie food web?
what is a simple boreal food web?
what is the northwest atlantic marine food web?
how complex is the rainforest food web?
what are marine food webs with and without parasites?
A=no parasites
B=parasites added
-notice the extreme increase in both complexity and diversity after the addition of parasites
