Science section 2 Flashcards
Mutualism
a symbiosis in which both partners benefit
Predation
One species uses another species as a resource. This includes herbivory and parasitism.
Competition
occurs when the demand for an ecological resource exceeds its
limited supply, causing organisms to interfere with each other
limiting resource
an environmental resource that
is the primary restriction on the productivity of
autotrophs in an ecosystem
Georgy Gause
led a very famous experiment: begins with two species of bacteria, P. Aurelia and P. Caudatum., and cultivates them in two separate laboratories. When grown separately, both species thrived. However, when Gause put the two species together, P. Aurelia thrived much as it had before while most of the P. Caudatum died off.
community
the populations that live in a certain area. Made up of multiple species
limiting resource
an environmental resource that
is the primary restriction on the productivity of autotrophs in an ecosystem
competitive exclusion principle
If a resource limits the growth and reproduction of multiple species, it cannot be shared: one species will succeed, and
the other will go extinct. This is a principle known as competitive exclusion.
niche
the role of an organism within a community
parasitism
An example of predation, in which animals, plants, fungi, or bacteria feed on or use another organism as a habitat,
causing injury but usually not death
numerical response
when prey density increases, so will predator density
functional response
when prey populations decrease, individual
predators change their behavior and switch from low-density to high-density prey.
food webs
summarizes the species that make up a community and the ways they are linked by various predator-prey interactions to form pathways of energy flow.
keystone species
a dominant species in a
community, usually a predator, with an influence on structure and function that is highly
disproportionate to its biomass
Pisaster star fish
The Pisaster starfish is a key predator that keeps other species in balance. If you remove it from the ecosystem, mussels (specifically, mytilus) end up consuming pretty much everything because there’s no species left to eat them.
In what way are beavers keystone species?
Beavers transform streams into ponds. If you remove them from the ecosystem, pond-animals/plants won’t have anywhere to live.
In what way are mycorrhizal fungi keystone species?
Mycorrhizal fungi live on the roots of many trees. They are critical for the growth process of the tree. If the fungi is removed, many tree habitats are lost.
In what way are old world fruit bats keystone species?
Old world fruit bats are the sole pollinators for hundreds of tropical plant species.
Primary succession
- begins with an event that leaves behind bare rock (e.g. glacial retreat, or volcanic eruption)
- early successional species are usually lichens and mosses. These organisms die and contribute organic matter to the soil
- later successional species are adapted to exploiting open, sunny areas with poor soil nutrients
Secondary succession
- begins on an area of land that is covered with bare soil, usually after an event like a wildfire or hurricane
- after that, it is basically the same process as primary succession
climax forest
outdated term for the plants in the “last” stage of succession. It is now recognized that because natural disturbances are a regular part of most forests, a late-successional stage is always a temporary, rather than a final
phenomenon, so the term climax is no longer used.
decomposers
a heterotroph that feeds on dead organic matter
Where is Organ Cave?
The southern Appalachia of West Virginia
What are the four “full-time residents” of Organ Cave?
A small distant relative of shrimp, crayfish, isopods, and amphipods
How has warming climate impacted organisms in Organ Cave?
Surface waters in the cave became too hot for many organisms during summer, so they became isolated in the consistently cold waters.
What resource do organisms in Organ Cave compete for?
proper sized rocks so they can avoid being washed downstream
Describe the energy flow in Organ Cave.
water flow brings in energy and nutrients, species competition regulates the use of this energy, and water flow takes out unused energy
Laws of thermodynamics
physical principles that govern all transformations of energy
first law of thermodynamics
energy can never be created or destroyed, but it can undergo transformation. The energy content of the universe remains constant
second law of thermodynamics
when energy is transformed, the quantity of energy remains the same, but its ability to do work diminishes
what is the primary source of energy on Earth?
the sun
primary producer
an organism that uses the energy from the Sun to produce usable forms of energy
photosynthesis
the process by which producers use solar energy to convert carbon dioxide and water
into glucose.
equation for photosynthesis
CO2+H2O+energy from the sun —> CH2O+O2
primary productivity
productivity by primary
producers, such as plants or algae; often measured
as biomass accumulated over a unit of time, or
sometimes by the amount of carbon fixed
Gross primary productivity
The total amount of solar energy converted to chemical energy by photosynthesis.
respiration
physiological process that is the opposite of photosynthesis. Cells use carbohydrates and oxygen to create carbon dioxide and water.
Equation for respiration
CH2O+O2—>H2O+energy(heat)
Net primary productivity
the gross primary productivity minus the energy that is expended during respiration
Net primary productivity equation
NPP=GPP-respiration
