52.3 Flashcards
what are intertidal zones?
Periodically submerged and exposed to the tides
what are characteristics of intertidal zones? (2)
High levels of oxygen and nutrients
Rocky or sandy substrate
How are intertidal organisms challenged?
by variations in temperature, salinity, and mechanical forces of wave action
What are sandy intertidal zones protected from?
waves
what are organisms that live in sandy intertidal zones (2)?
Supported by grass and algae
Animals in sandy zone bury themselves in sand- worms, clams, crustaceans
What kind of organisms are found in rocky intertidal zones?
attached algae
animals with structural adaptations for attaching to hard substrate
How has human activity affected intertidal zones?
Oil pollution and human development have disrupted many intertidal areas
What are oceanic pelagic zones characteristics? (2)
Constantly mixed by wind-driven oceanic currents
High levels of oxygen
how do nutrients levels differ in oceanic pelagic zones?
Turnover in temperate oceans renews nutrients in the photic zone
Year-round stratification in tropical oceans leads to lower nutrient concentrations
How large is the oceanic pelagic zone?
70% of earth’s surface
what is found in oceanic pelagic zones? (2)
Phytoplankton and zooplankton dominate the biome
Zooplankton- protists, worms, copepods, algae
How has human activity affected ocean pelagic zones? (2)
Overfishing has depleted pelagic fish stocks
Humans have polluted oceans with dumping and waste
What are coral reefs?
Formed from calcium carbonate skeletons of corals
how do coral reefs differ in different zones? (2)
Shallow reef-building corals like in photic zone in warm, clear water
Deep-sea corals live at depths of 200-1,500 m
what do corals require? (2)
high oxygen concentration
solid substrate
how does a coral reef progress?
fringing reef > barrier reef > coral atoll
What do corals form a mutalistic relationship with, and what do they provide?
zooxanthellae- single-celled algae
Algae provides organic molecules and energy
How has human activity affected coral reefs? (5)
Collection of coral skeletons, overfishing, global warming, pollution, and aquaculture are threats to coral reef ecosystems
what is the marine benthic zone?
Consists of the seafloor below surface waters of the neritic zone and the offshore pelagic zone
what is the neritic zone?
coast
how has organisms in the abyssal zone adapted?
to cold and high water pressure
What is the sea floor like?
Soft sediment, some rocky
What inhabits shallow areas of the marine benthic zone?
seaweed and algae
what inhabit deep sea hydrothermal vents?
by chemoautotrophic prokaryotes, echinoderms, and arthropods
How has human activity affected the marine benthic zone?
Overfishing and dumping of waste have depleted the fish population
How does species distribution arise?
ecological and evolutionary interactions through time
what is ecological time?
minute-to-minute time frame of interaction between organisms and the environment
what is evolutionary time?
- spans many generations and captures adaptations through natural selection
What does events in ecological time lead to, and an example?
evolution
galapagos finches
what influences species distribution?
biotic and abiotic factors
Example of factors influencing species distribution
temperature, water availability, and interspecific interactions affecting the distribution of cacti
What do ecologists question regarding species distribution?
Ecologists ask questions about where species occur and why species occur there
What is dispersal?
movement of individuals or gametes away from centers of high population density or from their area of origin
What can natural range expansion show?
influence dispersal on distribution
what does dispersal contribute to?
global distribution of organisms
what can long-distance dispersal lead to?
adaptive radiation
what is species transplant?
organisms that are intentionally or accidentally relocated from their original distribution
what does a successful transplant indicate?
that its potential range is larger than its actual range
What can species transplant cause?
Can disrupt communities or ecosystems they are introduced to
Why don’t some organisms occupy their full potential range?
Can be limited by habitat selection behavior
five biotic factors affecting distribution of organisms
Predation
Herbivory
Competition
Mutualism
Parasitism
six abiotic factors affecting distribution of organisms
Temperature
Water
Oxygen
Salinity
Sunlight
Soil
How do abiotic factors vary?
in space and time
Why does temperature affect distribution?
its effects on biological processes
How does temperature affect biological processes? (3)
Cells may freeze and rupture below 0 degrees c
proteins denature above 45 degrees c
Enzymes work best within certain temperature ranges
How do some animals regulate temperature?
Mammals and birds expend energy to regulate their internal temperature
How do desert organisms adapt regarding water?
Desert organisms exhibit adaptations for water conservation
How does water affect oxygen? (2)
Water affects oxygen availability as oxygen diffuses slowly in water
Cold water holds more dissolved oxygen than warm
How does oxygen availability differ in aquatic environments?
Oxygen concentrations can be low in deep oceans and deep lakes
How does salt affect organisms? (2)
Aquatic organisms are usually restricted to fresh or saltwater habitat
Terrestrial organisms are not adapted to high-salinity
how does salinity affect biological processes?
Salt concentrations affect water balance through osmosis
How does sunlight affect distribution? (4)
influences photosynthesis
shading creating competition
high levels can cause stress
photosynthesis in aquatic areas is limited to the surface since water absorbs light
How does rocks and soil limit distribution?
characteristics of soil limit plant distribution, and in turn limit animals that feed on them
3 characteristics of soil that affect plants
pH
physical structure
mineral composition
