Transcript BIO100 KEY CONCEPTS and TIDEPOOLS-

Biology & Geology 100
• Introduction to key biological concepts
• Introduction to tidepools
What is Natural History?
• the study of the natural environment with an
emphasis on identification, formation/origin
of physical features, life-history, distribution,
abundance, and inter-relationships.
– It often and appropriately includes an aesthetic
component.
The Natural Environment=Ecosystems
• An interacting unit of living and non-living
components.
– Living Things (biotic)
• Plants, algae, animals, fungi, microbes
• All the living things of an area = community
– Non-living things (abiotic)—the physical environment
• Water, temperature/heat, sunlight, wind/air, soil/minerals,
nutrients (found in air, water, & soil) etc…
– Created by geological (sometimes astronomical) factors
The Natural Environment = Ecosystems:
An interacting unit of living and non-living components
Abiotic = non-living
• Sunlight & Heat
• Air
• Water
• Earth
(minerals/soil)
Biotic = living
• Animals
• Plants
• Algae
• Microbes
Biological Factors
Physical Factors
Homage to Geology
• Geological forces creates diversity in
landscape and abiotic variability
• Variation in the physical landscape  habitat
diversity  habitat diversity  biological
diversity
– opportunity for different forms of live to evolve
and co-exist
Flow chart showing complexity of ecosystem interactions
Major Ecosystem Interactions
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Energy production, transfer, and loss
Nutrient movement
Tolerance
competition
predation
Symbiosis
Ecological Succession
Food
WebsTransfer
= energy =and
nutrient
movement
Energy
food
chains/webs
Sun = initial
source of energy
Producers:
--Plants
--algae
Herbivores
carnivores
consumers
Decomposers:
--fungi
--bacteria
Humans
Food Webs =
interconnected
food chains
Smaller
toothed
whales
Baleen
whales
Crab-eater
seals
Birds
Leopard
seals
Fishes
Sperm
whales
Elephant
seals
Squids
Carnivorous
plankton
Copepods
Euphausids
(krill)
Phytoplankton
Interactions and flow within an ecosystem
Nutrient Cycling: an example showing interactions between
physical environment and living things
• nutrients pass from one organism to the next through feeding and are then
cycled back through the ecosystem
Tolerance Ranges
• For every physical aspect of the environment
and for every substance used by an organism :
– (e.g., temperature, water, wind, minerals, nutrients, pH, etc):
– There is a minimum amount needed and a maximum
amount that can be tolerated.
– Between the minimum needed and maximum
tolerable is the “tolerance range)
Tolerance range
a simple schematic
too dry
Tolerance range
for the grass to
survive
there is enough to meet the grasses
needs, but not too much
too wet
for the grass to
survive
water
wet
dry
Competition
Competition for:
• Food
• Shelter
• space
• Mates
Competition happens:
• Between individuals of same
species
• Between different species
– Competitive exclusion
• Influences where organisms
are located
Competitive Exclusion
• Two species that compete for the same resources in
the same way cannot coexist long term
– The species that is the better competitor (in a
given environment) will exclude the other specie
at that location this is competitive exclusion
Tolerance range + Competition
a simple schematic
Limit due to tolerance
Limit due to competition =
competitive exclusion
too dry
Tolerance range
for “grass”
Bush is better
competitor in this
area; excludes grass
water
wet
dry
The brownbarnacle competitively excludes the gray barnacle from the lower
area even though the gray barnacle could tolerate that area
Tolerance
ranges
Area
found
Predation
• One thing eats another (e.g., one consumer eats another)
• Energy and nutrient acquisition
seal
Distribution of Living Organisms:
across the landscape is determined by a combination of
(things are where they are because) the following
• Physical factors
– specifically tolerance to physical factors and
availability of abiotic resources
• Competition
• Predation
• Dispersal
– has the organism been able to get to an area from its existing range
Common Factors Determining Distribution
(i.e., where things are found)
Found in this range
• Intolerant (too much)
• Predation
• Out competed
• Intolerant (too little)
• Predation
• Out competed
Also dispersal: is the organism or its offspring able to get to an area. If the organism is incapable
of reaching an area (or has not yet reached an area) then it won’t be found there.
barrier to dispersal (no lizards here)
• Intolerant (too little)
• Predation
• Out competed
• Intolerant (too much)
• Predation
• Out competed
Major Ecosystem Interactions
• Symbiosis: very/unusually close relationships among organism
Symbiosis
• Particularly close relationships between two or more
organisms
– Often (but not always) refers to situation when one
organism lives in or on another organism
Host (bigger)
• Mutualism
• Commensalism
• Parasitism
xx
Symbiot (smaller)
• Adaptation:
– A characteristic that makes an organism better suited to its
environment
• better able to tolerate, compete, be a predator or escape
predation, and reproduce
Our Goal = biologically interpret/assess
1. Why is this place the way it is; why are the
things that are here, here?
2. What can I tell about this place from what I
see?
The Rocky Shore:
Intro to Tidepools
TIDAL ZONES
Highest
Not generally covered by water; gets splashed and sprayed at high tide
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Intertidal
Zone
uncovered by most (not all) low tides
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Lowest
Covered by all high tides
Subtidal
Exposed only at negative tides
Never exposed
PHYSICAL GRADIENTS OF TIDE ZONES
1. WAVE SURGE/SHOCK
2. WATER
little surge/shock
Dryer
Significant
wave shock
subtidal
Less wave shock
Wetter
ZONATION
• Physical Zonation  Biological Zonation
• The existence of characteristic communities at
the different tide zones
• Zonation is based on:
– Tolerance to physical factors (often sets upper limit)
– Competition (competitive exclusion) and
– Predation (often sets lower limit)
Other variables that influence distributions
• Temperature
– increases with exposure and time
• Salinity
– Increases with exposure and time
– Can decrease during exposure with rain
• Oxygen
– decreases with exposure time
• Restricted Feeding
– Ability to feed and availability of nutrients decreases with
exposure.
• Limited Space
– Wet places and other refuges are in limited when tide is
out
Biological Zonation (examples)
Stress/problems and Adaptations of Rocky Shore
Stresses:
• Wave shock/surge
• Dehydration/drying
• High temperatures
• High salinity
• Feeding
• Predation
• competition
Adaptations/strategies
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Shape
Hold on tight/adhere
Flexibility
Mobility/moving
“close up” (e.g., operculum)
Tolerance
Hard shells
Rapid growth
Toxins
Filter feeding
Grazing
Be nocturnal
Color
Aggregation
ADAPTATIONS to Rocky Shore Env.
• To Exposure/Drying
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“run and hide”
“clam up”
Tolerant of drying
aggregation
• To Temperature Increases
– Physiology/morphology
– color
– “run and hide”
• To Salinity Changes
– Physiology
– “clam up”
• To Wave Shock
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“run and hide”
Low profile
Aggregation
“hold on tight”
Shells
“go with the flow”--bending
MARINE FOOD CHAINS
• Photosynthetic Producers
– Mostly phytoplankton, but some multicellular algae
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Zooplankton
Primary Consumers
Secondary Consumers
Scavengers/decomposers
Algae/Kelp
• Photosynthetic, but not plants
• Different groups based on colors
• Because they are in the inaccessible subtidal zone, often they
are best examined when washed up on shore
“FORAGING” MODES of the rocky seashore
• Photosynthesis--make their own food with sunlight energy
– Algae (free living and endosymbiots)
• Filter-feeders – filter/strain food out of water
– Made possible by movement of nutrient rich water—currents and tide
– shell fish/mollusks, barnacles, sponges, tunicates, tube worms
• Sessile predators – immobile, but actively capture prey
– Made possible by movement of nutrient rich water—currents and tide
– e.g., anemones,
• Grazers – mobile algae eating organisms
– snails, chitons, urchins, Sea hairs, some crabs
• Active/Mobile predators – move and eat other animals
– Sea Stars, some snails/molluscs, some crabs/lobsters, some fish,
• Scavengers/Detrivores—eat non-living things and stuff that
settles on bottom
– Lobsters, Crabs, rock lice/sea roaches
Niche
• The role an organism plays in its environment
• How an organism “makes its living”.
• All the ways a species uses its physical
environment/resources and all its interactions with
other living things.
• Examples of what a niche contains:
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What it eats
When it eats
How it gets food
What eats it
When is it active
What wastes does it put back into the environment
What resources it needs (nutrients, space, shelter, etc)
Diversity of living things