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, 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 (sometime astronomical) factors

Major Ecosystem Interactions• Energy production, transfer, and loss

– Photosynthesis makes food, then one organisms eats another

• Nutrient movement– uptake, transfer, and recycling of nutrients.

• Tolerance, competition, predation– What can organism handle, how well does it obtain resources,

what eats it and to what extent

• Ecological Succession– Change in community over time

• Symbiosis: very/unusually close relationships among organism

Energy & Nutrients• Usable energy created by photosynthesis from energy of sun. • Energy and nutrients pass from one organism to the next through feeding• Energy is lost, but nutrients cycle

sun

Energy & Nutrients• nutrients pass from one organism to the next through feeding and are

then cycled back through the ecosystem

Major Ecosystem Interactions• Ecological Succession

– Change in community over time

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

• Mutualism

• Commensalism

• Parasitism

Host (bigger) Symbiot (smaller)

x x

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?

Major Concepts• Tolerance:

– The amount of a physical condition that an organism can tolerate/live with

• Competition:– How good is it at getting resources compared to other individuals or

organisms/species• Predation:

– What eats/kills it and at what level• Adaptation:

– A characteristic that makes an organism better suited to its environement

• better able to tolerate, compete, be a predator or escape predation, and reproduce

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 rangea simple schematic

waterwet dry

too wet for the grass to survive

too dry for the grass to surviveTolerance range

there is enough to meet the grasses needs, but not too much

Competition

• Same species• 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

The brownbarnacle competitively excludes the gray barnacle from the lower area even though the gray barnacle could tolerate that area

Tolerance ranges

Area found

Distribution of Living Organisms across the landscape is determined by a combination of (things are where they are because):

• 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 (where things are found)

Found in this range

• Intolerant (too much)• Predation• Out competed

• Intolerant (too little)• Predation• Out competed

The Rocky Shore

TIDAL ZONES

Not generally covered by water; gets splashed and sprayed

• Covered and exposed twice daily

Covered and exposed once daily

• Exposed only at negative tides

Highest

Lowest

Intertidal

Zone

Subtidal Never exposed

PHYSICAL GRADIENTS OF TIDE ZONES

Dryer

Wetter

No wave surge/shock

Significant

wave shock

Less wave shocksubtidal

1. WAVE SURGE/SHOCK 2.

WATE

R

OTHER VARIABLES• 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

ZONATION• Physical Zonation Biological Zonation• The existence of characteristic communities

at the different tide zones• Based on:

– Tolerance to physical factors (usually sets upper limit)

– Competition (competitive exclusion) and Predation (usually sets lower limit)

Biological Zonation

Terrestrial Environments:it all begins with plants

Terrestrial Environments:it all begins with plants

THE CENTRAL IMPORTANCE OF PLANTS (and many producers)

• They form the base of the food chain– Biologically available energy and nutrients originate from

plants• Plants cannot move (animals can).

– Thus they are reflective of the physical conditions at a particular area.

• The type of plants in a location influences the type of animals at that same location– Via habitat structure and food availability (type and

amount)

• Terrestrial ecosystems/communities are usually identified by the plants groups they posses.

HOW PLANTS WORK• Use Water, CO2, and sunlight energy to make food (photosynthesis)

• This happens mostly in leaves (which collect sunlight and CO2)– WATER + CO2 SUGARS

HOW PLANTS WORK• Plants loose water through leaves• Some of this is necessary to get water to leaves for photosynthesis

– But too much water loss is bad

Abiotic (non-living) factors affecting the distribution of organisms

• Temperature

• Water

• Sunlight

• Wind

• Soil Conditions

– pH

– salt content/salinity

– sandy

– tightly packed

– organic content

Large Scale

Small Scale

HOW PLANTS WORK• Reproduction: plants do it with animals or the wind…or

water

How Plants Work• Seeds (with embryo) are dispersed

Asexual Reproduction in Plants

How plants obtain resources

• Obtaining water:– from soil (except aquatic plants) by roots.– lose water through leaves, but some water loss is required

to move it.– roots get it, leaves lose it.

• Obtaining Sun:– Leaves

• Obtaining carbon dioxide:– from leaves pores called stomata, but letting CO2 in allows

water to exit.

PLANT REPRODUCTION• Sexual Reproduction (flowers, cones, spores, etc)• Since plants can’t move:

– their sperm needs to disperse to eggs • animal pollinators, wind, or water)

– offspring (seeds and spores) need to disperse away from parents

• by animals, wind, water, or “explosive propulsion”

• Asexual (roots, stem base, runners, fragments)– Alternative reproduction includes self-fertilizing and

vegetative propagation (cloning).

Extra or Reference Slides

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:– 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)

ADAPTATIONS to Rocky Shore Env.• To Exposure/Drying

– “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– “run and hide”– Low profile– Aggregation– “hold on tight”– Shells– “go with the flow”--bending

FORAGING MODES• 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

MARINE FOOD CHAINS• Photosynthetic Producers

– Mostly phytoplankton, but some multicellular algae

• 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

Blade

Stipe

Holdfast