Population or not? The trees in a forest

List several biotic and abiotic factors.

Population Density =

Population/Area of Land*Low Density *High Density

Birth rate higher than death rate Grows slowly when population is small As population gets larger, growth speeds up

Exponential growth

6

Logistic growth

*Growth is LIMITED by LIMITING FACTORS *When population is small, growth is fast b/c plenty of resources. *As population approaches carrying capacity, growth slows or stabilizes

Carrying Capacity

The largest population an environment can support at any given time

Limiting Factors can be density-dependent or density- independent

• Is a Tornado caused by a large population?• No, it is density-independent

• Is shortage of food caused by a large population?• Yes, it is density-dependent

• Is a drought caused by a large population?• No. Density-independent

• Habitat encroachment by humans? • Density-independent

• Does a large population affect available drinking water?• Yes. Density-dependent

• Parasitism?• Density-dependent

• Competition• Density-dependent

Apply each of these terms to the picture below. Organism, community, population,

ecosystem, biome

What is an estuary?

Estuaries are highly productive ecosystems.• Estuaries provide a protected refuge for many

species.– birds migration– spawning grounds

• Estuaries are primarily threatened by land development.

A biome is a major community of organisms.

– long winters and short summers

– trees are conifers (cone shaped, with needles)

Source: Environment Canada

Banff, Canada

• Hot summers and cold winters

– These trees lose their leaves in the autumn to conserve water.

• Arid climate – what does arid mean? Tucson, Arizona

Source: National Oceanic Atmospheric Administration

– dry and warm during the summer; most precipitation falls as snow.

– warm through the year, with definite dry and rainy seasons.

– winter lasts 10 months– limited precipitation– permafrost

Barrow, Alaska

Source: National Oceanic Atmospheric Administration

– warm temperature– abundant

precipitation all year

Source: World Meteorological Organization

– neritic zone—from intertidal zone to continental shelf

– bathyal zone—from neritic zone to base of continental shelf

– abyssal zone –lies below 2000 m

Marine ecosystems – intertidal zone—between low and high tide

intertidal zoneneritic zone

bathyal

zone

abyssalzone

• The neritic zone has more biomass than any other zone.

• Plankton make up most of the biomass.– phytoplankton– zooplankton

What is the difference between a habitat and a niche?

• A habitat is the area in which an organism lives. (where)

• A niche includes the role that the organism plays in the environment. (how)

Types of SymbiosisInteraction Species A Species B

Mutualism Benefit (+) Benefit (+)

Commensalism Benefit (+) No Effect (0)

Parasitism Benefit (+) Harm (-)

Trophic Levels (feeding levels)

3

2

1

What percent of the energy of the plants is available to the

grasshoppers?

Ecological Succession

Succession occurs following a disturbance in an ecosystem.

2 types of succession: Primary and Secondary

• primary succession — started by pioneer species, such as lichens and mosses

• occurs in previously uninhabited area

• example: when bare rock is exposed by receding glacier

• secondary succession is started by remaining species

• occurs after fires or natural disasters

How do human activities impact our ecosystems?

• Pollute our air, water, & soil• Decrease biodiversity by

– Global climate change– Habitat fragmentation– Introducing non-native species

Humans and the Environment

As the human population grows, the demand for Earth’s resources increases.

Earth’s human carrying capacity is unknown.

Nonrenewable resources are used faster than they form.– coal– oil

Renewable resources cannot be used up or can replenish themselves over time.

– wind– water– sunlight

ACID RAIN

• Most common air pollutants are released by burning fossil fuels (electricity & transportation)

• Smog – Type of air pollution formed from sunlight fueling chemical reactions in the atmosphere with emissions from fossil fuel burning.

• Particulates (dust, soot, etc) & Ground-level ozone are the major components of smog

• Pollutants from fossil fuels combine with water vapor in the atmosphere to form acids.

NO2 will form HNO3 (nitric acid)

SO2 will form H2SO4 (sulfuric acid)

• 80% of our acid rain problem is generated by SO2 released during coal burning.

SMOG

Acid Deposition in the USWhat trends do you see in this map?

Can you explain why??

The greenhouse effect – Gasses in the atmosphere that naturally absorb longer wavelength of infrared reradiated by the Earth’s surface. The molecules vibrate due to the absorbed energy & transform it to longer wavelength of energy that radiates more heat (infrared) towards earth surface, causing warming.

Where do greenhouse gases come from??

• Decomposers– Bacteria release

methane in anaerobic respiration (cows!)

– Bacteria release nitrous oxide (N2O)during denitrification

• Consumers

– Release CO2 as they respire

• Combustion of fossil fuels – Electricity– Transportation

• Feedlots (cows)

HINT: Think back to your nutrient cycles!

Natural Sources of GHGs

Un-Natural Sources of GHGs

• Most common form of water pollution is from run-off of urban, industrial, and agricultural areas– Pesticides – ex. DDT (insecticide)– Industrial – ex. PCBs – Urban – ex. fertilizers, oils, paints

• Biomagnification – synthetic organic compounds are stored in fat of organisms and magnify in concentration as it moves up the food chain

• Indicator Species – organisms sensitive to toxin in the water & serve as warning signs of pollution (ex. frogs (most amphibians), trout)

Hmm….Do you know why most amphibians are indicator species??

Adaptations

• Tropisms in plants

• Hormones such as auxin

• Tadpoles eat algae, frogs eat insects

• Some desert plants, called succulents, store water in their stems or leaves

• Roots of prairie grasses extend deep into soil

Types of Adaptation• Anything that helps an organism survive in its

environment is an adaptation. 

• It also refers to the ability of living things to adjust to different conditions within their environments. 

– Structural adaptation – Protective coloration– Mimicry – Behavior adaptations– Migration– Hibernation

Structural adaptations

• A structural adaptation involves some part of an animal's body.

– Teeth – Body coverings    – Movement

Protective Coloration

• Coloration and protective resemblance allow an animal to blend into its environment. 

• Another word for this might be camouflage.  Their camouflage makes it hard for enemies to single out individuals.  

Mimicry• Mimicry allows one

animal to look, sound, or act like another animal to fool predators into thinking it is poisonous or dangerous.  

Behavior adaptations

• Behaviour adaptations include activities that help an animal survive. 

• Behavior adaptations can be learned or instinctive.

– Social behavior   – Behavior for protection