Ecological principlesEcological principlesSystems, Diversity, and Human

Interactions

What is Ecology?What is Ecology?Ecology is the study of how

organisms interact with on another and with their nonliving environment.◦Connections in nature◦Ecologists focus on understanding

interactions among organisms, a population, a community, an ecosystem and the biosphere! All of which we will examine!!

What are Organisms??What are Organisms??Organisms are any form of life.

◦One cell to multi-cellular species.◦If you look in the mirror you will see 10

trillion cells and about 200 different types of cells… all having different functions!

How many different species on Earth?◦Estimated = 3.6 million to 100 million◦So far we know 1.4 million (mostly

insects!)

Case Study: Have you Case Study: Have you thanked the insects Today?thanked the insects Today?Read Page 55 then take five

minutes to answer the portfolio question: Journal Entry #1.

Organisms make up a Organisms make up a PopulationPopulationA population is a group of

interacting individuals of the same species that occupy a specific area.

The place or environment where they live is its habitat.◦It may be as large as an ocean or as

small as the intestine in a termite!!The area over which we can find a

species is called its distribution or its range.

What is a community?What is a community?A community, or biological

community, consists of all the populations of the different species living and interacting within an area.

It is very complex and contains plants, animals, and many microorganisms.

What are Ecosystems?What are Ecosystems?An Ecosystem is a community of

different species that are interacting with one another but also with their physical environment of matter and energy

They can be natural or man made.◦Man made would be crop fields, farm

ponds, and reservoirs.◦All the Earth’s ecosystems together

make up the biosphere.

Examples of various Examples of various ecosystems.ecosystems.

Systems within the Systems within the BiosphereBiosphere

All of the earth’s ecosystems combined make up the biosphere. This includes ecosystems in the air, land and sea – the Earth’s life support systems.

But what if we change a But what if we change a component within an component within an Ecosystem:Ecosystem:Each component of an ecosystem is

important to the preservation and the health of the ecosystem.

When you change one factor you may create a domino affect – massive changes elsewhere.

If the temperature of earth changes it impacts the development of species. Since they are all linked this will in turn affect all other species in the ecosystem.

Humans interactions with an Humans interactions with an ecosystem ecosystem

Natural balance (characterized by the carrying capacity of a species) shifts when humans interact.

Sustainable practices are humans ways of minimizing their impact on the ecosystem and maintaining that natural balance.

EutrophicationEutrophicationEutrophication is a syndrome of

ecosystem responses to human activities that fertilize water bodies with nitrogen (N) and phosphorus (P), often leading to changes in animal and plant populations and degradation of water and habitat quality.

Nitrogen and phosphorus are essential components of structural proteins, enzymes, cell membranes, nucleic acids, and molecules that play a role in photosynthesis and other cellular functions .

Pristine aquatic ecosystems function in approximate steady state in which primary production of new plant biomass is sustained by N and P released as byproducts of microbial and animal metabolism.

◦Humans disrupt this balance by adding N and P to the water systems.

◦Nutrient enrichment of marine waters promotes the growth of algae.

◦The algae fuels bacterial growth in bottom waters and sediments.

Then….Then….Bacterial metabolism

consumes oxygen.

Bottom waters become hypoxic (low in oxygen) or anoxic (devoid of oxygen), creating conditions stressful or even lethal for marine invertebrates and fish.

Possible ResultsPossible ResultsSeagrass populations

decrease due to unavailability of light. Ecosystem balance is effected.

Some phytoplankton species excrete large quantities of mucilage during blooms that is whipped into foam by wind mixing and washes ashore, making beaches undesirable for holiday visitors.

Other phytoplankton (cyanobacteria) species produce toxic chemicals that can impair respiratory, nervous, digestive and reproductive system function, and even cause death of fish, shellfish, seabirds, mammals, and humans.

The economic impacts of harmful algal blooms can be severe as tourism is lost and shellfish harvest and fishing are closed across increasingly widespread marine regions.

Rivers and streams damage result in loss of fish stocks!

Nitrogen Eutrophication… Nitrogen Eutrophication… Portfolio: Bringing Dead Zones

back to Life – article and Questions.

The Earth is made up of The Earth is made up of Four Major Layers:Four Major Layers:

The Earth is made up of interconnected spherical layers that contain air, water, soil, minerals and life.

1. Atmosphere (air)1. Atmosphere (air)The thin membrane of air around

the planet. The atmosphere is made up of two parts

(for our purpose): ◦ Troposphere: The bottom layer just above sea

level. It contains most of the earth’s nitrogen and oxygen – and is where the weather occurs.

◦ Stratosphere: This is the upper layer. It contains mostly ozone (O3), which helps to filter out the sun’s harmful ultraviolet rays.

2. Hydrosphere – water 2. Hydrosphere – water The hydrosphere consists of the

Earth’s water - it is found as liquid water (surface and undergound), as ice (polar ice, icebergs and ice in frozen soil), and as water vapour.

3. Lithosphere – crust 3. Lithosphere – crust The lithosphere is made up of the

Earth’s crust and upper mantle. It contains non-renewable fossil fuels,

minerals and nutrients for plant growth.

4. Biosphere - (living and dead 4. Biosphere - (living and dead organisms)organisms)

The biosphere is where all living organisms exist and interact with one another and with non-living things.

The biosphere includes most of the hydrosphere (water), parts of the atmosphere

(air), and lithosphere (soil).

All life exists in the All life exists in the biosphere…biosphere…

In order for life to exist organisms need to obtain nutrients and minerals for growth and maintenance.

The Earth is a closed system; therefore, everything needs to be recycled once an organisms dies… it has to be broken down and released back into the ‘web of life’.

The Earths Cycles – Found The Earths Cycles – Found within the Biospherewithin the Biosphere

Carbon cycleCarbon cycleCarbon is the basic building block of the

carbohydrates, fats, proteins, DNA, and other organic compounds necessary for life.

The carbon cycle is based on CO2 from the aerobic respiration of organisms, volcanic eruptions, the weathering of carbonate rocks, and the burning of carbon containing compounds.

Aerobic respiration breaks down glucose and converts the carbon to the CO2 which is released into the troposphere.

Nitrogen CycleNitrogen CycleNitrogen is the atmosphere’s

most abundant element (78%).It is a crucial component of

proteins, many vitamins, and the nucleic acids DNA and RNA.

However, N2 (gas) cannot be absorbed and used directly as a nutrient by plants or animals.

The nitrogen cycle converts it to a usable form.

Phosphorus CyclePhosphorus CyclePhosphorus is typically found as a

solid form in rocks and salts in the Earth’s crust and very little circulates the atmosphere.

As weathering and erosion occur phosphorus is released into soil water, lakes, and rivers as phosphate ions that can be taken up by plants – which are then eaten by other organisms.

Sulphur CycleSulphur CycleSulphur enters the atmosphere

through natural sources and human activity.

It can create many problems for organisms and water systems as it falls from the atmosphere as acid precipitation.

Water CycleWater CycleOne of the most important cycles on

the Earth!!The water cycle recycles the fixed

supply of the Earth’s water. It falls to the Earth in forms of

precipitation and cycles through plants and animals.

It is different from other cycles as the chemical (H2O) stays unchanged but merely transforms from one state to another.

What are the Major Biological What are the Major Biological Components of Ecosystems?Components of Ecosystems?Organisms on our planet either

produce or consume food.◦Producers, also known as autotrophs,

make food from the environment◦Plants, algae, and phytoplankton are

the key producers in the biosphere.◦Producers make glucose (a

carbohydrate) through a process known as photosynthesis.

◦http://www.youtube.com/watch?v=mYbMPwmwx88&feature=related

More Producers…More Producers…Chemosynthesis occurs in some

bacteria that can convert simple compounds from the environment into more complex nutrient compounds WITHOUT sunlight.

All other organisms… All other organisms… ConsumersConsumersConsumers = heterotrophsThey obtain energy and nutrients from

feeding on other organisms or remains.Decomposers are consumers that

recycle organic matter (which we seen in cycles).◦Breakdown dead organic material =

detritus!In natural ecosystems there is little to

no waste as one organism’s waste serves as a resource for another.

Energy passed on…Energy passed on…All producers, consumers, and

decomposers use the chemical energy in glucose to fuel all their life processes.◦The survival of all individuals depends on

the flow of matter and energy through its body.

As an ecosystem, the whole survives primarily through the recycling of matter and the one-way energy flow.

Food chains

Energy Flow in Energy Flow in EcosystemsEcosystemsAll organisms, essentially, are

food for other organisms within an ecosystem.

Complete the assignment on Food Chains and Webs + Energy Flow in Ecosystems.

Origins and BiodiversityOrigins and BiodiversityLife on Earth developed as a result of

chemical and biological evolution.

•Chemical evolution: The formation of organic molecules took around one billion years to form.

• Biological evolution: Followed, - from single-celled prokaryotic bacteria to single-celled eukaryotic organisms to multi-cellular organisms. • It still continues 3.7 billion years later.

• We have knowledge of the evolution of species from fossils, radioactive dating, ice-core drilling, chemical analyses, and DNA analysis – however, many of these records are incomplete.

Evolution and Evolution and AdaptationAdaptation

Evolution is the change in a population’s genetic makeup over time.

◦ Populations evolve by becoming genetically different

◦ All species descend from earlier, ancestral species (theory of evolution – this is only one theory… there are others!)◦ Microevolution: small genetic changes in a

population◦ Macroevolution: long-term, large-scale evolutionary

changes.

Genetic ChangesGenetic ChangesA population’s gene

pool changes over time because of genetic mutations in DNA molecules.

These are passed on to the offspring and then through their reproduction more mutations can occur.

Genetic changes can lead to Genetic changes can lead to BiodiversityBiodiversityBiodiversity is the variation of life

forms within a given ecosystem, biome, or for the entire Earth.

Having a high biodiversity helps keep our economies running and keeps us alive!

Habitats with higher diversity and complexity lead to more stable environments with greater species and genetic diversity.

Evolution of Species – Two Evolution of Species – Two Main WaysMain Ways1. Isolation:1. Isolation:A new species can evolve as

a result of members becoming isolated from a population.

In speciation, two species will form because one species cannot form fertile offspring with the other but can with the one with similar genetic features.◦Geographic isolation and reproductive isolation

2. Natural Selection 2. Natural Selection Natural selection’s role in

microevolution occurs when members of a population have genetic traits that improve their ability to survive and produce offspring with those specific traits.◦Can include genetic traits

that are hereditary◦Adaptations to survive and

reproduce under certain environmental conditions.

Earth’s BiodiversityEarth’s BiodiversityThe biodiversity of our planet is

decreasing because of human activity.Biodiversity = speciation – extinctionIt is estimated that humans have

increased extinction rates by 100 to 1,000 times in the 20th century.

It is now predicted that by the end of the 21st century we may see the extinction of over half of the species now present on Earth.

Humans and our activities are destroying or degrading ecosystems that might be centers for future speciation.

1. Genetic Diversity1. Genetic DiversityGenetic diversity: the variety of genetic material within a species or a population.

◦ Mutations: changes in the genetic makeup of an organism (ex. insects and evolution).

◦ Migration: when an organism leaves one population and enters another one. The organism has to adapt to a new environment.

◦ Population size: the smaller the population the less genetic diversity it can contain and the fewer the variations in the genes for specific characteristics.

◦ Selective Breeding: Domesticated plants and animals have been modified over many generations by our choosing certain desired characteristics, the undesirable characteristics were eliminated.

Genetic Diversity in ChilisGenetic Diversity in Chilis

2. Species Diversity2. Species DiversitySpecies diversity: the number of species present in different habitats.

◦ The evolutionary and geological history of a region impacts its species diversity (ex. temperature in rainforest promotes diversity).

◦ Migration can introduce new species to an area where they were not present. This does not always increase populations if it is an invading species.

◦ The size of the area affects species diversity. The larger the area the larger the species diversity.

Species diversity is difficult to measure. This is because it is unknown how many species exist in the world and many rare species are still undiscovered.

3. Functional Diversity3. Functional DiversityFunctional diversity: the biological

and chemical processes such as energy flow and matter cycling need for the survival of species, communities, and ecosystems.

If matter is ‘lost’ or removed from an ecosystem the cycling of nutrients cannot occur therefore different species will be affected.

4. Structural Diversity4. Structural Diversity• Structural diversity

is the range of variation in the physical characteristics of habitat

• An ecosystem that provides niches for different organisms to survive will increase the diversity within the ecosystem.

5. Ecological Diversity5. Ecological Diversity

Ecological diversity: the variety of terrestrial and aquatic ecosystems found in an area or on the earth.

Many regions of the world share many general similarities in terms of the kinds of ecosystems present.

However, each area will differ in terms of their types of species, water sources, terrain (ex. rocky or sandy, slopes facing north or south), weather patterns (ex. hurricanes).

Ecosystem DiversityEcosystem DiversityAquatic

ecosystemsCoral reefsTropical rainforest TundraOld growth forestsMarine ecosystemsPlains

Factors that Lead to Loss of Factors that Lead to Loss of DiversityDiversityWhen species of plants and animals

go extinct, many other species are affected.

Some examples of factors leading to species extinction are:

Habitat destructionPollution

Species IntroductionsGlobal Climate Change

Exploitation

Human impact: modify or simplify ecosystems – logging, farming, grazing, unregulated hunting, pollution, urbanization, and the introduction of new species.

ExtinctionExtinctionWhen a population cannot adapt to

changing environmental conditions the species will become extinct.◦Species usually only last 1-10 million

years.◦Life has had to cope with natural disasters

that have eliminated species.◦ Introduction of new species can lead to

the extinction of another.

All species will become All species will become extinct…extinct…

When local environmental conditions change, some species will disappear at a low rate.

In a mass extinction, there is a significant rise in extinction rates◦Usually 25-70% of species are lost.◦There have been two mass extinctions on Earth.

◦As well, two mass depletions have also occurred (not as large as an extinction).

Why Should We Care About Why Should We Care About Biodiversity? Biodiversity?

Aesthetic pleasure Ecological: (environmental monitor,

ecological balance – keystone species) Educational Historical or cultural Natural Services: (air and water

purification, soil fertility, waste disposal,) Recreational Medicine Agriculture: (biological pest control, food

source, commercial product – wood) Moral or ethics

Future of Speciation?Future of Speciation?Humans select certain traits in a

population and try to breed them to produce the same traits in offspring.

◦Artificial selection to change populations to meet our needs.

◦Selective breeding to obtain desired traits

Genetic EngineeringGenetic EngineeringGenetic engineers have

transplanted genes from one species to another to create genetically modified organisms (GMO’S).◦ Genes from different species

that would never interbreed in nature are being transferred from one organism to another.

◦ Gene splicing (as it’s called) takes half as much time to develop a new crop or animal, as does traditional crossbreeding.

Genetic EngineeringGenetic EngineeringCloning produces a

genetically identical version of an individual.

Bio-pharming is a new field where genetically engineered animals act as biofactories to produce drugs, vaccines, antibodies, hormones, etc.

Where are they today?Where are they today?Scientists have used gene

splicing to develop modified crop plants, drugs, pest-resistant plants.Created genetically engineered

bacteria to clean up oil spills and other toxic pollutants.

They have cloned sheep and cows – in the future they may be able to clone humans!Engineered chickens that lay

low cholesterol eggs, tomatoes with genes to lower chances of certain cancers, and bananas and potatoes that treat various viral diseases in developing countries.

Fun Activity: How energy Fun Activity: How energy efficient are you?efficient are you?http://www.ecokids.ca/pub/

eco_info/topics/energy/energy_efficient/play_energyefficient.cfm