Grade 10 Living Environment Ms. Samson

What is Ecology?yThe study of multiple

organisms and their interaction with each other and the environment

y The collection of all living organisms in a geographic area, together with all the living and non-living things with which they interact. Physical aspects of an ecosystem include soil, water, and weather.Acquatic Ecosystems (water-based) ecosystems y Terrestral Ecosystems (land-based) ecosystems.y

y Biotic versus Abiotic factorsy

What is the definition and who can list at least 1 example for each?

Abiotic v. Biotic Factorsy The physical aspects of a habitat are called abiotic

factors, and the living organisms in a habitat are called biotic factors.

y Abioticy Temperature y Light y Air y Water y Soil

y The single abiotic factor most lacking in a particular

environment is called a Limiting Factor. e.g. water in a desert and temperature - Tundra.

y Bioticy Plants y Animals

y The place where a particular population of a

species lives is called its habitat.y The many different species that live together in a

habitat are called a community.

Activity Time!Think of a place in a forest that is close to a river that is rarely touched by humans. Imagine it is the size of two football fields. Write down as many species as you can think of that you would expect to see there.

Now, imagine that we removed every organism from your area. The nonliving surroundings that remain make up the abiotic factors. What would these factors include? List three without using your notes.

Interactions Within Communities

Within a given ecosystem, populations of different species interact in a community.Modified from Vincenza Pontieri, Trinity College School

An organism s biological characteristics, including the use of and interaction with abiotic and biotic resources in its habitat. It is also the organism s role or occupation within a community.

Ecological Niche

Modified from Vincenza Pontieri, Trinity College School

Categories of Organismsy There are 3 categories, also known as Trophic Levels! y 1. Producersy

Green plants that carry out photosynthesis. Producers are termed autotrophs because they are self-nourished; they don t depend on other species to feed.

y During photosynthesis, plants capture light energy with

their chlorophyll and use it to convert carbon dioxide and moisture (absorbed from air) into sugar (chemical energy). Oxygen is released as a by-product

Let s review the equation

6CO2 + 6H2O + Energy

C6H12O6 + 6O2

y Every major ecosystem has its particular

green plants that carry on photosynthesis and release chemical energy on which nonproducers feed.y Aquatic - algae & plankton y Terrestrial

plants

y 2. Consumersy

y

A) An organism that cannot make its own food, also known as a heterotrophs B)Consumers are subdivided into groups according to their food source.y

Primary, secondary and tertiary consumers

y Primary Consumersy Species that feed directly on producers (plant-eating

species). They are also called Herbivores. Examples include: elephants, goats, cattle

y Secondary Consumersy Species that feed on primary consumers. Secondary and higher order consumers are called Carnivores. Examples: fox, cat.

y Tertiary and Higher Level Consumersy Species that obtain their nourishment by eating other meat-eating species. Example: tiger

y Multiple Level Consumersy Species that obtain their nourishment from eating both

plants and animal species. Also called Omnivores

3. Decomposersy They are the final link in the food chain!!! Made up of

organisms that feed on dead matter and break it down to release chemical energy back into the soil for plants to re-use them. Examples: fungi, bacteria, insects, worms and others. y Feed on detritus matter (dead plants and animals), which is why they are called detritivores. Examples: crab, vulture, termites, wood beetle and crayfish. Also called scavengers.

A sequence of organisms directly dependent on one another for food.

Food web- An interconnection of many food chains.

y A food chain, explains what an organism might eat,

and what might eat it in a specific scenarioy Producers belong to the First Trophic Level. Primary

consumers, whether feeding on living or dead producers feed from the Second Trophic Level. Organisms that feed on other consumers belong to the Third Tropic Level. Only about 10% of the calories in plant matter survive from First to the Second trophic level.y Another way to look at this relationship is a food

pyramid

Predation

Interaction is beneficial to one species and lethal to another.

+/-

Biomagnificationsy The accumulation of a certain substances as one

moves up the food web.y What does this mean? y Let s talk about pesticides that farmers spray on

crops

Quick Recap

Quick answer: NOAlthough a food web is not REALLY connected like a spider web, food webs are drawn in a diagram similar to a spider web (with connecting arrows as the webbing) to show how the energy moves.

We are going to study 3 cycles Can anyone name one?

Carbon Cycley The carbon cycle is important in ecosystems because it

moves carbon, a life-sustaining element, from the atmosphere and oceans into organisms and back again to the atmosphere and oceans. If the balance between these two reservoirs is upset, serious consequences, such as global warming and climate disruption, may result. Scientists are currently looking into ways in which humans can use other, non-carbon containing fuels for energy. Nuclear power, solar power, wind power, and water power are a few alternate energy sources that are being investigated. Let s take a look at it

Carbon Cycle

What do the steps of the Carbon Cycle mean?Interactive Carbon Cycle

Water Cycle or Hydrologic Cycley Involves the cycling of water through the

biosphere. Water naturally exists in 3 forms: solid, liquid, and gas. Water constantly cycles through these forms while in the atmosphere (as water vapor or condensed as clouds), on the ground (as liquid water or snow), undergound (as groundwater), in the ocean, and as precipitation (rain, snow, sleet, hail, etc.). Water enters the atmosphere by a process known as evaporation, and then in condensation it forms clouds.

y Through precipitation the water falls back

down to earth. This cycle then repeats itself over and over again. At any given time just .005 percent of the worlds total water supply is moving through the hydrologic cycle. A drop of water will usually spend 9 days in it but, once it falls it can spend anywhere from 40 years (in a glacier) to 40,000 years (in the ocean) before going into the cycle. Every drop of water winds up moving through the hydrologic cycle. Lets take a look

Water Cycle

Nitrogen Cycley The nitrogen cycle is the process by which atmospheric

nitrogen (where most N is found) is converted to ammonia or nitrates, as seen in the diagram you are about to seey Nitrogen is essential to all living systems. To become a part of

an organism, nitrogen must first be fixed or combined with oxygen or hydrogen. Nitrogen is removed from the atmosphere by lightening and nitrogen fixing bacteria. During electrical storms, large amounts of nitrogen are oxidized and united with water to produce an acid which is carried to the earth in rain producing nitrates. Nitrates are taken up by plants and are converted to proteins.

y Next, the nitrogen passes through the food chain from

plants to herbivores to carnivores. When plants and animals eventually die, the nitrogen compounds are broken down giving ammonia (ammonification). Some of the ammonia is taken up by the plants; some is dissolved in water or held in the soil where bacteria convert it to nitrates (nitrification). Nitrates may be stored in humus or leached from the soil and carried to lakes and streams. It may also be converted to free nitrogen (denitrification) and returned to the atmosphere.

Nitrogen Cycle

List, Sort, Pair Time!y Count off in 6 s y Find your group members and spread out y The person that has the closest birthday to

Thanksgiving in each group needs to come and grab an envelope y When I say go, each group is going to complete one of the cycles y When you are done, I will come around and check your work before you move on to the next one

What does this say???

9JQHGGNU EQPHKFGP GPQWIJ QFTCY CE[ENGQP JG YJK GDQCTF YK JQW PQ GU!

It means

BIOMES

What is a Biome?

BiomesBi e L cati li ate S il Pla ts A i als

Midlatitudes Desert

Very hot days, cool nights. Less than 10 inches of precipitation a year

Poor in animal and plant decay products, but often rich in minerals

None to cacti, bunch grasses, shrubs, and a few trees

Tundra

High Northern latitudes

Grassland

Midlatitudes, interior continents

Very cold, harsh and long winters, short and cool summer. 4-10 inches of precipitation per year Cool in winter, hot in summer, 2575cm/yr

Nutrientpoor, permafrost layer a few inches down

Grasses, wildflowers, mosses, small shrubs

Rodents, snakes, lizards, tortoises, insects, and some birds. The Sahara in Africa is home to camels, gazelles, antelopes, small foxes, snakes, lizards, and gerbils Arctic foxes, hares, owls, hawks, weasels

Rich topsoil

Mostly grasses and small shrubs, some trees near sources of water

Prairie dogs, foxes, small mammals, snakes, insects, various birds. Giraffes, lions, zebras

Deciduous Forest y Midlatitudes y Mild summers, cold winters, 30-50 inches/yr y Rich topsoil over clay y Hardwoods, such as oak, beeches, hickory, maples y Wolves, deer, bears, birds, reptiles, insects Taiga y Mid to high latitudes y Very cold winters, cool summers. 20 inches/yr y Acid, mineral-poor decayed pine and spruce needles on surface y Mostly spruce, fir, and other evergreens y Rodents, snowshoe hares, bears, wolves, birds in summer Tropical Rainforest y Near the equator y Hot all year round. 80-100 inches/yr y Nutrient-poor y Greatest diversity of any biome. Vines, orchids, ferns, and a wide variety of trees y More species of insects, reptiles and amphibians than anywhere; monkeys, other small and large mammals, some places elephants, many colorful birds

AND SPECIES EXTINCTION

BIODIVERSITYHow many species are there?not really known estimates of 5-50 million living species only 1.75 million identified (mostly are insect) highest diversity in tropics, lowest at poles

What is the importance of biodiversity?Medicine: Many organisms are source of drugs (i.e., penicillin, cancer drugs); 25% of all pharmaceuticals contain ingredients derived from native plants, primarily found in tropics. Agriculture, forestry, aquaculture, animal husbandry: Diverse organisms to meet our many needs. Scientific value: Evolution, ecology, biogeochemistry, biology (we love to study everything!) Recreational and aesthetic value: Hunting, fishing, birding, etc. Commerce: Direct commercial interests, indirect businesses, ecotourism. Intrinsic value: Species have a right to exist.

BIODIVERSITY1. Species diversity: # of different kinds of organisms within community/ecosystem Genetic diversity: Diversity within a species; variety of different versions of the same genes within a species Ecosystem diversity: Richness and complexity of a community (e.g., variety of forests, lakes, deserts, grasslands. etc.)

2.

3.

Between 40 and 90% of species live in tropical forests

MINN. 1,700 plant 1 end.

ECUADOR 20,000 plant 4,000 end.

MADAGASCAR 10% of all known 5 times as many trees as US

ECOSYSTEM DIVERSITY Richness and ComplexityRichness: Not

just the number, but how they are distributed.

Species A Species B

1 99 1

2 50 50

# of species at each trophic level and the # of trophic levels.Complexity:

WHAT THREATENS BIODIVERSITY?5 mass extinctions last one wiped out dinosaurs

WHAT THREATENS BIODIVERSITY?Background extinction (95% of all extinctions) Mass extinction

Causes of Natural Extinction

Habitat Disruption Volcanic Eruptions Asteroid Impact Habitat Modification Climate Change Mountain-Building Sea Level Change Exotic Species Continental Drift

EXTINCTIONBackground rates1 mammal species every 400 years 1 bird species/200 yrs

Now, considering human impacts 50-3,000 X thebackground rate! 20-75 plant/animal species each day loss?

Human-Caused ExtinctionPrimary Causes.

1)

Habitat Destruction Introduction of Exotic Speciesy y y

2)

Competitors Predators Diseases

3) 4)

Pollution and Contamination Over Exploitation (excessive predation, food, fur, collecting, pest eradication, etc.)

Madagascar Modern Extinction Case Study.

Save Estimated 200,000+me! species of plants and animals found here are found nowhere else on earth.

5-12 species of flightless birds

X10 17 genera of lemurIsland classified as one of the world's top three "hotspots" for biodiversity. giant tortoises pygmy hippopotomi

ENDANGERED VS THREATENED

Threatened: population low but extinction less imminent Endangered: numbers are so low that extinction is imminent

Species Susceptibility to Extinction1. 2. 3. Small (localized) range (i.e., narrow habitat tolerance). Commercial value. Island dwellers (limited immigration; isolated evolution free from competitors, predators and diseases--fewer defenses when introduced). Low reproductive success. Large and/or flightless (easily hunted).

4. 5.

Habitat DestructionTropical rainforests cover 6% of earth s land surface area, but are believed to hold >50% of the plant and animal species.Tropical deforestation has greatest rate of species loss.

Ndoki

Malay lowland

Habitat Destruction

Exotic SpeciesKudzu

Exotic (alien) species introduced accidentally or intentionally into a new ecosystem causing disruption to the ecosystem s balance.Purple Loosestrife

Zebra mussels

OverexploitationParakeets removed from wild for household pets.

Removal of species from wild populations and drastically reducing their population numbers.Overhunting of whales.

Extinction of Siberian tiger for their coats.

Elephants killed for their ivory tusks.

Pollution and Global WarmingTemperature-sensitive salmon. Eutrophication of aquatic systems.

Three-legged frogs.

Human alteration of natural environment that adversely affects health of living things.

Peregine Falcon nearly driven to extinction due to use of DDT pesticide.

Melting polar ice caps reducing range for polar bears.

Seals caught in oil slick.