Ecology

5/1/12 Objective: To examine foundations of general ecology Do Now: – In your notes, define deciduous and coniferous trees Do Later: – Ch – General ecology crossword and niche activity

Ecology Study of the relationships between organisms and the environment – Biotic Factors - Living organisms – Abiotic Factors – Nonliving components Temperature Forms of energy Water Nutrients

Levels of Organization Organisms – Simplest level of study – Observing a single organism and its interaction with its environment

Levels of Organization Population – A group of individuals of the same species living in a geographic area.

Levels of Organization Community – The collection of all populations in a geographic area

Levels of Organization Ecosystem – The collection of biotic and abiotic factors in a geographic area

Review time! Classify each of these images as an organism, population, community or ecosystem.

Ecological Niche Niche – The role an organism plays in its environment – Where it lives Habitat Geographic distribution – How it lives Nocturnal, diurnal Daily habits and behaviors Reproduction – What it uses Food, resources – What it returns Products, wastes Predators What is the niche of a honeybee?

Ecological Niche Example: Koala bear – Geographic distribution: Eastern Australia Forest dweller – Food/shelter Live in and eat eucalyptus trees Poisonous to most other species – Predators Foxes, pythons, birds of prey (owls, eagles, etc.)

Reflection In your notes: – Describe the niche of humans in our environment – How has our niche changed over time?

5/2/12 Objective: To examine food webs and biomes Do Now: – Turn in homework activities – In your notes: describe your niche in Hyde School Do Later: Ch

Food Chains and Webs Food chains – Flow of energy from plants to top level predators – Interconnected to form food webs

Trophic Levels Trophic level – An organism’s position in the food chain flow of energy

Trophic Levels Producers – Green plants and algae – Use the sun’s energy to make sugars by photosynthesis – All energy on earth comes from the sun

Trophic Levels Primary consumers – Consumers of plants – a.k.a. Herbivores

Trophic Levels Secondary consumers – Consumers of herbivores – First level carnivores

Trophic Levels Tertiary consumers – Consumers of secondary consumers – Second level carnivores

Challenge Time Where do humans fall in a food pyramid?

Trophic levels Omnivores are consumers of: – Plants (producers) – Animals (consumers)

Trophic Levels Decomposers derive energy from decomposing dead organic matter

Practice time In your notes: – Construct a food chain, and label the trophic level of each individual. – When you’re done, you can expand your food chain into a food web.

Biomes Biome – a collection of ecosystems grouped together based on similar characteristics Tundra Deciduous forest Desert

Biomes of the World

Biomes The type of biome found in an area is determined by: – Predominant vegetation – Temperature – Precipitation (rain/snow)

Challenge question Why do you think the type of biome in an area is determined by its primary vegetation?

Challenge question Why do you think the type of biome in an area is determined by its temperature and precipitation?

Biomes of the World What type of biome do we live in?

Temperate Deciduous Forest Primary vegetation: Deciduous trees Temperatures: Cold winters to hot summers Precipitation: Moderate to high (30-60 in./year)

Adaptation Time Why do deciduous trees have broad, flat leaves? – Flat leaves increase surface area exposed to sunlight –  maximum photosynthesis

Temperate Deciduous Forest Why do deciduous trees lose their leaves? – In winter, precipitation is frozen and does not penetrate into the ground – Trees shed their leaves to decrease surface area and minimize water loss

Coniferous Forest Primary vegetation: Coniferous (evergreen) trees Temperatures: Long, cold winters. Short, wet summers. Precipitation: Mostly snow. Heavy melt in summer.

Challenge Time! Why do you think coniferous trees have needles instead of leaves? – Coniferous forests have low ground water – Northern latitudes  little sunlight

5/7/12 Objective: Old and new business Do Now: Put together your tree book – Binder – 7 protector sheets – Make a cover with paper and markers Do Later – Finish Hare-Lynx activity – Tree hunting!

Tree Book Final project: – Find 10/15 trees marked with a hidden ribbon – Trees are located on the main campus – Collect/press/identify leaves or needles – At least 10 entries in final tree book

Carrying Capacity Last class: – Plant life is the base of the food chain

Carrying Capacity Carrying capacity: – The maximum number of organisms that an area can sustain indefinitely – Limited by the amount of food and resources in an area

Carrying capacity Which trophic level do you think has the greatest impact on the carrying capacity of an area?

Carrying Capacity Carrying capacity tends to decrease in higher trophic levels – Energy is lost at each step of the food chain – Less higher-order consumers can find food

Population Dynamics Study of changes in the size and composition of populations

Models of Population growth Logistic Growth – Population increases rapidly until it approaches carrying capacity

Models of Population Growth Exceeding the carrying capacity leads to population crash

Models of Population Growth Where is the human population on our logistic growth curve?

Models of Population Growth UN estimate of population growth:

Models of Population Growth Central questions of human ecology – How are humans going to approach our carrying capacity? – Have we already exceeded it?