Ecology and Environmental Science
Ecology Concepts
Definition: The scientific study of interactions among organisms and their environment.
Key Levels of Ecological Organization:
Species: Group of similar organisms that can breed and reproduce fertile offspring.
Population: Group of individuals of the same species living in the same area.
Community: An assemblage of different populations living together in a defined area.
Ecosystem: All organisms in a place, together with their physical environment; includes biotic and abiotic factors.
Biome: Group of ecosystems sharing similar climates and typical organisms.
Biosphere: Combined portions of the Earth where all life exists, including land, water, and atmosphere (up to 8 km above land and 11 km below sea level).
Approaches to Ecological Data Collection
Methods:
Observation: Gathering information via watching environmental interactions.
Experimentation: Testing hypotheses through controlled environments.
Modeling: Using mathematical models to simulate ecological scenarios.
Earth's Global Systems
Interactions Between Systems:
Biosphere: Life forms.
Atmosphere: Air and weather.
Geosphere: Earth’s solid structure.
Hydrosphere: All water components.
Weather vs Climate
Weather: Short-term atmospheric conditions, changes in temperature and precipitation.
Climate: Long-term averages and patterns of temperature and precipitation over decades.
Greenhouse Effect: Gases (like CO2 and methane) trap heat, maintaining Earth’s temperature.
Earth’s Tilt and Seasons
Imagine Earth is like a spinning top that's leaning a little bit to the side — not standing up straight. It's tilted, like 23.5 degrees. Because of that tilt, the sunlight hits different parts of Earth differently.
In the middle (near the equator), the sun hits straight on — it's super warm there! That’s called the tropical zone.
A little farther out, the sun hits at a slant — it’s not super hot, not super cold. That’s called the temperate zone.
Way up near the top and bottom (the North Pole and South Pole), the sun barely hits — it’s really cold there! That’s the polar zone.
And because Earth is tilted and spinning around the sun, we get seasons like summer, winter, spring, and fall!
Global Winds and Currents
Global Winds: Result from the uneven heating of Earth and its rotation.
Wind Currents
Caused by unequal heating of earth
Air at the equator is heated by the sun and rises
The air travels away from equator, cooling and sinking
Cold air sinks, warm air rises
Ocean Currents
The water in the ocean moves around, kind of like how you stir your soup with a spoon. These movements are called ocean currents.
The sun warms some parts of the ocean, and other parts stay cold.
The wind also pushes the water around.
Big land pieces (the continents) get in the way and change the way the water moves, like walls in a maze!
Surface currents (the water at the top) can be warm or cold. They change the air above them — so if the water is warm, the air feels warmer. If the water is cold, the air feels cooler. That’s why they can change the weather and climate!
Deep ocean currents are like secret rivers at the bottom of the ocean:
Cold water near the North Pole and South Pole gets heavy and sinks down deep.
It flows along the bottom of the ocean, kind of like a slow, sneaky river.
Later, it comes back up in warmer places in something called an upwelling, like a bubble rising in a pot of soup!
Rainshadow Effect: Mountains block moist air, leading to wet and dry sides - moist air rises, cools, and condenses on one side, leaving dry conditions on the opposite side.
Climatogram
Reading a climatogram is like looking at a weather report all squished into one easy picture. 📈🌦 Here's how to do it:
Look at the two things being shown:
Bars (like tall rectangles) show rain (precipitation).
A line (going up and down) shows temperature.
Find the months at the bottom (the x-axis):
It shows January, February, March... all the way to December.
Look at the numbers on the sides:
One side (usually the left) tells you how much rain.
The other side (usually the right) tells you the temperature.
Read the bars:
Tall bars = lots of rain that month.
Short bars = not much rain.
Follow the line:
When the line goes up, it’s getting hotter.
When the line goes down, it’s getting colder.
👉 So a climatogram shows you how hot or cold and how rainy or dry a place is through the whole year!
Biomes
Types:
Tropical Rainforest: Warm, wet, thin nutrient-poor soil, high biodiversity year-round.
Tropical dry forest: Warm year-round, alternating wet-dry seasons, rich soil, deciduous plants, migrating animals
Tropical grassland: Warm, seasonal rainfall, frequent fires set by lightning, seasonal leaf loss, animals migrate during dry season
Temperate forest: Warm summers, cold winters, year-round precipitation, fertile soil, deciduous trees, some animals hibernate/migrate during winter
Northwestern coniferous forest: Mild temperatures, abundant precipitation in all seasons except summer, cool, dry summers, rocky, acidic soil, tall trees, varied animal diets
Boreal forest: (taiga), Mild summers, long, cold winters, moderate precipitation, acidic soil, dark-green conifers, animals have extra insulation, some migrate
Deserts: Low precipitation, extreme temperature variations, adapted flora and fauna.
Temperate Grasslands: Fertile soil, high grazing resistance, seasonal climates.
Tundra: Cold, dark winters, short soggy summers, adapted small flora.
Aquatic Ecosystems
Factors: Salinity, depth, temperature, flow rate, dissolved nutrient concentrations.
Ocean Zones:
Coastal and Intertidal: Experience tides and waves; support diverse organisms.
Open Ocean: Majority of ocean, featuring photic and aphotic zones; supports varied food chains.
Coral Reefs: Biodiversity hotspots influenced by many factors including water conditions.
Organisms of the deep ocean, tide pools, coral reefs
Deep Ocean
Animals live with very heavy water pressure and no light.
They eat dead animals or little bits of junk floating down.
Some are hunters, and some have good bacteria friends.
Some animals glow in the dark using bioluminescence (like a night-light!).
Around hydrothermal vents (hot underwater vents), there are weird creatures like tubeworms and shrimp that live off chemicals instead of sunlight.
Tide Pools
Little pools of water by the ocean.
They get covered with water when the tide comes in and uncovered when it goes out.
Animals there have to survive being splashed, dried out, heated by the sun, and slammed by waves.
Coral Reefs
Built by tiny animals called corals that live in groups.
Corals are like cousins of jellyfish and sea anemones.
They stick to rocks and catch food with tiny stinging arms.
Open Ocean
Tiny plants (phytoplankton) float at the top and make food from sunlight.
Tiny animals (zooplankton) eat the plants.
Fish, jellyfish, and bigger animals eat the zooplankton.
Even bigger animals (like sharks) eat the fish!
Wetlands
Bogs
Composed of spongy, acidic, nutrient poor soil
Marshes
low-lying, waterlogged land often covered with grasses, sedges, and other herbaceous plants
Swamps
forested wetland, dominated by trees, flooded with water
Estuaries
A wetland that forms where a river meets the sea
Primary Producers and Consumers
Primary Producers: Convert energy into usable forms via photosynthesis (e.g., CO2 + water → carbs + O2) or chemosynthesis.
Photosynthesis - process that uses energy from sun to convert CO2 + water → carbs + oxygen
Chemosynthesis - process that uses chem energy to make carbs
CO2 + O2 + hydrogen sulfide →( w/ chemical energy) carbs + sulfur compounds
Consumers: Depend on other organisms for energy and nutrients.
Energy Pyramids
Energy Flow: Approximately 10% of energy is transferred from one trophic level to the next.
Types of Pyramids:
Pyramid of Biomass: Represents living matter at each level.
Pyramid of Numbers: Displays the quantity of organisms at each trophic level, can vary in shape.
Biogeochemical Cycles
Water Cycle: Involves evaporation, condensation, and precipitation.
Carbon Cycle: Incorporates carbon reservoirs (atmosphere, hydrosphere, geosphere, biosphere) and human impacts like climate change.
Phosphorus Cycle: Includes phosphorus moving through geosphere and hydrosphere, critical for DNA/RNA formation.
Nitrogen Cycle: Essential for amino acids; includes nitrogen fixation by bacteria and denitrification processes.
Nitrogen fixation: bacteria convert nitrogen into ammonia (or nitrate/nitrite)
Denitrification: Bacteria convert nitrates→nitrogen