Ecology & Evolution SN2

Ecology Definition:
- Scientific study of interactions between organisms and their environment determining the distribution and abundance of organisms.
Key Points on Climate and Biomes:
- Interactions between organisms and the environment influence species distribution.
- Climate largely controls the structure and distribution of terrestrial biomes.

Systematic Variation:
- Climate varies systematically across the planet.
- Solar radiation drives variations in climate.
- Climatic variation influences broad-scale vegetation patterns.
Components of Climate:
- Four major abiotic components:
  - Temperature
  - Precipitation
  - Sunlight
  - Wind
- Global climate patterns are shaped by solar energy and Earth's movement in space.

Impact of Solar Angle:
- The angle at which sunlight strikes Earth affects heat and light intensity.
- Strongest intensity near the equator and diminishes towards the poles.
Photon Distribution:
- Equator receives more photons and less atmospheric interference.
- Poles receive approximately half the photons compared to the equator annually.

Temperature and Climate Zones:
- High latitudes: Polar climates (one cold season).
- Middle latitudes: Temperate climates (four seasons).
- Low latitudes: Tropical climates (two seasons).
Seasonality Factors:
- Caused by Earth's axial tilt and orbital path around the sun.

Global Air Patterns:
- Three cells per hemisphere: Hadley, Ferrel, Polar.
- Atmospheric circulation determines climate by redistributing solar energy and moisture.
Coriolis Effect:
- The turn of winds due to Earth's rotation; right in the northern hemisphere, left in the southern.

Moderation of Climate:
- The North Atlantic Drift warms Europe, keeping climates milder than similar latitudes.
- Currents can create significant differences (e.g., Thurso, Scotland vs. Juneau, Alaska) based on proximity to oceans.

Land vs. Water:
- Large temperature variations inland compared to coastal areas, where water moderates temperature.
Temperature Range:
- Inland Areas: Greater range of temperature.
- Maritime Areas: Smaller seasonal temperature changes.

Temperature Drops with Elevation:
- Approximately 6°C temperature drop per 1000 m elevation gain.
- Higher elevation results in thinner air unable to trap heat.
Rain Shadow Effect:
- Air rises on the windward side, cools, and precipitates. Dry air descends on the leeward side.

Defining Biomes:
- Major life zones characterized by vegetation or physical environments (terrestrial vs. aquatic).
- Climate is crucial in determining the location of biomes.
- Rainfall and temperature are key drivers.
Biomes in North America:
- Examples include:
  - Temperate Forest
  - Grassland
  - Boreal Forest
  - Tundra
  - Tropical Rainforest
  - Desert

Tropical Rainforest:
- High rainfall (200-400 cm/year).
- Avg. temperature: 25-29°C.
- High biodiversity and vertically layered trees.
Desert Biome:
- <30 cm rainfall/year.
- Extreme temperature variations (up to 50°C in the day, -30°C at night).
Temperate Deciduous Forest:
- 30-100 cm rainfall/year.
- Adapted trees that lose leaves in winter.
Boreal Forest:
- Largest terrestrial biome.
- Dense canopy; adapted coniferous trees; cold winters and warm summers.
Tundra:
- Cold winters (< -30°C) and cool summers (< 10°C).
- Permafrost restricts root growth; mainly mosses and lichens.

Factors Influencing Species Distribution:
- Both biotic (living) and abiotic (non-living) factors determine organism distribution.
- Examples of abiotic factors: temperature, water, and sunlight.
- Examples of biotic factors: competition, predation, and mutualism.
Dispersal:
- Movement of individuals away from densely populated areas contributes to global species distribution.