An Introduction to Ecology and the Biosphere Chapter 50 An Introduction to Ecology and the Biosphere

LE 50-3a Organismal ecology

LE 50-3b Population ecology

LE 50-3c Community ecology

LE 50-3d Ecosystem ecology

Rachel Carson – Silent Spring

Biotic Factors Biotic factors that affect the distribution of organisms may include: Interactions with other species Predation Competition

Abiotic Factors Abiotic factors affecting distribution of organisms: Temperature Water Sunlight Wind Rocks and soil

Sunlight Light intensity and quality affects photosynthesis Light is also important to development and behavior of organisms sensitive to photoperiod

Wind Wind amplifies effects of temperature by increasing heat loss from evaporation and convection Wind can change morphology of plants

Rocks and Soil Many characteristics of soil limit distribution of plants and thus the animals that feed upon them: Physical structure pH Mineral composition

Climate Four major abiotic components of climate: temperature, water, sunlight, and wind Climate is the prevailing weather in an area

LE 50-10a North Pole 60°N Low angle of incoming sunlight 30°N Tropic of Cancer Sunlight directly overhead at equinoxes 0° (equator) Tropic of Capricorn 30°S Low angle of incoming sunlight 60°S South Pole Atmosphere

LE 50-10b March equinox: Equator faces sun directly; neither pole tilts toward sun; all regions on Earth experience 12 hours of daylight and 12 hours of darkness. 60°N 30°N June solstice: Northern Hemisphere tilts toward sun; summer begins in Northern Hemisphere; winter begins in Southern Hemisphere. 0° (equator) 30°S December solstice: Northern Hemisphere tilts away from sun; winter begins in Northern Hemisphere; summer begins in Southern Hemisphere. Constant tilt of 23.5° September equinox: Equator faces sun directly; neither pole tilts toward sun; all regions on Earth experience 12 hours of daylight and 12 hours of darkness.

Wind direction East Pacific Ocean Sierra Nevada Coast Range LE 50-12 Wind direction East Pacific Ocean Sierra Nevada Coast Range

LE 50-13 Winter Spring Autumn Thermocline Summer O2 (mg/L) O2 (mg/L) 4 4 8 12 4 8 12 Lake depth (m) Lake depth (m) 8 8 16 16 0° 4° 2° 4° 24 4° 4° 24 4° 4° 4° 4° 4°C 4°C O2 concentration High (>8 mg/L) Medium (4–8 mg/L) Low (<4 mg/L) O2 (mg/L) O2 (mg/L) 4 8 12 4 8 12 Lake depth (m) Lake depth (m) 8 4° 22° 8 4° 20° 4° 18° 16 4° 8° 4° 6° 16 5° 24 4°C 4°C 24 Autumn Thermocline Summer

Aquatic biomes account for the largest part of the biosphere in terms of area They can contain fresh water or salt water Oceans cover about 75% of Earth’s surface and have an enormous impact on the biosphere

Littoral zone Limnetic zone Photic zone Pelagic zone Benthic zone LE 50-16a Littoral zone Limnetic zone Photic zone Pelagic zone Benthic zone Aphotic zone Zonation in a lake

(deepest regions of ocean floor) LE 50-16b Intertidal zone Neritic zone Oceanic zone Photic zone 200 m Continental shelf Pelagic zone Benthic zone Aphotic zone 2,500–6,000 m Abyssal zone (deepest regions of ocean floor) Marine zonation

Oligotrophic or Eutrophic?

Intertidal zone - Oregon

Pelagic – open ocean

Coral Reef – Red Sea

Deep Sea Hydrothermal vent – tube worms

Annual mean temperature (°C) LE 50-18 Desert Temperate grassland Tropical forest 30 Temperate broadleaf forest 15 Annual mean temperature (°C) Coniferous forest Arctic and alpine tundra –15 100 200 300 400 Annual mean precipitation (cm)

LE 50-19 30°N Tropic of Cancer Equator Tropic of Capricorn 30°S Chaparral Key Tundra Temperate grassland High mountains Tropical forest Temperate broadleaf forest Polar ice Savanna Coniferous forest Desert