In-Depth Ecology and Biosphere Notes chapter 52

Key Determinants of Species Distribution

• Environmental Factors:

  • Climate, temperature, and precipitation are major factors affecting terrestrial organisms.

  • Light and nutrient availability significantly impact aquatic organisms.

Ecology Overview

• Ecology: Scientific study of interactions between organisms and their environment (living + non-living).

• Interactions influence organism distribution and abundance.

• Research questions vary across biological hierarchy levels.

Levels of Ecological Research

1. Organismal Ecology:

   • Focuses on how an organism's structure, physiology, behavior adapt to environmental challenges.

   • Example question: "How do flamingos select a mate?"

2. Population Ecology:

   • Examines groups of the same species within a specific area and factors affecting their size and changes over time.

   • Example question: "What environmental factors affect the reproductive rate of flamingos?"

3. Community Ecology:

   • Studies interactions between different species and their community structures.

   • Example question: "What influences species diversity at an African lake?"

4. Ecosystem Ecology:

   • Analyzes interactions between organisms and physical factors, focusing on energy flow and chemical cycling.

   • Example question: "What controls photosynthetic productivity in an aquatic ecosystem?"

5. Landscape Ecology:

   • Looks at the mosaic of connected ecosystems and exchanges across them.

   • Example question: "How do terrestrial nutrients affect lake organisms?"

6. Global Ecology:

   • Studies the biosphere, examining global energy/material exchanges and their influence on organism distributions.

   • Example question: "How do global air patterns impact organism distribution?"

Climate and Ecological Distribution

• Climate: Long-term prevailing weather conditions in an area; key factor in organism distribution on land.

• Major components include: temperature, precipitation, sunlight, and wind.

• Global climate patterns affected by solar energy and Earth's movements, creating latitudinal variations.

Latitudinal Variation in Sunlight

• The intensity of sunlight varies based on its angle of impact.

  • Most direct in the tropics (23.5º N to 23.5º S).

  • Less intense in higher latitudes due to oblique angles.

Global Air Circulation & Precipitation

• Intense sunlight causes water evaporation, leading to rising warm, wet air which causes precipitation in the tropics.

• Dry air descends around 30º N/S, creating arid climates.

• Patterns create predictable global wind systems affecting climates globally.

Local Climate Influences

• Seasonality: Variation in daylight, solar radiation, and temperature due to Earth's axial tilt.

• Large bodies of water and mountain ranges modify local climates, with effects such as coastal moderation and rain shadows.

Vegetation and Climate Interaction

• Forests change local/regional climates by altering solar absorption and cooling through transpiration.

• Human activities like deforestation impact climate patterns, often making areas hotter and drier.

Microclimates

• Microclimates: Localized climate variations influenced by abiotic factors (e.g., temperature) and biotic factors (other organisms).

Terrestrial Biomes

• Biomes: Major life zones characterized by vegetation types or physical environments.

• Types include: tropical forests, savannas, deserts, chaparral, temperate grasslands, northern coniferous forest, temperate broadleaf forest, tundra.

• Climate and disturbance are major controls on biomes distribution and characteristics.

Characteristics of Various Biomes

• Tropical Forest: High rainfall; diverse flora and fauna; severe human impact (deforestation).

• Desert: Low precipitation; temperature extremes; adapted flora and fauna for water conservation.

• Savanna: Seasonal precipitation; dominant grasses; adapted to seasonal drought.

• Chaparral: Seasonal precipitation; adapted to fire.

• Temperate Grassland: Seasonal climate; dominated by grasses; significant agricultural conversion.

• Northern Coniferous Forest: Cold winters; diverse mammal presence; logging threats.

• Temperate Broadleaf Forest: Diverse layers; significant human habitation impact.

• Tundra: Low vegetation; cold temperatures; human extraction activities looming.

Aquatic Biomes

• Aquatic Biomes: Cover most of Earth's surface, varied by physical/chemical environments.

• Key aquatic zones include: photic, aphotic, benthic, and abyssal.

• Oceans: Vital for global oxygen production and climate influence.

Zonation in Aquatic Systems

• Structured into light penetration and depth regions; hydrological cycles influence nutrient availability.

• Communities vary with depth, light, and proximity to the shore, and are notably impacted by human activity.

Six Levels of Ecological Research

1. Organismal Ecology: Focuses on how an organism's structure, physiology, and behavior adapt to environmental challenges.

   • Example question: "How do flamingos select a mate?"

2. Population Ecology: Examines groups of the same species within a specific area and factors affecting their size and changes over time.

   • Example question: "What environmental factors affect the reproductive rate of flamingos?"

3. Community Ecology: Studies interactions between different species and their community structures.

   • Example question: "What influences species diversity at an African lake?"

4. Ecosystem Ecology: Analyzes interactions between organisms and physical factors, focusing on energy flow and chemical cycling.

   • Example question: "What controls photosynthetic productivity in an aquatic ecosystem?"

5. Landscape Ecology: Looks at the mosaic of connected ecosystems and exchanges across them.

   • Example question: "How do terrestrial nutrients affect lake organisms?"

6. Global Ecology: Studies the biosphere, examining global energy/material exchanges and their influence on organism distributions.

   • Example question: "How do global air patterns impact organism distribution?"

Climate Variations

Understanding how variations in sunlight intensity and air circulation/precipitation patterns across latitudes affect Earth's climate globally:

• Sunlight Intensity:

  • The intensity of sunlight varies based on its angle of impact, with the most direct light found in the tropics (23.5° N to 23.5° S) and less intense light in higher latitudes due to oblique angles.

• Air Circulation and Precipitation Patterns:

  • Intense sunlight leads to water evaporation, generating warm, wet air that causes precipitation in the tropics, while dry air descends around 30° N/S, creating arid climates. These patterns result in predictable global wind systems affecting climates.

Local and Regional Climate Influences

How seasons, water bodies, and mountains influence climate at local and regional levels:

• Seasonality:

  • Variations in daylight, solar radiation, and temperature are caused by Earth's axial tilt.

• Large Bodies of Water and Mountains:

  • These features affect local climates; for instance, they can lead to coastal moderation and rain shadows.

Terrestrial Biomes

Key features of terrestrial biomes:

• Biomes represent major life zones characterized by vegetation types or physical environments, which include tropical forests, savannas, deserts, chaparral, temperate grasslands, northern coniferous forests, temperate broadleaf forests, and tundras.

• Climate and disturbance are major controls on biomes distribution and characteristics.

Eight Terrestrial Biomes

• Tropical Forest: High rainfall; diverse flora and fauna; severe human impact (deforestation).

• Desert: Low precipitation; temperature extremes; adapted flora and fauna for water conservation.

• Savanna: Seasonal precipitation; dominant grasses; adapted to seasonal drought.

• Chaparral: Seasonal precipitation; adapted to fire.

• Temperate Grassland: Seasonal climate; dominated by grasses; significant agricultural conversion.

• Northern Coniferous Forest: Cold winters; diverse mammal presence; logging threats.

• Temperate Broadleaf Forest: Diverse layers; significant human habitation impact.

• Tundra: Low vegetation; cold temperatures; looming human extraction activities.

Aquatic Biomes

Zonation terms for lakes and marine environments:

• Zonation: Structured into light penetration and depth regions; hydrological cycles influence nutrient availability. Communities vary due to depth, light, and distance from shore, and human activity has a notable impact.

• Seasonal Water Turnover in Lakes: Important for nutrient cycling and oxygenation.

Eight Aquatic Biomes

• Lakes: Characterized by standing water with variation in zones (littoral, limnetic, benthic).

• Wetlands: Areas saturated by water, supporting various plant and animal life.

• Streams and Rivers: Flowing water ecosystems affected by surrounding landscapes.

• Estuaries: Transition areas between rivers and oceans with high nutrient availability.

• Intertidal Zones: Areas between land and ocean affected by tides.

• Oceanic Pelagic Zone: Open ocean with diverse marine life.

• Coral Reefs: Biodiverse underwater ecosystems formed by coral polyps.

• Marine Benthic Zone: Ocean floor habitat, supporting various organisms.