Environmental Science and Sustainability Summary

Environmental Science and Sustainability

Organization of the Environment (Ecology)

• Species: A group of similar organisms capable of interbreeding.

• Population: A subset of individuals of one species in a geographic area.

• Biological Community: Interaction of various species in a location.

Ecosystem

• A biological community of organisms and their abiotic environment, involving energy flow and matter cycling.

• Types of ecosystems include:

  • Aquatic: Freshwater (lakes, rivers) and Marine (oceans).

  • Terrestrial: Land-based systems.

Aquatic Ecosystems

• Freshwater Ecosystems: Affected by water temperature, sunlight, oxygen, nutrients, water movement.

  • Examples: Lakes, ponds, wetlands, rivers.

• Marine Ecosystems: Influenced by light, temperature, depth, distance from shore, and zones (photic vs. aphotic).

Wetlands

• Areas inundated with water, supporting specific vegetation adapted for saturated soils.

  • Functions: Pollutant absorption, flood control, biodiversity hot spots, recreation.

  • Characteristics: Hydric soils and vegetation.

Ecotones

• Transitional zones between ecosystems with higher species diversity.

Ecosystem Services

• Benefits from ecosystems categorized into:

  • Provisioning: Food, clean water, raw materials.

  • Regulating: Climate, floods, disease.

  • Cultural: Aesthetic, recreational, spiritual.

  • Supporting: Soil formation, photosynthesis.

Biomes

• Large geographic areas classified by climate, vegetation, and geographic features.

  • Influenced by latitude and altitude.

Species Interaction Roles

• Keystone Species: Critical for ecosystem balance; their removal leads to significant changes.

  • Examples: Predators, prey, ecosystem engineers (e.g., beavers).

• Indicator Species: Reflect environmental health (e.g., amphibians).

• Endemic Species: Restricted to specific regions (e.g., kangaroos in Australia).

• Invasive Species: Non-native species that harm ecosystems (e.g., zebra mussels).

Community/Species Interactions

• Competition: Harmful interaction between species over resources.

• Predation: Predator benefits from prey consumption.

• Symbiosis Types:

  • Mutualism: Both species benefit.

  • Parasitism: One benefits, other harmed.

  • Commensalism: One benefits, other unaffected.

  • Amensalism: One harmed, other unaffected.

Threats to Biodiversity

• Habitat change, pollution, invasive species, and overexploitation lead to biodiversity decline.

Trophic Dynamics

• Trophic Pyramid: Only ~10% of energy transfers between levels (grassland and aquatic systems have different structures).

  • Bioaccumulation vs Biomagnification: Accumulation of toxins in organisms; magnification through food webs.

Resilience and Disturbances

• Resilience: Ecosystem's ability to recover from disturbances.

• Influenced by nutrient replenishment, plant regeneration, and species dispersion.

Ecosystem Examples

• Forest Ecosystems: Temperate deciduous and coniferous types.

• Desert Ecosystems: Sonoran and Mojave Deserts.

• Freshwater Ecosystems: Lakes, rivers, and streams.

• Coastal Ecosystems: Marine habitats along coastlines, vital for biodiversity and water purification.