SUSTAINABILITY OF ECOSYSTEMS

Ecology is the study of how organisms interact with the living (biotic) and non-living (abiotic) components of their environment.
- It explores organisms in their natural habitat.
- It studies interactions between organisms and their surroundings.
- It looks at environmental factors influencing growth, feeding, and reproduction.

Biotic: The living part of the environment (e.g., plants and animal organisms).
Abiotic: Is the nonliving part of the environment (e.g.: wind and temperature).
Population: Organisms that group themselves with others of their own kind.
Community: Populations of different organisms interact with each other, forming a network of relationships within a shared environment.
Ecosystem: Communities of different organisms interact with both living and non-living factors in a specific area, forming a complex and interconnected system.

Terrestrial Ecosystems are land-based.
- Forests: High biodiversity, lots of trees, and variable climates (e.g., rainforests, temperate forests).
- Deserts: Hot or cold, minimal rainfall, and adapted species (e.g., cacti, camels).
- Grasslands: Open landscapes, few trees, and large herbivores (e.g., savannas, prairies).
- Tundra: Cold, permafrost, and low vegetation (e.g., Arctic tundra).

Aquatic Ecosystems are water-based.
- Freshwater: Rivers, lakes, ponds, and wetlands; home to fish, amphibians, and plants.
- Marine: Oceans, coral reefs, estuaries; largest ecosystem, rich in biodiversity.
- Estuaries: Where freshwater meets saltwater, highly productive zones.

Biotic Factors (Living Influences)
- Predation: The presence of predators controls population sizes.
- Competition: Organisms compete for food, space, and mates.
- Disease & Parasites: Can reduce population numbers significantly.
- Reproductive Rates: Birth rates vs. death rates determine population growth.
Abiotic Factors (Non-Living Influences)
- Climate & Weather: Temperature, rainfall, and natural disasters affect survival.
- Food & Water Availability: Essential for population stability.
- Habitat Destruction: Human activities like deforestation impact ecosystems.
- Pollution & Toxins: Can disrupt food chains and reduce biodiversity.

All energy in ecosystems originates from the Sun and flows through different components of the food web.
Energy is transferred from the Sun to producers (plants) through photosynthesis.
Energy moves through food chains, with some lost as heat at each level.

Different surfaces reflect or absorb solar energy at varying levels.
Light-colored surfaces (ice, snow) reflect sunlight, resulting in High Albedo.
Dark surfaces (forests, oceans) absorb heat, resulting in Low Albedo.
Infrastructure and urban development would impact the natural albedo of an environment.

Detritivores and decomposers break down dead organic matter, returning nutrients to the ecosystem.
They are essential in nutrient cycling and maintaining ecosystem balance.
Without them, dead plants and animals would accumulate, and nutrients wouldn’t be available for new growth.
Detritivores are organisms that consume dead organic matter (detritus) for nutrients; examples include earthworms, woodlice, millipedes, and dung beetles.
- Roles:
  - Physically break down organic material into smaller pieces.
  - Facilitate decomposition by making organic matter accessible to decomposers.
Decomposers are microorganisms (mainly fungi and bacteria) that chemically break down dead matter into nutrients; examples include mushrooms, molds, and bacteria.
- Roles:
  - Convert organic material into inorganic substances (like carbon, nitrogen, and phosphorus).
  - Release nutrients back into the soil, benefiting plant growth.

Food Chains are a linear sequence showing how energy transfers from one organism to another.
- Example: Grass → Grasshopper → Frog → Snake → Hawk
- Key Concept: Energy flows in one direction, with each step losing energy.
Food Webs are a more complex network of interconnected food chains showing multiple feeding relationships.
- Key Concept: Unlike a simple food chain, a food web better represents natural ecosystems.
- Example: Multiple herbivores eating plants, shared predators.

Energy originates from the sun and moves through organisms.
Producers capture sunlight and convert it into chemical energy.
Consumers obtain energy by eating other organisms.
Decomposers recycle nutrients back into the ecosystem.
10% Rule: Only about 10% of energy transfers to the next level, the rest is lost as heat.