Ecology Overview

Study Notes

Niche: An organism's role in its ecosystem, including resource use and inter-organism interactions.
Habitat: The natural environment where a species lives, e.g., honeybees in gardens and meadows.

Energy in ecosystems flows in one direction: from the sun to producers, then through consumers.
Producers: Organisms, such as plants and algae, that generate energy via photosynthesis.
Primary Consumers: Herbivores that consume producers.
Secondary Consumers: Carnivores that eat primary consumers.
Tertiary Consumers: Top predators feeding on secondary consumers.
Decomposers: Bacteria and fungi that breakdown dead material, recycling nutrients to soil.

Essential cycles: carbon, nitrogen, and water, crucial for ecosystem health.
Carbon Cycle: Involves carbon transfer among the atmosphere, oceans, soil, and living organisms through photosynthesis, respiration, and decomposition.
Nitrogen Cycle: Nitrogen conversion via nitrogen fixation, nitrification, and denitrification.
Water Cycle: Water circulates through evaporation, condensation, and precipitation across the Earth.
Example of Carbon Cycle: Plants absorb carbon dioxide during photosynthesis, converting it into glucose.

Biomes are vast areas characterized by specific climates, soils, flora, and fauna.
Major biomes include:
- Tropical Rainforests: Warm, wet, and highly biodiverse.
- Deserts: Dry, extreme temperature variations, and adapted organisms.
- Grasslands: Dominated by grasses, moderate rainfall, and occasional droughts.
- Temperate Forests: Seasonal climates with deciduous and evergreen trees.
- Tundras: Cold conditions with permafrost and limited vegetation.
- Aquatic Biomes: Include freshwater (rivers, lakes) and marine (oceans, coral reefs) systems.

Specific habitats in each biome provide resources for organisms' survival.
Example of a tropical rainforest habitat: The canopy hosting diverse birds, insects, and mammals, contrasted with the forest floor supporting decomposers and ground-dwelling animals.

Population dynamics examine how populations change over time.
Influencing factors include birth rates, death rates, immigration, and emigration.
Carrying Capacity: The maximum sustainable population size an environment can support.