Ecology Overview and Classifications

Introduction

• Ecology was coined by Ernst Haeckel, a German biologist, in 1869.
• Ecology studies the relationship between organisms and their environment.
• This applies to both plants and animals.

Classification of Ecology Based on Study Area

• Autecology focuses on a single species and its population, studying behavioral adaptations to the environment across its life cycle.
• Synecology focuses on communities, their composition, behavior and interaction with the environment.
  • Population Ecology examines a specific population.
  • Community Ecology examines a community of different species.
  • Ecosystem Ecology examines the interaction between communities and their environment.

Classification of Ecology Based on Environment or Habitat

• Aquatic Ecology studies organisms and their interactions in water:
  • Marine Ecology focuses on organisms in saltwater:
    • Oceans
    • Deep Sea
    • Estuaries
  • Freshwater Ecology focuses on organisms in freshwater:
    • Lotic (Running Water):
      • Rivers
      • Streams
      • Springs
    • Lentic (Standing Water):
      • Ponds
      • Lakes
• Terrestrial Ecology studies organisms in land:
  • Grassland Ecology
  • Forest Ecology
  • Edaphic Factors: Soil, pH, topography, minerals, etc.

Components of Ecosystem

• Abiotic Factors are non-living and affect the ecosystem:
  • Climate, light, water etc.
• Biotic Factors are living things affecting the ecosystem:
  • Disease, predators, food resources.

The Major Biological Components of Ecosystems

• Producers (Autotrophs) make their own food using energy from the environment:
  • Plants on land
  • Algae and plants in freshwater and marine ecosystems
  • Phytoplankton in open water
• Consumers (Heterotrophs) get energy by consuming other organisms:
  • Primary consumers (herbivores) eat producers
  • Secondary consumers (carnivores) eat other animals
  • Tertiary consumers (large carnivores) eat secondary consumers
  • Quaternary consumers (largest carnivores) eat tertiary consumers
  • Omnivores eat both plants and animals
• Decomposers (mostly bacteria and fungi) break down dead organic matter, releasing inorganic compounds back into the ecosystem for producers to use.

Ecological Pyramid

• A graphical representation of trophic structure and function, starting from producers at the base and progressively higher trophic levels.
• Pyramid of Numbers shows the number of individuals in each trophic level, often decreasing as you move up the pyramid.
• Pyramid of Biomass shows the amount of biomass in each trophic level, often decreasing as you move up the pyramid.
• Pyramid of Energy shows the energy available at each trophic level, decreasing as you move up the pyramid.

Trophic Structure

• Organisms in an ecosystem are organized into trophic levels based on their energy source and how they provide energy to other organisms in the food web.
• This structure relies on the sun's energy, with producers converting sunlight into usable energy for other organisms.

Food Chain

• A sequence of organisms in an ecosystem, showing who eats who to obtain nutrition.

Food Web

• A complex network of interconnected food chains within an ecosystem, depicting feeding relationships.

Grasslands

• Based on dominant vegetation, specific species, and climate conditions.
• Temperate grasslands
• Tropical grasslands
• Polar grasslands
• Grassland soils are fertile and contain large amounts of organic matter.

Estuaries

• Semi-enclosed coastal bodies of water where freshwater mixes with saltwater.
• Transition zone from land to ocean..
• Known as bays, sounds, lagoons, harbors, or bayous.
• Nutrient-rich, leading to high productivity and biodiversity.
• Salinity increases from the river to the ocean.
• Sediment settles out as water slows down.
• Pollutants are absorbed in estuaries.

Aquatic Ecosystem

• Ecosystem within a body of water:
  • Freshwater Ecosystem:
    • Pond Ecosystem: shallow, still water, marsh, aquatic plants
    • Lake Ecosystem: slow-moving water (pools, ponds, lakes)
    • River Ecosystem: flowing water from highlands to the sea
  • Marine Ecosystem: covers 71% of Earth's surface, contains 97% of Earth's water

Biogeochemical Cycle

• Energy flows through an ecosystem and dissipates as heat, while chemical elements are recycled.
• Movement of elements or compounds between living and non-living forms in the biosphere.
• Important cycles: water, carbon, nitrogen, phosphorous, and sulfur.

Key Elements for Life

• Carbon is essential for all organic molecules and fossil fuels.
• Nitrogen is needed for DNA, RNA, and proteins, crucial for agriculture.
• Phosphorus is key for DNA and RNA, important for fertilizers.
• Sulfur is vital for protein structure and is released by fossil fuel burning.

The Carbon Cycle

• Carbon enters plants and algae as CO2, incorporated through photosynthesis.
• Cellular respiration releases CO2 back into the atmosphere.
• Combustion and weathering also release CO2.
• Increased atmospheric CO2 can contribute to global warming.

The Nitrogen Cycle

• Nitrogen is a key component of living organisms, found in proteins and DNA.
• Nitrogen gas (N2) is converted to ammonia by nitrogen-fixing bacteria.
• Nitrification converts ammonia or ammonium to nitrate, used by plants.
• Nitrogen is a limiting nutrient, affecting growth.
• Runoff from fertilizers can cause eutrophication (algae blooms).

Nitrogen Fixation

• Conversion of nitrogen gas (N2) to ammonia.

Nitrification

• Conversion of ammonia or ammonium to nitrate, a form of nitrogen usable by plants.

Explore the fascinating field of ecology, which focuses on the relationships between organisms and their environments. This quiz covers various classifications of ecology, including autecology, synecology, and aquatic ecology. Test your understanding of the different types of ecological studies and their significance.