Ecosystems Basics

Ecosystems

• An ecosystem is a community of living organisms (biotic factors) and non-living components (abiotic factors) interacting with each other in a specific environment.
• Components of an ecosystem:
  • Biotic factors: plants, animals, microorganisms, fungi
  • Abiotic factors: light, temperature, water, soil, air, nutrients
• Ecosystems can be classified into:
  • Terrestrial ecosystems: forests, grasslands, deserts
  • Freshwater ecosystems: rivers, lakes, wetlands
  • Marine ecosystems: coral reefs, estuaries, open ocean

Biodiversity

• Biodiversity refers to the variety of different species of plants, animals, and microorganisms that live in an ecosystem or on Earth as a whole.
• Types of biodiversity:
  • Species diversity: number of different species
  • Genetic diversity: variety of genes within a species
  • Ecosystem diversity: variety of ecosystems
• Importance of biodiversity:
  • Maintains ecosystem services: pollination, pest control, climate regulation
  • Provides food, medicine, and other resources
  • Supports human well-being and livelihoods

Food Chains

• A food chain is a series of organisms that eat other organisms, with each level representing a different trophic level.
• Trophic levels:
  • Producers: plants and algae that make their own food through photosynthesis
  • Primary consumers: herbivores that eat producers
  • Secondary consumers: carnivores that eat primary consumers
  • Tertiary consumers: carnivores that eat secondary consumers
  • Decomposers: organisms that break down dead organic matter
• Energy flow in a food chain:
  • Energy is transferred from one trophic level to the next, with some energy lost as heat
  • Only about 10% of energy is transferred from one level to the next

Population Dynamics

• Population dynamics refers to the study of changes in population size and structure over time.
• Factors affecting population growth:
  • Birth rate: number of individuals born per unit time
  • Death rate: number of individuals dying per unit time
  • Immigration: movement of individuals into a population
  • Emigration: movement of individuals out of a population
• Population growth models:
  • Exponential growth: rapid growth in a population with unlimited resources
  • Logistic growth: growth slows as population approaches carrying capacity

Human Impact

• Human activities can have significant impacts on ecosystems and biodiversity:
  • Habitat destruction: deforestation, land conversion, pollution
  • Overexploitation: overfishing, overhunting, overharvesting
  • Climate change: global warming, ocean acidification
  • Invasive species: introduction of non-native species that outcompete native species
• Conservation strategies:
  • Protected areas: national parks, wildlife reserves, conservation areas
  • Sustainable resource management: sustainable forestry, fishing, and agriculture practices
  • Education and outreach: raising awareness about environmental issues and promoting behavior change

Ecosystems

• An ecosystem is a community of living organisms (biotic factors) and non-living components (abiotic factors) interacting in a specific environment.
• Biotic factors include plants, animals, microorganisms, and fungi, while abiotic factors include light, temperature, water, soil, air, and nutrients.
• Ecosystems can be classified into terrestrial (forests, grasslands, deserts), freshwater (rivers, lakes, wetlands), and marine ecosystems (coral reefs, estuaries, open ocean).

Biodiversity

• Biodiversity refers to the variety of different species of plants, animals, and microorganisms in an ecosystem or on Earth.
• Types of biodiversity include species diversity (number of different species), genetic diversity (variety of genes within a species), and ecosystem diversity (variety of ecosystems).
• Importance of biodiversity includes maintaining ecosystem services (pollination, pest control, climate regulation), providing food, medicine, and other resources, and supporting human well-being and livelihoods.

Food Chains

• A food chain is a series of organisms that eat other organisms, with each level representing a different trophic level.
• Trophic levels include producers (plants and algae that make their own food through photosynthesis), primary consumers (herbivores that eat producers), secondary consumers (carnivores that eat primary consumers), tertiary consumers (carnivores that eat secondary consumers), and decomposers (organisms that break down dead organic matter).
• Energy flow in a food chain involves energy transfer from one trophic level to the next, with some energy lost as heat, and only about 10% of energy is transferred from one level to the next.

Population Dynamics

• Population dynamics refers to the study of changes in population size and structure over time.
• Factors affecting population growth include birth rate, death rate, immigration, and emigration.
• Population growth models include exponential growth (rapid growth in a population with unlimited resources) and logistic growth (growth slows as population approaches carrying capacity).

Human Impact

• Human activities can have significant impacts on ecosystems and biodiversity, including habitat destruction, overexploitation, climate change, and invasive species.
• Conservation strategies include establishing protected areas, sustainable resource management, education, and outreach to raise awareness about environmental issues and promote behavior change.