Ecology Overview and Biosphere Parts

Ecology Overview

• Ecology is the study of how living organisms interact with each other and their environment, understanding ecosystems and human impacts.
• Environment encompasses all living and non-living things and their interactions on Earth.

Parts of the Biosphere

• The biosphere involves three interacting spheres:
  • Atmosphere: Earth's gaseous layer.
  • Lithosphere: Earth's solid outer layer (crust).
  • Hydrosphere: Water on Earth (mostly saltwater, some freshwater).

Sustainability and Stewardship

• Sustainability: The ability of populations to interact and reproduce indefinitely.
• Stewardship: Responsible environmental management for long-term sustainability and preventing collapse.

Photosynthesis and Cellular Respiration

• Photosynthesis: Plants use sunlight, water, and CO2 to produce carbohydrates (like glucose) and release oxygen.
• Cellular respiration: Cells break down glucose and oxygen to create carbon dioxide, water, and energy.

Nutrient Cycling

• Nutrients (e.g., nitrogen, carbon): Essential for organism growth and function, cycled within Earth's closed system.
• Organic substances: Contain carbon and hydrogen (e.g., sugars).
• Inorganic substances: Lack carbon and hydrogen (e.g., water, minerals).
• Recycling Process: Organisms use inorganic substances to create organic ones; decomposers break down dead matter, releasing inorganic nutrients back into the environment.

Definitions and Key Concepts

• Population: Number of species individuals in an area.
• Biotic Potential: Maximum offspring a species can produce in ideal conditions.
• Limiting Factors: Aspects (food, space, temperature) restricting population growth.
• Abiotic Factors: Non-living environmental aspects.
• Biotic Factors: Living environmental aspects (food, predators, competition).
• Biodiversity: Variety of organisms in an area.
• System: Interacting parts working together.
• Components: The individual parts within a system.
• Carrying Capacity: Maximum population an environment can sustain.
• Equilibrium: Occurs when birth and death rates are balanced.
• Biomes: Large geographic areas with specific climates and organisms.
• Ecosystems: Interplay of organisms and their non-living environment.
• Communities: Different species interacting within an area.
• Habitats: Specific locales where organisms live.
• Niche: An organism's specific role in an ecosystem.

Foundations of Healthy Ecosystems

• Ecosystem diversity supports stability and resource variety.
• Key nutrient cycles are water, carbon, nitrogen, and phosphorus.
• Energy flows from the sun through trophic levels, and 10% energy is transferred to each successive level.

Food Webs and Food Chains

• Food Chain: Linear energy transfer between organisms (e.g., grass → rabbit → fox).
• Food Web: A complex network of interconnected food chains.
• Trophic Levels:
  • Producers (Level 1): Convert sunlight to energy (plants).
  • Primary Consumers (Level 2): Eat producers.
  • Secondary Consumers (Level 3): Eat primary consumers.
  • Tertiary Consumers (Level 4): Top predators eating secondary consumers.
  • Decomposers: Break down dead matter to release nutrients.

Energy Flow in Ecosystems

• Ecosystems are dynamic interactions of biotic and abiotic factors.
• Energy enters as sunlight and moves via trophic levels, diminishing by 90% at each level as heat loss.

Autotrophs and Symbiosis

• Autotrophs: Organisms that produce their own food (e.g., plants).
• Symbiosis: Interactions between different species:
  • Mutualism: Benefits both species.
  • Commensalism: Benefits one species, with no effect on the other.
  • Parasitism: Benefits one species at the expense of another.

Nutrient Cycles

• Water Cycle: Water movement between atmosphere, land, and oceans (evaporation, condensation, precipitation, infiltration).
• Carbon Cycle: Carbon exchange between living organisms and the environment (photosynthesis, respiration, fossil fuels).
• Nitrogen Cycle: Bacteria conversion of nitrogen (nitrogen fixation, nitrification, ammonification, denitrification).

Predation, Competition, and Energy Transfer

• Predation: One organism hunts and eats another.
• Competition: Organisms compete for limited resources.
• Energy Transfer: Energy flows up the food chain, diminishing with each transfer, 10% transferred to the next trophic level.

Energy Pyramid

• Illustrates energy flow through trophic levels. Energy decreases as you move up the pyramid.

Bioaccumulation and Biomagnification

• Bioaccumulation: Toxins accumulate in organisms over time.
• Biomagnification: Toxin concentrations increase as you move up the food chain.

Human Impact on Ecosystems

• Monoculture: Growing only one crop type reduces biodiversity and disrupts ecosystems.
• Pesticides: Harm non-target species and reduce biodiversity.
• Deforestation: Reduces biodiversity and degrades habitats and soil quality.

Biodiversity Hotspots

• High biodiversity regions under threat from human activities, needing conservation effort.
• High numbers of endemic plant species.
• Significant habitat loss (70%+).

Toxins and Ecosystem Health

• Pesticides: Chemicals that kill pests, harming other organisms and disrupting balance in ecosystems.
• Bioaccumulation and Biomagnification: Toxins accumulate, increasing concentration in higher trophic levels.

Math Part

• Only 10% of energy is transferred to the next trophic level. Examples provided demonstrate this decrease in energy from producer to consumer.

Explore the fundamentals of ecology, including the interactions among organisms and their environment. Learn about the biosphere's components, sustainability, stewardship, and the processes of photosynthesis and cellular respiration. This quiz will deepen your understanding of ecosystem dynamics and human impacts.