Transcript Ecology
Ecology Objectives: • To understand ecological levels of organization. • To describe the flow of energy through an ecosystem. • To describe and analyze the components of the water, carbon, nitrogen and phosphorous cycles. • To identify the effects that destruction of habitats, pollution, urbanization, and natural disasters have on population. What is ecology? • The scientific study of relationships between organisms and their environment. • It explains how living organisms affect each other and the world they live in. Why is ecology important? • Allows us to understand how the natural world around us works • Allows us to understand how organisms (plants & animals) are shaped by their surroundings (environment) Ecology Issues Today • Exploding Human Population • 6 billion people in 1996 • 7.8-12.5 billion people by the year 2050 • More of the Earth’s resources necessary to support humans • Food, space, energy The Sixth Mass Extinction • Human impact has destroyed the habitats of many bird species. • Hawaii, 60 species now extinct The Thinning Ozone Layer • Ozone layer protects Earth’s living organisms by absorbing UV radiation. • Hole: low ozone level over Antarctica • Sunburns and skin cancer Climatic Changes • Greenhouse Effect: gases in the atmosphere trap heat emitted from the Earth’s surface, insulating and warming the Earth • Burning fossil fuels releases gases that trap heat in the atmosphere. (carbon dioxide, methane, & nitrous oxide) As these gases build up, they trap more heat near the Earth’s surface, causing Earth’s climate to become warmer than it would naturally. Interconnectedness • Key Theme: All organisms affect and are affected by the living and non-living components of their environment • The next slide shows different species that are ecologically connected. Describe some ways they are connected. How is the environment organized? • The parts of an environment are organized into two categories: 1. Abiotic Factors 2. Biotic Factors Nonliving Environment • Abiotic Factors (A=“not” Bio= “living”)– the nonliving parts of an organism’s environment • Abiotic factors affect an organism’s life • Examples: • Soil, temperature, pH, sunlight • Precipitation, air currents, and humidity Living Environment • Biotic Factors: All the living parts of an environment • All organisms depend on others, directly or indirectly, for food, shelter, reproduction, or protection. • Examples: competitors, decomposers, and predators Biotic or Abiotic? • Abiotic Biotic or Abiotic? Biotic Biotic or Abiotic? Abiotic Biotic or Abiotic? Biotic *Phosphorus *Calcium Potassium *Nitrogen *Sulfur Biotic Factors? Abiotic Factors? Levels of Organization • Now that you can identify biotic and abiotic factors, we will organize their interactions at different levels • Ecologists have arranged an organism’s interactions into different levels according to complexity. Levels of Organization 1st Level: Organism • The simplest level in ecological organization • An organism is an individual living thing. • Bacterial cell or elephant • Scientists study the adaptations that allow organisms to overcome challenges of their environment 2nd Level: Population • A group of organisms, all the same species, which interbreed and live in the same place at the same time • Scientists study the members of a single species; how they share their environment. (Food, water, etc.) 3rd Level: Community • Biological Community is made up of all the populations of different species that live in the same place at the same time; all biotic factors • Here: zebras and wildebeest • Scientists study how the species interact 4th Level: Ecosystem • All the biotic and abiotic parts of an environment found in a particular place. • Populations of plants and animals that interact with each other in the same place and the abiotic factors of that area. Ecosystem • Two Types: 1. Terrestrial (Land) 2. Aquatic (Water) a. Freshwater (lakes, ponds, rivers) b. Saltwater/Marine (oceans) 5th Level: Biosphere • The portion of Earth that supports life (13 mi. thick) • Life is found in air, on land, and in fresh and salt water • If the Earth were the size of an apple, the biosphere would be as thick as the apple’s skin.