Ecology

What is Ecology? Ecology is the study of interactions among organisms and between organisms and their environment. Biosphere contains the combined portions of the planet in which life exists, including land, water, and air or atmosphere. Biotic – the living part of the environments Abiotic- the nonliving part of the environment

Introduction to Ecology http://www.copernicusproject.ucr.edu/ssi/HSBiologyResources.htm Intro to Ecology and Biomes

Levels of Organization Species is a group of organisms so similar to one another that they can breed. Population are groups of individuals that belong to the same species and live in the same area. Communities are assemblages of the different populations that live together in a defined area. Ecosystem is a collection of all the organisms that live together in a particular place as well as their nonliving or physical environment. Biome is a group of ecosystems that have the same climate and similar dominant communities.

Energy Flow Sunlight is the main source of energy for life on Earth. Some types of organisms rely on the energy stored in inorganic chemical compounds. Autotrophs (producers) use energy from the sun to change inorganic compounds into complex organic molecules.

Energy Flow Autotrophs The best know autotrophs are those that harness the power of the sun through photosynthesis. They use this energy to convert carbon dioxide and water into oxygen and glucose. The second type of autotrophs use chemical energy to make carbohydrates. This is performed by several types of bacteria.

Energy Flow Consumers Heterotrophs (consumers) rely on other organisms for their energy and food. Herbivores obtain energy by eating plants. Carnivores obtain energy by eating animals. Omnivores eat both plants and animals. Detritivores feed on the remains of plants, animals and other dead matter. Decomposers breaks down organic matter into inorganic matter.

Introduction to Energy Flow http://www.copernicusproject.ucr.edu/ssi/HSBiologyResources.htm Intro to energy flow

Feeding Relationships Energy flow through an ecosystem in one direction, from the sun or inorganic compounds to autotrophs (producers) and then to various heterotrophs (consumers) and finally to decomposers Food Chains are a series of steps in which organisms transfer energy by eating or being eaten. Food webs show the complex interactions within an ecosystem. (many food chains liked together) Each step in a food chain or web is called a trophic level. Producers make up the first step, consumers make up the higher levels.

Food Webs & Food Chains http://www.copernicusproject.ucr.edu/ssi/HSBiologyResources.htm Food webs and food chains

Food Chain A food chain indicates the transfer of energy from producers through a series of organisms which feed upon each other.

Aquatic Food Chain

A food web is a series of interrelated food chains which provides a more accurate picture of the feeding relationships in an ecosystem, as more than one thing will usually eat a particular species.

Ecological Pyramids An ecological pyramid is a diagram that shows the relationship amounts of energy or matter contained within each trophic level in a food web or food chain. Energy Pyramid only 10% of the energy available within one trophic level is transferred to organisms at the next trophic level.

Energy Pyramid 2

Pyramids Continued Biomass pyramids show the total amount of living tissue available at each trophic level. This shows the amount of tissue available for the next trophic level. Numbers pyramid shows the number of species at each trophic level. Because each trophic level harvests only about one tenth of the energy from the level below, it can support only about one 10th the amount of living tissue.

Biomass Pyramid

Trophic Levels

Pyramids http://www.copernicusproject.ucr.edu/ssi/HSBiologyResources.htm Food pyramids

What trophic levels are humans in this food chain?

Cycles of Matter Unlike the one-way flow of energy, matter is recycled within and between ecosystems. These cycles are the water cycle, Nutrient Cycle, Carbon Cycle, nitrogen cycle and phosphorus cycle.

Carbon Cycle http://www.copernicusproject.ucr.edu/ssi/HSBiologyResources.htm Carbon Cycle - The movement of carbon, in its many forms, between the biosphere, atmosphere, oceans, and geosphere is described by the carbon cycle The Carbon Cycle is a complex series of processes through which all of the carbon atoms in existence rotate. The same carbon atoms in your body today have been used in countless other molecules since time began. The wood burned just a few decades ago could have produced carbon dioxide which through photosynthesis became part of a plant. When you eat that plant, the same carbon from the wood which was burnt can become part of you. The carbon cycle is the great natural recycler of carbon atoms. Unfortunately, the extent of its importance is rarely stressed enough. Without the proper functioning of the carbon cycle, every aspect of life could be changed dramatically.

Carbon Cycle

Water Cycle http://www.copernicusproject.ucr.edu/ssi/HSBiologyResources.htm Water Cycle - The cycle starts when the sun's heat evaporates water from the oceans into the atmosphere to form clouds. When the conditions are just right, the clouds release water as rain or snow. Most of the rain falls in the oceans, but the rest falls onto land. Rivers and streams collect water from the ground and return it to the ocean so the whole cycle can start all over again. The water cycle never ends because the salty ocean water constantly supplies fresh water to the continents. http://earthguide.ucsd.edu/earthguide/diagrams/watercycle/index.html

The Water Cycle

Nitrogen Cycle http://www.copernicusproject.ucr.edu/ssi/HSBiologyResources.htm Nitrogen Cycle - The nitrogen cycle represents one of the most important nutrient cycles found in terrestrial ecosystems (Figure 9s-1). Nitrogen is used by living organisms to produce a number of complex organic molecules like amino acids, proteins, and nucleic acids. The store of nitrogen found in the atmosphere, where it exists as a gas (mainly N2), plays an important role for life. This store is about one million times larger than the total nitrogen contained in living organisms.

Nitrogen Cycle

Oxygen Carbon Cycle http://www.copernicusproject.ucr.edu/ssi/HSBiologyResources.htm Oxygen Carbon cycle