Unit 1 BIntro to Ecology The Biosphere all

Unit 1 BIntro to Ecology

The Biosphere: • all life on Earth and all the parts of the Earth where life exists • Ecology is the study of the interactions of all of the organisms and their environments in the biosphere

Levels of Organization in the Biosphere 1. Organism- one individual of a certain species 2. Population- group of individuals of the same species living in the same area 3. Community- different populations living together in the same area 4. Ecosystem- all the organisms in a certain place together with their physical environment 5. Biome- a group of ecosystems with similar climates and typical organisms 6. The Biosphere- all living things from all biomes on the planet

• Where is the biosphere located and what does it include? o The biosphere is everywhere on our planet where there is life. This can be far above the land where birds fly, deep into the oceans where sea creatures live, or even deep underground where extreme bacteria can inhabit vents and volcanoes. It includes all the living things and the abiotic features of the planet that they interact with and rely upon. o Because there is life nearly everywhere on Earth, the word biosphere is a very broad term and the Earth itself is essentially our biosphere.

Fill in each box with the correct level of organization in the biosphere (the size of the box indicates the broadness of each category). Include a word or two to help you remember what each grouping means. _________- ________________- In in as e cr g ________- ity ex pl m Co Levels of Organization in the Biosphere _________Population- ___________-

Environments: • The conditions or factors surrounding an organism • Consist of biotic and abiotic factors

Biotic Factors • Any living part of the environment • Includes animals, plants, fungi, bacteria, etc.

Abiotic Factors • Any nonliving (physical) part of the environment • Examples: sunlight, heat, precipitation, humidity, wind, water, soil, etc.

What are the Biotic and Abiotic Factors in this Environment?

Biotic and Abiotic Factors are Closely Linked The mucky shoreline, biotic, abiotic or both? Both! Abiotic- soil, water, sand, etc. Biotic- bacteria, fungi, small animals like worms, etc.

Energy, Producers, and Consumers

Energy • Organisms must get energy in order to function • Different organisms get their energy in different ways • Almost all energy on Earth starts from the sun!

1. Autotrophs • Organisms that capture energy from sunlight or chemicals and turn it into food • Also called primary producers

Primary Producers • Most commonly use energy from the sun to create sugars and starches (photosynthesis) • Important examples: plants, algae, photosynthetic bacteria

Chemosynthesis • When primary producers turn the energy in chemicals (like hydrogen sulfide) into carbohydrates. o Mostly bacteria o Found in extreme environments (deep ocean, hot springs, volcanoes)

2. Heterotrophs • Eat other organisms for food. • Also called consumers

Types of Consumers * Put these definitions in the correct bubbles on pg. 6 in the notes. Classified by the way they acquire energy • Carnivores- kill and eat other animals • Herbivores- eat plant materials • Omnivores- eat both plant and animal materials • Scavengers- consume carcasses of organisms that have died or that were killed by predators • Decomposers- feed by chemically breaking down organic matter into detritus, debris from decomposing plants and animals (Ex: fungi and bacteria) • Detritivores- feed on detritus particles (Ex: earthworms)

Types of Consumers

Food Chains and Food Webs

Energy Flows One Way • Almost all energy on Earth starts from the sun! • Energy flows through an ecosystem in a one way direction from producers to consumers

• Food Chain- a series of steps in which organisms transfer chemical energy by eating and being eaten. (food molecules are chemicals) Phytoplankton = algae that is floating and not attached to something **Read an arrow as “is eaten by”

Food Webs • Food web- a network of complex interactions formed by the feeding relationships among the organisms of an ecosystem Algae Plants

Decomposers and Detritivores are Important in Food Webs • Dead plant and animal material must be broken down so the molecules can be reused for new life • Decomposers (bacteria and fungi) are heterotrophs that break down this dead plant and animal material into detritus o This releases nutrients into the soil for new primary producers to grow (“recycles nutrients”) • Detritus is eaten by detritivores (like crayfish, grass shrimp, and worms), further releasing nutrients into the soil

Food Web Disturbances • Environmental changes can cause changes in a food web Krill

Food Web Disturbances • How would a decrease in the krill population affect the Antarctic food web? • What do ecologists mean when they say that killer whales indirectly depend on krill for survival?

Trophic Levels • Each step of a food chain or food web is called a trophic level • First trophic level- always primary producers • All other trophic levels are occupied by different types of consumers

Ecological Pyramids • Illustrations used to show the amounts of energy or matter in each trophic level of a food web • Three types of pyramids: energy, biomass, and numbers

Pyramids of Energy • Show the amount of energy available at each trophic level • Only 10% of the energy in one trophic level is passed to the next level up. • The rest of the energy is either used by the organisms to do life processes (like growth, reproduction, respiration, etc. ), or released as heat How much of the energy available to the producers is available to the third -level consumers?

Pyramids of Biomass • Biomass is the total amount of living tissue in a trophic level • Primary Producers will have the greatest biomass o There must be enough producers to provide energy for all of the consumers

Pyramids of Numbers • Show the number of individuals at each trophic level • If the main producer is a large organism, the base of the numbers pyramid will be small Pyramid of Numbers Grass Pyramid of Numbers

Niches and Community Interactions

Tolerance: q. The ability to survive and reproduce under a variety of environmental circumstances. q. Outside the optimum range causes stress (struggling to maintain homeostasis). q. For any environmental factor, going beyond the upper or lower limit can lead to death.

Habitat • The general place where an organism lives • Organisms will live where they can tolerate (or handle) the conditions

Niche • What an organism does in its habitat, how it interacts with its environment, and how it contributes to an ecosystem • Example: “The red fox's habitat might include forest edges, meadows and the bank of a river. The niche of the red fox is that of a predator which feeds on the small mammals, amphibians, insects, and fruit found in this habitat. Red foxes are active at night. They provide blood for blackflies and mosquitoes, and are host to numerous diseases. The scraps left behind after a fox's meal provide food for many small scavengers and decomposers. ” • Make a list of things in your niche

Competition • When organisms attempt to use the same resource, competition occurs o Example: the roots of different plants compete for water, nutrients, and space in the soil

Types of Competition • Intraspecific- competition between members of the same species • Interspecific- competition between members of different species.

The Competitive Exclusion Principle: • The idea that no two species can occupy exactly the same niche, in the same habitat, at the same time • If two species try to do this, one of three things can happen: o 1 species will compete better for the niche and the other species will die out o 1 species will compete better for the niche and the other species will move away o The two species will split or share the niche. Ex: rainforest lizards that eat the same bugs can occupy different parts of the forest

What Is a Biome? • Large regions of land that are characterized by a specific type of climate and certain types of plant and animal communities. • Made up of many individual ecosystems • Vary according to their location from the equator (latitude)