Studying Life Introduction to Ecology Studying Life The

Studying Life & Introduction to Ecology

Studying Life The word biology means the study of life, from the Greek word bios meaning “life” and –logy meaning “study of”. Biology is the science that seeks to understand the living world. Our world is filled with many things, some of them living (biotic), some of them non-living (abiotic). A living thing is called an organism.

Biotic or Abiotic?

8 Characteristics of Living things All organisms share the following characteristics: 1. made up of cells—a cell is a collection of living matter enclosed by a barrier. Some living things are unicellular (made of one cell) and some are multicellular (made of multiple cells).

8 Characteristics of Living things 2. reproduce—the way organisms produce new organisms. There are two types of reproduction: sexual—two cells from parents unite to form a new organism asexual—a new organism has a single parent

8 Characteristics of Living things 3. based on a universal genetic code— organisms inherit traits based on their DNA or RNA. 4. grow and develop—all living things grow and change during at least some part of their lives.

8 Characteristics of Living things 5. obtain and use materials and energy— these are necessary to stay alive. The combination of chemical reactions through which an organism builds up or breaks down materials as it carries out its life processes is called metabolism.

8 Characteristics of Living things 6. respond to their environment— organisms are able to detect and respond to stimuli. 7. maintain a stable internal environment— the process by which they do this is called homeostasis. Organisms keep many internal conditions stable, such as temperature and water content.

8 Characteristics of Living things 8. change over time—individual organisms experience many changes over their lifetimes, but the basic traits they inherit stay the same. Groups of organisms, however, evolve into new organisms over very long periods of time.

Characteristics of Living things Examples of biotic organisms: plants, animals, bacteria, fungus, algae Examples of abiotic factors: rain, sunshine, temperature, rocks, rivers

Introduction to Ecology

Ecology is the scientific study of interactions between organisms and their environment. Ecology comes from the Greek oikos meaning “house” and –logy meaning “study of”. The largest of nature’s “houses” is the biosphere. The biosphere contains all the portions of the planet on which life exists, including land, water, and air.

Ecological Organization To understand relationships within the biosphere, scientists organize living things into different levels, ranging from the single individual up to the entire biosphere. 1. Individual-Smallest category, a single living organism Ex: Elk

Ecological Organization 2. Populations—groups of individuals of the same species living in the same area. (species—a group of organisms so similar to one another that they can breed and produce fertile offspring. ) Ex: a herd of Elk 3. Communities—groups of different populations that live together in a defined area. Ex: Elk, moose, beaver, rabbit, trees, bushes, grasses in a forest

Ecological Organization 4. Ecosystem—collection of all the organisms that live in a particular place, along with their non-living environment. Ex: all those communities and abiotic factors like the river, the soil, the rain, the sunshine 5. Biome—a group of ecosystems that have the same climate and similar dominant communities. Ex: Boreal forest biome

Ecological Organization 6. Largest: biosphere—the entire surface of the Earth.

Ecological Organization Organisms living together in a population, community, ecosystem, etc. compete with each other for the resources in their environment. This competition keeps population levels low enough to support life without using up all the resources.

Energy Flow in Ecology

Energy Flow in Ecology Sunlight is the main energy source for all life on Earth. Of all the sun’s energy that reaches the surface of the Earth, only about 1% is used by living things. There are some organisms that use energy stored in chemical compounds, but most organisms rely on the sun’s energy.

Energy Flow in Ecology Organisms that can capture the sun’s energy and use that energy to produce food are called autotrophs (auto means “self”, troph means “to feed”). Examples of autotrophs are plants, some algae, and certain bacteria.

Energy Flow in Ecology Since autotrophs make their own food, they are also called producers. Most autotrophs use photosynthesis to make food from the sun’s energy. Some use chemosynthesis, in which they break down chemical bonds for energy to make food.

Energy Flow in Ecology Organisms that must take in food from the outside are called heterotrophs (hetero means “other”, troph means “to feed”). Since heterotrophs have to eat other organisms, they are also called consumers.

Heterotrophs that hunt and kill are called predators, the organisms that get hunted and killed are called prey. Types of Heterotrophs: herbivores only eat plants detritivores feed on dead matter omnivores eat both plants and animals scavengers eat dead animals carnivores only eat animals decomposers break down dead matter o Heterotrophs that hunt and kill are called predators, the organisms that get hunted and killed are called prey.

Energy Flow in Ecology Energy flows through an ecosystem in only one direction: Sun producers consumers The energy stored by producers is passed through the ecosystem along a food chain —a series of steps in which organisms transfer energy by eating and being eaten.

Energy Flow in Ecology/ Food Chain In a prairie, an example of a food chain would be: grass antelope coyote In a food chain, the producer is always first, followed by an herbivore consumer, followed by another consumer that is either an omnivore or a carnivore. There can be many stages in a food chain.

Energy Flow in Ecology Use the space on your paper to make 3 food chains using the organisms on the screen. Each should have at least 3 organisms: grass coyote small fish snake grasshopper seaweed owl mouse shark berries big fish toad hawk squirrel mountain lion

Energy Flow in Ecology A food web is a complex interaction of many different food chains in an ecosystem.

Warmup What is the difference between a food chain and a food web? What affect would eliminating a producer from a food chain have?

Ecological Pyramids

Ecological Pyramids Each step in a food chain or a food web is called a trophic level. Producers make up the first trophic level, consumers make up the second, third, or higher trophic levels. Each consumer depends on the trophic level below it for energy.

Ecological Pyramids The first consumer in the food chain is the primary consumer. This is usually an herbivore, sometimes an omnivore. The second consumer is called the secondary consumer and is either an omnivore or a carnivore. The third consumer is called a tertiary consumer and is usually a carnivore. The fourth consumer is called a quaternary consumer and is usually a carnivore.

Ecological Pyramids An ecological pyramid is a diagram that shows the amount of energy or matter contained within each trophic level of an ecosystem. There are three common types of ecological pyramids:

Energy Pyramids An energy pyramid shows the amount of energy transferred to each trophic level. **Only about 10% of the energy available in one trophic level is transferred to the organisms at the next trophic level. The rest of the energy is used for that organism’s life processes. **

Biomass Pyramids A biomass pyramid shows the total amount of living tissue within each trophic level.

Pyramid of numbers A pyramid of numbers shows the numbers of individuals in each trophic level.

Ecological Pyramid: Color the bottom (biggest level) green (grass, berries, algae) Second level yellow Third level blue Top (4 th) red Label first side with: producer, primary consumer, secondary consumer, tertiary consumer Label second side with: autotroph, 1 st order heterotroph, 2 nd order heterotroph, 3 rd order heterotroph Label third side with: plants, herbivores, carnivores, top carnivores Label forth side with: 100% energy, 1% energy, 0. 1% energy AS WELL AS biomass: 35, 000 kg on the bottom calculate the rest

Cycling of Matter

Cycling of Matter Unlike the one-way flow of energy, matter is recycled within and between ecosystems. Elements, unlike chemical compounds, and other forms of matter are passed from one organism to another and from one part of the biosphere to another through biogeochemical cycles. Matter can cycle because matter is not used up, but transformed.

Cycling of Matter Water Cycle—water moves between the ocean, atmosphere, and land. Condensation Evaporation & Transpiration Precipitation Runoff

Cycling of Matter Carbon Cycle — 4 main types of processes move carbon through its cycle: 1. Biological processes: photosynthesis takes up carbon from the air and respiration releases carbon back into the air. 2. Geochemical processes: erosion and volcanic activity release carbon dioxide.

Cycling of Matter (Carbon Cycle) 3. Mixed biogeochemical processes: burial and decomposition of dead organisms and their conversion under pressure into fossil fuels stores carbon underground. 4. Human activities: mining, burning forests and fossil fuels, release carbon dioxide into the air. Driving cars

Cycling of Matter Nitrogen Cycle All organisms need nitrogen to make amino acids which link together to form proteins. Nitrogen occurs in the atmosphere as nitrogen gas, as ammonia NH 3 and as charged ions in the waste of organisms and dead and decaying organic matter. Most of the nitrogen is in the atmosphere (the air = 78% nitrogen gas), but most organisms cannot use this form of nitrogen directly.

Cycling of Matter (Nitrogen Cycle) Bacteria convert nitrogen gas into ammonia so that other organisms can use it in a process called nitrogen fixation. Nitrogen fixation occurs in the roots of plants called legumes. Nitrogen gets put back into the atmosphere when other soil bacteria convert nitrates into nitrogen gas in denitrification.

Warmup Draw a diagram (good, labeled one) including the carbon, nitrogen, and water cycles. (If you want to do three separate diagrams, you may)

Habitat, Niche, Symbiosis, and Succession

What shapes an ecosystem? Biotic and abiotic factors shape an ecosystem. Together, they determine the survival and growth of an organism and the productivity of the ecosystem in which the organism lives. The area where an organism lives is called its habitat. A habitat includes both biotic and abiotic factors that describe where an organism lives.

Niche The niche is the full range of physical and biological conditions in which an organism lives and the ways in which the organism uses those conditions. This is how an organism lives. A niche includes the type of food an organism eats, how it gets food, which species it uses for food, what physical conditions the organism needs to survive, when and how the organism reproduces.

Niche No two species can share the same niche in the same habitat, there would be too much competition.

Community Interactions Community interactions affect the ecosystem. Some important interactions are: Competition occurs when organisms attempt to use the same resource in the same place at the same time. Predation is an interaction in which one organism captures and feeds on another.

Symbiosis is any relationship in which two species live closely together. There are three main types of symbiosis: § Mutualism—both species benefit. Ex: flowers and bees (+ / +) § Commensalism—one species benefits, the other is neither helped nor harmed. Ex: barnacles and whales (+ / Ø) § Parasitism—one organism lives in or on another and harms it. Ex: dogs and fleas (+ / -)

Ecological Succession Ecological succession is a series of predictable changes that occurs in a community over time. There are two main types of succession: Primary succession occurs on surfaces where there is no soil. Ex: after a volcano erupts, everything is covered with lava and destroyed, including the soil. The first species to come into an area are called pioneer species. Lichens are often the pioneer species on volcanic rock. As the lichens grow, they break down the rock to form the new soil.

Succession Secondary succession occurs when a disturbance changes a community without destroying the soil. This often occurs when humans clear cut a forest or a forest fire burns out of control. Once a community becomes stable again, those species populating it are called the climax community and succession stops. A climax community is very stable and long -lasting.

Succession Primary Secondary