1. Chapter 13

2.  Ecology is the scientific study of interactions among organisms and between organisms and their environment, or surroundings.

3.  Biotic factors are biological influences on organisms within an ecosystem. e.g. birds, trees, mushrooms, bacteria  Abiotic factors are physical or nonliving factors that shape ecosystems. e.g. climate, nutrient availability, soil type, sunlight

4.  Biosphere- Everything on the planet! Biome- A group of ecosystems that have the same climate and dominant communities.  Ecosystem- A collection of all the organisms that live in a particular place along with the abiotic factors in the area.  Community- assemblages of different populations that live together in a defined area.  Population- groups of individuals that belong to the same species and live in the same area.  Individual

5.  Observing  Experimenting- both in the lab and in the natural ecosystems  Modeling- models are used to gain understanding into phenomena that occur over long periods of time or large spatial scales.

8.  Producers get their energy from non- living resources.  Producers are also called autotrophs because they make their own food. Photosynthetic organisms- use energy from sunlight to make their food. (plants, some bacteria) Chemosythetic organisms- use energy stored within bonds of inorganic molecules, such as Hydrogen sulfide, to make their food. (some bacteria)

9.  Consumers are organisms that get their energy by consuming living or once-living resources.  Consumers are also called heterotrophs because they feed off of different things. Herbivores- eat plants Carnivores- eat animals Omnivores- eat both plants and animals Detritivores- eat detritus, dead tissue Decomposers- break down organic matter (bacteria and fungi)

10.  Think about these words: Heterotroph Autotroph Chemotroph  What does the suffix TROPH mean?

11.  Specialists are consumers that primarily eat one specific organism or a very small number of organisms.  Generalists are consumers that have a varying diet.

12.  Think of an example of a specialist.  Think of an example of a generalist.  Are specialists or generalists more likely to survive a change in the environment? Why?

13.  A keystone species is a species that has an unusually large effect on its ecosystem.  The loss of a keystone species in an ecosystem can cause a ripple effect.  Example: Beavers

14.  Energy flows through an ecosystem in one direction. From the sun to autotrophs to various heterotrophs  Food Chains: a series of steps in which organisms transfer energy by eating and being eaten.

15.  Food Webs In most ecosystems, feeding relationships are more complex then what can be shown in a food chain. Food webs show many different possibilities that could occur.

17.  Each step in a food chain or food web is called a trophic level. First Trophic Level- producers Second Trophic Level- primary consumers (normally herbivores) Third Trophic Level- secondary consumers (carnivores) Forth Trophic Level- tertiary consumers (top carnivores if last level)

18.  What Ecosystem did you do?  How many Trophic Levels are found in your food web?  What are the producers?  What are the primary consumers?  What are the top consumers?

20.  An ecological pyramid is a diagram that shows the relative amounts of energy or matter contained within each trophic level.  Three types Energy pyramids Biomass pyramids Pyramids by number

21.  Energy pyramids are based on the fact that only about 10% of the energy in each trophic level can be passed to the next. Energy is used up by the organisms and released as heat into the environment.

22.  Biomass is the total amount of living tissue within a trophic level.  Biomass pyramids represent the amount of potential food available for each trophic level in an ecosystem.  Because energy is lost between each trophic level, there is normally much less biomass of top consumers than producers.

23.  Ecological pyramids based on the number of individuals in each trophic level  Like the biomass pyramid, because energy is lost between each trophic level, there are normally much fewer top consumers than producers, however, this is less true than for biomass. e.g. Trees can support many herbivorous organisms.

26.  Matter is recycled within and between ecosystems.  Elements and compounds move through organisms and the environment in biogeochemical cycles.

30.  When an ecosystem is limited by a single nutrient this substance is the limiting nutrient.  Fertilizers can be applied to solve this problem.