2Chapter 3 Outline 3-1: What is Ecology? 3-2: Energy Flow Interactions and InterdependenceLevels of OrganizationEcological Methods3-2: Energy FlowProducersConsumersFeeding RelationshipsEcological Pyramids
3Chapter 3 Outline 3-3: Cycles of Matter Recycling in the Biosphere The Water CycleNutrient CycleCarbon CycleNitrogen CyclePhosphorus CycleNutrient Limitation
4Interactions and Interdependence Ecology: The study of interactions among organisms and between organisms and their environment (or Surroundings)Biosphere: The combined portions of the planet in which all life exists including land, water, and atmosphere.
5Levels of Organization To understand relationships within the biosphere, ecologists ask questions about events and organisms that range in complexity from a single individual to the entire biosphere.
6Levels of Organization Levels that ecologists study interaction:Species: groups of organisms that can breed to produce fertile offspringPopulation: groups of individuals that belong to the same species and live in the same area.Community: groups of populations in an areaEcosystem: collection of all the organisms that live in an area AND all the nonliving components.
7Levels of Organization Larger systems are also studied BiomesBiomes: groups of ecosystems that have the same climate and similar dominant communities.
8Ecological Methods Three basic approaches to study ecology: Observing ExperimentingModelingScientists make models to understand complex phenomena (ex. Global Warming)Many Models are math formulas
9Producers Sunlight is the main energy source for life on Earth Only a few organisms can use chemical compounds as their energy sourceAutotrophs: organisms that use energy from the environment to produce their own food.Ex. All plants, some bacteria, and some algae.
10Producers Autotrophs are also called producers. Plants make their own food through PhotosynthesisOrganisms that produce their own food from chemicals are called chemoautotrophs and use the process of chemosynthesis. (Bacteria)
11ConsumersOrganisms (animal, fungi, many bacteria) that annot make their own food must eat other organisms that can!Heterotrophs: organisms that rely on organisms for energy and food.
12Consumers Types of consumers: Herbivores Carnivores Omnivores Detritivores – feed on dead plant and animal matter (Detritus)Decomposers – break down organic matter.
13Feeding Relationships Energy flows through an ecosystem in one direction:Sun autotrophs (producers) heterotrophs (consumers)The energy stored by producers is passed through an ecosystem through a food chain: a series of steps in which organisms transfer energy by eating and being eaten.Ex. In Marine food chains, producers are algae, eaten by plankton, eaten by fish, etc.
14Feeding Relationships Food Webs: links many food chains togetherComplex feeding network in an ecosystem
15Feeding Relationship Trophic Levels Each step in a food chain or Food WebEX. Producer 1st Level
16Ecological PyramidsEcological pyramid: a diagram that shows the relative amounts of energy or matter contained within each trophic level in a food chain or web.
17Ecological Pyramid Three types of pyramids in ecology: Energy pyramid Only about 10% of the energy available within one trophic level is transferred to organisms at the nest trophic level. (Organisms use most energy for respiration, movement, reproduction, etc.)
18Three Types of Pyramids Biomass Pyramid:Biomass: Total amount of living tissue within a trophic level.Shows the amount of potential food available for each trophic level.Pyramid of NumbersShows the number of individual organisms at each trophic level.
19Three types of Pyramids Energy PyramidShows the relative amount ofenergy available at each trophiclevel. Organisms use about 10percent of thisenergy forlife processes.The rest is lostas heat.Pyramid of NumbersShows the relativenumber of individualorganisms at eachtrophic level.Biomass PyramidRepresents the amount ofliving organic matter at eachtrophic level. Typically, thegreatest biomass is at thebase of the pyramid.
20Recycling in the biosphere In addition to energy, organisms need water, minerals, and other compounds in order to liveUnlike energy that flows one-way through an ecosystem, matter is recycled within and between ecosystems.Elements, chemical compounds, and other forms of matter are passed from one part of the biosphere to another through biogeochemical cycles.Matter cycles within biosphere because it is not used up, just converted from on form to another.
21The Water CycleWater moves between the ocean, atmosphere, and land. Water enters the atmosphere as water vapor (a gas).Evaporation: the process by which water changed from a liquid to an atmospheric gasTranspiration: water lost into the atmosphere from a plant.After evaporation, the water vapor condenses into droplets to form clouds. When the droplets become large and dense enough, the water returns to the Earth in the form of Precipitation.
23Nutrient CyclesNutrients: All the chemical substances that an organism needs to sustain lifeEvery living organism needs nutrients to build tissues and carry out essential life functions. Like water, nutrients are passed between organisms and the environment through biogeochemical cycles.
25The Carbon CycleCarbon is important because it is a component of skeletons, it is the atmosphere, and is the building block of many macromolecules.Four main types of processes move carbon through its cycle:Photosynthesis and respirationErosion and Volcanic activityDecompositionHuman activities (ex. Burning Fossil Fuels)
27The Nitrogen CycleAll Organisms require nitrogen to make amino acids (which make proteins).Nitrogen gas is in the atmosphere, but only some types of bacteria can break it down to be used by plants and animalsNitrogen fixation – the process of converting nitrogen gas into ammonia(after this other bacteria convert ammonia into nitrates to be absorbed by plant roots)
28Nitrogen CycleWhen organisms die, decomposers return nitrogen to the soil as ammonia. Other soil bacteria convert it back to nitrogen gas in a process called denitrification.
30The Phosphorus CyclePhosphorus is essential to living things because it is used to build DNA and RNA.It is not found in the atmosphere like carbon and nitrogen. Phosphorus is in rocks, soil and ocean sediments. It is released when rocks and sediments wear down.
32Nutrient LimitationEcologists are interested in the primary productivity (the rate at which organic matter is created by producers)Limited by available nutrientsLimiting nutrients – a single nutrient that is limiting growth in an ecosystem
33Nutrient LimitationBecause of this farmers use fertilizers to boost productivity.Fertilizers usually contain nitrogen, phosphorus, and potassiumWhen aquatic ecosystems receive runoff from fertilized fields, there is a boom of algae growth (producers).Algal Bloom: a huge increase in the growth of algae.If there are not enough consumers to eat this algae, it will cover the surface of the water and disrupt the ecosystem.