Ecosystems

Primary Vocabulary Terms o Ecosystem o Biomass o Law of Conservation of Energy o Law of Conservation of Matter o Trophic levels o Detritus o Producers o Consumers (primary, secondary, tertiary) o Omnivores o Detritovores (Decomposers) o Calorie

Additional Vocabulary Terms o Ecology o Trophic levels o Herbivores o Carnivore o Omnivores o Chemotrophs o Phototrophs o Photosynthesis o Cellular Respiration o Chemosynthesis o How energy flows through an ecosystem o Ecological pyramid (numbers, biomass, energy)

Overview of 8-3 Ecosystems o Ecosystem o Classification of Organisms in an Ecosystem Trophic levels Trophic levels o Biomass o Flow of Energy Through Ecosystems Producers, Consumers & Decomposers Producers, Consumers & Decomposers Ecological Pyramid Ecological Pyramid Ecosystem Productivity Ecosystem Productivity

Ecology o Ecology “eco” house & “logy” study of “eco” house & “logy” study of The study of interactions among and between organisms in their abiotic environment The study of interactions among and between organisms in their abiotic environment Broadest field in biology Broadest field in biology o Biotic- living environment living environment Includes all organisms Includes all organisms o Abiotic- non living or physical environment non living or physical environment Includes living space, sunlight, soil, precipitation, etc. Includes living space, sunlight, soil, precipitation, etc.

Ecology o Biology is very organized o Ecologists are interested in the levels of life above that of organism

Ecosystems o Ecosystem All the organisms (living things) in a given area and the abiotic (physical, non-living) environment All the organisms (living things) in a given area and the abiotic (physical, non-living) environment Organisms and abiotic features interact in an ecosystem Organisms and abiotic features interact in an ecosystem Ecosystems can vary in size Ecosystems can vary in size Ecosystems can overlap and organisms can move between ecosystems Ecosystems can overlap and organisms can move between ecosystems

Biotic Features o Biotic Features All the living things in a given area, include: All the living things in a given area, include: Species Species A group of similar organisms whose members freely interbreed and produce fertile offspring A group of similar organisms whose members freely interbreed and produce fertile offspring Population Population A group of organisms of the same species that occupy that live in the same area at the same time A group of organisms of the same species that occupy that live in the same area at the same time Community Community Al the populations of different species that live and interact in the same area at the same time Al the populations of different species that live and interact in the same area at the same time

Abiotic Features o Abiotic Features All the non-living things in a given area, include: All the non-living things in a given area, include: Weather Weather Water Water Topography Topography Nutrients Nutrients Physical features Physical features Atmosphere Atmosphere

Thermodynamics o Study of energy and its transformations o System- the object being studied Closed System- Does not exchange energy with surroundings (rare in nature) Closed System- Does not exchange energy with surroundings (rare in nature) Open System- exchanges energy with surroundings Open System- exchanges energy with surroundings

Law of Conservation of Energy o Energy cannot be created or destroyed; it can change from one form to another Ex: organisms cannot create energy they need to survive- they must capture it from another source Ex: organisms cannot create energy they need to survive- they must capture it from another source o Also known as the 1 st Law of Thermodynamics

Law of Conservation of Energy o However, When energy is converted form one form to another, some of it is degraded to heat When energy is converted form one form to another, some of it is degraded to heat o Also known as the 2 nd Law of Thermodynamics

Law of Conservation of Matter o Matter cannot be created or destroyed; it can change from one form to another Ex: plants convert carbon dioxide and water into glucose and oxygen Ex: plants convert carbon dioxide and water into glucose and oxygen

Solar Energy

Energy Reactions in an Ecosystem o Photosynthesis or Chemosynthesis – transform solar energy or chemical energy from inorganic substances into chemical energy that living things can use o Respiration - releases energy trapped by photosynthesis or chemosynthesis in the cells of living things to do biological work

Photosynthesis o Biological process by which energy from the sun (radiant energy) is transformed into chemical energy of sugar molecules o Energy captured by plants via photosynthesis is transferred to the organisms that eat the plants 6 CO H 2 O + radiant energy C 6 H 12 O H 2 O + 6 O 2

Cellular Respiration o The process where the chemical energy captured in photosynthesis is released within cells of plants and animals o This energy is then used for biological work Creating new cells, reproduction, movement, etc. Creating new cells, reproduction, movement, etc. C 6 H 12 O O H 2 O 6 CO H 2 O + energy

Trophic Levels o Trophic Level- includes a group of organisms that obtain food in a similar manner Producers Producers Herbivores Herbivores Carnivores Carnivores Omnivores Omnivores Detritivores Detritivores

Energy Flow o Passage of energy in a one-way direction through an ecosystem Producers Producers Primary consumers Primary consumers Secondary consumers Secondary consumers Decomposers Decomposers

Food Chains- The Path of Energy Flow o Energy from food passes from one organisms to another Each “link” is called a trophic level Each “link” is called a trophic level

Food webs represent interlocking food chains that connect all organisms in an ecosystem

Flow of nutrients in an ecosystem

Ecological Pyramids o Graphically represent the relative energy value of each trophic level Important feature is that large amount of energy are lost between trophic levels to heat Important feature is that large amount of energy are lost between trophic levels to heat o Three main types Pyramid of numbers Pyramid of numbers Pyramid of biomass Pyramid of biomass Pyramid of energy Pyramid of energy

Pyramid of Numbers o Illustrates the number of organisms at each trophic level Usually, organisms at the base of the pyramid are more numerous Usually, organisms at the base of the pyramid are more numerous Fewer organisms occupy each successive level Fewer organisms occupy each successive level o Do not indicate the biomass of the organisms at each level or the amount of energy transferred between levels

Pyramid of Biomass o Illustrates the total biomass at each successive trophic level Biomass: measure of the total amt of living material (dry material) Biomass: measure of the total amt of living material (dry material) o Illustrates a progressive reduction in biomass through trophic levels

Biomass of a trophic level Not consumedconsumedDigested Body building growth Gained by the next trophic level Released as:Heat Inorganic nutrients Undigested Undigested fecal waste Trophic detritus

o Only uses samples from populations, so difficult to measure biomass exactly. o Time of year that biomass is measured affects the result. o Organisms of the same size do not necessarily have the same energy content.

Pyramid of Energy o Illustrates how much energy is present at each trophic level and how much is transferred to the next level Most energy dissipates between trophic levels Most energy dissipates between trophic levels o Explains why there are so few trophic levels Energy levels get too low to support life Energy levels get too low to support life

Energy of a trophic level utilizedProducing food Growth and development including regeneration Not utilized about 10% for animals and 20% for plants Stored as flesh (becomes part of the biomass) Available for the next trophic level

10% Law of Energy Transfer (Lindemann 1942) During the transfer of energy from organic food from one trophic level to the next, only about ten percent of the of energy from organic matter is stored as flesh. The remaining is lost during transfer, broken down in respiration, or lost to incomplete digestion by higher trophic levels.

Only 10% of energy at a particular trophic level is incorporated to the next trophic level. Rapid loss of energy explains why food chain rarely has 5 links. Rapid loss of energy explains why food chain rarely has 5 links.

General pyramid trends o A healthy ecosystem will always have the most energy available in the first trophic level. o The number of trophic levels are limited. At each trophic level, there is a dramatic reduction in energy. o Eating at lower trophic levels means more resources available.

QUICK REVIEW! All organisms in an ecosystem need _______ from food to live. An energy ________ shows how much food energy is passed from one ________ to another through food chains. __________ have the largest spot at the base of the pyramid. Altogether, only about _____ of the food energy at each level gets passed up to the next level. All organisms in an ecosystem need _______ from food to live. An energy ________ shows how much food energy is passed from one ________ to another through food chains. __________ have the largest spot at the base of the pyramid. Altogether, only about _____ of the food energy at each level gets passed up to the next level. energy pyramid Producers 10% organism