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Learn about the study of ecology and its levels, including ecosystems and communities. Explore the concepts of niches, interactions between species, and the importance of keystone species. Discover how energy flows through ecosystems and the cycling of nutrients.
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What is Ecology? • Ecology is the study of interactions between organisms and the living and non-living components of their environment.
BIOSPHERE- broadest, most inclusive = the thin volume of Earth and its atmosphere that supports life.
ECOSYSTEMS- includes all of the organisms and the non-living environment found in a particular place.
COMMUNITIES- includes all the interacting organisms living in an area.
POPULATIONS- includes all the members of a species that live in one place at one time. • ORGANISMS- simplest level= individual
HABITAT- WHERE LIVING ORGANISMS LIVE. • NICHE- A SPECIES WAY OF LIFE, OR THE ROLE THE SPECIES PLAYS IN ITS ENVIRONMENT.
Autotrophic & Heterotrophic • A species method of getting nutrition. • Autotrophic= make their own nutrients • Heterotrophic= consume other organisms to gain their nutrients • Some unicellular species use both methods • EX: Euglena
Heterotrophs are divided into different groups depending on the organic material source and method of consuming them CONSUMERS: • Are heterotrophs that feed on living organisms by ingestion • DETRITIVORES- • organisms that eat detritus ( dead parts of plants, feces, various parts of dead animals) by internal digestion SAPROTROPHS – • obtain organic nutrients from dead organic matter by external digestion. • Secrete digestive enzymes then absorb. • EX: fungi and bacteria • Also known as decomposers
ECOSYSTEMS • Autotrophs & heterotrophs gain inorganic nutrients for the abiotic environment • C, H, O, & N are needed by getting them from compounds in the food • There are other inorganic nutrients needed that are obtained by the abiotic environment • EX: calcium, potassium, and sodium
The niche concept • Every organism has a specific role in their ecosystem. • Where the organism lives • What and how it eats • Its interactions with other species • The habitat where the organism lives is within tolerable levels/zone • Ex: abiotic factors
Symbiotic Relationships • Symbiosis: 2 or more species live together in a close long-term relationship where at least one of them benefits. • Examples: Parasitism, Mutualism Commensalism
one species feeds on the other species known as a host. (one benefits while the other is harmed) Parasitism-
Mutualism • Cooperative relationship which both species benefit and neither harmed.
Commensalism • One species benefits and the other is not affected
Honey Badger & Honey Guide Honey Guide bird loves honey but can’t break the beehive to get to the honey. He leads the Honey Badger, who also loves honey, to the bee hive. The honey badger breaks open the beehive, eats his fill and leaves the rest of the honey for the honey guide bird.
Brown Bear & Scavenging Gulls The scavenging gulls wait for the bears to eat their fill of salmon and when the bears leave the gulls devour whatever is left.
Cowbirds & Forest nesting birds Cowbirds lay their eggs in the nests of forest nesting birds & the forest nesting birds often raise cowbird young rather than their own offspring.
Ant & Aphid The ant strokes the aphid and the aphid secretes a type of honeydew for the ant to eat. With the ant around the aphid, the aphid is protected against predatory insects.
Mistletoe & Mesquite Mistletoe seeds are dropped on the mesquite tree. The seeds germinate & grow into the tree. The “roots” of the mistletoe absorb water and nutrients from the mesquite tree.
Mimicry • Resemblance of a distasteful or poisonous species http://www.youtube.com/watch?NR=1&v=t-LTWFnGmeg&feature=endscreen
Camouflage • The ability to blend in with the environmental surroundings http://www.youtube.com/watch?v=LDhUzafXm8A
Keystone Species A species that plays a critical role in maintaining the structure of an ecological community and whose impact on the community is greater than would be expected based on its relative abundance or total biomass. Without the keystone species, the ecological community to which it belongs would be greatly altered and many other species would be negatively impacted.
Keystone Species Watch video
Energy Flow- Understanding • Most ecosystems rely on a supply of energy from the sun • Light energy is converted to chemical energy in carbon compounds by photosynthesis • Chemical energy is converted to kinetic energy in muscle contractions. • Chemical to electrical in nerve cells • Chemical to heat energy in heat-generating adipose tissue • Living organisms cannot convert heat to other forms of energy.
Trophic Level (feeding/energy level)- consists of all organisms feeding at the same energy level
Energy in an Ecosystem ENERGY FLOWS THROUGH THE SYSTEM & NUTRIENTS CYCLE All organisms need energy to carry out essential functions, such as growth, movement, maintenance & repair, reproduction and thinking. To do these functions they need energy. The amount of energy an ecosystem receives & the amount that is transferred from organism to organism has an important effect on the ecosystem’s structure.
Heat loss • Heat from cell respiration= warm body • Eventually heat passes from hotter to colder bodies, so… • Heat produced in living organisms is eventually lost to the abiotic environment
What is the 1st law of thermodynamics? Energy can be transferred, but it cannot be created or destroyed.
How can this be true when we can see the relationship between producers and consumers in ecology & the loss of energy along the way? Because the energy lost is lost to the biosphere earth, but it is kept within the universe.
If nothing is lost, explain where the energy goes when a piece of paper is burned. The matter becomes ash & smoke; and the heat, which is the energy that used to be held in the molecular bonds of the paper is dispersed to the universe.
If nothing is lost, where does the food energy go when you eat a meal? Most of the energy is lost as heat during cell respiration and the matter is converted into the molecules of your body or discarded as feces.
If energy is lost from the biosphere constantly as heat into the atmosphere, where does the replacement energy come from to keep the energy flow of each ecosystem going? There is a constant supply of energy from the sun.
Biomass has energy What is Biomass? The total mass of a group of organisms. This includes: cells & tissues including carbohydrates & other carbon compounds It is expressed in g m-2 yr-1 (grams per meter squared per year) Ecologists can measure the amount of energy added per year by groups of organisms to their biomass
When ecologists measure this, they find…. The energy added to biomass in each successive trophic level is less. The tiers get smaller as you move up the trophic levels because only a small portion of the energy in the biomass of organisms in one level will ever become part of the next trophic level. Energy transferred from the sun to the autotrophs and between consumers varies between ecosystems Ideally 10% is transferred from one trophic level to the next but the amount lost is variable.
