Ecological interactions (article) | Ecology | Khan Academy
Revise how organisms in an ecosystem are interdependent with BBC Accessibility links . An ecosystem is two or more populations of organisms ( usually many more) in Animals in an ecosystem compete for food, mates and their territory. commensalism, the relation between two different kinds of organisms when one of interdependent organisms inhabiting the same region and interacting with species, group of similar organisms that can breed and produce fertile offspring. Predation (+ -) is another winner-loser relationship but it is not symbiosis. fight for the same limited resource such as food, shelter, a mate, or sunlight, there is usually If the competition is long-term and occurs between two different species .
Some relationships are beneficial to both parties, while others have a clear benefit for one at the expense, or even death, of the other. At the microscopic scale, herbivory includes the bacteria and fungi that cause disease as they feed on plant tissue.
Microbes that break down dead plant tissue are also specialized herbivores. Browsers and grazers, from aphids and caterpillars to deer and bison, are more familiar herbivores.
Even insects and animals that eat seeds are considered herbivores. Brooklyn Botanic Garden is a habitat where herons hunt for crayfish, monarchs feed on milkweed, and woodpeckers nest and forage for insects. Some herbivores consume entire plants, or enough to kill them. Others only eat a portion of the plant, and so the plant can recover. Current research, however, is revealing that herbivory has some potential benefits to plants.
- How are organisms in an ecosystem interdependent? - OCR 21C
- Ecological interactions
- Plant/Animal Relationships
One example is canopy grazing by insects, which allows more light to penetrate into the lower layers of the forest. Gypsy moth grazing on canopy trees in some areas of Virginia's Blue Ridge Mountains, for instance, has resulted in more light penetration and therefore a more diverse and productive ground layer. Herbivores and Their Food Plants Bison, sheep, and other grazers - Succulent forbs, grasses, grass-like plants Deer and other ungulate browsers - Leaves and twigs of woody plants such as willows, arborvitaes, yews Beaver - Tree bark, young shoots, leaves Rodents - Succulent forbs, grasses, grass-like plants Rabbits - Succulent forbs, grasses, bark Voles - Roots, bark Caterpillars - Leaves; in some cases, of specific species Monarch butterfly - Milkweeds Gypsy moth - Oaks and other hardwoods Aphids - Plant juices; in some cases, of specific species Many birds - Seeds and fruits Locusts - All plants; seeds, leaves, and stems Plants and Their Pollinators Pollination is the transfer of the pollen from one flower to the stigma, or female reproductive organ, of another, which results in fertilization and, ultimately, the formation of seeds.
The earliest plants were pollinated by wind, and for some modern plants this is still the most expedient method. Many trees, all grasses, and plants with inconspicuous flowers are designed for wind pollination. Bright, showy flowers evolved for another purpose—to attract a pollinator. Many plants depend on animals for pollination. Insects, birds, even bats are important for perpetuating plants. The flowers of these plants evolved in concert with their pollinators, and their form reflects the form and habits of their pollinators.
Bee-pollinated plants are often irregular in shape, with a lip that acts as a landing pad to facilitate the bee's entry into the flower. Butterfly-pollinated flowers are often broad and flat, like helicopter pads. The flowers of many plants are brightly colored to attract their insect pollinators, and many offer nectar as an enticement. Hummingbirds, with their long beaks, pollinate tubular flowers.
Bats require open flowers with room for their wings, such as those of the saguaro cactus. In the tropics, birds and bats take the place of insects as pollinators. Hummingbirds and honeycreepers, for example, have distinctive beaks that have evolved to exploit flowers.
Often, a beak may be so specialized that it is only effective on a small group of flowers. The pollinators, in turn, have evolved to take advantage of the flowers. A successful pollinator typically has good color vision, a good memory for finding flowers, and a proboscis, or tongue, for attaining nectar.
Animal pollination has obvious advantages for plants. Many pollinators cover great distances, which insures genetic diversity through outcrossing, or the transfer of pollen to unrelated individuals. The 'predator' is the hunter and the 'prey' is the hunted organism b.
Cheetah hunting a gazelle for food Even plants can be predators, while at the same time are producers! Symbiosis 3 main types 1.
Symbiosis is a relationship where two different species live together in very close contact. There are three main types of symbiotic relationships. Commensalism An example of commensalism: As cattle, horses and other livestock graze on the field, they cause movements that stir up various insects. As the insects are stirred up, the cattle egrets following the livestock catch and feed upon them.
The egrets benefit from this relationship because the livestock have helped them find their meals, while the livestock are typically unaffected by it.
Barnacles on a whale's tail taken from my kayak in Glacier Bay, Alaska do not harm the whale, but benefit the barnacles a. A type of symbiotic relationship where one organism benefits by living on or with another the 'host'but neither harms nor helps the host.
Cattle stir up insects while grazing and egrets eat them seen in picture on left. The seed is dispersed, but doesn't harm the animal.
Mutualism In a symbiotic mutualism, the clownfish feeds on small invertebrates which otherwise potentially could harm the sea anemone, and the fecal matter from the clownfish provides nutrients to the sea anemone. The clownfish is additionally protected from predators by the anemone's stinging cells, to which the clownfish is immune.
Alice algae took a lichen to Freddie fungus and now they live in symbiotic bliss - Wendy Carroll Upon seeing the Star of Bethlehem orchid, Charles Darwin predicted that a moth with an extra long proboscis must exist. A hundred years later, the moth was finally "caught in the act," fulfilling Darwin's prediction.
Click on the photo for a great article on the story.
Interdependence of Living Things ( Read ) | Biology | CK Foundation
One of the best examples of mutualism is pollination. Flowers provide nectar as food to the pollinators such as bees, some bats, birds while the pollinators move pollen from one plant to the next so that they can make seeds for reproduction. There is a beautiful video of pollination on the page on this website called "Nature's Weird and Wonderful" ii. Another great example of mutualism is the type of seed dispersal where an organism eats the fruit, but poops out the seed.
When you click on this image, it will give link you to a video about pollination of milkweed, which is a bit more complicated and interesting. Seed dispersion can be a form of mutualism when the animal eats the seed- bearing fruit and the seed is later pooped out iii.
Some organisms benefit each other AND cannot live without each other.
This type of mutualism is called obligate mutualism. The algae produces its own food and shares it with the fungus, while the fungus provides a place for the algae to grow and retains water to share with the algae. Organisms that make their own food by using sunlight or chemical energy to convert simple inorganic molecules into complex, energy-rich organic molecules like glucose are called producers or autotrophs.
Some producers are chemosynthesizers using chemicals to make food rather than photosynthesizers; instead of using sunlight as the source of energy to make energy-rich molecules, these bacteria and their relatives use simple chemicals as their source of energy.
Chemosynthesizers live in places with no sunlight, such as along oceanic vents at great depths on the ocean floor. No matter how long you or a giraffe stands out in the sun, you will never be able to make food by just soaking up the sunshine; you will never be able to photosynthesize.
Producers use the food that they make and the chemical energy it contains to meet their own needs for building-block molecules and energy so that they can do things such as grow, move, and reproduce.
All other life depends on the energy-rich food molecules made by producers — either directly by eating producers, or indirectly by eating organisms that have eaten producers. Not surprisingly, ecologists also have terms that describe where in the food chain a particular consumer operates.
A primary consumer eats producers e.
And it can go even further: A single individual animal can act as a different type of consumer depending on what it is eating.
When a bear eats berries, for example, it is being a primary consumer, but when it eats a fish, it might be a secondary or a tertiary consumer, depending on what the fish ate! All organisms play a part in the web of life and every living thing will die at some point. This is where scavengers, detritivores which eat detritus or parts of dead thingsand decomposers come in. They all play a critical role that often goes unnoticed when observing the workings of an ecosystem.
BBC - GCSE Bitesize: Classification
They break down carcasses, body parts and waste products, returning to the ecosystem the nutrients and minerals stored in them. This interaction is critical for our health and health of the entire planet; without them we would be literally buried in dead stuff. Crabs, insects, fungi and bacteria are examples of these important clean-up specialists. Another category of interactions between organisms has to do with close, usually long-term interaction between different types of organisms.
These interactions are called symbiosis. The impacts of symbiosis can be positive, negative, or neutral for the individuals involved. Organisms often provide resources or services to each other; the interaction is mutually beneficial.
For example, ants living in a tree may protect the tree from an organism that would like to make the tree its next meal, and at the same time the tree provides a safe home for the ants.Competition In Animals - Food, Territory and Mates - GCSE Biology