Community COMMUNITY : interactions between the LIVING organisms in the ecosystem

NICHE

The role of an organism in its environment. –Type of food it eats –Where it gets it’s food –Its reproduction cycle –What temperatures it can withstand Two species cannot occupy the same niche.

Predator-Prey

Interspecific Between Example: Chipmunks and squirrels competing for pine nuts. Spruce, Pine, Fir trees competing for space, nutrients, and sunlight

Intraspecific Within Example: Coral larvae settle to establish new colonies are competing for space with other coral larvae of the same species

Which type of competition is most challenging for organisms?

Intraspecific Niches and habitats same or more similar than between species

Mutualism Crocodiles try to eat most birds that come near them. But one kind of bird can walk about among crocodiles and be quite safe. In fact, these birds even lay their eggs in the same place where the crocodiles lay their eggs! The birds are called water dikkops and they eat insects that bother the crocodiles. Of course, this gives the birds an easy meal, but it also makes the crocodiles more comfortable. So the birds are really helping the crocodiles and maybe that’s why the crocodiles don’t harm them.

What aphids have that ants want is something called honeydew, a sweet substance that is excreted by aphids through their anus and contains surplus sugar from the aphid's diet. Ants protect aphid eggs during the winter, and carry the newly hatched aphids to new host plants, where the aphids feed on the leaves and the ants get a supply of honeydew.winter plants

For the bees, the pollen and nectar from many flowers is an important source of fats, proteins, vitamins, and minerals. The nectar is a source of energy. Bees gradually switched from eating other insects to flowers as their source of food. With the passage of time, bees have become completely dependent on flowers as a food source. As bees travel from one blossom to another, pollen clings to their fuzzy bodies. It is then transferred to the other flowers of the same species. This pollinates or fertilizes the plant. Plants then can produce their own fruits and seeds.

commensalism

Pseudoscorpions hitching ride on a fly’s leg, Costa Rica. Pseudoscorpions, tiny relatives of true scorpions, often engage in the practice of phoresy, or hitchhiking. Ecologists still debate whether pseudoscorpions sometimes harm the organisms that carry them around, but many believe that the pseudoscorpions gain a ride without any real cost to their carriers. If so, this is a good example of a commensalism, a relationship in which one partner benefits and the other neither benefits nor is hurt. Pseudoscorpions are quite small (typically about 1/10 of an inch or 3 mm long) but are impressive predators. Although they do not have the stinger of a true scorpion, they have poison glands in their pincers and feed heavily on tiny arthropods such as mites and springtails.