Ecosystem Interactions Among Species

What Affects Populations of Species? organism population community ecosystem biosphere https://youtu.be/GxE1SSqbSn4 What Affects Populations of Species? 2

Interactions and Populations All populations of species in an ecosystem strive for survival What do you think populations of species need in order to survive?

Resources: food, water, safe shelter, mates, space, materials But there are many factors that affect a population’s survival

Is there a difference between a population and a community? Yes. A population is made up of members of one species (who breed) and live in a specific area, more or less isolated from other members of their species. A community is made up of a collection of populations of different species interacting within a specific area, functioning more or less as a unit with certain identifiable characteristics.

Biotic and Abiotic Interactions Biotic Interactions: Interactions between living things. Example: How would a flower and a bee interact? How would a moose and a parasite interact? Abiotic Interactions: Interactions between living and non-living things Example: How would a deer be affected by a dry and hot weather?

Abiotic Interactions Terrestrial: temperature, water, light and nutrient availability Aquatic: same as above plus light availability, acidity, and salt concentration Tolerance range: The range in which a species can survive Optimal range: The range of abiotic factors a species is best adapted to

Ecological Niche An organism’s niche is its ecological role habitat = address vs. niche = job Spot in food web Habitat Breeding area Time of day that its active 8

Species Interactions Competitive Exclusion Hawk Owl Food mice / small rodents Habitat trees (fields) trees (forest) Time of Day Daylight Nighttime Adaptations Long wings for soaring Great distance vision Short wings for weaving Great night vision Amazing hearing Competitive Exclusion No two similar species can occupy the same niche at the same time 9

Biotic Interactions There are three main ways in which species in populations interact with each other: Predator-Prey interactions Competition Symbiosis

1) Predator-Prey Interactions the act of one organism eating another organism in order to obtain food. Prey animals adapt in order to avoid being eaten. Ex. Camouflage or the ability to run very fast. - Mimicracy: one species that looks like another species.

Predation When one organism consumes another organism Examples: Wolf hunting a deer Lady bugs eating aphids Owl hunting a mouse

2) Competition interactions between two or more organisms competing for the same resource in a given habitat.

Competition Organisms might compete for resources such as food and materials, mates or territory/habitat Interspecific: competition between species Intraspecific: competition within organisms of the same species Examples: Interspecific: cheetahs and lions both compete for antelope; spruce and ash trees compete for sunlight Intraspecific : two male deer competing for a female

Competition Neither species benefits For example, by the early 1950s the American chestnut ( Castanea dentata) had been eliminated as a dominant canopy species in deciduous forests of eastern North America by the accidental introduction of a fungal pathogen known as chestnut blight (Endothia parasitica). Other tree species took advantage of their sudden release from competition with the chestnut by opportunistically filling in the canopy gaps that were left by the mature chestnut trees.

3) Symbiosis a close interaction between two different species where one species lives in, on, or near another species. Three types of Symbiosis: Mutualism Commensalism Parasitism What do you think each of these mean?

Mutualism A relationship between two species where both benefit. The yucca moth both pollinates and feeds on the yucca plant; acacia ants live in the thorns of, defend, and are fed by the acacia tree in which they live; Butterfly-weed provides food for and is pollinated by butterflies like Pipevine Swallowtails. Many plants and their pollinators have evolved mutualistic relationships.

Clown fish and sea anemone The clownfish have a protected territory and the sea anemone needs the mucus from the clown fish to make their venom

Parasitism When two organisms coexist and one organism benefits while the other is harmed Examples: Dogs and Cats + Fleas, ticks, intestinal worms Lampreys and salmon Leeches Bed bugs mosquitoes

Parasitism http://www.micro.utexas.edu/courses/levin/bio304/com&pop/communities.html

Zombie Ants A parasitic fungus can infect an ant. The fungus then takes over the control center of the ant and manipulates it forcing it to climb to the highest point available and then latch on to the vegetation. The fungus then pushes through the ants head releasing spores and uses the ants body for nutrition.

Commensalism When two organisms coexist and one organism benefits while the other remains unharmed Examples: Cattle and the egret: the egret consumes insects that have been disturbed while the cattle forage Barnacles and scallops: the barnicles have a place to live and the scallop is unaffected

Remora sharks: Remora sharks are endowed with an adhesive disk on the dorsal surface of their heads. They use this adhesive disk to “hitch a ride” on larger animals, usually whales, which tend to be sloppy eaters. When food floats away from the whale’s mouth, the remora can unhitch itself and collect the scraps of food floating by. Commensalism http://www.nearctica.com/ecology/pops/commens.htm

Other Examples of Biotic Interactions Mutualism –Ex: the boxer crab carries around anemones in its claws. The anemone protects the boxer crab from predators, and the anemone eats scraps of food that the boxer crab drops. Commensalism –Ex. A bird building a nest in a tree (tree doesn’t suffer) Parasitism –Ex. Leach or a tick sucking blood from an animal. SEE PAGE 62-63 for MORE EXAMPLES

Which type of Symbiosis? 1 3 2

Which type of Symbiosis? Image 1 – parasitic tick on a dog Image 2 - As buffalo eats grass, the egrets (birds) eat the insects that they stir up. The buffalo is unaffected. Image 3 – The bee feeds from the flower’s nectar, but it also helps cross-pollenate the flower so it can reproduce.

What relationship is this? clown fish & sea anemone ants & acacia impala & oxpeckers 27

More examples mutualism +/+ commensalism +/0 predation +/- competition -/- 28

Comparing Relationships type of interaction sign effects mutualism +/+ both species benefit from interaction commensalism +/0 one species benefits, one unaffected competition  -/- each species affected negatively predation, parasitism, herbivory +/- one species benefits, one is disadvantaged Neutralism 0/0 Neither species benefits or is harmed

Species Interactions competition (-/-) predation / parasitism (-/+) compete for limited resource competitive exclusion! predation / parasitism (-/+) Parasite: an organism whose ecological niche is closely linked to its host causing discomfort and possibly death to host mutualism (+/+) (symbiotic) lichens (algae & fungus) commensalism (+/0) barnacles attached to whale 30