Community

2. Community • Instead of a single population in a region these organisms are referred to as communities. • Community-Consists of an association of population of different species that live and interact in the same place at the same time. • This definition is broad because it refers to a ecological categories of various sizes and levels of interactions.

3. Communities have characteristic s that single population don’t including community structure and community functioning, and include • Number and types of species present • Relative abundance of each species • Interactions among different species • Community resilience to disturbances • Energy and nutrients flow throughout the community • Productivity

4. Community Ecology-the description and analysis of patterns and processes within the community. • Includes a wide variety of communities • Pond community • Pine forest community • Sagebrush desert community

5. Communities are difficult to study because of large number of organisms and different species that interact in different ways • These species can: • Compete for food, water, space • Kill and eat each other • Form intricate associacations

6. Facilitation- work in positive way to enhance and modify the local environment • Ex. Alpine plants in cold region grow faster when near other plants • Each organism plays its own role includes: producer, consumer, or decomposer • Communities vary in: • Size • Lack precise boundaries • Rarely completely isolated

7. Communities affect one another in ways that aren’t always apparent, this means that communities are nested within larger communities Ex- A forest is a community, but a rotting log is also one in the forest

8. Ecosystem • Ecosystem- Is a biological community and it is an abiotic environment combined. • Abiotic is the non living environment that’s constant and are essential for organisms and consist of minerals, air, water, and sunlight • Ecosystem are broad entities that refer to ecological units of various sizes. Also consisting of all the interactions between the living world and physical environment.

9. Within in each ecosystem an organism takes its own role called ecological niche • A niche includes all biotic and abiotic aspects of the species existence meaning, physical, chemical, biological factors that the species need. • Also the local environment known as the habitat as well as what the species eats, what it eats, what the organism competes with, and how it interacts with and influences.

10. These dimensions can be hard to study so niches are brought down to a few variables including feeding behaviors or the ability to tolerate temperature extremes • Species are usually capable of using much more of its environments resources or living in a wider assortment of habitats than it actually does. This is known as Fundamental niche.

11. But various factors like competition with other species will exclude them from the fundamental niche leading them to pursue a realized niche. Ex- the Green Anole of Florida lives on walls and tree trunks hunting insects and spiders. Then Brown Anoles from Cuba were introduced and began to out compete the green anoles forcing them to live higher in the trees removing a piece of their fundamental niche.

12. A species structural, physiological, and behavioral adaptations determines its tolerance for environmental extremes. • If any feature is tampered with that organism can not live there. • Environmental factors make it hard to establish niches, this can be solved though by establishing a limiting resource which is a scarce or unfavorable will restrict niches

13. Most that have been studied were the mineral content in soil, temperature extremes, and precipitation amounts. • By these interactions those factors help define ecological niches

14. Competition- occurs when two or more individuals attempt to use the same essential resource, such as food, water, shelter, living space, or sunlight • Competition can occur two ways: • Intraspecific- which is competition between individuals in a population. • Interspecific- which is competition between species

15. Competition is not straight forward instead it relies on different factors in the components such as the relationship between conifers and flowering plants. • The flowering plants make nectar that attract bugs that eat the bugs that feed on the leaves of the conifers allowing both species to grow

16. When two species are similar such as the green and brown anoles their fundamental niches will overlap leading to competition exclusion principle. • Competition Exclusion Principle- when one species excludes another from its niche as a result of interspecific competition.

17. Two species can compete for the some necessary resource and not be total competitors because if two species with the same ecological niche cannot coexist • Coexistence only occurs when one of two niches are reduced like the anoles. • In conclusion one species will always be limited by another

18. When two species coexist one will have adverse effects stating that over time natural selection will favor only one. • Resource partitioning- reduced competition among coexisting species as a result of each species niche differing from the other in one or more ways • Partitioning is documented in south America with several animals that coexist eating the same resource by developing specialized parts reducing competition

19. Resource partitioning includes: timing of feeding, location of feeding, and nesting sites Ex- Warbler • Character displacement- diverging in traits in two similar species living in the same geographic area Ex- Solanum flowers are similar in where they occur but differ in flower size what kind of bees pollinate them

20. This character displacement reduces competition between two species because their differences give them some what different ecological niches in the same environment. • Predation- is the consumption of one species, the prey, by another, the predator • Predation includes: • Animals eating other animals • Animals eating plants (herbivory)

21. Predation is an evolutionary arms race with the predators tactics and the preys tactics. • This means that those with better strategies of staying alive will be favored by natural selection within the species • Coevolution- when a predator is more efficient at catching prey exerts a strong selective force on its prey which over time may evolve some sort of countermeasure acquired by the prey in turn acts as a strong selective force on the predator

22. Aposematic coloration- conspicuous colors or patterns which advertise a species unpatability to potential predator also known as warning coloration • Prey often develop different kinds of defenses like: • Retreat to burrows • Barbed quills or shells • Groups or herds • Poisons and bright colors

23. Cryptic coloration- colors of markings that help them hide from predators by blending into their physical surrounding Ex- caterpillars that resemble twigs or stick bugs • Batesian mimicry- a defenseless species resemble a dangerous species to be protected Ex- Scarlet king snake mimics coral snakes

24. Müllerian mimicry- different species that are dangerous of distasteful all look the same • Symbiosis- is any intimate relationship or association between members of two or more species • Symbionets may benefit from, be unaffected by, or harmed by the relationship

25. Products of coevolution • Three forms: • Mutualism • Commensalism • Parasitism