LEC. Biology Ecosystems Benchmark 1 Describe common ecological relationships between and among species and their environments.

“Ecology is the study of the interrelationships among all living organisms (biotic) and the nonliving elements (abiotic) in and affecting our world. Biotic components live and die; most abiotic components are in a continuous cycle of building up and being reduced. These ebbs and flows make life possible by seeking a balance among all components, living and nonliving.”

Competition Territory Carrying capacity Natural balance Population Dependence Survival Biotic Factors Abiotic factors Key concepts

Each species is sensitive to changes in abiotic interactions which influence the development of the community and the stability and persistence of community is influenced by biological interactions. The interactions between species may be competition for space or as the result of survival, Migration. For example, species BZ may have a negative effect upon species LM. If species BZ is parasitic, then it depends on the presence of other species as hosts or partners. Environmental changes removing the host species will cause species BZ reliant on them to disappear.

Biotic FactorsAbiotic Factors Ecosystems consist of many factors. Non-living components Living components water, sunlight, temperature, pH plants, animals (including humans) bacteria The Biotic and Abiotic Factors affect each other: for example an abiotic factor like pH in soil affects the growth of plants in that soil.

A woman’s work is …never done!

“The balance of nature is disturbed when even a single organism is removed or added within a community because a community is a group of interacting species in a given area. Everything in the community is dependent on each other; they are all connected. The relationships may be positive or negative, but any alteration results in change.”

Populations and Carrying CapacityCarrying Capacity

Animals that live in packs or herds and plant colonies, such as: wolves, bison, lilies and other bulb plants various forms of algae Real-world contexts

Question One Question Two Question Three

Which one(s) of the following would be considered an abiotic factor? a)Elm treeElm tree b)WaterWater c)Rock portion of soilRock portion of soil d)RabbitRabbit e)TemperatureTemperature Return to question menu

Any living organism or materials coming from living things are considered biotic. Abiotic factors are those that were never living…

Any living organism or materials coming from living things are considered biotic. Abiotic factors are those that were never living…

Identify which of the following factors would cause the carrying capacity to increase for a population and which would cause it to decrease. 1.Increasing food supplyIncreasing food supply 2.Increasing droughtIncreasing drought 3.Increasing predatorsIncreasing predators 4.Increasing pollutionIncreasing pollution 5.Increasing sunlightIncreasing sunlight Return to question menu

1.Increase-more food would cause the population size to increase Return to the question

2.Decrease-decreasing rain would cause plants to die then animals Return to the question

3. Decrease-increasing predators would hunt and kill members of the population Return to the question

4. Decrease-pollutants will harm or kill members of the population Return to the question

5Increase-more sunlight will promote plant growth which will increase the population size of other members. Return to the question

In an ecosystem, there are populations of bobcats, rabbits and grass. Bobcats eat rabbits and rabbits eat grass. Indicate what would happen to the other two populations given the following: 1)Decreasing grass populations due to droughtDecreasing grass populations due to drought 2)Disease kills all of the bobcatsDisease kills all of the bobcats 3)Rabbits population begins to increase uncontrollablyRabbits population begins to increase uncontrollably Return to question menu

1.The population of rabbits would begin to starve then the bobcat population would have less food and their population would go down Return to the question

2. Without the bobcats, the rabbit population would increase. More rabbits would eat more grass causing the population to decrease Return to the question

3. With more rabbits, the grass population would go down but the bobcat population would go up. Return to the question