As you can see above the grass is acting as the producer and gives energy to the deer. The deer would be the primary consumer and would then give energy to the coyote who would be the secondary consumer.
There are about 4 abiotic factors that can affect a food web. They are: the sun, water, soil, and climate or temperature. Too much or too little of any of these can off-set the balance of a food web. For example if the sun somewhere all of a sudden doesn’t shine enough and give off enough energy the plants will start to die, if there aren’t enough plants to feed the primary consumers like a rabbit, then they will start to die. If primary consumers like the rabbit start to die then secondary consumers like a coyote will die. This would be a continuous cycle until there is no food web. If one thing is disturb then everything is.
In every food web or food chain there will always be a predator and prey. This is nature’s way of keeping the balance of everything. For example a coyote is a predator to a deer. If there are too many deer and not enough coyotes to eat the deer, we can soon be overpopulated by deer and then what the deer eat, like grass, would eventually run out and then the deer will have to adapt or die. If there are too many coyotes and not enough deer the coyotes will eventually eat all of the deer and will then have to either adapt or die. With the right amount of prey and predators things will stay balanced but if one changes it affects everything.
In my food web and food chain all of the animals are found in the Temperate Deciduous Forest Biome. In the direction of the arrows you can see how energy is transferred. For example the sun would give energy to the grass and then the grass being a producer (organism creates their own food or energy) would be eaten by white tailed deer. The white tailed deer is a primary consumer(herbivore, or animal that eats mainly plants to get energy at the second level of all food chains) which means it is first to receive energy directly from a producer. The white tailed deer would then be eaten by a coyote which is a secondary consumer (carnivores that feed on herbivores to receive energy) because it is second to receive energy from the producer. This could keep going and consumers could get eaten and pass on energy but it will eventually stop because as it keeps going the amount of energy being passed down decreases with each consumer until there is no energy left. Unlike matter that can transfer and travel in a cycle, energy can only go one way and will eventually end as new energy keeps being produced.
If an invasive species such as a wolverine was introduced to the temperate deciduous forest biome it could start to eat all of the deer and would then leave the coyote with nothing to eat. They would therefore have to adapt or die. If the coyotes start to eat the wolverines to the point where there aren't enough left to eat deer the deer could then overpopulate the biome. As you can see any little change can affect everything.Density dependent factors are factors that regulate population growth and depends on the density of the population. A few examples would be: shelter, competition, disease and the balance of predators to prey. For example if the predator-prey relationship becomes off balance it can affect the population. If there become too many predators, they can eat all of the prey and reduce the population and then end up starving the predators. But if there becomes too many prey and not enough predators, overpopulation can occur and then throw the food chain off.
Density Independent factors are factors that regulate population growth and do not dependent on the density. A few examples would be natural disasters like:floods, fires, storms, and droughts. Also the fluctuation of the temperature.For example, during a long summer there hasn't been any rain for almost 4 to 5 months and all of the water around is drying up. Animals are slowly becoming thirsty and running out of water. If the animals don't move to find water they will die of dehyrdration and will throw the population off balance as many species will die, because of depending on water.
Density dependent factors are factors that can be controlled by the population, and density independent factors cannot be controlled by the population.
Johansson, Philip. The temperate forest: a web of life. Berkeley Heights, NJ: Enslow Publishers, 2004. Print.
"Difference Between Density Dependent and Density Independent | Difference Between | Density Dependent vs Density Independent." Difference Between Similar Terms and Objects. N.p., n.d. Web. 29 Apr. 2012. <http://www.differencebetween.net/language/words-language/difference-between-density-dependent-and-density-independent/>.
An energy pyramid shows how energy is transferred from the sun to an organism to organism. It demonstrates how with each new level energy is reduced. For example if the producer, or a plant, recieves 100% of energy from the sun then it is going to use alot of that energy to make their own food and to power other functions. When the plant is eaten 100% of that energy will not be available and given the primary consumer, or rabbit, won't eat the entire plant it will only receive a little percent of energy thats left. This is continuous as consumers get consumed the energy passed on decreases because each consumer uses the energy for life processes and alot of the remaining energy is released into the environment as heat. A general rule to determine how much energy an organism will recieve is by taking one-tenth of the previous number and thats about the amount of energy the new consumer will recieve. For example the grass recieves 100% of energy, so you just take one-tenth of that and you get 10% so this is how much energy the rabbit will consume, and this just keeps going. In the energy pyramid above the highest amount of total energy available is .1% because the tertiary consumer is on top.
Miller, Kenneth R., and Joseph S. Levine. Miller & Levine biology. Foundation ed. Boston, Mass.: Pearson, 2010. Print.
"Sun Banners - Bing Images." Bing. N.p., n.d. Web. 23 Apr. 2012. <http://www.bing.com/images/search?q=Sun+Banners&view=detail&id=0B18E14733A44EC353C9E5FC251A39596E87DBC8
"cottontail rabbits - Bing Images." Bing. N.p., n.d. Web. 24 Apr. 2012. http://www.bing.com/images/searchq=cottontail+rabbits&view=detail&id=A52191BB967C50B94D8E4A1BDA26071C0E1CF7FE&first=0&FORM=IDFRIR&adlt=strict.
