Food-web Diagram
Janice Spencer
BIO/101
December 15, 2014

Food-web Diagram
As defined in Chapter 20 of our text from week five, an ecosystem is a biological community and the abiotic factors with which the community interacts. In order to maintain, the energy must flow continuously through an ecosystem, from producers to consumers and decomposers. Trophic relationships determine an ecosystem’s routes of energy flow and chemical cycling (Simon, Dickey, & Reece, 2013). According to the text in chapter 20, ecologists are working to revitalize some ecosystems by planting native vegetation, removing barriers to wildlife, and other means. There are hundreds of restoration projects under way in the United States to help restore ecosystems to their natural state. One of the most ambitious endeavors is the Kissimmee River Restoration Project in south-central Florida. Each year the U.S. Army Corps of Engineers and the South Florida Water Management District releases a comprehensive report evaluating monitoring of data within the ecosystem of the Everglades. This information is available online at http://www.bit.ly/SSR 2014.
According to research, “the Everglades contain a vast array of plants and animals that have adapted to the wet subtropical environment.” A few examples include birds such as the whooping crane, great blue, white, and tricolored herons, wood stork, and the cape-sable seaside sparrow. Land mammals such as the raccoon, skunk, opossum, bobcat and the white-tail deer are also a part of this environment; other animals include the American gator, the west-Indian Manatee, and the bottle nose dolphin. There are a number of species on the federal threatened or endangered lists, many more are rare, species of special concern, or included on state lists. The one most endangered species is the Florida panther with only about 100 remaining in the wild. Although the Everglades is widely recognized for some of its flora (plants of a particular district) and fauna (peculiar region of animals), it is also comprised of many lesser-known plants, animals, and fish that are part of a living, dynamic ecosystem (Plants and Animals of the Everglades). Though there are more than 100 marsh species that live in water year round, its most popular wetland plant is saw-grass. Floating aquatic plants that dominate the waterscape include bladderwort, white water lily, spatterdock and maiden-cane. The tiniest member of the Everglade plant community is periphyton algae, it is the base of food webs and floats in mats on or just below the water’s surface (Plants and Animals of the Everglades).
The diagram below gives an overview of the Everglades food web and its major feeding interactions. The arrows indicate who eats whom, and the color code indicates the trophic levels and food transfers. In most cases, primary consumers feed on the same plant species, and one species of primary consumer may eat several different plants. As indicated in the diagram the plants (saw grass, swamp lily, and algae) start out as the producers which are eaten by the primary consumers and one secondary consumer (the opossum).
The primary consumers shown in the diagram are the snail, deer, mosquitofish and green sea turtle. We then see that the snail kite, great blue heron, opossum and raccoon are all secondary consumers, the alligator, panther and bobcat are tertiary, and finally the python and anaconda are quaternary (creately.com).
The two organisms that I chose to discuss from the food web is the snake and the tiger/panther. Snakes have a very long slender body with 100 to 300 vertebrae. They have a light skeleton, and are made up in a way to move freely. The major organs of the snake is the head (skull), esophagus (part of the digestive system that runs adjacent to the air sac from the throat to the stomach), trachea (part of the respiratory system, wind pipe), and the heart (the right and left atria receive blood from the lungs and body and pass it to the ventricle to be circulated again). The head/skull is built loosely so as to permit it to swallow large prey. The sense of organs are quite different in snakes than those of mammals and other animals. They rely primarily on their senses of smell and touch. The tongue is actually the smelling device. A small organ located on the roof of the oral cavity called the “vomeronasal organ” or “jacobson’s organ” allows the snake to identify and perceive the smell as prey, predator or otherwise (Snake anatomy and physiology).
The second organism (the tiger), has an endoskeleton, similar to that of humans and many other birds and animals. This means that the skeleton is on the inside of the body (protecting the internal organs). The internal organs of a tiger include: lungs – respiration, heart – blood circulation, liver – processing of chemicals, brain, stomach – breakdown of food, kidney- filters blood and removes waste, intestines – breakdown and digestion of food, and the bladder – holding of urine until ready for excretion.
The spine, which consists of 30 vertebrae and extends to the very tip of the long tail is another skeletal feature that gives the tiger extra strength and flexibility (Tigers skeleton and internal organs).
Like other invasive species, we change the environment of the other organisms that share our habitats. The organs of each of these species provide them with the necessary tools of survival and reproduction of its kind. According to chapter 19 of our text, life history traits are shaped by evolutionary adaptation; they may vary within a species and may change as the environmental context changes. Most populations probably fall between the extreme opportunistic life histories (reaching sexual maturity rapidly, and producing many offspring with little or no parental care). Insects and equilibrial life histories develop slowly and produce few, well-cared-for offspring of many larger-bodied species (Simon, Dickey, & Reece, 2013).

The goal of conservation should not only be to preserve individual species but to sustain ecosystems, where natural selection can continue to function, and to maintain the genetic variability on which natural selection acts. There are two growth models discussed in chapter 19: the exponential model is the accelerating increase that occurs when growth is unlimited, and the logistic model is slowed by limiting factors. “The exponential model predicts that the larger a population becomes, the faster it grows, while the logistic model predicts that a population’s growth rate will be small when the population size is either small or large, and highest when the population is at an intermediate level relative to the carrying capacity” (Simon, Dickey, & Reece, 2013).
Unfortunately, the Everglades is continuously being degraded by humans. The same characteristics that make the Everglades so unique also make it sensitive to human impact. The major potential threat is the danger of loss of habitat from urban development, the mismanagement of water distribution, the decline of water quality, and the continued appearance and expansion of invasive species (Challenges to a sensitive and fragile ecosystem).
In conclusion, for most of the decade, Comprehensive Everglades Restoration Plan (CERP) has suffered delays, lack of funding and bureaucratic infighting, and has produced no meaningful results. In 2009, however, an infusion of federal funding and the State of Florida’s decision to purchase significant land in the Everglades (currently under sugarcane cultivation) created new hope and opportunities. One key project involves adding bridges to the Tamiami Trail Roadway…directing traffic above and not through the fragile marsh (NRDC: Florida Everglades, 10/20/2009).

References:
Challenges to a Sensitive and Fragile Ecosystem,
Retrieved from http://www.everglades.org/challenges

Journey to Restore America’s Everglades
Retrieved from http://www.evergladesplan.org/facts-info/syutkma.animals.aspx

NRDC: Florida Everglades
Retrieved from http://www.nrdc.org/water/conservation

Simon, E., Dickey, J., and Reece, J. 2013. Campbell essential biology with physiology, (4th ed.). Pearson Education, Inc.

Tigers skeleton and internal organs
Retrieved from http://www.tigers.org.za/skeleton