Overview of Ecology Topics: Energy Flux, Food Webs and Resources

gracilis to acquire resources and outcompete B. rapa would increase as the ratio of B. gracillis to B. rapa increased. This hypothesis was based on the influence of community composition in interspecies competitive intensity (Elmendorf and Moore 2007). Competitive ability of invasive species are more intense when this species dominates within the community (Elmendorf and Moore 2007). However, by reversing the ratio, and allowing the non-invasive B. gracilis to dominate within the community, this would decrease the competitive ability of B. rapa, and consequently increase the competitive ability of B. gracilis. In doing so, high numbers of B. gracilis would overwhelm and inhibit B. rapa from colonizing the

Ecology has been the study of different interactions amongst organisms with the abiotic environment (Pimm and Smith, 2007), examining how ecosystems have thrived upon these relations. Ecosystems have depended on the continued availability of energy supplied ultimately by plants through the process of photosynthesis. Plants have lived in association with each other from having occupied the same niche in nature (Khan and Hussain, 1999). Numerous plants have

the base of every ecosystem. Some populations remain stable and some die out, but the specific factors consistently affect the size of each population. In a stable predator-prey relationship, the predator eats the prey, however they both need each other to survive. As the number of predators begins to increase, the prey population will decrease, resulting in a decrease in predators, and the cycle continues to change over time. When there are irregular quantities, an unstable predator-prey relationship will develop causing one species of animals to die out. In this lab, our goal was to investigate how the population of predators (wolves)

Moving forward with selection, it can be noted how populations of species change over time in response to biotic interactions and their environment. Many examples could be used; the vicious Asian giant hornets

In healthy lakes and streams, nutrients are needed for the growth of alar that forms the base of a complex food web supporting the entire aquatic ecosystem (Lindberg 2012). Based off of this background information, a second experiment was conducted to study the community ecology within the LSU University Lake. This experiment arose interest in observing the amount of ammonia (abiotic factor) in the lake water and its effect on the concentration of chlorophyll (biotic factor). The data retrieved in this experiment lead to the question, if there is an increase in the amount of ammonia in the LSU University Lake, would that result in an increase of chlorophyll concentration due to an increase in nutrient availability? The null hypothesis states that in an aquatic ecosystem, the different levels of ammonia will have no effect on the concentration of chlorophyll present in the University Lake. Inversely, the alternative hypothesis states that in an aquatic ecosystem, the different levels of ammonia will have an effect on the concentration of chlorophyll present in the University

n the planet we are surrounded by many different ecosystems, and each one fits within another. These biological systems that have a relation in living communities are known as our complex ecosystem (1). Since each of these communities end up working peacefully with one another they become a product of coevolution, or as many biologists have referenced this giant community as the Greek earth goddess, Gaia. Coevolution is generally focused on plants and animals, and how two or more species interact causing a result of a mutualistic relationship (2). Once a scientist acknowledges how these species interact, they end up with a conclusion of how each species has different variations, adaptations, and how their fitness works within their ecosystem.

Two examples of interspecific competition, which is the competition for limited resources between individuals of different species are lions and leopards because both feed on the same prey, and two different species of trees in a dense forest because they compete for the incoming sunlight (Diamond, 1978).

If resources are limiting, one species, with an advantage, will drive the other to extinction. The competitive exclusion principle refers to the idea that complete competitors cannot coexist. In an environment where resources are constant and limiting, one species will always have some sort of advantage for competing for these resources. For the other species, the only way out of the situation is to become extinct, or move to another niche. Gause experimented with this theory with two species of Paramecium, where he kept them competing under constant conditions. One species would always outcompete the other. The only way for the other to outcompete the first is if the resources were manipulated.

In this laboratory, we hypothesized that density of Daphnia was the primary driver for feeding rate. We thought that if we increase the number of Daphnia in the sample, than the feeding rate would increase. As a result, in this experiment, density had a significant effect on the feeding rate of the Daphnia; it was found that higher densities of competitors, such as the sample containing 24 Daphnia, caused higher feeding rates. By increasing the density of Daphnia, competition caused the Daphnia to increase their feeding rate compared to lower or no competition at low densities, as it is advantageous to have a faster feeding rate in the presence of other competitors to insure they get enough food. This experiment was an example of intraspecific competition, where the Daphnia were competing with other Daphnia, the same species, for

Population cycles within predator-prey relationships are generally discussed within the lens of the Lotka-Volterra Predator-Prey Model; independently developed by Alfred Lotka and Vito Volterra (Cann, 307). This model portrays an entire prey cycle as a four-part sequence: 1) “an increase in the prey population is followed by an increase in the predator population,” 2) “the resulting increase in predation is followed by a decline in the prey population,” 3) “with fewer prey available, the predator population declines,” and 4) “the decline in

Apex predators are capable of directly and indirectly influencing the function of their environments by generating trophic cascades in response to their addition, or removal, from an ecosystem. Apex predators can alter the behavior and abundance of other animal species, as well as influence the productivity and diversity of plant species within their ecosystems. A trophic cascade can be referred to as the presence, or lack thereof, of an apex predator that directly affects lower trophic level consumers (e.g. herbivores) and thereby indirectly alters producer (i.e. plant) abundance or distribution. Trophic cascades have been recognized in all of Earth’s major biomes, especially in aquatic and insect filled systems.

Organisms within a predator-prey relationship are intertwined in a co-evolutionary battle for survival. Each depends on food, shelter, the environment, and the random chance of evolution in order to maintain balance in the relationship. If chance favors one side too heavily, it throws the species into disequilibrium and can lead to the demise of one or more species. Because of the potential severity of the consequences, it is important to investigate the contributing factors that help maintain a healthy predator-prey dynamic. In order to reach solid conclusions, a well-rounded research approach is required, lest one side of this is disproportionally represented. First, the survival mechanisms of prey will be explored through the example of

depend on these prey are left to change their eating habits. A change to a particular organisms eating habits greatly creates gaps in the food web, which produces a ripple effect through the whole ecosystem. (12). For instance, Sharks when they are deprived of their prey, they switch to prey of other predators. With the sharks, eating the prey of the other predators, this causes a decline in the population of that specific prey. (13). When the population levels of that specific prey start to lower, this leads to competition between the shark and the other predator. As the shark and the other predator compete for the same species, this causes the prey to eat more smaller fish. With this continuous cycle of competition over food, several animals

Biological Relationship The biological relationship between C. denticulata and C. columna is interspecific competition. Interspecific competition is the main biotic factor affecting the distribution of C. denticulata and C. columna. A biotic factor is an environmental factor caused by living things. Interspecific competition is competition between two species competing for the same resource. Both species are competing for space on the rocks as far down the shore as possible.

INTRODUCTION: Symbiosis is the theme of this chapter as well as the theme throughout the world. Both organisms may benefit from the relationship or one organism may benefit while the other may suffer. When looking at life in the grand scheme, symbiosis is everywhere. It occurs within our own bodies as well as in many other organisms around the world. Evolutionary biologist, Toby Kiers, makes two valuable points when describing symbiosis. Kiers states that, “We need to separate important from harmonious. The micro biome is incredibly important but it doesn’t mean that it’s well balanced. Both partners may benefit, but there’s this inherent tension. Symbiosis is conflict – conflict that can never be totally resolved.”(Yong, 2016). There is