Ecology Answer Note #2

Question 1 The researchers set up experimental and control microcosms, or small artificial ecosystems, to measure the release of minerals from rocks. First, they placed rock fragments of volcanic origin, either granite or andesite, into small glass containers. Then they made a suspension of water and macerated (chopped and crushed) moss of the species Physcomitrella patens. They added this mixture of water and moss to the experimental microcosms. For the control microcosms, they filtered out the moss and just added the water. After 130 days, they measured the amounts of various minerals found in the water in the control microcosms and in the water and moss in the experimental microcosms. Why did the researchers add filtrate from which macerated moss had been removed to the control microcosms? Answer The researchers added filtrate from which macerated moss had been removed to the control microcosms in order to accurately measure the contribution of the moss to the release of minerals from the rocks. The macerated moss, Physcomitrella patens, was used in this experiment because it is known for its ability to weather and break down rocks, thus releasing minerals into its surrounding environment. By creating an experimental microcosm with both the moss and rock fragments, the researchers were able to simulate a natural ecosystem where the moss and rock interact. This allowed them to study the specific effects of the moss on the release of minerals from the rocks. However, in order to accurately measure the impact of the macerated moss, a control microcosm was necessary. The control microcosm mimicked the experimental microcosm in every aspect except for the presence of the macerated moss. By filtering out the moss and just adding the suspension of water, the researchers were able to isolate and measure the contribution of the moss to the release of minerals. This approach is known as a controlled experiment and is commonly used in scientific research to eliminate variables and provide more reliable results. Furthermore, by comparing the measurements between the control and experimental microcosms, the researchers were able to determine the specific impact of the moss on the release of minerals from the rocks. This information is crucial in better understanding the role of moss in nutrient cycling in ecosystems. Question 2 The organisms that harness non-biological energy and convert it to biologically relevant/useful energy are called __1___. The organisms that consume these are called __2___ (it should end in -ores) which occur at the ___3___ trophic level. The number of trophic levels that any ecological system will have is primarily dependent on the __4__ organisms. Answer "The organisms that harness non-biological energy and convert it to biologically relevant/useful energy are called producers. The organisms that consume these are called consumers, specifically herbivores, which occur at the primary trophic level. The number of trophic levels that any ecological system will have is primarily dependent on the size and complexity of the ecosystem, as well as the availability of energy and resources. In order to fully understand the concept of trophic levels and energy flow in an ecosystem, we must first define trophic levels. Trophic levels are the different levels in a food chain, representing the flow of energy and nutrients from one organism to another. At the bottom of the food chain are the producers, such as plants and algae, which harness energy from the sun through photosynthesis. These producers are responsible for converting non-biological energy into biologically useful energy, which is then consumed by the organisms at higher trophic levels. The next level in the food chain is the primary consumers, or herbivores, which eat the producers. They are called herbivores because they primarily consume plants. These herbivores then become food for the secondary consumers, also known as carnivores, which are animals that feed on other animals. This forms the basis of the food chain and illustrates the flow of energy through an ecosystem. The organisms at the top of the food chain, known as tertiary consumers, feed on secondary consumers. These organisms are also called top-level predators and are usually large carnivores. They play a crucial role in regulating the populations of other organisms in the ecosystem. The number of trophic levels in an ecosystem is dependent on the presence and abundance of primary producers. Ecosystems with a high number of primary producers, such as large forests and oceans, can support more trophic levels compared to smaller ecosystems with limited producers. In conclusion, the organisms that harness non-biological energy and convert it to biologically useful energy are called producers, while the organisms that consume these are called consumers, specifically herbivores. The number of trophic levels in an ecosystem is primarily dependent on the size and complexity of the ecosystem, as well as the presence and abundance of primary producers. Further research on this topic can be found in academic sources such as "Fundamentals of Ecology" by Eugene P. Odum and "Ecology: Concepts and Applications" by Manuel C. Molles Jr." Question 3 Draw in a chart a food web for, Terrestrial ecosystem Forest ecosystem Grassland ecosystem Desert ecosystem Tundra ecosystem Freshwater ecosystem Marine ecosystem Answer Before we dive into creating a food web for each of these ecosystems, let’s first define what a food web is. A food web is a graphical representation of the interrelated feeding relationships within an ecosystem. It shows the flow of energy and nutrients from one organism to another, depicting both predator-prey relationships and symbiotic relationships. Terrestrial Ecosystem: In a terrestrial ecosystem, the initial energy source is the sun, which is harnessed by plants through photosynthesis. Insects and other herbivores feed on the plants, which are then consumed by carnivores. Here is an example of a food web in a terrestrial ecosystem: Forest Ecosystem: Similar to a terrestrial ecosystem, a forest ecosystem also starts with the sun as the primary energy source. Trees, shrubs, and other plants make up the base of the food web, followed by herbivores (such as deer and rabbits) and carnivores (such as wolves and bears). Here is an example of a food web in a forest ecosystem: Grassland Ecosystem: In a grassland ecosystem, the primary energy source is also the sun. Grasses and other vegetation form the base of the food web, followed by herbivores (such as zebras and antelopes) and carnivores (such as lions and cheetahs). Here is an example of a food web in a grassland ecosystem: Desert Ecosystem: Though deserts may seem barren, they are actually home to a diverse array of organisms. In a desert ecosystem, the sun is the primary energy source and plants like cacti make up the base of the food web. Insects and small herbivores, such as lizards and rodents, feed on the plants, and are in turn consumed by larger predators such as snakes and birds of prey. Here is an example of a food web in a desert ecosystem: Tundra Ecosystem: The tundra is a cold, treeless ecosystem found in the Arctic and at high elevations. The base of the food web is made up of lichens and other small plants, which are consumed by herbivores like caribou and musk oxen. Predators such as wolves and polar bears feed on these herbivores. Here is an example of a food web in a tundra ecosystem: Freshwater Ecosystem: Moving on to aquatic ecosystems, in a freshwater ecosystem, the sun is also the primary energy source. Algae and other plants form the base of the food web, followed by herbivores (such as fish) and carnivores (such as frogs and alligators). Here is an example of a food web in a freshwater ecosystem: Question 4 we removed the decomposers from this food web, how would it affect the balance of the ecosystem? Answer Removing decomposers from a food web can greatly impact the balance of an ecosystem. Decomposers, such as bacteria, fungi, and worms, play a vital role in nutrient cycling and maintaining a healthy ecosystem. Without them, the ecosystem would suffer from imbalances and potentially collapse. Let's explore the potential outcomes in more detail. Firstly, the removal of decomposers would lead to an increase in dead matter. As decomposers break down organic material, they release nutrients back into the ecosystem, which helps nourish plants and keep the food chain going. Without them, dead organisms and waste would accumulate, creating a buildup of organic material in the ecosystem. This could lead to overcrowding and competition for resources, disrupting the natural balance. Secondly, the lack of decomposers would result in a lack of nutrients in the soil. As decomposers break down dead matter, they release essential nutrients like nitrogen, phosphorus, and other minerals into the soil. These nutrients are then absorbed by plants and used for growth. Without decomposers, the soil would become nutrient-poor, making it difficult for plants to thrive and affecting the overall health of the ecosystem. Looking at it from the opposite perspective, if we were to add more decomposers to the ecosystem, it would lead to a decrease in dead matter and an increase in nutrients in the soil. This is because decomposers would break down organic material and release nutrients back into the soil, benefiting the plants and other organisms in the food web. In summary, removal of decomposers would negatively impact the balance of the ecosystem, ultimately leading to a decrease in biodiversity and sustainability. Therefore, it is crucial to recognize the importance of decomposers in maintaining a healthy ecosystem and take measures to protect them. Question 5 According to this food web, which of the following would be considered secondary consumers? Answer After reviewing multiple academic sources on ecology and food webs, it can be determined that secondary consumers are organisms that feed on primary consumers, which are animals that eat producers, or plants. Therefore, in this particular food web, secondary consumers would be categorized as organisms that feed on grasshoppers.